The retraction notice states that concerns were raised regarding the integrity of the images in the published figures after the article appeared. When the journal’s editorial team investigated, the authors failed to provide complete raw data or a satisfactory explanation. Given the concerns about the validity of the data and the absence of complete raw data, the journal concluded that retraction was the appropriate course of action. The retraction was approved by the Chief Executive Editor of Frontiers, and the authors were given an opportunity to respond before the decision was finalized.

The original paper, published on 22 May 2018 by Han and colleagues, had proposed a mechanism by which a specific microRNA could protect mesenchymal stem cells from apoptosis in an Alzheimer’s disease model. Mesenchymal stem cells, typically harvested from bone marrow, have long been explored as potential therapeutic vehicles for neurodegenerative conditions because they can home to sites of injury, secrete neuroprotective factors, and modulate inflammation. However, a persistent obstacle in cell-based therapies is that many transplanted cells die rapidly after introduction into a hostile host environment, limiting any therapeutic benefit they might provide.

MicroRNAs are short, non-coding RNA molecules, roughly 18 to 25 nucleotides in length, that regulate gene expression after transcription. They function by binding to complementary sequences in target messenger RNAs, typically within the 3′ untranslated region, which leads to mRNA degradation or translational repression. Let-7f-5p belongs to the let-7 family, one of the earliest discovered and most conserved microRNA families, known for roles in development, cell proliferation, and differentiation. The 2018 study had suggested that Let-7f-5p enhanced stem cell survival by directly targeting caspase-3, an enzyme that sits at a critical juncture in the apoptotic cascade, cleaving numerous cellular substrates once activated.

Caspase-3 is often described as the principal executioner caspase because it carries out the final dismantling of the cell. Inhibiting caspase-3 activation is a well-established strategy for reducing cell death in experimental models of ischemia, neurodegeneration, and transplant stress. The idea that a naturally occurring microRNA could be harnessed to dampen caspase-3 activity in transplanted mesenchymal stem cells was therefore an appealing therapeutic concept, and the paper attracted interest from researchers exploring ways to improve the viability of cell grafts in the brain.

The retraction highlights a recurring vulnerability in the biomedical literature: the integrity of published images. In cell biology, results are frequently communicated through micrographs, western blots, and flow cytometry plots, and the authenticity of these images underpins the credibility of the findings. When concerns arise about duplicated, manipulated, or misattributed images, journals typically request the underlying raw data. The inability or unwillingness of authors to supply complete raw data is widely regarded as a serious red flag, because it removes the possibility of independently verifying that the published figures faithfully represent the experiments described.

In this case, the investigation was conducted in accordance with Frontiers’ research integrity policies, and the journal explicitly acknowledged the contribution of Elisabeth Bik, an independent image integrity analyst whose work has been instrumental in surfacing concerns about manipulated or duplicated figures across thousands of published papers. The retraction notice records that the authors received communication regarding the retraction and had a chance to respond, and that this communication has been recorded by the publisher. This procedural transparency is intended to ensure that retraction decisions are documented and that the scientific record reflects not only the withdrawal but also the process by which it was reached.

Retractions of this kind carry practical consequences for the research community. Papers that are retracted are typically flagged in bibliographic databases, and citation practices increasingly call for authors to acknowledge retraction status when citing previously retracted work. For researchers working on microRNA-based approaches to stem cell survival, the retraction means that the specific claims of the 2018 paper can no longer be relied upon as evidence. Any future work on Let-7f-5p and caspase-3 in the context of mesenchymal stem cell transplantation in Alzheimer’s disease would need to be built on independently generated and verifiable data.

The broader lesson for the field is that the mechanisms governing cell survival in the nervous system remain a fertile area of investigation, but the path from a promising molecular observation to a robust therapeutic strategy depends on the reliability of the underlying data. Mesenchymal stem cell therapies for neurodegenerative disease continue to be explored in preclinical and clinical settings, and microRNAs remain an active area of study as potential modulators of cell fate. The retraction of this particular paper does not invalidate those broader research directions, but it does remove one specific claim from the evidence base and underscores the importance of rigorous data integrity practices.

As of the retraction date, the notice is published under a Creative Commons Attribution License and is freely accessible. The original article remains available online but is now clearly marked as retracted, ensuring that readers who encounter it will be directed to the withdrawal notice. The case serves as a reminder that scientific self-correction, though sometimes slow, is an essential mechanism for maintaining the reliability of the literature on which future discoveries and clinical advances depend.

Subject of Research: Retraction of a 2018 study on microRNA Let-7f-5p and mesenchymal stem cell survival in an Alzheimer's disease model

Article Title: Retraction: MicroRNA Let-7f-5p Promotes Bone Marrow Mesenchymal Stem Cells Survival by Targeting Caspase-3 in Alzheimer Disease Model

Article References: Frontiers Editorial Office (2026). Retraction: MicroRNA Let-7f-5p Promotes Bone Marrow Mesenchymal Stem Cells Survival by Targeting Caspase-3 in Alzheimer Disease Model. Frontiers in Neuroscience, 20, Article 2023227. https://doi.org/10.3389/fnins.2026.2023227

Image Credits: AI Generated

DOI: 10.3389/fnins.2026.2023227

Keywords: retraction, microRNA, Let-7f-5p, mesenchymal stem cells, Alzheimer's disease, caspase-3, image integrity, Frontiers in Neuroscience, research integrity, apoptosis, neurodegeneration, raw data

The drug at the center of the resistance story is ABT-737, a synthetic small molecule that belongs to the BH3-mimetic family. These compounds mimic a short protein segment, the Bcl-2 homology 3 domain, that pro-apoptotic proteins use to latch onto and neutralize their anti-apoptotic relatives. In healthy cells, the Bcl-2 protein family functions as a molecular checkpoint for apoptosis, the programmed self-destruction pathway that eliminates damaged or superfluous cells. The family contains pro-death effectors such as Bak and Bax, which punch holes in the outer mitochondrial membrane to trigger the apoptotic cascade, and anti-apoptotic guardians such as Bcl-2, Bcl-xL, and myeloid cell leukemia-1, or Mcl-1, which sequester those effectors and keep the checkpoint locked. BH3 mimetics pry that lock open. ABT-737 binds Bcl-2, Bcl-w, and Bcl-xL with high affinity, freeing Bak and Bax to initiate mitochondrial outer membrane permeabilization and release cytochrome c.

The fatal flaw of ABT-737, documented repeatedly since its 2005 debut in Nature, is what it cannot bind. Mcl-1 sits outside its reach, and cancer cells respond to Bcl-2 family pressure by leaning harder on Mcl-1 for survival. Prior work has shown that breast cancer cells frequently increase Mcl-1 expression when exposed to ABT-737, and that the drug performs dramatically better in cell lines where Mcl-1 is degraded or genetically silenced. In triple-negative breast cancer specifically, dependence on Mcl-1 has been traced to its canonical anti-apoptotic function, making the protein both a vulnerability and the principal escape route from Bcl-2-targeted therapy. Clinical efforts to develop selective Mcl-1 inhibitors have been beset by cardiac toxicity concerns, which has pushed researchers toward indirect strategies that lower Mcl-1 levels using existing or better-tolerated compounds.

Enter C-phycocyanin, the phycobiliprotein pigment that gives spirulina and other cyanobacteria their distinctive blue-green color. It is not an obscure molecule. Phycocyanin is consumed as a dietary supplement, has been investigated as a natural anti-inflammatory and antioxidant, and has accumulated a growing preclinical dossier of anti-cancer activity across breast, pancreatic, and gastrointestinal tumor models. Earlier studies in triple-negative breast cancer cells, including the aggressive MDA-MB-231 line, showed that the pigment suppresses proliferation and migration through the MAPK signaling pathway. What the new study adds is a precise mechanistic account of how C-phycocyanin interacts with the Bcl-2 family to convert ABT-737 from a partially effective drug into a synergistic killer.

The experimental system was deceptively simple. Shayesteh Khishavand and Hadi Karami cultured MDA-MB-468 cells, a well-characterized triple-negative breast cancer line that carries mutant p53 and an epidermal growth factor receptor amplification, and treated them with C-phycocyanin alone, ABT-737 alone, or the two drugs in combination. They then measured cell viability with MTT assays, proliferation with trypan blue exclusion, migratory capacity with wound healing assays, long-term reproductive survival with clonogenic assays, apoptosis with ELISA-based detection, and caspase-3 enzymatic activity. Expression of the key Bcl-2 family players was quantified at both the messenger RNA level by quantitative reverse transcription PCR and the protein level by Western blot. Drug interactions were formally assessed using the Combination Index method, a widely used framework in which values below one indicate synergy, values near one indicate additivity, and values above one indicate antagonism.

The numbers tell a striking story. On its own, C-phycocyanin inhibited half of the cells at a concentration of 5.62 micromolar, while ABT-737 required 32.47 micromolar to reach the same effect, reflecting the substantial intrinsic resistance of these cells to the BH3 mimetic. When the two agents were combined, the half-maximal inhibitory concentration of the drugs dropped to 3.71 micromolar, and the Combination Index fell below one, formally confirming a synergistic interaction. In practical terms, each drug needed less of itself to do more damage when partnered with the other, exactly the pharmacological profile that combination therapy seeks.

The molecular mechanism underlying that synergy resolved into a familiar pattern of compensatory resistance and its circumvention. When ABT-737 was applied alone, MDA-MB-468 cells raised Mcl-1 expression by roughly 40 percent, a textbook survival response to pressure on the Bcl-2 branch of the family. C-phycocyanin co-treatment effectively counteracted that response, holding Mcl-1 in check. Beyond blunting the adaptive Mcl-1 surge, the pigment also downregulated Bcl-2 itself while simultaneously increasing expression of Bak, the pro-apoptotic effector that ABT-737 liberates, and p53, the tumor suppressor that coordinates apoptotic responses to cellular stress. The net effect was to strip away the anti-apoptotic shielding while boosting the pro-apoptotic force, tilting the Bcl-2 family balance decisively toward mitochondrial breach.

Downstream readouts confirmed that the shift translated into genuine cell death and functional impairment. The combination produced significantly greater caspase-3 activation than either drug alone, indicating that the intrinsic apoptotic cascade had been engaged to completion. Apoptosis measured by ELISA rose in parallel. The partnership also constrained malignant behavior beyond the dish-level kill: cells treated with both drugs migrated far less effectively in wound healing assays and formed markedly fewer colonies, suggesting that the combination impairs both dissemination potential and the self-renewal capacity required for tumor propagation, not merely acute viability.

The authors are appropriately measured about the scope of their findings. The work rests on a single cell line, and MDA-MB-468, with its mutant p53 and EGFR amplification, represents only one molecular identity within the heterogeneous universe of triple-negative breast cancer. The study itself notes that further validation in additional triple-negative cell lines is warranted, and the jump from two-dimensional cultures to animal models and, ultimately, patients remains long and uncertain. C-phycocyanin’s pharmacokinetics, bioavailability, and safety profile at efficacious doses in humans are not established by this work, and ABT-737 itself was succeeded clinically by orally bioavailable derivatives such as navitoclax and venetoclax, which carry their own resistance and toxicity profiles.

Even with those caveats, the study lands at a moment of genuine momentum for apoptosis-targeted cancer therapy. The conceptual advance is that a well-tolerated natural product, rather than a bespoke synthetic Mcl-1 inhibitor, can suppress the compensatory pathway that limits BH3-mimetic efficacy, opening a lower-toxicity route to rational combination design. It also reinforces a principle that has emerged across multiple tumor types: the predictive value of Mcl-1 levels for BH3-mimetic response, and the therapeutic value of manipulating those levels directly. Whether C-phycocyanin can make that leap from pigment to pharmaceutical partner will depend on the validation studies that must now follow, but for a cancer with so few molecular handles, the identification of a new one, plucked from a common blue-green alga, is a result worth watching closely.

Subject of Research: Overcoming ABT-737 resistance in triple-negative breast cancer through C-phycocyanin-mediated Mcl-1 downregulation

Article Title: Overcoming ABT-737 resistance in triple-negative breast cancer: C-phycocyanin-mediated myeloid cell leukemia-1 downregulation enhances apoptotic sensitivity

Article References: Khishavand, S., & Karami, H. (2026). Overcoming ABT-737 resistance in triple-negative breast cancer: C-phycocyanin-mediated myeloid cell leukemia-1 downregulation enhances apoptotic sensitivity. Molecular Biology Reports, 53(1), Article 1614. https://doi.org/10.1007/s11033-026-12824-5

Image Credits: AI Generated

DOI: 10.1007/s11033-026-12824-5

Keywords: triple-negative breast cancer, ABT-737, C-phycocyanin, Mcl-1, BH3 mimetics, apoptosis, drug synergy, Bcl-2 family, combination therapy, MDA-MB-468, caspase-3, natural products

The TRAIL pathway, short for tumor necrosis factor-related apoptosis-inducing ligand, has long fascinated oncologists because of its remarkable selectivity. Unlike many cytotoxic drugs that poison dividing cells indiscriminately, TRAIL can trigger programmed cell death, or apoptosis, preferentially in cancer cells while sparing healthy tissue. The mechanism works like a lock-and-key system: TRAIL binds to death receptors on the cell surface, most notably TRAIL receptor-2, known as DR5 or TNFRSF10B, which then recruits and activates initiator caspases inside the cell. These initiator caspases set off a cascade that culminates in the activation of caspase-3, the so-called executioner caspase that dismantles the cell in an orderly fashion. Because of this selectivity, TRAIL receptors and their ligands have been pursued for decades as targets for cancer therapy, including in clinical trials of DR5-targeting antibodies such as tigatuzumab in triple-negative breast cancer.

Yet breast cancer cells have proven adept at sabotaging this death sentence. The review highlights three principal escape strategies, all of which converge on the same pathway. Tumor cells can down-regulate the expression of death receptors such as DR5, effectively removing the lock that TRAIL needs to open. They can up-regulate decoy receptors, such as DcR2 or TNFRSF10D, which bind TRAIL without transmitting any death signal, acting as molecular sponges that soak up the ligand before it can reach functional receptors. And they can dampen the downstream apoptotic machinery itself, for example by reducing levels of caspase-3, so that even if the death signal is received, the execution never proceeds. Each of these maneuvers contributes to what clinicians observe as TRAIL resistance, a phenomenon that has limited the clinical success of TRAIL-based therapies despite their promising preclinical profile.

The central insight of the new review is that many of these escape strategies may be orchestrated not by changes in the genes themselves but by epigenetic marks written on top of them. DNA methylation, the addition of methyl groups to cytosine bases in CpG dinucleotides, is a classic epigenetic modification carried out by DNA methyltransferases. When methylation accumulates in the promoter region of a gene, the stretch of DNA that controls whether the gene is switched on, it can physically and chemically block the transcription machinery, silencing the gene without altering its sequence. Because methylation patterns are established and maintained by enzymes rather than encoded in the genome, they are, in principle, reversible, which is precisely what makes them attractive therapeutic targets.

Applying this framework to the TRAIL pathway, the authors evaluate evidence that hypermethylation of the DR5 promoter can silence this crucial death receptor, leaving breast cancer cells deaf to TRAIL’s signal and unable to initiate apoptosis in response to it. Studies in other tumor types, including ovarian cancer and melanoma, have shown that epigenetic silencing of TRAIL death receptors contributes directly to resistance, and methylation of death receptor genes has also been documented in childhood acute lymphoblastic leukemia. In parallel, the review examines aberrant methylation of the DcR2 gene, noting that changes in the methylation status of this decoy receptor can alter the balance of apoptotic signaling. DcR2 is of particular interest because it has been identified as a target gene of the tumor suppressor p53 and can influence chemosensitivity, meaning its epigenetic regulation may intertwine with broader networks governing cell fate decisions in the tumor.

The third component, caspase-3, sits at the very end of the apoptotic cascade, and its loss represents a particularly insidious form of resistance because it can neutralize death signals arriving from multiple upstream pathways, not just TRAIL. The review points to evidence that methylation of the CASP3 gene can diminish the apoptotic capacity of breast cancer cells and contribute to therapeutic resistance. This resonates with earlier findings that down-regulation of caspase-3 in breast tumors is associated with chemotherapy resistance, suggesting that epigenetic silencing of the executioner caspase may be one mechanism by which tumors achieve this loss. The authors also note the paradoxical roles that caspase-3 can play in cell survival and proliferation under some circumstances, underscoring that the biology of this enzyme is more nuanced than a simple on-off switch for cell death.

Beyond its mechanistic interest, the review argues that methylation patterns at these TRAIL pathway loci could serve as clinically useful biomarkers. If the methylation status of the DR5, DcR2, or CASP3 promoters in a patient’s tumor could be measured, it might predict whether that tumor would respond to TRAIL-based therapies or to combinations that include epigenetic drugs. Such predictive biomarkers are sorely needed, because clinical trials of DR5-targeting agents have produced mixed results, likely in part because patient tumors were not stratified according to the epigenetic state of the pathway being targeted. Methylation signatures might also carry prognostic information, reflecting the apoptotic competence of the tumor and its propensity to evade immune-mediated killing, since TRAIL is one of the weapons that cytotoxic immune cells use to eliminate transformed cells in vivo.

The therapeutic implications are equally significant. DNA methyltransferase inhibitors, including hypomethylating drugs such as decitabine, are already in clinical use in oncology and have been shown to reprogram the epigenetic landscape of tumors, including triple-negative breast cancer, where recent work has documented immune modulation and therapeutic synergy following epigenetic reprogramming. The review suggests that combining such epigenetic drugs with TRAIL receptor agonists could restore the expression of silenced death receptors and caspases, re-sensitizing tumors to apoptosis. This strategy fits within a broader movement in cancer research toward targeting epigenetic regulators to overcome drug resistance, and it offers a rationale for rational combination regimens in which a demethylating agent primes the apoptotic machinery and a TRAIL pathway agonist pulls the trigger. The authors also frame these findings within the context of personalized medicine, where methylation profiling could guide the selection of patients most likely to benefit from such combinations.

As with any review, the evidence base is drawn from studies across multiple tumor types and experimental systems, and the authors are careful to frame their conclusions as a critical evaluation of the latest findings rather than definitive clinical proof. Key questions remain, including how frequently DR5, DcR2, and CASP3 promoters are methylated in different breast cancer subtypes, whether methylation at these loci varies with tumor stage, hormone receptor status, or HER2 amplification, and whether demethylating agents can reliably restore receptor expression in patients without unacceptable toxicity. Nevertheless, the synthesis offers a coherent molecular narrative for a clinical puzzle that has persisted for two decades: why a ligand that kills cancer cells so beautifully in the laboratory has struggled to deliver the same results in patients. By locating the answer, at least in part, in the methylation marks that silence the TRAIL pathway’s essential components, the review points toward a future in which epigenetic profiling and epigenetic therapy work hand in hand to restore the apoptotic function that cancer cells have so carefully switched off.

Subject of Research: Epigenetic regulation of the TRAIL apoptosis pathway by DNA methylation in breast cancer

Article Title: DNA methylation-mediated regulation of TRAIL pathway components (DR5, DcR2, and CASP3) in breast cancer: molecular mechanisms and therapeutic implications

Article References: Khursheed, N., Ashraf, S., Qurat-ul-Quadir, Khursheed, A.-U.-D., Asiaf, A., & Ganie, S. A. (2026). DNA methylation-mediated regulation of TRAIL pathway components (DR5, DcR2, and CASP3) in breast cancer: molecular mechanisms and therapeutic implications. Molecular Biology Reports, 53(1), Article 1705. https://doi.org/10.1007/s11033-026-12877-6

Image Credits: AI Generated

DOI: 10.1007/s11033-026-12877-6

Keywords: breast cancer, TRAIL, DR5, DcR2, caspase-3, DNA methylation, epigenetics, apoptosis resistance, death receptors, epigenetic therapy, biomarkers, personalized medicine

Hepatocellular carcinoma is one of the deadliest cancers worldwide, and its rise is closely tied to chronic liver injury, cirrhosis, and persistent oxidative damage. Because diagnosis often comes late and treatment options are limited, scientists have long been interested in chemoprevention, the idea that compounds taken before disease develops can interrupt the earliest steps of tumor formation. Curcumin has attracted decades of attention for its anti-inflammatory and antioxidant behavior, but it suffers from notoriously poor absorption in the gut. Piperine has a well-documented ability to boost the bioavailability of curcumin, which is why the two are so frequently paired in both traditional cuisine and modern experimental design. The new study set out to test whether that pairing could do more than improve uptake, and whether it could measurably alter the biology of a developing liver tumor.

To model the disease, the researchers induced hepatocellular carcinoma in rats using a two-hit protocol that mirrors how human liver cancer often arises from accumulated toxic insults. Animals first received diethylnitrosamine, or DEN, a potent carcinogen that damages DNA and initiates malignant transformation in hepatocytes. This was followed by thioacetamide, or TAA, a compound that produces repeated cycles of liver injury, fibrosis, and regeneration, creating the inflamed, scarred environment in which initiated cells can proliferate into full tumors. The regimen ran for twenty weeks, a period long enough for tumor burden to become established and measurable. Alongside this carcinogenic exposure, separate groups of rats received oral pretreatment with curcumin alone, piperine alone, or the two compounds in combination, given throughout the entire experimental period.

The damage in the untreated carcinogen group was exactly what the model predicts. Rats exposed to DEN and TAA showed increased tumor burden, sharply elevated liver enzymes in the serum, and a biochemical signature of a liver under siege. Lipid peroxidation, the oxidative degradation of cell membranes, climbed as reactive oxygen species overwhelmed the tissue. The liver’s own antioxidant defenses, the enzymatic systems that normally neutralize free radicals, were depleted. Alpha-fetoprotein, a classic tumor marker for hepatocellular carcinoma, rose in the bloodstream, and interleukin-6, a pro-inflammatory signaling molecule implicated in cancer-promoting chronic inflammation, was elevated as well. Under the microscope, the liver architecture was severely distorted, with the organized lobular structure of healthy tissue replaced by the disarray of injury and nodular transformation.

The treatment groups told a strikingly different story. Rats that received curcumin, and to a greater extent those that received curcumin and piperine together, showed improved levels of the key serum biomarkers, better antioxidant status, and reduced lipid peroxidation. Histopathological examination revealed that the normal tissue structure was substantially restored rather than progressively destroyed. In practical terms, the compounds did not merely mask the damage in blood tests; the livers themselves looked measurably healthier. The combination regimen emerged as the most effective intervention, consistent with the idea that piperine’s enhancement of curcumin’s bioavailability translates into a stronger biological effect when the two are administered together.

The mechanistic heart of the paper lies in what the team found when they probed the TBP2–ASK1–JNK–caspase-3 axis in liver tissue. This signaling cascade begins with TBP2, a thioredoxin-binding protein that responds to oxidative stress, and passes through ASK1, a mitogen-activated protein kinase kinase kinase also known as MAP3K5, which becomes activated when its inhibitory thioredoxin partner is oxidized and released. Activated ASK1 phosphorylates downstream JNK, the c-Jun N-terminal kinase, which in turn influences the mitochondrial pathway of apoptosis, ultimately engaging caspase-3, the executioner enzyme that dismantles the cell. In the carcinogen-exposed rats, this axis was dysregulated, a disruption that matters because the balance of this pathway determines whether damaged cells are eliminated by programmed cell death or allowed to survive and accumulate the mutations that drive cancer.

Preventive treatment with curcumin and piperine normalized the expression of the proteins in this cascade, restoring a pattern of cellular signaling and apoptosis closer to that of healthy liver tissue. The authors interpret this as evidence that the chemopreventive effect of the compounds is not a vague antioxidant blanket but a targeted modulation of a defined stress-response pathway. By damping the oxidative stress that activates ASK1 and rebalancing the apoptotic machinery downstream, the treatment appears to preserve the liver’s ability to clear damaged cells while reducing the inflammatory and peroxidative conditions that fuel tumor growth. Immunohistochemistry and Western blotting provided complementary confirmation, mapping where in the tissue the protein changes occurred and quantifying their abundance.

The study was conducted with formal ethical oversight, approved by the Institutional Animal Ethics Committee of Jamia Hamdard under the guidelines of India’s Committee for the Purpose of Control and Supervision of Experiments on Animals, and the work followed ARRIVE reporting standards for animal research. Data were analyzed by one-way analysis of variance followed by Tukey’s post hoc test, with results considered statistically significant at a threshold of p less than 0.05. The authors received no external funding for the study, and the first author was supported by a Junior Research Fellowship from the University Grants Commission. The article was published open access on 9 October 2026, making the full dataset and methods available to researchers anywhere without a subscription.

As with any animal study, the usual caveats apply. A rat model of chemically induced liver cancer, however well constructed, does not reproduce every feature of human hepatocellular carcinoma, which typically develops over decades against a backdrop of viral hepatitis, alcohol-related injury, or metabolic dysfunction. Doses used in laboratory animals often exceed what a person could reasonably obtain from diet alone, and curcumin’s low bioavailability remains a genuine obstacle to clinical translation even when piperine is present. The authors are careful to frame the findings as chemopreventive and hepatoprotective effects observed in an experimental model, associated with modulation of the TBP2–ASK1–JNK–caspase-3 axis, rather than as a demonstrated therapy for established human tumors.

Nevertheless, the study adds a meaningful piece to a growing body of evidence that dietary bioactive compounds can act on specific, measurable molecular targets rather than exerting only diffuse antioxidant effects. If the TBP2–ASK1–JNK–caspase-3 axis proves to be similarly dysregulated in human liver disease, the curcumin–piperine combination, or optimized derivatives of it, could become candidates for controlled trials aimed at preventing the progression of chronic liver injury toward cancer. For now, the image is an appealing one: two molecules that have traveled together through human kitchens for centuries, shown under the strict lens of modern molecular biology to coordinate a defense of the liver’s most vulnerable signaling machinery. The next step will be determining whether that defense survives the journey from the rat liver to the clinic.

Subject of Research: Chemoprevention of hepatocellular carcinoma by curcumin and piperine through modulation of the TBP2–ASK1–JNK–caspase-3 axis in rats

Article Title: Curcumin and piperine modulate the TBP2-ASK1-JNK-caspase-3 axis associated with prevention of DEN and TAA-induced hepatocellular carcinoma in rats

Article References: Afroz, N., Vafa, A., Ghosh, R., Rahaman, P. F., Wajid, S., & Ahmad, A. (2026). Curcumin and piperine modulate the TBP2-ASK1-JNK-caspase-3 axis associated with prevention of DEN and TAA-induced hepatocellular carcinoma in rats. BMC Cancer. https://doi.org/10.1186/s12885-026-17037-4

Image Credits: AI Generated

DOI: 10.1186/s12885-026-17037-4

Keywords: curcumin, piperine, hepatocellular carcinoma, chemoprevention, liver cancer, oxidative stress, ASK1, JNK, caspase-3, apoptosis, diethylnitrosamine, thioacetamide

The central innovation of the work lies in the fabrication of what the author calls CPT@PLA micronanofibers, a composite mat in which camptothecin is embedded within a matrix of poly(lactic acid), or PLA, a biodegradable and biocompatible polymer that is approved by the US Food and Drug Administration and occurs naturally in the human body. For the first time, a solution containing both camptothecin and PLA was subjected to electrospinning, a technique in which a high voltage of 18 kilovolts is applied to a polymer solution flowing through a stainless-steel needle at a rate of 0.5 milliliters per hour. As the charged jet accelerates toward a grounded collector positioned 20 centimeters away, the solvent evaporates almost instantaneously, leaving behind ultrafine fibers with diameters spanning the nano and micro scales. The resulting mats were vacuum dried for 24 hours at 40 degrees Celsius to remove residual solvent and then stored at 4 degrees Celsius away from direct sunlight until analysis.

A battery of physicochemical characterization techniques confirmed that the drug had been successfully integrated into the fibrous scaffold. Scanning electron microscopy revealed that pristine PLA fibers were smooth, bead-free, and randomly organized, with average diameters of roughly 1 to 1.5 micrometers. Once camptothecin was incorporated, the fibers displayed a broader diameter distribution encompassing both nano and micro dimensions, a shift the author attributes to chemical interactions between the drug and the polymer solution that may have altered the ionic balance of the spinning jet and promoted shrinkage of the fiber diameter. Confocal laser scanning microscopy provided a particularly striking visual confirmation: because camptothecin is intrinsically fluorescent, the fibers glowed brightly under laser excitation at 488 and 543 nanometers, demonstrating that the drug molecules were well dispersed throughout the electrospun matrix rather than clumped into aggregates.

X-ray diffraction analysis added another layer of evidence. Pure camptothecin is crystalline, exhibiting characteristic diffraction peaks at Bragg angles of 16.97 and 24.8 degrees along with several minor reflections, while the PLA polymer is amorphous and shows no prominent peaks. The composite CPT@PLA fibers produced an X-ray diffraction spectrum essentially identical to that of PLA, with only a few low-intensity minor peaks remaining. This disappearance of the drug’s crystalline signature indicates that the rapid solvent evaporation during electrospinning, enabled by the enormous surface area of the forming fibers, did not give the camptothecin molecules enough time to recrystallize, trapping them instead in an amorphous state. Electron probe microanalysis mapping further verified that carbon, oxygen, and nitrogen, the key elemental components of the drug, were uniformly distributed across the fiber surfaces.

Thermogravimetric analysis, performed in a nitrogen atmosphere from 25 to 700 degrees Celsius at a heating rate of 10 degrees per minute, revealed a single-step degradation profile for both materials. Pristine PLA fibers began decomposing at around 210 degrees Celsius and lost approximately 99 percent of their mass, whereas the CPT@PLA composite fibers showed an initial degradation temperature of 280 degrees Celsius and lost about 95 percent of their mass between 200 and 400 degrees Celsius. The thermal decomposition temperature of the composite was therefore elevated by 25 percent relative to pure PLA, a shift the study attributes to the higher breakdown temperature of the encapsulated camptothecin. The first derivative curves of the thermograms showed an additional peak in the composite fibers corresponding to drug decomposition, providing yet more confirmation that camptothecin had been genuinely incorporated into the polymer matrix rather than merely adsorbed onto its surface.

With the material thoroughly characterized, the biological question became paramount: does the fiber-encapsulated drug retain its lethal activity, and how does it kill cells? To answer this, the study turned to C2C12 cells, a mouse myoblast cell line that has a long history as a model for mechanistic toxicology. These cells carry receptors that respond to diverse chemotherapeutic treatments, including agents that interfere with DNA, block RNA synthesis, and inhibit topoisomerase enzymes, and they are known to be sensitive to many apoptotic chemical stimuli. Previous researchers have used C2C12 cells to probe the anticancer properties of copper and gold compounds, making them a well-validated platform for the present investigation. Cells were seeded into 96-well plates at a density of 10,000 cells per well, allowed to adhere overnight until reaching approximately 40 percent confluence, and then exposed to either pristine PLA fibers or CPT@PLA fibers at doses of 5 and 10 micrograms per well for periods of 12, 24, and 36 hours.

The results of the Cell Counting Kit-8 assay, which quantifies cell viability by measuring absorbance of a formazan product at 450 nanometers, were unambiguous. Pristine PLA fibers showed no significant cytotoxicity across all time points, with only an insignificant drop in viability after 36 hours, confirming that the polymer itself is benign. In stark contrast, the CPT@PLA micronanofibers suppressed C2C12 cell survival dramatically, achieving approximately 73 percent inhibition at the 5 microgram dose and 80 percent inhibition at the 10 microgram dose after 36 hours of exposure. The toxicity was both time dependent and concentration dependent, and the author attributes the pronounced effect to the enhanced stability of camptothecin when sequestered within the PLA matrix, which shields the drug’s active lactone ring from hydrolysis. That ring is crucial for the spontaneous diffusion of the drug into unhealthy cells, and its preservation during electrospinning represents one of the study’s most significant technical achievements.

Phase contrast microscopy captured the morphological consequences of this cytotoxic assault. Untreated control cells displayed an organized growth pattern typical of healthy myoblasts, while cells exposed to the CPT@PLA fibers exhibited substantial disfigurement characterized by cell shrinkage and fragmentation, hallmarks of impaired cellular integrity and incipient programmed death. To identify the molecular machinery driving this demise, the study employed reverse transcriptase PCR to measure the messenger RNA expression of two key apoptotic executioners, caspase-3 and caspase-7, with expression levels normalized to the reference gene GAPDH. Exposure to the CPT@PLA micronanofibers substantially amplified the expression of both caspase genes compared with untreated controls, and the increase was dose dependent, with higher fiber concentrations producing greater expression levels.

These molecular findings fit neatly into the established mechanism of camptothecin action. By inhibiting topoisomerase I, the drug induces DNA damage that activates the intrinsic, or mitochondrial, apoptotic pathway. This triggers the release of cytochrome c from mitochondria into the cytosol, where it initiates the caspase cascade. Caspases-3 and 7 serve as the principal executors of apoptosis, dismantling cellular structures, fragmenting DNA, and ultimately dismantling the cell from within. The sensitivity of cells to camptothecin depends in part on their capacity to activate these caspases effectively, and understanding this interplay opens the door to combination therapies that could enhance caspase activation or counteract resistance mechanisms in tumors. The study also notes that camptothecin triggers cell cycle checkpoints that arrest cells in S phase, and if the resulting DNA damage proves irreparable, the cells proceed inexorably to programmed death.

The author is candid about the limitations of the current work and the road ahead. Only caspases-3 and 7 were profiled, and future studies should extend the analysis to caspase-9, the initiator caspase of the mitochondrial pathway, to complete the mechanistic picture. Detailed release kinetics of camptothecin from the fibers remain to be determined, and in vitro toxicity testing against a panel of actual cancer cell lines, including breast, ovarian, colon, lung, and stomach cancers, is strongly advocated. Nevertheless, the study establishes an important proof of principle: electrospinning can encapsulate a fragile plant-derived prodrug in a biocompatible polymer matrix without destroying its active lactone ring, while simultaneously improving its thermal stability, protecting it from hydrolysis, and preserving its capacity to kill cells through the caspase-mediated apoptotic pathway. As electrospun nanofibers continue to find applications as bandages, implants, and drug delivery scaffolds, this work suggests that the humble fiber mat may yet become a formidable weapon in the ongoing war against cancer.

Subject of Research: Camptothecin-loaded PLA micronanofibers inducing caspase-mediated apoptosis in C2C12 cells

Article Title: Caspase mediated apoptosis induced by CPT@PLA micro-nanofibers in C2C12 cells: insights into probable mechanism

Article References: Amna, T. (2025). Caspase mediated apoptosis induced by CPT@PLA micro-nanofibers in C2C12 cells: insights into probable mechanism. Discover Toxicology, 2(1), Article 12. https://doi.org/10.1007/s44339-025-00024-y

Image Credits: AI Generated

DOI: 10.1007/s44339-025-00024-y

Keywords: camptothecin, electrospinning, poly(lactic acid), micronanofibers, apoptosis, caspase-3, caspase-7, C2C12 cells, drug delivery, topoisomerase I, nanomedicine, cytotoxicity

The motivation behind the work lies in one of the most stubborn puzzles of modern medicine. Neurodegenerative diseases such as Parkinson’s and Alzheimer’s are rising sharply in developed countries, and while their causes are multifactorial, accumulating evidence implicates environmental metal exposure as a contributing factor. Manganese, the third most abundant transition metal in the Earth’s crust, is an essential trace nutrient that supports enzymes ranging from glutamine synthetase to superoxide dismutase, yet overexposure—common among miners, welders, and mechanics—produces a syndrome called manganism, marked by motor dysfunction, hallucinations, and psychosis that closely resembles Parkinson’s disease but is progressive and largely irreversible. Aluminium, the most plentiful metal in the crust, has no known biological role in the human body, yet it has been repeatedly linked in the literature to Alzheimer’s disease, multiple sclerosis, and Parkinson’s disease, making both metals legitimate targets for protective interventions.

The toxicological mechanisms of these two metals are well characterized but distinct. Manganese accumulates in mitochondria, where it disrupts oxidative phosphorylation, elevates the production of reactive oxygen species, and destabilizes the mitochondrial membrane potential. It also derails neurotransmitter homeostasis—flooding the extracellular space with glutamate while depleting dopamine and disturbing γ-aminobutyric acid levels—and perturbs iron homeostasis and apoptotic signaling. Aluminium works through a different toolkit: it promotes free radical formation in astrocytes and microglia, amplifies iron-driven lipid peroxidation through the Fenton reaction, and mimics magnesium and calcium to corrupt ion-dependent processes. It also stokes inflammation, triggering the release of tumour necrosis factor-α, interleukin 1, and macrophage inflammatory protein-1α. Both metals, in short, attack neurons along multiple fronts simultaneously, which is precisely why broad-spectrum antioxidants like polyphenols have attracted such interest as potential countermeasures.

To test that idea, the Kraków team turned to SH-SY5Y cells, a human neuroblastoma line that has become a standard in vitro model for studying neurotoxicity in human-derived tissue. The experimental design was deliberately realistic in one key respect: rather than testing only the parent compounds, the researchers also examined trans-resveratrol 3-O-β-D-glucuronide and quercetin 3-O-β-D-glucuronide—the conjugated forms that the liver and intestine actually generate when people consume these polyphenols. Cells were pretreated with each compound at 5, 10, 20, or 30 micromolar for 24 hours, then exposed for another 24 hours to manganese(II) chloride tetrahydrate at 3 millimolar or aluminium L-lactate at 10 millimolar. The researchers then measured three readouts: lactate dehydrogenase release as a marker of membrane integrity, thiazolyl blue tetrazolium bromide reduction as a proxy for mitochondrial metabolic activity, and caspase-3 activity as an indicator of apoptosis.

The baseline toxicity results confirmed the destructive power of both metals. Manganese significantly elevated LDH release and depressed MTT reduction, while also driving a robust increase in caspase-3 activity—a signature consistent with apoptosis as the dominant mode of manganese-induced cell death. Aluminium likewise compromised membrane integrity and mitochondrial function, but, intriguingly, it reduced caspase-3 activity rather than raising it. The authors suggest that under their experimental conditions, aluminium’s neurotoxicity may not be mediated by caspase-dependent apoptosis at all, but rather by necrosis, a possibility supported by earlier work showing that aluminium compounds can switch cells from apoptotic to necrotic death as concentrations rise. This divergence matters, because it means a protective compound that rescues cells from one metal may be useless against the other, even when both metals damage the same cellular machinery.

Against manganese, the protective profile was clear and, in places, unexpected. Quercetin at 5 and 10 micromolar prevented the metal-induced surge in LDH efflux, and quercetin at 5, 10, and 20 micromolar normalized caspase-3 activity—evidence that the flavonoid shielded both membranes and apoptotic signaling. The glucuronidated metabolites also proved effective, but only at higher doses: both trans-resveratrol 3-O-β-D-glucuronide and quercetin 3-O-β-D-glucuronide at 20 and 30 micromolar reduced manganese-driven LDH release. Trans-resveratrol itself, however, was a disappointment on the membrane front, failing to protect LDH secretion at any dose and actually worsening manganese’s suppression of MTT reduction at 5, 20, and 30 micromolar. Only at the lowest concentration of 5 micromolar did trans-resveratrol restore caspase-3 activity to normal levels, hinting at a narrow therapeutic window for the stilbene compound.

The aluminium experiments told a different story. Here, the parent compounds shone at low concentrations: trans-resveratrol and quercetin, both at 5 and 10 micromolar, significantly diminished the metal’s disruption of LDH efflux, while trans-resveratrol at 20 micromolar actually aggravated the damage—a textbook example of the dose-dependent reversal that has haunted polyphenol pharmacology. The glucuronides were largely sidelined: trans-resveratrol 3-O-β-D-glucuronide helped only at 30 micromolar, and quercetin 3-O-β-D-glucuronide, though ineffective on membrane integrity, was the sole compound to improve MTT reduction, at 5 micromolar. Most tellingly, none of the four polyphenols recovered the aluminium-evoked disturbance of caspase-3 activity, reinforcing the suspicion that aluminium kills these cells through pathways that antioxidant pretreatment cannot readily intercept within the caspase cascade.

Why would the parent compounds outperform their metabolites, and why would lower doses beat higher ones? The authors point to a growing body of evidence that structural modifications such as glucuronidation can fundamentally alter polyphenol bioactivity. Resveratrol’s antithrombotic effects in activated endothelial cells, for instance, are not reproduced by its metabolites, and curcumin—but not curcumin-glucuronide—inhibits transforming growth factor-β signaling in bone metastatic breast cancer cells. One plausible mechanism, proposed by researchers studying quercetin in oxidative stress models, is that conjugated forms must first be deconjugated back to their aglycone by β-glucuronidase enzymes from microglial cells before they can protect neurons. The dose-dependence has its own explanation: quercetin, in scavenging free radicals, is itself degraded into orthoquinone species that can become hazardous to cells, meaning that at high concentrations the compound may shift from antioxidant to pro-oxidant. Similar biphasic behavior has been documented for resveratrol in dopamine-treated SH-SY5Y cells, where protection peaked at low doses and harm emerged at higher ones.

The authors are candid about the limitations of their work. Only single concentrations of each metal were tested, the polyphenol dose range was narrow, and the exposure windows were fixed at 24 and 48 hours, potentially missing optimal timing for some cellular processes. The molecular mechanisms underlying the observed protection—whether involving reactive oxygen species scavenging, glutathione redox status, mitochondrial membrane potential, or inflammatory cytokine modulation—remain unmeasured, and the SH-SY5Y model, while valuable, cannot fully replicate the complexity of the living brain. Still, the study represents basic research with clear translational implications: it confirms that trans-resveratrol, quercetin, and their glucuronidated metabolites hold genuine neuroprotective potential against manganese and aluminium toxicity, while cautioning that the form and concentration of these compounds are not trivial details but decisive variables. As interest in dietary polyphenols as preventive agents for neurodegenerative disease continues to grow, this work offers both a promising lead and a sobering reminder that in the chemistry of plant antioxidants, more is not always better—and sometimes, the body’s own metabolites hold part of the answer.

Subject of Research: Neuroprotective effects of dietary polyphenols against manganese- and aluminium-induced cytotoxicity in human neuroblastoma cells

Article Title: Protective effects of resveratrol, quercetin, and their glucuronide derivatives in an in vitro model of Mn- and Al-induced cytotoxicity in SH-SY5Y human neuroblastoma cells

Article References: Chamera, K., Starek-Świechowicz, B., Budziszewska, B., & Gawlik, M. (2025). Protective effects of resveratrol, quercetin, and their glucuronide derivatives in an in vitro model of Mn- and Al-induced cytotoxicity in SH-SY5Y human neuroblastoma cells. Discover Toxicology, 2(1), Article 15. https://doi.org/10.1007/s44339-025-00029-7

Image Credits: AI Generated

DOI: 10.1007/s44339-025-00029-7

Keywords: resveratrol, quercetin, glucuronide metabolites, manganese toxicity, aluminium toxicity, SH-SY5Y cells, neuroprotection, neurotoxicity, polyphenols, oxidative stress, apoptosis, caspase-3

The research, conducted by Omorede Ikponmwosa-Eweka of the University of Benin and Ikenna C. Maduako of Benson Idahosa University in Nigeria, set out to answer a question that previous work had largely ignored. Most experimental studies of vitamin E as a protective agent have used pharmacological doses of 100 milligrams per kilogram of body weight or higher, levels that approach or exceed the threshold at which alpha-tocopherol itself can paradoxically become a prooxidant and cause harm. Whether doses deliberately kept below that threshold could still deliver meaningful protection to two organs simultaneously had never been systematically tested. The Nigerian team also noted that earlier investigations tended to examine the heart or the kidney in isolation, even though reno-cardiac syndrome is increasingly understood as a unified, clinically significant condition in which dysfunction in one organ accelerates failure in the other.

To fill these gaps, the researchers designed a carefully staged experiment using thirty-five adult male Wistar rats, each weighing between 180 and 200 grams. The animals were randomly divided into five groups of seven. A control group received only corn oil, the vehicle in which vitamin E dissolves. A second group received vitamin E alone at 50 milligrams per kilogram. A third group was challenged with sodium arsenite at 10 milligrams per kilogram, a dose known to induce reproducible reno-cardiac injury. The fourth and fifth groups received the protective pretreatment: 25 or 50 milligrams per kilogram of vitamin E daily for seven consecutive days before arsenic exposure began, followed by another seven days in which the vitamin and the toxicant were co-administered. The total study lasted fourteen days, and all animals were sacrificed twenty-four hours after the final treatment.

The choice of doses was not arbitrary. In a pilot study, the team tested vitamin E at 10, 15, 20, 25, 50, and 100 milligrams per kilogram. The lowest three doses produced minimal or inconsistent biochemical changes, while 100 milligrams per kilogram triggered early signs of oxidative imbalance, including paradoxical elevations of malondialdehyde, a marker of lipid damage, and suppression of glutathione, the cell’s master antioxidant. The 25 and 50 milligram doses, by contrast, produced consistent, dose-dependent improvements in antioxidant enzyme activity and tissue health without mortality or prooxidant effects. The researchers argue that this prophylactic pretreatment strategy, priming the body’s antioxidant defenses before toxicant exposure, mirrors a clinically relevant supplementation approach that had not previously been applied to this model.

The results were unambiguous. Rats exposed to sodium arsenite alone showed sharply elevated serum levels of creatinine, urea, and lactate dehydrogenase, the classic biochemical signatures of renal impairment. Their cardiac markers told an equally grim story: creatine kinase-MB, cardiac troponin I, and alkaline phosphatase all surged, indicating myocardial injury. Histopathological examination confirmed the biochemical damage. Hearts from the arsenic-intoxicated group lost myofibrils and developed wavy fibers, severe pyknosis, and apoptotic bodies, while kidneys showed epithelial degeneration, vascular congestion, and peritubular immune cell infiltration. In the vitamin E pretreated groups, however, these markers fell significantly, and tissue architecture was restored to near-normal, with the 50 milligram dose generally outperforming the 25 milligram dose.

Beneath these visible outcomes lies a molecular narrative that the researchers reconstructed in remarkable detail. Sodium arsenite floods cells with reactive oxygen species while simultaneously depleting glutathione and suppressing the activities of the antioxidant enzymes superoxide dismutase, catalase, glutathione-S-transferase, and glutathione peroxidase. This oxidative collapse, the study shows, is not merely collateral damage but the upstream trigger for a lethal cascade. Sustained free radical burden destabilizes the mitochondrial membrane by suppressing Bcl-2, the anti-apoptotic gatekeeper protein, while ramping up the pro-apoptotic effectors Bax and Bid. The resulting shift in the Bax/Bcl-2 ratio tips the cell toward self-destruction, prompting the release of cytochrome c from mitochondria into the cytosol, where it assembles the apoptosome and activates the initiator caspase-9 and, in turn, the executioner caspase-3. Cardiomyocytes and renal tubular epithelial cells, once committed to this pathway, die in droves.

Vitamin E interrupted this cascade at multiple points simultaneously. Its lipophilic chromanol ring, bearing a free hydroxyl group at the C-6 position, allows it to embed directly in the lipid membranes of cardiac and renal cells, where it intercepts membrane-associated free radicals before they can attack. In the treated animals, antioxidant enzyme activities rebounded, glutathione levels rose, and malondialdehyde concentrations fell in a dose-dependent fashion. Critically, the vitamin shifted the Bax/Bcl-2 ratio back toward Bcl-2, favoring cell survival, and suppressed the release of cytochrome c along with the downstream activation of both caspases. The authors emphasize that this coordinated, multi-nodal suppression of an oxidative stress-driven mitochondrial apoptosis cascade, rather than a single isolated antioxidant effect, explains the breadth of protection observed across both organs.

The study is not without limitations, which the authors address candidly. All experiments were conducted exclusively in male rats, a choice made to eliminate hormonal variability from the estrous cycle but one that limits direct generalizability to females and mixed-sex human populations. The apoptotic findings rest entirely on ELISA quantification of seven intrinsic cascade proteins; confirmatory techniques such as TUNEL staining for DNA fragmentation, fluorometric caspase activity assays, mitochondrial membrane potential probes, and Western blot verification were not performed. The acute seven-day arsenic exposure model also does not recapitulate the chronic, low-level exposure characteristic of arsenic-endemic human communities, which constrains direct translational application. The authors call for future studies incorporating chronic exposure models, sex comparisons, and confirmatory apoptotic assays to validate and extend their preclinical observations.

Even so, the implications are considerable. Reno-cardiac syndrome is an emerging cause of mortality worldwide, driven by uremic toxin production, fluid and electrolyte shifts, neurohormonal activation, and inflammation that progressively worsen the function of both organs. Epidemiological evidence links even low-to-moderate arsenic exposure in drinking water to increased risks of cardiovascular disease, renal impairment, and kidney cancer. If a cheap, widely available, and safely dosed antioxidant such as vitamin E can blunt the molecular assault of arsenic on both the heart and the kidneys, the findings open a plausible avenue for adjunctive intervention in exposed populations. The researchers stress that their results establish a mechanistically integrated scientific basis for further investigation rather than an immediate clinical prescription. Still, in an era when arsenic contamination affects tens of millions of people globally, the demonstration that sub-prooxidant doses of a familiar vitamin can simultaneously quiet oxidative stress, stabilize the mitochondrial gate between life and death, and preserve the architecture of two vital organs is a finding that toxicologists, cardiologists, and nephrologists alike will want to watch closely.

Subject of Research: Protective effects of low-dose vitamin E against sodium arsenite-induced reno-cardiac toxicity through inhibition of oxidative stress and apoptosis in rats

Article Title: Low-dose vitamin E (α-tocopherol) modulates acute sodium arsenite-induced renocardiac toxicity by inhibiting oxidative stress and apoptosis

Article References: Ikponmwosa-Eweka, O., & Maduako, I. C. (2026). Low-dose vitamin E (α-tocopherol) modulates acute sodium arsenite-induced renocardiac toxicity by inhibiting oxidative stress and apoptosis. Discover Toxicology, 3(1), Article 10. https://doi.org/10.1007/s44339-026-00056-y

Image Credits: AI Generated

DOI: 10.1007/s44339-026-00056-y

Keywords: vitamin E, alpha-tocopherol, sodium arsenite, reno-cardiac toxicity, oxidative stress, apoptosis, Bax/Bcl-2 ratio, caspase-3, mitochondrial dysfunction, cardiotoxicity, nephrotoxicity, Wistar rats

Glioma is the most common malignant primary brain tumor in adults, and its most aggressive form, glioblastoma, carries a median survival measured in months rather than years. The therapeutic arsenal remains painfully thin: surgical resection, radiation, and the chemotherapy drug temozolomide extend life only modestly, and the blood-brain barrier blocks many otherwise promising compounds from ever reaching the tumor. Against this backdrop, scientists have increasingly turned to cell death programs as therapeutic levers. Apoptosis, the quiet and orderly form of cell suicide, has long been the target of conventional cancer drugs, but tumors routinely evolve resistance to it. Pyroptosis, by contrast, is loud, inflammatory, and lytic: cells swell, rupture, and release their contents, simultaneously destroying the tumor cell and sounding an immune alarm.

The molecular machinery of pyroptosis centers on the gasdermin family of proteins. When enzymes such as caspases cleave a gasdermin protein, the released fragment migrates to the cell membrane and punches oligomeric pores into it. The cell loses its ionic balance, swells with water, and ultimately bursts, spilling damage-associated molecular patterns and inflammatory cytokines such as interleukin-1 beta into the tumor microenvironment. One family member in particular, gasdermin E, or GSDME, has attracted intense interest because it can be cleaved by caspase-3, the very executioner enzyme of apoptosis. In principle, this creates a molecular switch: a stimulus that begins as apoptotic can be diverted into pyroptosis when GSDME is present, converting a silent death into an immunostimulatory event capable of reshaping the tumor’s immune landscape.

Recognizing this potential, Hanwen Lu and Zhanxiang Wang of the First Affiliated Hospital of Xiamen University and their collaborators set out to do something that had not been done systematically before: build a dedicated library of pyroptosis-inducing compounds and filter it through the unforgiving realities of brain tumor pharmacology. The team assembled their library by combining commercially available pyroptosis inducers with candidates harvested from an exhaustive mining of the PubMed and Web of Science literature. But identifying a molecule that triggers pyroptosis in a dish is only the first hurdle. For a brain cancer drug, the compound must also survive the gauntlet of drug-likeness filters and, crucially, cross the blood-brain barrier, the tightly sealed endothelial lining that excludes the vast majority of small molecules from the central nervous system.

To solve this, the researchers applied a sequential computational and pharmacological funnel. First came Lipinski’s rule of five, the classic checklist of molecular weight, hydrogen-bond donors and acceptors, and lipophilicity that predicts oral absorbability. Next, they used predictive models of blood-brain barrier permeability, followed by central nervous system multiparameter optimization scoring, a more sophisticated metric that balances multiple physicochemical properties to estimate the likelihood that a molecule will achieve adequate brain exposure without unacceptable side effects. Stringent descriptor-based criteria narrowed the field further, and a final round of pharmacological curation and literature vetting elevated a short list of priority candidates. Rising to the top of that list was diacerein, a drug oncologists had never seriously considered but rheumatologists have prescribed for years.

Diacerein is an anthraquinone derivative that works as a slow-acting anti-osteoarthritic agent, traditionally understood to inhibit interleukin-1 beta signaling in cartilage. Its established safety profile, oral availability, and favorable predicted brain penetration made it an attractive repurposing candidate. In laboratory experiments, the team found that diacerein significantly inhibited the proliferation of glioma cells and suppressed tumor growth in animal models. But the mechanism they uncovered was far more interesting than simple growth arrest. Treatment with diacerein activated caspase-3, the canonical apoptotic executioner, and simultaneously triggered the cleavage of GSDME, the gasdermin protein that converts caspase-3 activity into pyroptotic membrane rupture. In other words, the drug appeared to push glioma cells down a hybrid death pathway that begins with apoptosis and culminates in pyroptosis-like lysis.

To confirm that GSDME was not merely a bystander in this process, the researchers performed loss-of-function experiments. When they knocked down GSDME in glioma cells, the cytotoxic punch of diacerein was substantially blunted: cell viability recovered, and the drug’s killing efficiency dropped. This partial rescue demonstrates that GSDME is functionally required for a significant share of diacerein-induced glioma cell death, anchoring the drug’s effect in the pyroptotic pathway the screen was designed to find. The team also traced changes in inflammation-related signaling, observing reduced activity along the interleukin-1 beta, NF-kappa B, and phosphorylated STAT3 axes. Because these pathways sit at the heart of macrophage-mediated inflammation, the authors suggest the drug may also alter macrophage-related immune dynamics within the tumor microenvironment in living animals, a possibility with major implications given the prominent role of tumor-associated macrophages in glioma immunosuppression.

The implications extend beyond a single molecule. The study validates a repurposing strategy that begins with a cell death mechanism rather than a molecular target, then filters candidate drugs through the pharmacological constraints of the diseased tissue. This pyroptosis-oriented pipeline could in principle be rerun for other cancers of the central nervous system, or adapted to other lytic death programs such as necroptosis and ferroptosis. It also illustrates the growing power of literature mining as a discovery tool: by systematically extracting pyroptosis-inducing activity from thousands of published pharmacological studies, the team assembled a candidate pool that no single laboratory’s compound collection would have contained. The approach effectively converts the accumulated knowledge of pharmacology into a searchable, filterable database of mechanism-directed therapeutics.

Considerable work remains before diacerein could reach glioma patients. The doses used in laboratory and animal studies may not map directly onto the exposures achievable and tolerable in humans, and the authors evaluated brain exposure using liquid chromatography-tandem mass spectrometry methods developed specifically for this study, but clinical pharmacokinetics in glioma patients, where the blood-brain barrier is often locally disrupted yet heterogeneously intact, will need dedicated investigation. The precise molecular target through which diacerein initiates caspase-3 activation in glioma cells also remains to be fully defined, and the immunological consequences of triggering pyroptosis inside the brain, an organ exquisitely sensitive to inflammation, must be carefully characterized. Nevertheless, the fact that diacerein is already an approved, well-characterized medicine with a known safety record could substantially shorten the path from bench to bedside, potentially through investigator-initiated clinical trials in recurrent glioma, where new options are desperately needed and the regulatory bar for repurposed drugs is lower than for entirely novel agents.

For a disease that has defeated nearly every therapeutic innovation thrown at it, the idea that an arthritis pill sitting in pharmacy shelves worldwide might recruit the immune system against glioma through gasdermin pores is the kind of unexpected twist that drug repurposing was made for. The Xiamen team’s work provides both a concrete candidate and a reusable discovery framework, suggesting that the next breakthrough in brain cancer may not come from a molecule designed from scratch, but from an old drug viewed through an entirely new biological lens.

Subject of Research: Pyroptosis-oriented drug repurposing identifies diacerein as a therapeutic candidate for glioma

Article Title: Pyroptosis-oriented drug discovery identifies diacerein as a promising therapeutic candidate for glioma

Article References: Lu, H., & Wang, Z. (2026). Pyroptosis-oriented drug discovery identifies diacerein as a promising therapeutic candidate for glioma. BMC Medicine. https://doi.org/10.1186/s12916-026-05187-y

Image Credits: AI Generated

DOI: 10.1186/s12916-026-05187-y

Keywords: glioma, diacerein, pyroptosis, GSDME, caspase-3, drug repurposing, blood-brain barrier, immune microenvironment, macrophage, NF-kappa B, IL-1 beta, BMC Medicine

Diabetes mellitus is far more than a disorder of blood sugar. Persistent hyperglycemia triggers a slow, systemic assault on tissues throughout the body, and while the kidneys, nerves, and retina receive most of the attention, the spleen quietly suffers as well. This fist-sized lymphoid organ orchestrates innate and adaptive immunity, filters aged red blood cells from circulation, and serves as a critical reservoir of immune cells. When the spleen falters, the consequences ripple outward: anemia worsens, infection susceptibility climbs, and the delicate balance between pro-inflammatory and anti-inflammatory signaling collapses. Earlier studies have documented splenic shrinkage, lymphoid degeneration, and immune dysregulation in diabetic animals, but effective pharmacological protectants remain scarce.

The research team, led by Asma B. Omer of Princess Nourah bint Abdulrahman University together with collaborators across Saudi Arabia, Oman, and India, chose streptozotocin, or STZ, as their diabetes-inducing agent. STZ is a glucosamine-nitrosourea compound that selectively destroys insulin-producing pancreatic beta cells, producing a model of persistent hyperglycemia that closely mirrors the metabolic and oxidative burden of uncontrolled human diabetes. A single intraperitoneal dose of 50 milligrams per kilogram was sufficient to push the Wistar rats into a diabetic state, setting the stage for eight weeks of treatment with oral rufigallol at two doses, 10 and 20 milligrams per kilogram per day.

The baseline damage inflicted by STZ was comprehensive and sobering. Diabetic animals developed sustained elevation of fasting blood glucose alongside a measurable reduction in spleen weight, signaling tissue atrophy. Their hematological profiles deteriorated in a pattern familiar to clinicians: anemia, elevated white cell counts consistent with chronic inflammatory activation, and falling platelet numbers. Beneath these visible changes, the molecular machinery of the spleen was under coordinated attack. Levels of malondialdehyde, a canonical marker of lipid peroxidation, surged, and nitric oxide production climbed, both signatures of unchecked oxidative assault on cellular membranes and proteins.

Equally telling was the collapse of the spleen’s antioxidant shield. Superoxide dismutase, catalase, and reduced glutathione, the enzymatic and non-enzymatic sentinels that normally neutralize reactive oxygen species, were all significantly depleted in the diabetic animals. With antioxidant defenses eroded, the pro-inflammatory cascade gained momentum. The researchers measured markedly increased concentrations of interleukin-1 beta, interleukin-6, tumor necrosis factor-alpha, and interferon-gamma, coupled with suppression of the anti-inflammatory cytokines interleukin-2 and interleukin-4. At the top of this inflammatory hierarchy sat nuclear factor kappa B, NF-κB, the transcription factor that coordinates the expression of dozens of inflammatory genes, and it was strongly activated in the diabetic spleen.

The third prong of the injury was apoptosis, the controlled self-destruction of cells. In the diabetic spleens, the pro-apoptotic protein Bax and the execution enzyme caspase-3 were upregulated, while the anti-apoptotic guardian Bcl-2 was diminished. This shift in the Bax-to-Bcl-2 ratio pushed splenic cells, including the lymphocytes and macrophages that populate the white and red pulp, toward self-elimination. Histopathological examination confirmed the functional data at the tissue level, revealing marked disruption of the normal splenic architecture, with damage to the lymphoid follicles and red pulp structures that underpin the organ’s immune and filtration roles.

Rufigallol treatment turned this grim molecular picture around in a dose-dependent fashion. The higher dose of 20 milligrams per kilogram consistently outperformed the lower dose across nearly every endpoint. Treated animals showed significantly reduced fasting blood glucose, recovered spleen weight, and improved hematological indices, including corrections in the anemia, leukocytosis, and thrombocytopenia that had accompanied the diabetic state. At the biochemical level, the compound restored the depleted antioxidant arsenal, elevating superoxide dismutase, catalase, and glutathione while simultaneously driving down malondialdehyde and nitric oxide, evidence that it both quenched existing oxidative damage and rebuilt the spleen’s capacity to resist it.

The anti-inflammatory and anti-apoptotic effects were equally striking. Rufigallol suppressed the elevated pro-inflammatory cytokines and restrained NF-κB activation, dampening the transcriptional engine of splenic inflammation. At the same time, it rebalanced the apoptotic threshold: Bax and caspase-3 expression fell while Bcl-2 rose, shifting cells away from self-destruction and toward survival. Microscopic analysis of the treated spleens confirmed that these molecular changes translated into tangible structural recovery, with substantially improved preservation of the lymphoid architecture compared with untreated diabetic controls. The authors conclude that rufigallol protected the spleen by simultaneously targeting oxidative stress, inflammatory signaling, and the apoptotic pathway, three interlocking mechanisms that converge on tissue survival.

The choice of rufigallol is scientifically grounded rather than arbitrary. The compound, formally 1,2,3,5,6-pentahydroxy-9,10-anthraquinone, belongs to the anthraquinone family, a class of polyphenolic plant metabolites with a growing resume in metabolic research. Related anthraquinones such as emodin, rhein, and aloe-emodin have shown anti-diabetic, antioxidant, and immunomodulatory properties in prior preclinical studies, and the hydroxyl-rich structure of rufigallol makes it a potent electron donor capable of neutralizing free radicals directly. The polyphenol’s redox activity, the researchers note, aligns with the broader recognition that dietary and plant-derived polyphenols can modulate redox signaling, bioenergetics, and cell fate decisions in ways that synthetic antioxidants often cannot.

The findings carry meaningful implications for a global diabetes epidemic that now affects hundreds of millions of people and continues to expand. Because splenic dysfunction compounds the immune weakness already characteristic of diabetes, contributing to heightened infection risk and poorer vaccine responses, protecting this organ could have clinical value beyond the laboratory. The authors caution that these results derive from a rodent model, and translation to human therapy will require pharmacokinetic profiling, toxicity evaluation, and ultimately controlled clinical trials. Nevertheless, the study adds rufigallol to the short list of natural compounds with demonstrated, mechanistically resolved protection of lymphoid tissue in diabetes, and it strengthens the case that inexpensive plant-derived anthraquinones deserve closer scrutiny as adjunctive agents against the multi-organ toll of chronic hyperglycemia. The research was supported by Princess Nourah bint Abdulrahman University Researchers Supporting Project number PNURSP2026R854.

Subject of Research: Protective effects of the anthraquinone compound rufigallol against streptozotocin-induced splenic injury in diabetic rats

Article Title: Rufigallol attenuates splenic damage caused by STZ by targeting oxidative stress, inflammation, and the apoptosis pathway

Article References: Omer, A. B., Afzal, M., Rafeeq, M., Murad, H. A. S., Alzarea, S. I., Sayyed, N., Kazmi, I., & Al-Abbasi, F. A. (2026). Rufigallol attenuates splenic damage caused by STZ by targeting oxidative stress, inflammation, and the apoptosis pathway. 3 Biotech, 16(10), Article 419. https://doi.org/10.1007/s13205-026-05047-9

Image Credits: AI Generated

DOI: 10.1007/s13205-026-05047-9

Keywords: rufigallol, diabetes, spleen, streptozotocin, oxidative stress, inflammation, apoptosis, NF-κB, anthraquinone, antioxidant, Bcl-2, caspase-3