Rose-Powered Nanoparticles Strike Cancer Cells and Superbugs in One Green Recipe

Scientists have brewed up a new weapon against cancer and drug-resistant bacteria using one of the world’s most fragrant plants. A research team led by Nada H. Aljarba of Princess Nourah bint Abdulrahman University and Munirah F. Aldayel of King Faisal University has synthesized selenium-doped nickel oxide nanoparticles with the help of Damask rose leaf extract, and shown in laboratory tests that the particles can kill cervical cancer cells, dismantle bacterial membranes, and even suppress the genes that make pathogens dangerous. The work, published in the Journal of the Saudi Chemical Society, is notable for combining an eco-friendly synthesis route with an unusually broad biological evaluation, covering anticancer, antibacterial, antibiofilm, anti-virulence, antioxidant, and enzyme-inhibitory activities in a single study.

The choice of manufacturing method matters as much as the material itself. Conventional nanoparticle synthesis typically relies on toxic reducing chemicals, high energy input, and multi-step procedures that raise environmental and biocompatibility concerns. Green synthesis sidesteps these problems by using plant extracts, microbes, or purified biomolecules to reduce metal ions and stabilize the resulting particles. In this case, the researchers boiled dried Rosa damascena leaves in water at 80 degrees Celsius for 30 minutes, filtered the extract, and then mixed it with solutions of nickel nitrate and sodium selenite. After adjusting the pH to roughly 10 with sodium hydroxide and stirring for two hours, a greenish precipitate formed. The solid was washed, dried, and calcined at 400 degrees Celsius for two hours to yield crystalline selenium-doped nickel oxide nanoparticles.

The rose extract is not merely a benign solvent; it is the chemical engine of the reaction. Gas chromatography-mass spectrometry revealed that the extract is dominated by phenylethyl alcohol at 30.25 percent, eugenol at 10.48 percent, anethole at 9.59 percent, and caryophyllene at 5.07 percent, alongside monoterpenes such as p-cymene and D-limonene. High-performance liquid chromatography confirmed a rich phenolic and flavonoid inventory, with the flavonoid apigenin accounting for 62.59 percent of identified compounds, followed by quercetin, rutin, hesperidin, gallic acid, ferulic acid, and quinic acid. These molecules carry multiple hydroxyl and conjugated groups that donate electrons to reduce metal ions, while functional groups such as hydroxyl and carboxyl moieties cap the particle surfaces and regulate growth. The same phytochemicals are themselves biologically active, which means the finished nanoparticles carry a built-in layer of therapeutic chemistry.

A battery of characterization techniques confirmed that the synthesis worked as intended. Ultraviolet-visible spectroscopy showed a strong absorption band near 240 nanometers and a shoulder around 436 nanometers, and a Tauc plot analysis yielded an optical band gap of approximately 3.12 electronvolts, notably lower than the 3.6 to 4.0 electronvolts typical of pure nickel oxide. That narrowing is a chemical fingerprint of selenium doping, which introduces localized defect states and oxygen vacancies into the nickel oxide lattice. Fourier-transform infrared spectroscopy detected a characteristic nickel-oxygen stretching band near 626 per centimeter, together with peaks from the plant-derived organic coating. X-ray diffraction indexed the particles to face-centered cubic nickel oxide, with no separate crystalline selenium phase detected, indicating that selenium was incorporated into the lattice or dispersed in an amorphous state rather than forming its own crystals.

Electron microscopy painted a picture of quasi-spherical particles averaging 41.8 plus or minus 20 nanometers in diameter, though the distribution was fairly broad, a common consequence of phytochemical-mediated nucleation. Energy-dispersive X-ray spectroscopy confirmed the presence of nickel, oxygen, and selenium, and elemental mapping showed the three elements uniformly distributed throughout the sample, supporting genuine doping rather than surface segregation. Dynamic light scattering told a more complicated story: the hydrodynamic diameter in water was 285.3 nanometers with a polydispersity index of 0.517, reflecting an adsorbed layer of plant molecules and some aggregation. The zeta potential of plus 15.1 millivolts indicated moderate colloidal stability. Thermogravimetric analysis traced the loss of adsorbed water below 200 degrees Celsius and the decomposition of residual phytochemicals between 200 and 350 degrees Celsius, while BET measurements revealed a low surface area of 0.753 square meters per gram but a mesoporous structure with an average pore diameter of 26.96 nanometers.

The anticancer results were the most striking. In MTT assays, the nanoparticles killed HeLa cervical cancer cells with an IC50 of 239.4 micrograms per milliliter, while normal Vero cells required 407.9 micrograms per milliliter to reach the same level of toxicity, a selectivity index of roughly 1.7. Cancer cells are thought to be more vulnerable because they already operate at elevated levels of intracellular reactive oxygen species, so additional oxidative stress from selenium and nickel oxide pushes them past a survival threshold that healthy cells can still tolerate. Flow cytometry using Annexin V and propidium iodide staining showed that viable HeLa cells plummeted from 96.2 percent to 44.5 percent after treatment, while early apoptotic cells rose from zero to 32.6 percent and late apoptotic cells to 20.7 percent, confirming that programmed cell death, not necrosis, was the dominant outcome.

Cell cycle analysis added a second mechanism. Untreated HeLa cells were mostly in S phase, but treated cells accumulated dramatically in the G2/M phase, rising from 6.9 percent to 66.5 percent, with the G1 population vanishing entirely. This arrest suggests the nanoparticles damage DNA or interfere with checkpoint machinery, preventing cells from entering mitosis. Quantitative real-time PCR then connected the dots at the molecular level: expression of the executioner caspase-3 rose 3.2-fold and the pro-apoptotic protein BAX rose 2.8-fold, while the anti-apoptotic Bcl-2 fell to 0.42-fold of control levels. The resulting BAX-to-Bcl-2 ratio increased 6.67-fold, a classic signature of the intrinsic mitochondrial apoptotic pathway being switched on.

On the microbial front, the nanoparticles showed broad-spectrum activity against Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli, with inhibition zones between 15.56 and 18.4 millimeters, minimum inhibitory concentrations of 200 to 400 micrograms per milliliter, and bactericidal concentrations of 200 to 800 micrograms per milliliter. Pseudomonas aeruginosa was the most susceptible, with matching MIC and MBC values of 200 micrograms per milliliter, while the thick peptidoglycan wall of Staphylococcus aureus offered comparatively more resistance. Biofilm assays showed concentration-dependent disruption, peaking at 68.79 percent inhibition for S. aureus, 55.03 percent for P. aeruginosa, and 52.89 percent for E. coli at 1000 micrograms per milliliter. Protein leakage assays quantified membrane damage at up to 54.64 percent, and transmission electron microscopy captured treated bacteria with ruptured envelopes and leaking cytoplasm.

Perhaps most intriguing for the era of antibiotic resistance, the nanoparticles acted as anti-virulence agents. At half the inhibitory concentration, they suppressed key Pseudomonas virulence genes, cutting lasB expression to 55.40 percent of control levels, algD to 46.36 percent, and toxA to 41.28 percent. Because lasB encodes elastase, a tissue-damaging enzyme, algD drives alginate production for biofilm formation, and toxA controls toxin secretion, silencing these genes disarms the pathogen without necessarily killing it, a strategy that exerts weaker selective pressure for resistance than conventional bactericidal drugs. The particles also showed moderate antioxidant activity, with DPPH and ABTS radical-scavenging IC50 values of 478.18 and 640.03 micrograms per milliliter respectively, and inhibited the carbohydrate-digesting enzymes alpha-amylase and alpha-glucosidase with IC50 values of 481.05 and 232.52 micrograms per milliliter, the latter suggesting possible relevance to glycemic control.

The authors are careful to frame these findings as a promising beginning rather than a therapeutic endpoint. All experiments were conducted in vitro, and the nanoparticles’ moderate colloidal stability and partial aggregation could complicate formulation. Future work will need to verify reactive oxygen species generation and mitochondrial depolarization directly, test the particles in animal models, assess long-term biosafety, and explore whether they can synergize with existing antibiotics. Still, the study demonstrates that a simple aqueous extract of rose leaves can orchestrate the creation of a doped metal oxide nanomaterial with selective anticancer action, membrane-rupturing antibacterial power, gene-silencing anti-virulence effects, and antioxidant chemistry, all from a green, low-cost, and potentially scalable process. If subsequent in vivo studies hold up, phyto-mediated selenium-doped nickel oxide nanoparticles could join the growing arsenal of multifunctional nanomaterials aimed at two of medicine’s toughest targets at once.

Subject of Research: Green synthesis of selenium-doped nickel oxide nanoparticles and their anticancer and antimicrobial mechanisms

Article Title: Green-synthesized selenium-doped nickel oxide nanoparticles: Biological activities and mechanistic insights into anticancer and antimicrobial effects

Article References: Aljarba, N. H., Aldayel, M. F., AlMotwaa, S. M., Al-Otaibi, W. A., & Soliman, M. K. Y. (2026). Green-synthesized selenium-doped nickel oxide nanoparticles: Biological activities and mechanistic insights into anticancer and antimicrobial effects. Journal of Saudi Chemical Society, 30(4), Article 47. https://doi.org/10.1007/s44442-026-00097-3

Image Credits: AI Generated

DOI: 10.1007/s44442-026-00097-3

Keywords: green synthesis, selenium-doped nickel oxide, nanoparticles, Rosa damascena, anticancer, apoptosis, antibacterial, antibiofilm, anti-virulence, antioxidant, enzyme inhibition, HeLa cells