The core chemistry is elegant in its simplicity. Plant extracts are rich in phytochemicals—polyphenols, flavonoids, tannins, terpenoids, alkaloids, and proteins—that perform a dual role. First, they donate electrons to dissolved metal ions, reducing silver nitrate or chloroauric acid into neutral atoms that nucleate into nanoscale clusters. Second, the same biomolecules adsorb onto the growing particle surfaces, acting as capping agents that prevent aggregation and confer colloidal stability. The review emphasizes that this dual functionality means a single leaf extract can replace both the reducing agent and the stabilizer that would otherwise require two separate synthetic chemicals. Screening studies cited in the review show that many medicinal plants, not just a handful of exotic species, can reliably produce stable silver nanoparticles, with extracts such as Aloysia citrodora demonstrating reproducible synthesis and measurable biological activity.

Microorganisms take an alternative route to the same destination. Bacteria such as Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa, along with fungi like Aspergillus niger, use reductase enzymes and cell-wall proteins and polysaccharides to convert metal salts into nanoparticles either inside the cell or, more usefully for industry, in the surrounding culture medium. Extracellular synthesis is preferred because it simplifies downstream purification and scales more easily. The review notes that culture conditions—growth medium composition, incubation temperature, pH, and precursor concentration—exert strong control over particle size, shape, and surface functionality, giving microbial systems an edge in uniformity for therapeutic and antimicrobial applications. Algae add a further dimension: their extraordinary capacity to hyperaccumulate heavy metal ions, combined with a biochemical arsenal of carbohydrates, pigments, vitamins, and bioactive compounds, positions microalgae as particularly promising and cost-effective nano-factories, a field the authors describe as phyco-nanotechnology.

What determines the final properties of a green-synthesized nanoparticle? The review is emphatic that the answer lies in the reaction parameters. Extract composition, pH, temperature, metal ion concentration, and incubation time all shape particle size, morphology, and stability. Extracts rich in biopolymers tend to yield particles with superior colloidal stability and functional performance in biomedical settings. A striking mechanistic insight highlighted by the authors is the formation of a biomolecular corona: surface-bound proteins, polyphenols, and carbohydrates adsorb onto the nanoparticle and dynamically define its biological identity. This corona, rather than the pristine metal core, governs cellular uptake, biodistribution, toxicity, and overall bioactivity—meaning that understanding corona formation is critical for predicting how green-synthesized silver nanoparticles will behave in vivo.

Characterization is where the field shows both its rigor and its weaknesses. The standard toolkit includes UV–visible spectroscopy, which tracks surface plasmon resonance to confirm nanoparticle formation and monitor size evolution; X-ray diffraction, which reveals crystal lattice structure; Fourier-transform infrared spectroscopy, which identifies the amine, carbonyl, and thiol functional groups responsible for capping; and scanning and transmission electron microscopy, which resolve particle morphology down to the nanometer scale. Energy-dispersive spectroscopy confirms elemental composition. But the review delivers a pointed critique: many studies rely on a single analytical technique, report averaged values without adequate statistical treatment, and rarely correlate synthesis parameters with structural characteristics and functional performance. This inconsistency makes cross-study comparison difficult and obscures batch-to-batch variability, undermining the reproducibility that clinical and industrial translation demands.

The applications surveyed are strikingly broad. In medicine, green-synthesized silver nanoparticles exhibit broad-spectrum antimicrobial effects against bacterial and fungal pathogens, with documented success in wound healing and infection treatment, though activity varies considerably with particle size, surface chemistry, and biological source. Gold nanoparticles, prized for their unique optical absorption and biocompatibility, serve as drug and gene delivery vehicles and as agents in photothermal cancer therapy, where they convert light into localized heat that kills tumor cells. Iron oxide nanoparticles are being explored as contrast agents for magnetic resonance imaging, while selenium-based particles show antioxidant and anti-inflammatory activity in dermatological disease models, with studies measuring cytokine modulation offering stronger evidence of disease-modifying effects than purely phenotypic observations.

Beyond the clinic, the review highlights environmental and agricultural frontiers. Green-synthesized nanoparticles demonstrate strong adsorption and photocatalytic degradation of pollutants in water and soil, including dye decolorization and antibiotic breakdown. In agriculture, nanofertilizers promise improved nutrient use efficiency and reduced fertilizer runoff, while nanopesticides—such as neem-derived formulations—offer targeted pest control with lower chemical loads on soil and water. Antimicrobial nanoparticles are also finding roles in food packaging and textiles. Yet the authors temper this enthusiasm with caution: nanoparticle recovery, environmental persistence, soil accumulation, effects on non-target organisms, and long-term consequences for crop ecosystems remain insufficiently studied, and results often conflict across different crops, soil types, and concentrations.

The review also examines phytotoxicity with unusual nuance, since the same nanoparticles promoted as agricultural enhancers can harm plants under the wrong conditions. Particles smaller than roughly 20 nanometers penetrate root tissues more easily, and their high surface-to-volume ratio drives reactivity, oxidative stress, and membrane damage. Shape matters too: high-aspect-ratio particles interact differently with cell surfaces than spheres, altering adhesion, uptake, and ion release. Dose-response relationships are clear—low to moderate concentrations may even stimulate growth, while higher doses overwhelm plant defenses, generating reactive oxygen species, chlorosis, and biomass loss. Crucially, these effects are combinatorial rather than additive: a particle that is harmless or beneficial in one species can be lethal in another, depending on cuticle thickness, root anatomy, antioxidant capacity, and metal detoxification machinery.

The honest accounting of limitations may be the review’s most valuable contribution. Biological sources are inherently variable—plant extract chemistry shifts with species, growth conditions, season, and extraction method, producing inconsistent particle size, shape, and yield. Precise control of pH, temperature, and concentration is harder than in chemical synthesis, threatening batch-to-batch consistency. The biomolecules responsible for reduction and stabilization are often incompletely identified, complicating mechanistic understanding, and purification from complex biological matrices can alter surface properties. Scaling up remains constrained by contamination risks in microbial systems and the challenge of maintaining nanoparticle stability over time. The authors argue that standardized protocols, full-scale characterization, systematic toxicological profiling, and regulatory readiness must be integrated into future development frameworks before green nanotechnology can move reliably from laboratory benches to clinics and factories.

Looking forward, the review sketches a roadmap that pairs optimism with rigor. Deeper mechanistic insight—aided by omics technologies and computational modelling—should enable more predictable and scalable synthesis, while good manufacturing practice-compliant production of biogenic nanoparticles could accelerate their adoption in drug delivery, diagnostics, biosensing, and targeted therapeutics. Their photocatalytic prowess points toward sustainable environmental cleanup at industrial scale. The central message is that green synthesis is no longer a niche curiosity but a genuine contender to replace hazardous conventional methods, provided the field embraces the standardization, comparative study design, and safety validation that separate promising laboratory results from real-world impact. If it does, the humble leaf, bacterium, and alga may become the preferred chemical plants of the nanotechnology age.

Subject of Research: Green synthesis of metal and metal oxide nanoparticles using plant extracts and microorganisms

Article Title: A comprehensive review of green synthesis methods and applications of nanoparticles derived from plant extracts and microorganisms

Article References: Syed, S. M., Kulkarni, S., Patil, M., & Satpute, K. (2026). A comprehensive review of green synthesis methods and applications of nanoparticles derived from plant extracts and microorganisms. Discover Green Chemistry, 1(1), Article 6. https://doi.org/10.1007/s44509-026-00006-2

Image Credits: AI Generated

DOI: 10.1007/s44509-026-00006-2

Keywords: green synthesis, nanoparticles, plant extracts, microorganisms, silver nanoparticles, gold nanoparticles, algae, biomolecular corona, photocatalysis, nanofertilizers, antimicrobial, environmental remediation

Secondary metabolites occupy a curious place in biology. Unlike primary metabolites such as sugars, amino acids, and nucleotides, which are essential for growth and reproduction, secondary metabolites are optional extras from the organism’s point of view. Yet they are anything but optional for the ecosystems around them. Alkaloids deter herbivores, flavonoids shield leaves from ultraviolet radiation, tannins inhibit microbial attacks, and terpenoids perfume flowers to attract pollinators. What has captured the attention of nanotechnologists is that many of these compounds carry functional chemical groups—hydroxyl, carbonyl, and carboxyl moieties among them—that are ideally suited to mediating the transformation of metal salts into nanoscale particles suspended in water.

The core chemistry is conceptually simple. When an extract rich in phenolic acids or flavonoids is mixed with, say, a silver nitrate solution, the electron-donating capacity of the metabolites reduces silver ions to metallic silver atoms. These atoms then nucleate and grow into clusters, a process classically described by the LaMer model of monodisperse hydrosol formation, first articulated in 1950. Crucially, the same metabolites that drive the reduction also adsorb onto the surfaces of the growing particles, forming a stabilizing shell that prevents the clusters from clumping together into bulk precipitate. This dual role—reductant and capping agent in one molecule—is what makes plant and microbial extracts so attractive as single-pot synthesis media.

The review catalogs the major phytochemical players in detail. Flavonoids such as hesperidin, naringin, and diosmin have been shown to generate silver nanoparticles with demonstrable antibacterial effects. Tannins, the astringent polyphenols abundant in many woody plants, can reduce gold salts to produce nanoparticles that have been coated onto cotton textiles for the catalytic degradation of Congo red dye. Terpenoids have been credited with mediating a range of metal and metal oxide syntheses with biomedical relevance. Saponins, alkaloids, and phenolic acids round out the roster, each contributing characteristic functional groups that influence how quickly ions are reduced and how the resulting particles are shaped and stabilized.

Perhaps the most consequential point the authors emphasize is that the identity and concentration of the metabolites directly govern the physical properties of the nanoparticles that emerge. Particle size, morphology, surface charge, and colloidal stability all depend on which molecules are present and in what proportions. Because different plant species, and even different tissues within the same plant, harbor distinct metabolic profiles, the choice of extract becomes a design variable. A leaf extract rich in one class of polyphenol may yield small, spherical silver particles, while a seed extract dominated by tannins may produce larger, anisotropic structures. This tunability, the review suggests, is both an opportunity and a challenge: it offers enormous flexibility but demands careful standardization of extracts if reproducible, scalable production is the goal.

The advantages over conventional synthesis routes are laid out clearly. Physical methods such as laser ablation and sputtering, and chemical methods relying on borohydrides, hydrazine, or organic solvents, typically demand high energy inputs, generate toxic byproducts, or leave hazardous residues on particle surfaces. Green synthesis with secondary metabolites operates at or near ambient conditions, uses water as the preferred solvent, and produces particles whose organic coating is often biocompatible by default. That last point matters enormously for biomedical applications, where residual chemical surfactants can compromise cell viability and trigger inflammatory responses. The review notes that reduced toxicity, lower energy requirements, and cost-effectiveness are the recurring advantages cited across the literature it surveys.

On the application side, the breadth is striking. Biologically synthesized metal and metal oxide nanoparticles have demonstrated antimicrobial activity against bacterial and fungal pathogens, antioxidant capacity relevant to oxidative-stress disorders, and anticancer and anti-inflammatory effects documented across numerous cell and preclinical studies. Silver nanoparticles made with potato steroidal alkaloids have been deployed against phytopathogenic fungi, while zinc oxide nanoparticles biosynthesized through microbial routes show antimicrobial promise. In environmental remediation, iron-based nanoparticles produced with plant extracts serve as adsorbents for water treatment, and silver nanoparticles paired with nano-fibrillated cellulose from citrus peel waste have been used to remove cadmium and chromium from contaminated water. Catalytic degradation of industrial dyes, colorimetric detection of metal ions, and biosensing round out the environmental and analytical applications.

Agriculture emerges as a particularly promising frontier. The review highlights the role of metal and metal oxide nanoparticles in crop stress management, including the mitigation of heavy metal toxicity in plants, as well as nanosensing of biotic threats. Nanoparticles are being explored as components of fertilizers and pesticides, as delivery vehicles in precision farming, and as tools in plant biotechnology, including the emerging use of nanoparticles to advance CRISPR-Cas genetic engineering of plants. The biocompatibility and colloidal stability conferred by metabolite capping layers make these particles plausible candidates for agricultural formulations that must survive field conditions without harming soil microbiota. The authors also point to biomedical devices and food technology as sectors where green-synthesized particles could find roles, from antimicrobial fabrics to food preservation systems.

The review does not shy away from the field’s limitations. Reproducibility remains a persistent concern, since natural extracts vary with season, geography, plant age, and extraction protocol. The precise molecular mechanisms by which particular metabolites reduce particular metal ions are still being worked out, and scaling laboratory successes to industrial production volumes poses engineering challenges that green chemistry has not yet fully solved. Studies of fungal production of copper oxide nanoparticles, for example, have taken a physiological and metabolic approach to identify which secondary metabolites are actually responsible, underscoring how much fundamental biochemistry remains to be mapped. Toxicological questions about the nanoparticles themselves, particularly in food applications, also demand continued scrutiny.

What the review ultimately makes the case for is a convergence of two traditionally separate domains: natural products chemistry and materials science. The authors argue that deliberately leveraging plant- and microbe-derived metabolites offers a sustainable path to scalable nanoparticle production capable of meeting global needs in medicine, agriculture, and environmental management. As demand for nanomaterials grows across sectors, the prospect of manufacturing them with molecules that organisms already produce—rather than with petrochemical reagents and energy-hungry reactors—represents exactly the kind of cross-disciplinary innovation that green chemistry advocates have long promised. The next step, the review implies, is moving from elegant laboratory demonstrations to standardized, mechanistically understood, industrially viable processes, a transition that will require chemists, biologists, and engineers to speak the same molecular language.

Subject of Research: Green synthesis of metal and metal oxide nanoparticles using plant and microbial secondary metabolites

Article Title: Significance of secondary metabolites for synthesis of metal and metal oxide nanoparticles and their applications

Article References: Nazneen, S., Azra, B. H., Keerthi, M. M., Ashraf, A. M., Rajasekar, G., Rasool, A., & Anand, A. (2026). Significance of secondary metabolites for synthesis of metal and metal oxide nanoparticles and their applications. The Science of Nature, 113(5), Article 120. https://doi.org/10.1007/s00114-026-02168-2

Image Credits: AI Generated

DOI: 10.1007/s00114-026-02168-2

Keywords: secondary metabolites, green synthesis, nanoparticles, metal oxide nanoparticles, phytochemicals, flavonoids, tannins, antimicrobial, environmental remediation, biomedicine, agriculture, sustainable nanotechnology

The research team, led by Mubarak Muhammad and Botan Salihi of Tishk International University in the Kurdistan Region of Iraq, together with colleagues from Koya University, Universiti Malaysia Sarawak and Universiti Malaya, set out to answer a question that global health authorities have been asking with growing urgency: can traditional medicinal plants be moved from folk knowledge into evidence-based conventional medicine? The World Health Organization has repeatedly noted the worldwide integration of traditional complementary medicine into everyday health care, and plants such as P. odoratum, which is consumed both as a culinary herb and as a remedy across Asia, represent exactly the kind of candidate that deserves rigorous scrutiny rather than anecdotal enthusiasm or dismissive neglect.

Methodologically, the review is a model of caution. The authors searched PubMed, Scopus, Google Scholar and ScienceDirect, applied a PICOS framework to define populations, interventions, comparisons, outcomes and study designs, and then assessed the quality of the included work using two separate instruments: the revised Cochrane Risk-of-Bias tool, known as RoB 2, for randomized trials, and SYRCLE’s risk-of-bias tool, which is tailored to preclinical laboratory animal studies. Because the studies differed so widely in plant extracts, doses, models and endpoints, the heterogeneity was judged too high for a meta-analysis, the statistical technique that pools numerical results across trials. Instead, the team provided descriptive summaries, a decision that reflects an honest reading of the data rather than an attempt to manufacture a single headline number from incomparable experiments.

What emerged from those 34 studies is a spectrum of biological activity that is unusually wide for a single botanical. The most consistently reported effects were antimicrobial and antioxidant. Extracts of the plant showed activity against a range of microorganisms, and the review highlights the abbreviation MRSA, methicillin-resistant Staphylococcus aureus, among the targets examined, a detail that will catch the eye of anyone tracking the antibiotic resistance crisis. Antioxidant activity, meanwhile, ties the herb to one of the central narratives of modern pharmacology: the scavenging of reactive oxygen species that damage DNA, proteins and lipids, and that underlie chronic inflammation, aging and a long list of degenerative diseases.

The molecular signatures reported across the included studies read like a map of the signaling pathways most intensively studied in current drug discovery. Researchers working with P. odoratum extracts have measured effects on nuclear factor kappa B, the master transcription factor of inflammation; on the Nrf2 pathway, the cellular thermostat for antioxidant defense; on the Akt/mTOR axis, a growth and survival circuit central to cancer biology; on mitogen-activated protein kinase signaling; and on inflammatory mediators such as tumor necrosis factor-alpha, interleukin-6, cyclooxygenase-2, inducible nitric oxide synthase and prostaglandin E2. Other studies traced changes in the balance of Bax and Bcl-2, proteins that decide whether a damaged cell lives or enters programmed death, and in matrix metalloproteinase-9 and vascular endothelial growth factor A, both implicated in tumor invasion and blood supply.

Those mechanisms translate into a striking range of reported outcomes. Beyond direct antimicrobial and free-radical scavenging effects, the review catalogued anti-inflammatory actions, anticancer effects, including modulation of cell cycle arrest at the G2/M transition and suppression of Epstein-Barr virus-related markers, and protective activities against a suite of organ-specific disorders. The abbreviation list of the paper hints at the breadth: streptozotocin-induced anti-diabetic models, experiments with human fetal osteoblasts, work on the HT-29 human colon tumor cell line, and even references to amyloid-beta 42, the peptide that aggregates in the brains of Alzheimer’s patients. In other words, laboratories around the world have thrown a remarkable variety of disease models at this one plant, and a meaningful fraction of those experiments have come back positive.

Quality assessment offered the review’s most reassuring finding. According to both the RoB 2 and SYRCLE instruments, the majority of the studies assessed demonstrated a low risk of bias. That matters because the systematic review literature on medicinal plants is littered with poorly controlled experiments, small sample sizes and selective reporting, problems that have rightly made clinicians skeptical of the field. Here, the authors found that a substantial share of the preclinical work met modern standards of rigor, which strengthens the case that the reported effects are genuine biological phenomena rather than artifacts of sloppy methodology. The review was funded by Tishk International University with additional support from Malaysia’s Higher Institution Centre of Excellence program, and the funders played no role in the design, analysis or interpretation of the study.

Yet the review’s headline conclusion is a warning as much as a promise. The entire evidence base is derived predominantly from in vitro experiments and animal studies, with only limited clinical data available. A plant extract that kills bacteria in a petri dish, dampens NF-kappa-B signaling in cultured cells and protects a mouse from chemically induced diabetes has cleared none of the hurdles that matter most to a physician: absorption, distribution, metabolism, toxicity at human doses, drug interactions and, above all, demonstrated benefit in randomized, placebo-controlled human trials. History is full of botanical compounds that dazzled in the laboratory and vanished at the clinic door, and the authors are explicit that well-designed clinical trials and further mechanistic investigations are warranted before any recommendation can be made for integrating P. odoratum into conventional practice.

The translational path forward is nonetheless concrete. The diversity of activities documented in the review suggests that the plant’s secondary metabolites, the chemical compounds it produces for its own defense, interact with multiple pharmacological targets at once, a profile that could yield lead molecules for antibiotic adjuncts, anti-inflammatory agents or antioxidant therapeutics. Standardizing extracts, isolating the active constituents and identifying the precise molecular interactions would be the natural next steps, followed by the preclinical toxicology that separates a promising phytochemical from a drug candidate. The review’s descriptive framework gives researchers a consolidated map of what has already been tested, which plant parts and extraction methods were used, which pathways were probed and where the gaps in coverage lie, potentially saving years of duplicated effort.

For now, the significance of the paper lies less in any single result than in its demonstration that a widely eaten herb has accumulated a serious, quality-controlled body of laboratory evidence. Polygonum odoratum has traveled from market stalls in Hanoi and Bangkok through 34 peer-reviewed studies to a formal systematic review registered in PROSPERO, and it arrives there with its reputation intact but its clinical file nearly empty. Whether the Vietnamese coriander on a dinner plate becomes the source of a future prescription will depend on the clinical trials the authors call for, and on whether the pathways modulated in glass dishes and animal models survive the far harsher test of the human body. The herb, at least, has earned the chance to make that attempt.

Subject of Research: Systematic review of the antimicrobial, antioxidant and other biological activities of the medicinal plant Polygonum odoratum

Article Title: Exploration of Polygonum odoratum as a medicinal plant with promising antimicrobial and antioxidant effects for translational use in conventional medicine: a systematic review

Article References: Muhammad, M., Salihi, B., Star, H., Abdullah, Y. A., Hama-Salim, H., Hama, H. A., Ali, A., Chung, H. H., & Loong, S. K. (2026). Exploration of Polygonum odoratum as a medicinal plant with promising antimicrobial and antioxidant effects for translational use in conventional medicine: a systematic review. BMC Complementary Medicine and Therapies. https://doi.org/10.1186/s12906-026-05577-y

Image Credits: AI Generated

DOI: 10.1186/s12906-026-05577-y

Keywords: Polygonum odoratum, Vietnamese coriander, antimicrobial, antioxidant, systematic review, medicinal plants, anti-inflammatory, anticancer, MRSA, preclinical studies, traditional medicine, drug discovery

The study, published in the journal Discover Plants, was led by Krishna Poonia of DAV (PG) College in Dehradun, together with colleagues from CCS Haryana Agricultural University, DNA Labs-A Centre for Applied Sciences, HNB Garhwal University and Maya Devi University. The team set out to close a persistent gap in the literature: while individual studies have examined pumpkin’s antimicrobial activity, its phytochemistry, or its oil content in isolation, few have integrated all three lines of evidence into a single evaluation of the fruit’s waste fractions.

The researchers procured fresh Cucurbita maxima fruits from a local market in Dehradun, in the northern Indian state of Uttarakhand, and had the plant material authenticated by the Botanical Survey of India. After separating the peels and seeds, surface sterilizing them with 70 percent ethanol and drying them, the team ground the material into powders and extracted it using three solvents—water, ethanol and acetone—chosen to capture compounds of differing polarity. Each extract then underwent qualitative phytochemical screening using standard colorimetric tests to detect classes of secondary metabolites.

The screening revealed a rich chemical inventory. Carbohydrates, alkaloids, phenolics, glycosides and quinones were confirmed across the extracts, while terpenoids and steroids appeared in selected samples. Proteins and emodins showed up primarily in the aqueous extracts, a sign that water is particularly effective at pulling out polar compounds. Notably, tannins were detected only in peel extracts, hinting that the outer skin harbors a defensive chemical arsenal of its own. Phlobatannins, coumarins and leucoanthocyanins, by contrast, were absent or fell below detectable limits. These metabolites matter because phenolics, flavonoids, alkaloids and terpenoids are widely associated with antioxidant, anti-inflammatory and antimicrobial effects.

To dig deeper into the peel’s chemistry, the team turned to gas chromatography–mass spectrometry, or GC–MS, a technique that separates volatile and semi-volatile compounds and identifies them by their fragmentation patterns. Using a triple quadrupole instrument with electron ionization at 70 electronvolts and helium as the carrier gas, the analysis identified a staggering 91 phytocompounds in the peel extract, of which 17 were classed as major constituents. Roughly 60 to 65 percent of the extract consisted of triterpenoids and sterols, a profile characteristic of the waxy cuticular matrix that coats plant surfaces.

The single most abundant compound was germanicol acetate, making up 26.62 percent of the extract, followed by 24-norursa-3,12-diene at 14.63 percent and the sterol chondrillasterol at 8.58 percent. A second major group of terpenoids and isoprenoids, accounting for about 10 to 12 percent, included phytol at 7.23 percent and neophytadiene at 2.77 percent—both widely reported for antioxidant and antimicrobial activity. Smaller fractions contained fatty acid esters such as ethyl linoleate, along with nutritionally notable minor constituents including squalene and tocopherol derivatives, compounds prized for their antioxidant and chemoprotective properties.

The functional payoff came from the antibacterial assays. Using the Kirby–Bauer disk diffusion method, the researchers tested crude extracts against four bacterial strains obtained from culture collections: Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae. Peel extracts consistently outperformed seed extracts. The standout result was the aqueous peel extract, which produced an inhibition zone of 16.0 plus or minus 0.4 millimeters against Pseudomonas aeruginosa—the largest observed in the study. Across all strains and extracts, inhibition zones ranged from 10 to 16 millimeters.

The pattern of susceptibility was revealing. Pseudomonas aeruginosa, a Gram-negative opportunistic pathogen notorious for its antibiotic resistance, proved the most vulnerable to the pumpkin extracts, while Escherichia coli and Klebsiella pneumoniae showed comparatively modest inhibition of 10 to 12 millimeters. The authors caution that Gram-negative outer membranes can restrict the penetration of many antimicrobial compounds, yet the strong response of P. aeruginosa shows that susceptibility was not dictated by Gram reaction alone. Solvent choice also mattered: water and ethanol generally recovered more active antibacterial constituents from the peel than other solvents, suggesting that polar or moderately polar compounds drive much of the inhibition.

The seeds offered a different kind of value. Using Soxhlet extraction with n-hexane at around 60 degrees Celsius, the team recovered crude pumpkin seed oil at a yield of 18 percent by weight—a moderate lipid content that underscores the seeds’ potential for food, cosmetic and pharmaceutical applications. Pumpkin seed oil is already recognized for its nutritional and functional significance, and this yield demonstrates that even discarded seeds from processing waste contain commercially meaningful quantities of lipid material.

The broader implications reach into the growing field of waste valorization—the conversion of agricultural by-products into value-added products. With fruit and vegetable waste posing a mounting environmental and economic challenge, the study argues that pumpkin peels and seeds should be viewed not as refuse but as a low-cost feedstock for natural antimicrobials, antioxidants and oils. The authors caution that practical applications will require further work, including testing standardized extract concentrations, purifying individual compounds, determining minimum inhibitory concentrations and elucidating mechanisms of action. Still, the message is clear: the part of the pumpkin most people throw away may be among its most chemically valuable.

Subject of Research: Phytochemical profiling, antibacterial activity and oil recovery from pumpkin peel and seed waste

Article Title: Phytochemical profiling, antibacterial activity and valorization potential of Cucurbita maxima peel and seed waste

Article References: Phytochemical profiling, antibacterial activity and valorization potential of Cucurbita maxima peel and seed waste. (n.d.). https://doi.org/10.1007/s44372-026-00869-6

Image Credits: AI Generated

DOI: 10.1007/s44372-026-00869-6

Keywords: Cucurbita maxima, pumpkin waste, phytochemicals, antibacterial activity, GC-MS, germanicol acetate, pumpkin seed oil, waste valorization, Soxhlet extraction, antimicrobial, triterpenoids, food waste

The review describes L. aspera as an annual herb reaching 15 to 60 centimeters in height, distributed widely across tropical and subtropical Asia, including India, Bangladesh, Nepal, Malaysia, and Mauritius. Its taxonomic classification places it in the Lamiaceae family alongside mint and basil, and its vernacular names across Indian languages reflect deep cultural familiarity. The plant blooms white, sessile, zygomorphic flowers from August to September, and every part, from roots to seeds, has found a place in traditional healing. In Ayurveda and Siddha medicine, the whole plant is used as a carminative, antipyretic, antiseptic, anti-inflammatory, and anti-snake venom agent, treating conditions ranging from jaundice and dyspepsia to rheumatism and respiratory ailments.

What gives the plant its versatility is an unusually rich phytochemical inventory. The review identifies roughly sixty chemical compounds spanning multiple structural classes, including flavonoids, alkaloids, terpenoids, glycosides, sterols, phenolic compounds, and fatty acids. Notable constituents include the triterpenoids ursolic acid and oleanolic acid, the diterpenes leucasperones A and B and leucasperols A and B, isopimarane glycosides known as leucasperosides A, B, and C, and the oleanane-type triterpenoid lactone leucolactone isolated from the roots. Seed oil contains linoleic, oleic, palmitic, stearic, and linolenic acids, while leaf volatiles are dominated by alpha-farnesene, alpha-thujene, and menthol. Lignans such as nectandrin B and macelignan, along with long-chain aliphatic ketones and alcohols, round out a chemical repertoire that rivals many cultivated medicinal species.

The pharmacological evidence assembled by the authors is striking in its breadth. Antimicrobial studies show that dichloromethane leaf extracts inhibit pathogens including Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans at minimum inhibitory concentrations between 75 and 425 micrograms per milliliter, while methanolic whole-plant extracts, rich in flavonoids and phenolics, produce broad inhibition zones against both Gram-positive and Gram-negative bacteria. Antioxidant assays reveal that leaf flavonoids scavenge DPPH radicals with an IC50 of just 9.25 micrograms per milliliter, outperforming the reference compound gallic acid at equivalent doses. Perhaps most intriguingly, recent work has used the plant’s phytochemicals as reducing and stabilizing agents to biosynthesize chitosan-zinc oxide nanocomposites, which achieved up to 88.19 percent ABTS radical scavenging, a result attributed to synergistic interactions between the nanoparticle surfaces, chitosan functional groups, and the plant’s phenolic compounds.

Anti-inflammatory findings are similarly compelling. Extracts of the whole plant reduced cytokine production in mouse macrophage cells by 24 to 39 percent, suppressing interleukin-1 beta, a key pro-inflammatory mediator, and aqueous leaf extracts inhibited heat-induced red blood cell membrane denaturation by 73.25 percent at 100 micrograms per milliliter, nearly matching the standard drug diclofenac. In diabetes models, aqueous leaf extracts lowered blood glucose in streptozotocin-induced diabetic rats to 98.35 milligrams per deciliter at 400 milligrams per kilogram, outperforming the reference drug glibenclamide in some comparisons, while methanolic extracts reduced serum glucose by up to 42.10 percent in glucose-loaded mice. Researchers attribute these effects partly to the substantial quantities of oleanolic and ursolic acid found throughout the genus.

The review also documents hepatoprotective activity across several liver injury models, with extracts protecting against damage induced by paracetamol, carbon tetrachloride, lead acetate, and d-galactosamine by normalizing liver enzymes, reducing lipid peroxidation, and elevating antioxidant defenses such as glutathione peroxidase and catalase. Cytotoxicity studies against breast cancer cell lines showed that flavonoid and alkaloid fractions inhibited MCF-7 cell growth with IC50 values of 247.56 and 236.45 micrograms per milliliter respectively, while dichloromethane and ethyl acetate extracts suppressed proliferation in triple-negative MDA-MB-231 cells at concentrations as low as 3 to 5 micrograms per milliliter, suggesting potential as a source of leads against aggressive cancers.

Beyond these headline activities, the plant demonstrated analgesic effects across six pain models in mice, with a 700 milligrams per kilogram dose reducing responses by up to 84.74 percent, alongside verified anthelmintic, antipyretic, anti-ulcer, anti-asthmatic, anti-psoriatic, and anti-obesity properties. One of the more striking findings concerns snakebite: a triterpenoid isolated from the methanolic extract, 1-hydroxytetratriacontane-4-one, showed potent antidote activity against spectacled cobra venom in mice, and chitosan-based nanoparticles loaded with the plant extract neutralized Indian cobra venom toxicity. As a larvicide, the isolated compound catechin killed mosquito larvae, and silver nanoparticles synthesized from leaf extracts showed strong activity against the dengue vector Aedes aegypti, positioning the weed as an inexpensive bioresource for vector control.

Safety data support the plant’s traditional standing. Acute and sub-acute toxicity studies conducted under OECD guidelines 423 and 425 found no lethality or adverse behavioral changes at doses up to 2,000 milligrams per kilogram across multiple extract types and animal models, establishing median lethal doses above that threshold. The plant has already entered commercial use in homeopathic preparations, notably L. aspera 30CH dilutions marketed for asthma, cough, jaundice, dysentery, and intermittent fevers, and mother tinctures valued for their antipyretic and antimicrobial qualities. Its nutraceutical profile, marked by favorable mineral content and negligible heavy metal contamination, further suggests applications in functional foods, while its essential oils show promise as eco-friendly biopesticides.

Yet the review’s authors are candid about the gaps that separate preclinical enthusiasm from clinical reality. Most pharmacological data derive from in vitro experiments and animal studies, human trials are scarce, and variations in plant parts, extraction methods, and experimental protocols complicate comparisons across studies. Chronic toxicity, reproductive safety, genotoxicity, pharmacokinetics, and herb-drug interactions remain essentially uncharacterized, and many studies use crude extracts without adequate phytochemical standardization. Overexploitation also threatens wild populations, prompting calls for tissue culture conservation, transgenic development, and metabolite enhancement. The authors argue that the path forward lies in isolating novel bioactive compounds, standardizing formulations, applying nanotechnology-based delivery systems, and ultimately conducting randomized clinical trials. If those steps succeed, a weed once dismissed from the margins of wastelands may yet earn a place in the modern pharmacopoeia.

Subject of Research: Phytochemistry, pharmacological activities, and clinical applications of the medicinal plant Leucas aspera

Article Title: A comprehensive review of the phytochemistry, pharmacological activities and clinical applications of Leucas aspera

Article References: Pathak, M., Gaba, V., & Joshi, B. C. (2026). A comprehensive review of the phytochemistry, pharmacological activities and clinical applications of Leucas aspera. Discover Chemistry, 3(1), Article 525. https://doi.org/10.1007/s44371-026-00971-4

Image Credits: AI Generated

DOI: 10.1007/s44371-026-00971-4

Keywords: Leucas aspera, phytochemistry, pharmacological activities, Dronapushpi, Ayurveda, antimicrobial, anti-inflammatory, antidiabetic, hepatoprotective, snake venom, larvicidal, natural products

The scale of the problem is enormous. In 2012 alone, the United States spent nearly 20 billion dollars on chronic wound care, while the United Kingdom reported expenditures of roughly 184 million pounds. Despite that investment, conventional dressings—films, foams, wafers, nanofibers, patches, and standard bandages—continue to fall short. The review catalogues their recurring weaknesses: poor antibacterial efficacy, inadequate mechanical strength, low exudate absorption, insufficient gas permeability, painful removal, and a failure to sustain the moist microenvironment that skin needs to regenerate. Chronic wounds compound the difficulty because they become trapped in a prolonged inflammatory state, failing to progress through the normal sequence of hemostasis, inflammation, proliferation, and remodeling, and they are frequently life-threatening when infection takes hold.

Hydrogels offer a fundamentally different starting point. These three-dimensional hydrophilic polymer networks, built from natural polymers such as alginate, gelatin, and chitosan or synthetic ones like polyvinyl alcohol and polyethylene glycol, can absorb and retain large volumes of water, mimic the extracellular matrix, and support cell proliferation, migration, and angiogenesis. The review distinguishes three structural classes. Physical hydrogels, held together by hydrogen bonds, ionic interactions, and hydrophobic forces, are reversible and stimuli-responsive, making them injectable and ideal for minimally invasive delivery, though they lack mechanical durability. Chemical hydrogels, crosslinked covalently with agents such as genipin or EDC/NHS chemistry, are robust and stable, enabling sustained drug release and long-term implantation, but can carry cytotoxicity risks from crosslinkers. Hybrid hydrogels combine both networks, balancing strength with responsiveness and enabling self-healing, shape-memory, and on-demand drug release at dynamic wound interfaces.

The engineering behind these materials is increasingly sophisticated. The authors describe how the Flory–Rehner theory of polymer swelling provides a quantitative framework for tuning hydrogel expansion to match the viscoelastic properties of native tissue. Crosslinking strategy determines nanoparticle loading, spatial distribution, and release kinetics: free radical polymerization yields tight pore networks that retain nanoparticles and prolong release, while ionic calcium–alginate crosslinking permits faster diffusion and burst release. Surface interactions—electrostatic attraction, hydrogen bonding, hydrophobic association—between nanoparticles and the polymer matrix further shape biological performance. In a particularly promising green-synthesis approach, phytochemicals from medicinal plants rich in flavonoids, phenolics, alkaloids, and terpenoids are being formulated into nanoparticles, dramatically improving their solubility, bioavailability, and controlled delivery thanks to high surface-area-to-volume ratios, then embedded into hydrogels for topical wound application.

Among the nanomaterials reviewed, silver nanoparticles remain the most extensively studied antimicrobial agents. In supramolecular hydrogels, silver complexes with polysaccharide chains to enable prolonged, pH- and temperature-responsive release that eradicates bacterial bioburden while simultaneously suppressing inflammatory cytokines, shifting the wound environment toward resolution and regeneration. Even more striking are dopamine-modified gelatin constructs carrying silver nanoparticles, which combine radical-scavenging antioxidant activity with synergistic antibacterial action under near-infrared irradiation, using photothermal conversion to accelerate healing and enhance epithelial and dermal appendage regeneration. In vivo studies show that silver-loaded hydrogels shorten the inflammatory phase and speed wound closure, performing a dual role as antimicrobial shield and immune modulator.

Copper nanoparticles add another mechanistic dimension. Embedded within methacrylate-modified gelatin networks, they exploit localized surface plasmon resonance under near-infrared light to generate localized heat that intensifies bactericidal activity in situ. Released copper ions disrupt bacterial membranes while also acting as an essential cofactor in angiogenesis, driving fibroblast proliferation and endothelial cell tube formation. Animal studies confirm that copper nanoparticle hydrogels combined with photothermal therapy markedly restrict infection, reduce inflammation, and accelerate granulation and vascularization. Gold nanoparticles, meanwhile, contribute robust surface chemistry and stability as carriers for growth factors and as components of plasmon-enhanced dressings that couple therapy with wound monitoring.

Zinc and cerium bring immunomodulatory and antioxidant firepower. Glycyrrhizic acid hydrogels crosslinked with zinc ions generate an intrinsically immunoregulatory matrix that shifts macrophages from the pro-inflammatory M1 phenotype toward the pro-healing M2 state without any exogenous additives—a decisive advantage in diabetic wounds where persistent M1-driven inflammation blocks repair. Zinc oxide nanoparticles contribute antimicrobial and enzyme-mimetic antioxidative functions that counter oxidative stress. Ceria nanoparticles, often incorporated into cerium-containing bioactive glass within gelatin methacryloyl hydrogels, dynamically scavenge reactive oxygen species through the redox cycling of cerium ions while stimulating endothelial migration and neovascularization, attacking the twin bottlenecks of chronic wounds: infection and inadequate blood vessel formation.

Polydopamine nanoparticles and chitosan-based systems round out the toolkit. Polydopamine serves as adhesive, antioxidant, photothermal agent, and secondary functionalization platform—when hybridized with silver it produces hydrogels that are self-healing, injectable, remoldable, and light-responsive, conforming to irregular wound shapes and allowing painless removal and reapplication. Chitosan’s cationic nature lets it bind directly to anionic bacterial membranes, delivering intrinsic bactericidal, hemostatic, and anti-inflammatory action without external agents, and carboxymethyl chitosan hydrogels crosslinked with nanocellulose can self-heal and dissolve on demand, minimizing scar formation in burn care. The review also highlights structural reinforcement with reduced graphene oxide and cellulose nanocrystals, glucose oxidase-modified hydrogels that release exosomes in response to elevated glucose in diabetic wounds, enzyme-responsive matrices cleaved by overexpressed matrix metalloproteinases, ROS-labile linkers that trigger antioxidant release selectively, and mussel-inspired catechol-functionalized adhesives borrowed from marine biology.

Preclinical outcomes across these platforms are consistently encouraging: accelerated wound closure, decreased microbial burden, enhanced cellular activity, improved collagen deposition, and vascular network formation. But the authors are careful about translation. Remaining barriers include nanoparticle aggregation, dose-dependent cytotoxicity, long-term tissue retention, variability in synthesis reproducibility, sterilization limitations, and regulatory compliance. Looking ahead, they point to the integration of biosensors, artificial intelligence-driven stimulus-responsive delivery, and patient-specific 3D-printed hydrogel platforms tailored to individual wound geometries and biochemistries. The trajectory, they argue, is a shift from passive to proactive wound care—smart, adaptable, multifunctional systems that sense the wound microenvironment and respond in real time.

What makes this review resonate beyond the laboratory is the convergence it documents. Nanotechnology, polymer chemistry, immunology, and biofabrication are no longer parallel tracks; they are being fused into single dressings that kill bacteria, quench oxidative stress, reprogram immune cells, deliver growth factors on cue, and monitor their own performance. For millions of patients whose wounds refuse to heal—and for health systems spending billions managing them—nanoparticle-infused hydrogels represent one of the most credible paths yet from bench to bedside.

Subject of Research: Nanoparticle-infused hydrogel dressings for enhanced wound healing and tissue regeneration

Article Title: Enhancing wound healing with nanoparticle-infused hydrogels: a review of current applications and future prospects

Article References: Enhancing wound healing with nanoparticle-infused hydrogels: a review of current applications and future prospects. (n.d.). https://doi.org/10.1007/s44340-025-00030-1

Image Credits: AI Generated

DOI: 10.1007/s44340-025-00030-1

Keywords: hydrogels, wound healing, nanoparticles, antimicrobial, tissue regeneration, smart wound dressings, stimuli-responsive hydrogels, silver nanoparticles, zinc oxide nanoparticles, ceria nanoparticles, diabetic wounds, nanobiotechnology

The starting material could hardly be more accessible. Sukkary dates are among the most prized varieties in Saudi Arabia, prized for their nutritional value, and their seeds are routinely thrown away. The researchers collected seeds from household waste, washed and dried them, ground them into a fine powder, and then extracted the oil using ethyl acetate, a relatively mild and environmentally friendlier solvent than the harsh organic solvents often used in phytochemistry. After macerating 50 grams of seed powder in 400 millilitres of solvent overnight, they centrifuged and dried the mixture, then analysed the resulting oil by gas chromatography coupled with mass spectrometry.

The GC-MS profile revealed a rich phytochemical inventory. Nine major compounds were identified, dominated by gamma-sitosterol, which accounted for nearly 20 percent of the extract, followed by bis(2-ethylhexyl) hexanedioate at about 16.6 percent and a sterol derivative at roughly 14.7 percent. Bioactive fatty acids such as oleic acid and lauric acid were also present in significant proportions, alongside squalene, a terpenoid known for anti-inflammatory and antioxidant properties. This composition matters because sterols and fatty acids are increasingly recognised as pharmacologically interesting molecules, and previous studies have linked date seed extracts to antioxidant, anti-inflammatory, cardiovascular, and even anticancer effects. In other words, the oil is not merely a filler; it is an active ingredient in its own right.

To deliver that oil, and an antibiotic alongside it, the team turned to emulsion electrospinning, a technique that spins a liquid emulsion into ultrathin fibers under a high-voltage electric field. The polymer blend consisted of polyvinyl pyrrolidone, or PVP, a hydrophilic and widely used pharmaceutical carrier, mixed in a nine-to-one ratio with POVAcoat, a polyvinyl alcohol-based copolymer grafted with acrylic acid and methyl methacrylate. Ciprofloxacin, a common antibiotic, was dissolved directly into the date seed oil at a concentration of 10 milligrams per millilitre, and this drug-oil solution was then blended into the aqueous polymer mixture to form a stable emulsion. Under an applied voltage of 16 kilovolts, a feeding rate of 0.4 millilitres per hour, and a tip-to-collector distance of 16 centimetres, the emulsion was drawn into continuous nanofibers over a 20-hour spinning run.

The crucial trick of emulsion electrospinning is that it produces core-shell architecture without the complexity of coaxial spinning. As the solvent evaporates and the fiber solidifies, the oil phase migrates to the center, forming a nanoscale core of drug dissolved in date seed oil, wrapped in a protective polymeric shell. Transmission electron microscopy confirmed this structure directly, revealing core-shell fibers with total diameters ranging from roughly 72 to 169 nanometres. Scanning electron microscopy showed uniform, bead-free fibers with average diameters between 150 and 270 nanometres, depending on the formulation. Adding the oil increased fiber diameter, a sign that the viscous oil phase was genuinely incorporated into the fiber rather than sitting on the surface.

Thermal and spectroscopic analyses painted a consistent picture of molecular intimacy between the components. Thermogravimetric analysis showed that the drug-loaded fibers remained stable up to several hundred degrees Celsius, while differential scanning calorimetry revealed shifts in glass transition and melting temperatures that pointed to hydrogen bonding between PVP, POVA, and ciprofloxacin. Fourier transform infrared spectroscopy corroborated these interactions, detecting characteristic carbonyl and hydroxyl bands, along with a new peak near 750 wavenumbers attributed to the chloride counterion of ciprofloxacin. Viscosity measurements added a further layer of insight: the oil-rich formulation was the most viscous of all the samples tested, which the authors link to the stability of the emulsion and the quality of the resulting fibers.

The drug delivery performance was the most striking result. When ciprofloxacin was simply blended into PVP fibers, more than 60 percent of the drug leached out within the first hour, a classic burst release that wastes medication and risks toxicity. Adding POVA slowed that burst to about 30 percent in the first hour. But when the drug was dissolved in date seed oil and encapsulated in the core of the PVP/POVA fibers, the release became remarkably gentle: only 36 percent of the drug was released over a full 48 hours, with the shell acting as a diffusion barrier. Drug loading efficiency climbed to roughly 93 percent in the oil-containing formulation, compared with about 31 percent for the simple PVP blend, indicating that the oil phase dramatically improved how much drug the fibers could hold.

Kinetic modelling of the release data suggested that Fickian diffusion was the dominant mechanism, with the Korsmeyer-Peppas model providing the best fit. In practical terms, this means the drug molecules migrate gradually through the swollen polymer shell rather than being ejected by matrix erosion, a behaviour well suited to wound dressings where a steady, low-level antibiotic supply is more useful than a sudden dump. The authors note that the loaded antibiotic remained effective beyond 48 hours in a wound-like environment, a timescale that could help prevent infection during the critical early stages of healing while reducing the frequency of dressing changes.

Antimicrobial testing reinforced the case for the date seed oil as more than a passive carrier. In agar well diffusion assays, the oil itself inhibited the growth of Escherichia coli and Pseudomonas aeruginosa in a concentration-dependent manner, producing inhibition zones of up to 14 and 12 millimetres respectively at the highest dose tested. When the oil was incorporated into the nanofiber mats, the fibers gained broad-spectrum activity against both Gram-negative and Gram-positive bacteria, including Staphylococcus aureus and Staphylococcus epidermidis, with the drug-and-oil-loaded formulation showing the largest inhibition zones of all. The polymer blend alone showed no antibacterial effect, confirming that the oil was the active ingredient. Taken together, the results suggest that a material once destined for the compost heap can be re-engineered into a biocompatible, antimicrobial, sustained-release drug delivery system, a small but compelling demonstration of how circular economy thinking and nanomedicine can converge on the same humble seed.

Subject of Research: Biocompatible core-shell nanofibers made from date seed oil and synthetic polymers for antimicrobial controlled drug delivery.

Article Title: Fabrication of new biocompatible polymeric core shell nanofibers incorporated with antimicrobial date seed oil for drug delivery system

Article References: Radwan, E. S., El-Newehy, M., Abdulhameed, M. M., Almoutiri, N. D., & Al-Enizi, A. M. (2026). Fabrication of new biocompatible polymeric core shell nanofibers incorporated with antimicrobial date seed oil for drug delivery system. Results in Chemistry, 30, Article 103839. https://doi.org/10.1016/j.rechem.2026.103839

Image Credits: AI Generated

DOI: 10.1016/j.rechem.2026.103839

Keywords: date seed oil, nanofibers, electrospinning, drug delivery, ciprofloxacin, antimicrobial, core-shell structure, PVP, biowaste, controlled release, wound healing, green chemistry

Duckweeds, members of the family Lemnaceae, are the smallest flowering plants on Earth, yet they punch far above their weight nutritionally. Under optimal conditions they can produce six to ten times more protein per hectare than soybean, and they do so without requiring any arable land, thriving instead on the surface of nutrient-rich ponds, lakes and wetlands. Their amino acid profile aligns with World Health Organization recommendations for human nutrition, and previous work has shown that methionine and tryptophan levels exceed FAO guidelines by 76 percent and 24 percent respectively. Sri Lanka’s tropical climate and abundant inland water bodies make the country an ideal setting for year-round duckweed cultivation, yet until now the nutritional and bioactive properties of its native species had remained largely unexplored.

The research team, led by scientists at the National Institute of Fundamental Studies in Kandy, collected the four species from Puttalam, Soragune, Peradeniya and Bolgoda between May and June 2023, authenticated them at the National Herbarium in Peradeniya, and cultivated them under controlled greenhouse conditions before analysis. Proximate analysis revealed protein contents ranging from 17.34 to 26.45 percent of dry weight, with Landoltia punctata showing the highest protein levels of the four. Carbohydrate content ranged from 6.95 to 14.55 percent, crude fat from 3.69 to 3.92 percent, ash from 8.03 to 9.55 percent and crude fiber from 5.26 to 9.49 percent. Spirodela polyrhiza stood out for its significantly higher fat, carbohydrate and crude fiber contents, while Lemna minor had the highest moisture.

Mineral analysis using inductively coupled plasma optical emission spectroscopy showed that potassium dominated the elemental profile, ranging from 20.17 to 50.07 grams per kilogram of dry weight, with Lemna perpusilla accumulating the most potassium and sodium. Calcium ranged from 11.03 to 25.46 grams per kilogram, with Spirodela polyrhiza also leading in magnesium and calcium. Crucially for food safety, the levels of lead and cadmium in all four species fell below the thresholds set by the World Health Organization and the European Commission, addressing one of the chief concerns about using duckweed grown in natural waters for human consumption, since these plants are well known to absorb heavy metals from contaminated aquatic environments.

Perhaps the most striking nutritional finding came from the fatty acid analysis. Omega-3 fatty acids, including alpha-linolenic acid and eicosapentaenoic acid, constituted between 44.42 and 50.38 percent of total fatty acids across all four species. Alpha-linolenic acid was the most abundant individual fatty acid in three of the species, ranging from 29.53 to 46.44 percent, followed by palmitic and linoleic acids. The unsaturated-to-saturated fatty acid ratios ranged from 1.54 to 2.71, and polyunsaturated fatty acids vastly outnumbered monounsaturated ones. The favorable omega-6 to omega-3 ratios, typically between 5:3 and 4:1, are associated with reduced risk of inflammation, cardiovascular disease and cancer, positioning duckweed as a rare plant-based source of these essential fats.

Beyond basic nutrition, the extracts displayed remarkable bioactivity. In alpha-amylase inhibition assays, which measure the potential to slow starch digestion and blunt post-meal blood sugar spikes, Spirodela polyrhiza and Landoltia punctata achieved an IC50 of just 0.14 micrograms per milliliter, while Lemna minor showed the strongest overall inhibition across all solvents. Every duckweed extract outperformed acarbose, the standard antidiabetic drug, which required an IC50 of 12.16 micrograms per milliliter. On the anti-obesity front, a 60 percent ethanol extract of Spirodela polyrhiza inhibited pancreatic lipase with an IC50 of 1.39 micrograms per milliliter, approaching the potency of the pharmaceutical drug orlistat, while Lemna minor consistently posted the lowest IC50 values across solvents.

The antimicrobial results were equally compelling. Spirodela polyrhiza produced the largest inhibition zone against Escherichia coli at 17.33 millimeters and showed notable activity against Aspergillus niger, while Landoltia punctata excelled against Staphylococcus aureus, Candida albicans and Aspergillus niger. Lemna minor inhibited both bacterial strains and both fungi, consistent with earlier studies. The researchers attribute these effects to a rich arsenal of secondary metabolites, including flavonoids, phenolics, tannins, saponins, terpenoids and phytosterols such as beta-sitosterol, which disrupt microbial membranes and cellular functions. Liquid chromatography-mass spectrometry identified rutin as the most abundant polyphenol in all four species, at 2.96 to 3.06 micrograms per milligram of dry matter, along with vanillic, gallic, chlorogenic, caffeic, ferulic and p-coumaric acids in varying combinations.

The phenolic profile may explain much of the observed bioactivity. Rutin, which was especially abundant in Lemna minor, is known to inhibit starch-digesting enzymes through competitive and mixed-type inhibition involving hydrogen bonding and hydrophobic interactions, and previous studies have found it more effective than quercetin at blocking alpha-amylase and alpha-glucosidase. Gallic acid and catechin, detected in Landoltia punctata and Lemna minor, are established lipase inhibitors, aligning with the strong anti-obesity activity observed in those species. Meanwhile, the p-coumaric and ferulic acids found in Spirodela polyrhiza and Landoltia punctata are known to disrupt microbial membranes, correlating with their antimicrobial performance. Fourier transform infrared spectroscopy confirmed the presence of five distinct amide absorption bands and carbohydrate-associated signals, providing molecular evidence of the protein-rich composition.

Safety testing using the brine shrimp lethality assay showed low to moderate toxicity, with LC50 values exceeding 4000 parts per million for the tested extracts, well above concentrations that would raise concern. The authors caution, however, that the study has limitations: the bioactivity assays were conducted in vitro, and animal or human trials will be needed to confirm therapeutic potential and bioavailability. Long-term toxicological data, sensory evaluation and processing techniques to improve palatability also remain unexplored. Because duckweed’s composition is highly sensitive to water quality, nutrient availability and environmental stress, careful management of cultivation conditions will be essential to ensure consistent safety and nutritional value.

Even with those caveats, the implications are significant for a developing country like Sri Lanka, where protein and micronutrient deficiencies persist. Duckweed requires no farmland, grows year-round in tropical wetlands, doubles as a wastewater treatment agent and can even serve as a platform for producing pharmaceutical biomolecules such as vaccines and antibodies. The researchers conclude that these four native species, with their high-quality protein, exceptional omega-3 content, potent enzyme inhibition and broad antimicrobial activity, are strong candidates for development as nutrient-dense, affordable functional foods. If future trials validate the laboratory findings, the humble duckweed floating quietly on Sri Lanka’s ponds could become a cornerstone of sustainable nutrition, proving that some of the most powerful solutions to global food and health challenges may be the smallest plants of all.

Subject of Research: The nutritional composition and bioactive properties of four duckweed species in Sri Lanka

Article Title: Nutritional composition and bioactive properties of four duckweed species in Sri Lanka

Article References: Nutritional composition and bioactive properties of four duckweed species in Sri Lanka. (n.d.). https://doi.org/10.1186/s44399-026-00043-z

Image Credits: AI Generated

DOI: 10.1186/s44399-026-00043-z

Keywords: duckweed, nutrition, omega-3 fatty acids, antidiabetic, anti-obesity, antimicrobial, polyphenols, protein, Sri Lanka, functional food, food security, phytochemicals