The research team, led by Omar Arroyo-Xochihua, focused on RAW 264.7 macrophages, a murine cell line that has become the workhorse of inflammation research worldwide. These cells were stimulated with lipopolysaccharide, or LPS, a molecule found in the outer membrane of Gram-negative bacteria that reliably triggers a full-blown inflammatory response. Once the macrophages were activated in this way, the scientists treated them with an ethanol-water extract of E. menziesii and with four fractions separated by polarity: hexane, dichloromethane, ethyl acetate, and a residual aqueous fraction. The goal was to see whether any of these preparations could rein in the cellular storm that LPS ignites.

Before any biological testing could begin, the team needed to know what was actually inside the seaweed. Using proton nuclear magnetic resonance spectroscopy, or 1H-NMR, they generated chemical fingerprints of the crude extract and each fraction. The spectra revealed a rich assortment of proton signals spanning alkyl, hydroxyl, amino, alkene, and aromatic regions. Three regions stood out. Signals between 1.10 and 1.25 parts per million corresponded to the methyl groups of fucoidan, a sulfated polysaccharide abundant in brown seaweed cell walls. Signals between 5.0 and 5.8 parts per million marked the anomeric protons of fucoidan’s sugar rings. And a dense cluster between 3 and 5 parts per million pointed to mannitol, a sugar alcohol that brown algae use as a carbon transport molecule and osmolyte.

Safety came first. Using the MTT assay, which measures mitochondrial activity as a proxy for cell health, the researchers exposed macrophages to concentrations ranging from 12.5 to 1000 micrograms per milliliter over 24 and 48 hours. The extract and all fractions kept cell viability at or above 90 percent across the tested range, and the calculated half-maximal inhibitory concentration exceeded 1000 micrograms per milliliter at both time points. Only the highest concentration of the crude extract showed any hint of toxicity at 48 hours, and it was excluded from further experiments. Hydrogen peroxide, used as a positive cytotoxicity control, killed cells as expected, confirming the assay was working. The result establishes that the seaweed preparations are safe for cellular experimentation at the doses that produced biological effects.

With safety established, the team turned to a scratch assay, a simple but informative test of cell migration. A sterile pipette tip drags a wound-like gap through a confluent monolayer of macrophages, and researchers then measure how quickly cells migrate in to close the gap. LPS alone impaired migration, leaving the scratched area largely open at 48 hours. Treatment with the crude ethanol-water extract significantly reversed this effect, reducing the free scratched area by up to 40 percent at 24 hours compared with the LPS-stimulated control. The aqueous fraction performed even better, showing significant scratch closure at both 24 and 48 hours, with reductions approaching 10 percent of the original wound area remaining at the later time point. Curcumin and indomethacin, included as natural and pharmacological controls, also promoted closure, but the seaweed treatments held their own against these benchmarks.

The most technically ambitious part of the study came next. Rather than guessing which compounds were responsible, the researchers applied multivariate data analysis, specifically Orthogonal Partial Least-Squares modeling, to correlate the NMR spectra with the scratch closure measurements. The resulting statistical model was strikingly robust, with explained variance values above 0.95 and predictive Q-squared values of 0.97 and 0.93 at 24 and 48 hours respectively, and cross-validation confirmed the model was not overfitted. The contribution plots revealed that proton signals in the 0.6 to 3 parts per million region were the main contributors to the anti-migratory rescue effect. This region encompasses the methyl groups of fucoidan and the alcohol protons of mannitol, providing chemometric evidence that these two abundant seaweed metabolites are the likely active principles.

Phagocytosis, the process by which macrophages engulf debris and pathogens, told a more nuanced story. Measured with a neutral red uptake assay, phagocytic activity surged in LPS-stimulated cells, as expected. The crude extract brought this activity back down below the levels seen in unstimulated controls, suggesting a normalizing rather than suppressive effect. Interestingly, the dichloromethane, ethyl acetate, and aqueous fractions each increased phagocytic activity above unstimulated baseline levels, hinting that different components of the seaweed may push macrophage behavior in different directions depending on the chemical context. The hexane fraction showed no significant effect either way.

The clearest anti-inflammatory signal emerged from the cytokine measurements. Using reverse transcription quantitative PCR and enzyme-linked immunosorbent assays, the team quantified both messenger RNA and secreted protein levels of interleukin-1 beta and interleukin-6, two pro-inflammatory cytokines central to the M1 macrophage phenotype that LPS induces. The crude extract cut IL-1 beta mRNA expression to less than half of the LPS-stimulated level and kept IL-6 fold change below 3, with corresponding reductions at the protein level that matched the effect of indomethacin. The aqueous fraction also significantly reduced both cytokines, though its protein-level effects were less complete. Notably, neither curcumin nor indomethacin achieved significant reductions in cytokine gene expression in this system, making the seaweed’s performance at the transcript level particularly noteworthy.

The mechanistic story fits with a growing body of literature on sulfated polysaccharides. Fucoidan’s negatively charged sulfate groups are thought to interact electrostatically with inflammatory mediators, and studies of fucoidan from related brown seaweeds have shown that it can block the NF-kappa B signaling pathway, a master transcriptional switch for inflammatory genes. Mannitol, meanwhile, has been shown to reduce markers of M1-like macrophage and microglial activation in animal models of neuroinflammation, possibly through osmotic effects that alter immune cell behavior. The authors caution that the compounds in a crude extract may act synergistically or even antagonistically, and that a single murine cell line in a monolayer cannot capture the full complexity of inflammation in a living organism. Future work, they suggest, should test human cell lines, explore nitric oxide and other inflammatory mediators, and pursue full metabolomic profiling.

Still, the implications are considerable. Non-steroidal anti-inflammatory drugs remain among the most widely consumed medications on Earth, and their long-term use is linked to gastrointestinal damage, ulcers, and elevated cardiovascular risk. Marine organisms remain a strikingly underexplored source of alternatives; between 1981 and 2019, more than fifty natural products and derivatives for treating inflammation were approved, yet marine species account for only a small fraction of the research effort. Egregia menziesii, with its limited range from Alaska to Baja California and its documented safety across multiple cell types and whole-organism models, now joins the shortlist of seaweeds with credible immunomodulatory credentials. If the fucoidan and mannitol hypothesis holds up in more complex systems, the feather boa kelp swaying in the Pacific surf could one day contribute to medicines that quiet inflammation without the collateral damage of current drugs.

Subject of Research: Anti-inflammatory activity and chemical profiling of Egregia menziesii extracts in LPS-activated macrophages

Article Title: Chemical profiling of Egregia menziesii and anti-inflammatory potential in LPS-activated RAW 264.7 macrophages

Article References: Arroyo-Xochihua, O., Sánchez-Medina, A., López-Franco, Ó., Olivares-Bañuelos, T. N., & Zepeda, R. C. (2026). Chemical profiling of Egregia menziesii and anti-inflammatory potential in LPS-activated RAW 264.7 macrophages. Molecular Biology Reports, 53(1), Article 1529. https://doi.org/10.1007/s11033-026-12685-y

Image Credits: AI Generated

DOI: 10.1007/s11033-026-12685-y

Keywords: Egregia menziesii, brown seaweed, fucoidan, mannitol, macrophages, inflammation, cytokines, 1H-NMR, chemometrics, RAW 264.7, sulfated polysaccharides, natural products

In a study published in the journal Plant Biosystems, Youssra Aalilou of Mohammed V University in Rabat and her colleagues report the first comprehensive laboratory and computational evaluation of the antidiabetic potential of C. spongiosus, a branching brown seaweed of the family Cladostephaceae. The work combined classic enzyme inhibition assays with a battery of modern computational tools, including molecular docking, binding interaction analysis, molecular dynamics simulations and ADMET predictions, to ask a deceptively simple question: can this marine organism, and the nine small molecules previously identified in its extracts, meaningfully block the two key enzymes that drive post-meal glucose spikes?

The experimental design followed a logic that medicinal chemists have refined over decades. The researchers prepared five extracts of the alga using solvents of increasing polarity, a technique that separates the plant’s chemical inventory into fractions rich in different classes of compounds, from nonpolar lipids to highly polar phenolics and sugars. Each extract was then tested for its ability to inhibit alpha-glucosidase and alpha-amylase, the two carbohydrate-hydrolyzing enzymes of the human digestive tract whose blockade is the pharmacological basis of widely prescribed antidiabetic drugs such as acarbose. Inhibiting these enzymes delays the conversion of complex carbohydrates into absorbable glucose, flattening the blood sugar curve that follows a meal and easing the chronic metabolic stress that damages blood vessels, nerves and organs in diabetic patients.

The results were striking. Among all five extracts, the ethanol extract emerged as the clear standout, delivering the strongest dual inhibition of both enzymes. In quantitative terms, the ethanol extract inhibited alpha-glucosidase at 4.28 mmol acarbose equivalents per gram of extract, a standard measure expressing potency relative to the clinical drug acarbose. Against alpha-amylase, it recorded 0.54 mmol acarbose equivalents per gram in the iodine assay and, in the more sensitive DNSA colorimetric assay, an IC50 value of just 9.73 micrograms per millilitre, meaning that a very small concentration of the extract was enough to halve the enzyme’s activity. Values in this range, particularly for a crude, unfractionated natural extract, suggest a rich reservoir of inhibitory molecules working in concert.

But crude extracts are chemical black boxes, and the Moroccan-led team wanted to open it. Drawing on nine compounds that their earlier phytochemical work had already identified in C. spongiosus extracts, the researchers ran a full computational workup on each molecule to see which of them could plausibly account for the enzyme inhibition measured in the test tube. Molecular docking was used to computationally fit each compound into the active sites of alpha-glucosidase and alpha-amylase and to estimate binding energies, while binding interaction analysis mapped the specific hydrogen bonds, hydrophobic contacts and other forces holding each ligand in place at the atomic scale.

Docking alone can be misleading, however, because enzymes are not rigid sculptures. To test whether the predicted complexes would survive in a more realistic, dynamic environment, the team turned to molecular dynamics simulations, in which the protein-ligand complexes are allowed to move and flex in a simulated watery solution over time. Compounds whose binding falls apart in such simulations are usually artifacts of static docking; those that remain stably wedged in the active site are far more credible drug leads. In this study, several molecules displayed favorable interactions and stable binding profiles throughout the analyses, with four compounds standing out from the crowd: loliolide, isololiolide, herniarin and a monocrotaline isomer.

These four molecules make an intriguing chemical cast. Loliolide and isololiolide are structurally related carotenoid degradation products, small oxygenated lactones that have attracted growing attention in marine and plant natural products research for antioxidant and pharmacological properties. Herniarin is a simple methoxylated coumarin, a compound class with a long medicinal pedigree, and coumarin derivatives have previously been reported to show antidiabetic activity in other marine and coastal plants. The monocrotaline isomer represents a pyrrolizidine alkaloid scaffold, though the authors note that the toxicology of this class warrants careful attention, which is precisely why the study did not stop at binding predictions.

That attention came in the form of ADMET prediction, a computational screening step that estimates how a candidate molecule would behave in the human body across absorption, distribution, metabolism, excretion and toxicity. Using graph-based pharmacokinetic prediction tools, the researchers assessed whether their top-scoring enzyme inhibitors possessed drug-like properties or carried red flags that would disqualify them from further development. The integration of this pharmacokinetic layer with docking and dynamics data reflects a broader shift in natural products research, where the question is no longer simply whether a compound binds a target, but whether it could ever become a usable medicine.

The broader context makes the findings timely. Marine ecosystems remain dramatically underexplored compared with terrestrial biodiversity, yet seaweeds are already known to produce an extraordinary diversity of bioactive molecules, from phlorotannins and sulfated polysaccharides to carotenoids and terpenes, with reported activities spanning antioxidant, antimicrobial, anti-inflammatory and antihyperglycemic effects. Brown macroalgae in particular have accumulated a growing body of evidence supporting functional food and pharmaceutical applications. C. spongiosus itself has been the subject of seasonal volatile and antioxidant profiling in earlier studies, and the current work builds directly on the same team’s prior phytochemical characterization of the species, completing a pipeline that runs from specimen collection in the marine ecosystem to validated biological application.

For now, the results remain at the preclinical, exploratory stage: enzyme assays in vitro and simulations in silico, not human trials. The authors are careful to frame the work as identifying C. spongiosus as a promising marine source of bioactive compounds with potential applications in antidiabetic drug discovery, rather than as a ready-made therapy. Yet the convergence of strong dual enzyme inhibition in the ethanol extract, a shortlist of compounds with stable predicted binding to both therapeutic targets, and preliminary drug-likeness profiling gives the field exactly what early-stage natural product discovery needs: a prioritized set of molecules and a mechanistic hypothesis worth testing in the wet lab. If follow-up studies confirm that loliolide, isololiolide, herniarin or their algal companions inhibit carbohydrate digestion as potently in living systems as the computations suggest, the modest tufted seaweed clinging to Atlantic and Mediterranean rocks may yet contribute to the global fight against diabetes.

Subject of Research: Antidiabetic activity of the brown alga Cladostephus spongiosus evaluated through in vitro enzyme inhibition and computational molecular analysis

Article Title: First comprehensive in vitro and in silico investigations of the antidiabetic activity of Cladostephus spongiosus (Cladostephaceae): from marine ecosystem to biological application

Article References: Aalilou, Y., Qostal, M., Karfi, W. E., Rossafi, B., Mortada, S., Hassoun, M., Moussa, H., Zengin, G., Ak, G., Ullah, R., Alotaibi, A., Chtita, S., Bouyahya, A., Meddah, B., & Faouzi, M. E. A. (2026). First comprehensive in vitro and in silico investigations of the antidiabetic activity of Cladostephus spongiosus (Cladostephaceae): from marine ecosystem to biological application. Plant Biosystems, 160(5), Article 253. https://doi.org/10.1007/s44473-026-00264-9

Image Credits: AI Generated

DOI: 10.1007/s44473-026-00264-9

Keywords: Cladostephus spongiosus, brown algae, antidiabetic, alpha-glucosidase, alpha-amylase, molecular docking, molecular dynamics, ADMET, loliolide, herniarin, marine natural products, type 2 diabetes