Search Results (376)

Phytoalexins are antimicrobial compounds of diverse chemical classes whose production is triggered in plants in response to pathogen infection. This study demonstrated that spraying with a celery flavonoid-rich extract (CFRE) or a spinach flavonoid-rich extract (SFRE) enhanced the production of phytoalexins in cucumber leaves artificially infected with powdery mildew incited by Podosphaera fusca. High-performance liquid chromatographic (HPLC) analysis revealed a noticeable increase in the content of phenolic acids, including caffeic acid, ellagic acid, ferulic acid, gallic acid, p-coumaric acid, and syringic acid, as well as the flavonoid rutin in both non-inoculated and inoculated leaves of cucumber seedlings treated with CFRE and SFRE, compared to healthy untreated leaves used as a control. Fluorescence microscopy revealed the accumulation of phenolic acid compounds in chloroplasts and at the periphery of epidermal cells. Overall, results suggest the reduced severity of P. fusca infection following the application of CFRE and SFRE in cucumber leaves could be due, at least in part, to the production of phytoalexins of polyphenolic nature. These findings provide insights into the mechanisms of systemic resistance induced by CFRE and SFRE. Moreover, they confirm these two natural flavonoid-rich products could be promising alternatives to synthetic chemical fungicides for the safe and ecofriendly control of cucumber powdery mildew. Full article

The rise in multidrug-resistant bacterial strains and persistent infections such as Lyme disease caused by Borrelia burgdorferi highlights the need for novel antimicrobial agents. The present study explores the antioxidant, antibacterial, and cytotoxic properties of extracts from submerged mycelial biomass of Fomitopsis pinicola, cultivated in synthetic and lignocellulosic media. Four extracts were obtained using hot water and 80% ethanol. The provided analysis of extracts confirmed the presence of various bioactive compounds, including flavonoids, alkaloids, and polyphenols. All extracts showed dose-dependent antioxidant activity (IC₅₀: 1.9–6.7 mg/mL). Antibacterial tests revealed that Klebsiella pneumoniae was most sensitive, with the L2 extract producing the largest inhibition zone (15.33 ± 0.47 mm), while the strongest bactericidal effect was observed against Acinetobacter baumannii (MBC as low as 0.5 mg/mL for L1). Notably, all extracts significantly reduced the viability of stationary-phase B. burgdorferi cells, with L2 reducing viability to 42 ± 2% at 5 mg/mL, and decreased biofilm mass, especially with S2. Cytotoxicity assays showed minimal effects on NIH 3T3 cells, with slight toxicity in HEK 293 cells for S2 and L1. These results suggest that F. pinicola extracts, particularly ethanolic L2 and S2, may offer promising natural antimicrobial and antioxidant agents for managing resistant infections. Full article

To explore an industrial fermentation approach for traditional mung bean sour pulp, this study isolated core microorganisms including lactic acid bacteria and yeasts from naturally fermented samples and constructed a synthetic microbial community. The optimized community consisted of Lactiplantibacillus pentosus, Lactococcus garvieae, and Cyberlindnera jadinii at a ratio of 7:3:0.1 and was used to ferment cooked mung bean pulp with a material-to-water ratio of 1:8 and 1% sucrose addition. Under these conditions, the final product exhibited significantly higher levels of protein (4.55 mg/mL), flavonoids (0.10 mg/mL), polyphenols (0.11 mg/mL), and vitamin C (7.75 μg/mL) than traditionally fermented mung bean sour pulp, along with enhanced antioxidant activity. The analysis of organic acids, free amino acids, and volatile compounds showed that lactic acid was the main acid component, the bitter amino acid content was reduced, the volatile flavor compounds were more abundant, and the level of harmful compound dimethyl sulfide was significantly decreased. These results indicate that fermentation using a synthetic microbial community effectively improved the nutritional quality, flavor, and safety of mung bean sour pulp. Full article

Tomato crops are treated with high concentrations of synthetic fertilizers and insecticides to increase yields, but the careless use of these chemicals harms the environment and human health and affects plant pathogen resistance. The effect of foliar spray of three concentrations of chitosan (500, 1000, and 2000 mg L⁻¹) on plant growth, yield, fruit quality, and physiological performance in two tomato varieties (Floradade and Candela F1) was studied. Physiological traits such as photosynthesis, chlorophyll content, and leaf area index of the plants were positively affected by chitosan, an effective compound that biostimulates growth, with increases in biomass of organs with respect to the control treatment. Chitosan also improved tomato quality, such as increases in polyphenols, antioxidant capacity, flavonoids, carotenoids, vitamin C, and total soluble solids in both tomato varieties. Finally, yield increased by 76.4% and 65.4% in Floradade and Candela F1, respectively. The responses of tomato plants to chitosan application were different depending on the variety evaluated, indicating a differential response to the biostimulant. The use of chitosan in agriculture is a tool that has no negative effects on plants and the environment and can increase the productive capacity of tomato plants. Full article

Tuberaria lignosa (Sweet) Samp. (Cistaceae) is a herbaceous species native to southwestern Europe, traditionally used to treat wounds, ulcers, and inflammatory or infectious skin conditions. This study aimed to characterize the phytochemical profile of its aqueous leaf extract and evaluate its skin-related in vitro biological activities. The phenolic composition was determined using UHPLC-HRMS/MS, HPLC-DAD, and quantitative colorimetric assays. Antioxidant activity was assessed against synthetic free radicals, reactive oxygen and nitrogen species, transition metals, and pro-oxidant enzymes. Enzymatic inhibition of tyrosinase, hyaluronidase, collagenase, and elastase were evaluated using in vitro assays. Cytocompatibility was tested on human keratinocytes and NIH/3T3 fibroblasts using MTT and resazurin assays, respectively, while wound healing was evaluated on NIH/3T3 fibroblasts using the scratch assay. Antifungal activity was investigated against several Candida and dermatophyte species, while antibiofilm activity was tested against Epidermophyton floccosum. The extract was found to be rich in phenolic compounds, accounting for nearly 45% of its dry weight. These included flavonoids, phenolic acids, and proanthocyanidins, with ellagitannins (punicalagin) being the predominant group. The extract demonstrated potent antioxidant, anti-tyrosinase, anti-collagenase, anti-elastase, and antidermatophytic activities, including fungistatic, fungicidal, and antibiofilm effects. These findings highlight the potential of T. lignosa as a valuable and underexplored source of bioactive phenolic compounds with strong potential for the development of innovative approaches for skin care and therapy. Full article

Metal chelation to bioactive small molecules is a well-established strategy to enhance the biological activity of the resulting complexes. Among the widely explored structural motifs, the combination of prominent metal centers with naturally inspired derivatives has attracted considerable attention. One such promising platform is the flavone scaffold, derived from flavonoids and studied since ancient times. Flavones are plant-derived compounds known for their diverse biological activities and health benefits. They exhibit significant structural variability, primarily through backbone modifications such as hydroxylation. Importantly, coordination of metal ions to hydroxylated flavone cores often improves their natural bioactivities, including anticancer and antimicrobial effects. In this review, we summarize transition metal complexes incorporating hydroxyflavone (OH–F) ligands reported over the past 15 years. We provide a concise overview of synthetic approaches and structural characterization, with a particular emphasis on coordination modes (e.g., maltol-type, acetylacetonate-type, catechol-type, and others). Furthermore, we discuss biological evaluation results, especially anticancer and antimicrobial studies, to highlight the therapeutic potential of these complexes. Finally, we suggest directions for the future development of metal-based agents bearing hydroxyflavone moieties through several critical points in terms of the accuracy, reproducibility, and relevance of biological studies involving metal-based compounds. Full article

Vitexin and isovitexin are dietary flavonoids widely distributed in food and medicinal plants. They have attracted increasing attention owing to their diverse pharmacological activities and favorable safety profiles. These compounds exhibit therapeutic potential across multiple biological systems, including the immune, nervous, respiratory, cardiovascular, and endocrine systems, through antioxidant, anti-inflammatory, anticancer, antibacterial, and neuroprotective mechanisms. Although previous reviews have addressed the pharmacological effects of vitexin and isovitexin, most are limited in scope—either focusing solely on vitexin or restricted to specific disease models such as cancer or diabetes. Moreover, some studies are outdated and do not reflect the recent advances in synthetic modification, green extraction technologies, and systems pharmacology. This review aims to provide a comprehensive evaluation of the pharmacological properties, pharmacokinetics, and clinical relevance of vitexin and isovitexin, highlighting their potential in disease prevention and treatment. A literature search was conducted using Web of Science, PubMed, and Google Scholar, with keywords including “vitexin”, “isovitexin”, “disease”, and “mechanism”. Here, we summarize the current research on the pharmacological effects of vitexin and isovitexin in metabolic disorders, inflammatory diseases, cancer, and neurodegenerative conditions, focusing on their molecular mechanisms and therapeutic targets. Furthermore, we discussed their toxicity, bioavailability, pharmacokinetics, and clinical research findings. Vitexin and isovitexin hold promise as therapeutic agents or adjuncts for multiple diseases with potential applications in modern medicine and healthcare. However, their pharmacological mechanisms, clinical efficacy, and potential synergistic effects with other therapeutic agents remain unclear. Further systematic research is needed to clarify molecular targets and optimize their therapeutic applications. Full article

Polymorphous Light Eruption (PLE) is a prevalent UV-induced photodermatosis characterized by abnormal immune responses, oxidative stress, and cutaneous inflammation. Alpha-glucosylrutin (AGR), a chemically modified flavonoid widely used for its antioxidant and photoprotective effects, has shown clinical efficacy; however, its synthetic origin and classification as a potential skin sensitizer and aquatic toxin raise safety and environmental concerns. These limitations underscore the need for safer, naturally derived alternatives. In this study, we investigated the comparative efficacy of quercetin (QC) and hesperidin (HPN)—two plant-based flavonoids—against AGR in in vitro and ex vivo models of sun-induced skin damage. An optimized QC:HPN 8:1 (w/w) complex significantly restored antioxidant enzyme activities (SOD: 4.11 ± 0.32 mU/mg; CAT: 1.88 ± 0.04 mU/mg) and suppressed inflammatory cytokine production (IL-6: 155.95 ± 3.17 pg/mL; TNF-α: 62.34 ± 0.72 pg/mL) more effectively than AGR. β-hexosaminidase secretion, a marker of allergic response, was reduced to 99.02 ± 1.45% with QC:HPN 8:1, compared to 121.33 ± 1.15% with AGR. QC alone exhibited dose-dependent cytotoxicity at ≥10 μg/mL, whereas HPN maintained >94% cell viability at all tested concentrations. These findings highlight the QC:HPN 8:1 complex as a safe, natural, and effective alternative to synthetic AGR for preventing and managing PLE and UV-induced dermal inflammation. Further research should focus on clinical validation and formulation development for topical use. Full article

Preservatives are essential for ensuring the stability, safety, and efficacy of pharmaceuticals, cosmetics, and food products. However, synthetic preservatives often raise toxicity concerns. This study evaluated Rosmarinus officinalis (rosemary) leaf extracts and coffee by-products from Coffea arabica and Coffea canephora as potential natural preservatives for emulsions. Antimicrobial activity was assessed against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans, along with cytotoxicity tests on human keratinocytes and antioxidant activity. The most effective extracts were incorporated into an oil-in-water emulsion for evaluation. C. arabica extracts showed the best results among coffee samples, with 43.53 mg GAE/g (gallic acid equivalents) and 2.32 mg QE/g of total phenolics (quercetin equivalents) and flavonoids, and minimum inhibitory concentrations (MICs) of 12.5 mg/mL against Escherichia coli, and 25 mg/mL against Staphylococcus aureus and Pseudomonas aeruginosa. Rosemary extract showed 158.01 ± 23.67 mg GAE/g and 1.95 ± 0.05 mg QE/g, with MICs of 2.5 mg/mL against E. coli, 1.25 mg/mL against P. aeruginosa, 0.3 mg/mL against S. aureus, and 0.08 mg/mL against Candida albicans. However, rosemary extracts displayed complete inhibition of keratinocyte growth at 20 µg/mL. A combination of both extracts had synergistic effects against S. aureus and P. aeruginosa. The emulsion met microbial safety standards in the challenge test for bacteria but not yeast. The results suggest that rosemary extracts enhance the potential of coffee by-product as a preservative system, and as a multifunctional excipient system in cosmetics, offering preservation and antioxidant protection. However, further strategies, such as adding other ingredients or adjusting the formulation pH, are required to ensure yeast inhibition. Full article

Urolithiasis (UL) is the presence of stones in the kidneys or urinary tract; its prevalence has increased worldwide. Thus, strategies have been sought to reduce it and one of them is the use of medicinal plants due to their accessibility, low cost, and cultural traditions. Studies on traditional medicinal plants in UL mainly documented results of litholytic and urinary parameters. Although, stone formation is related to oxidative stress and inflammation, and only a few studies are focused on these types of biomarkers. Thus, the aim of the present review was to summarize studies showing the antioxidant and anti-inflammatory effects of traditional medicinal plants used in UL management. We performed a scoping review; the database sources used were MEDLINE/PubMed, Google Scholar, SpringerLink, Scielo and Redalyc. From a total of 184 studies screened, six were included from China (2), India (3), and Corea (1). These studies have shown the antioxidant and anti-inflammatory effects of traditional medicinal plants, including Glechoma longituba (G. longituba), Bergenia ligulate (B. ligulate), Lygodium japonicum (L. japonicum), Citrus limon (C. limon), Xanthium strumarium (X. strumarium) and Tribulus terrestris (T. terrestris). They have also described their molecular mechanism of antioxidant and anti-inflammatory effects through the activation of antioxidant genes induced by Nrf2 or by suppressing the inflammatory gene expression by the inhibition of NFκ-B. These effects could be modulated by their bioactive compounds, such as polyphenols, flavonoids, tannins, saponins, and terpenes, present in these plants. This review summarizes the antioxidant and anti-inflammatory effects of traditional medicinal plants and highlights their molecular mechanisms of action and main bioactive compounds. This evidence may be used in biotechnology and synthetic biology areas for the development of new products from plant-derived compounds to reduce the high recurrence rates of UL. Full article

The apple tree (Malus domestica), a member of the Rosaceae family, holds significant economic value but faces postharvest challenges, like blue mold caused by Penicillium expansum and gray mold caused by Botrytis cinerea. While synthetic fungicides are widely used, their limitations highlight the need for sustainable alternatives. This study explores the antifungal properties of extracts from Celtis australis, Olea europea var. sylvestris, Chamaerops humilis, and Asparagus albus against these pathogens. In vitro tests assessed mycelial growth inhibition, whereas in vivo trials consisted of measurement of weight loss, firmness, total soluble solids, titratable acidity, and maturity index. Moreover, the phytochemical traits of the extracts were determined using the Folin–Ciocalteu method and HPLC. The results revealed notable antifungal activity, particularly for Celtis australis extract at a concentration of 300 g L⁻¹, which led to significant mycelial growth inhibition (61% for P. expansum and 41% for B. cinerea), a reduction in diseases’ severity (39% and 50%), and a notable decrease in diseases’ incidence (43% and 48%), respectively. Phytochemical analysis reflected the presence of phenols and flavonoids in the tested extracts. Importantly, the natural treatments helped preserve the apples’ quality during storage. Molecular docking studies further revealed that major compounds in Celtis australis extract inhibit the 14α-demethylase enzyme, a key target in fungal sterols biosynthesis. Full article

Public concerns about the health risks of synthetic antioxidants have prompted the meat industry to look for natural alternatives rich in phenols with strong antioxidant properties. This study investigates the use of blackcurrant (BCP), lingonberry (LP), and sour cherry (SCP) powders as natural substitutes for synthetic nitrites in reformulating two clean-label salami types, smoked and cooked and smoked and scalded, with a focus on their effects on oxidative stability during processing and refrigerated storage (4 °C). Nitrite-free formulations were prepared with each fruit powder at three inclusion levels to provide total phenolic contents of 90, 200, and 300 mg gallic acid equivalents (GAE)/kg of processed meat. A nitrite-containing control (90 mg/kg) and an additive-free control were included for comparison. The phytochemical profiles of powders were characterized by total phenolic, flavonoid, monomeric anthocyanin contents, and L-ascorbic acid levels. Antioxidant activity was assessed via 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and ferric reducing antioxidant power (FRAP) assays. Salami samples were analyzed for proximate composition, and lipid oxidation was monitored at 0, 15, and 30 days of storage using peroxide value, inhibition of oxidation, p-anisidine value, TOTOX, and thiobarbituric acid value. Fruit powders demonstrated dose- and type-dependent inhibition of primary and secondary lipid oxidation, enhancing oxidative stability during processing and storage. After 30 days of storage, oxidation markers in fruit-enriched salami remained below recommended thresholds, confirming effective control of lipid oxidation. The inhibitory potential followed the order BCP > LP > SCP, consistent with antioxidant profiles as reflected by DPPH and FRAP values. BCP at 300 mg GAE/kg showed a stronger lipid oxidation inhibition than sodium nitrite. Promising improvements in lipid oxidation resistance were also observed with LP at 300 mg GAE/kg and BCP at 200 mg GAE/kg. These findings highlight the potential of fruit-derived antioxidants to support the development of more sustainable, value-added meat products without compromising quality. Full article

Chymotrypsin inhibitors were initially considered mainly as anti-nutritional factors. However, the potential for their use as therapeutics has been recognized, particularly in the control of cancer, neurodegenerative diseases, and inflammatory processes. The search for new, effective, and safe chymotrypsin inhibitors has become important not only for food and feed safety reasons, but also in the search for new compounds with potential for use in the pharmaceutical industry. Oxidative stress is also an integral etiological factor in the development of the aforementioned pathological conditions. Antioxidants supplied with food can have an impact on reducing the probability of developing these diseases. Herbaceous plants are a valuable reservoir of biologically active chemical compounds, which can show both inhibitory effects against a number of enzymatic reactions and have antioxidant activity. The compounds found within them are also often characterized by higher bioavailability and safety than their synthetic analogs. In the present study, phytochemical characterization of plant materials Galium aparine L., Galium verum L., Solidago virgaurea L. and Solidago canadensis L. was performed, in order to search for new, potential substances with chymotrypsin inhibitor and antioxidant properties. Antioxidant and inhibitory activities against chymotrypsin were determined using effect-directed HPTLC. The total content of phenolic compounds and flavonoids and antioxidant activity were also determined in UV-Vis spectrophotometric tests. Both plant species showed antioxidant and chymotrypsin inhibitory activity. Among the methanol and methanol:water extracts, the extracts from Solidago sp. showed stronger inhibitory and antioxidant activity. However, in the case of dichloromethane extracts, Galium aparine inhibited chymotrypsin activity in a stronger manner than Solidago sp. The results indicate the application potential of compounds obtained from these plants as chymotrypsin inhibitors and antioxidant agents. Full article

The growing demand for sustainable phytosanitary products has renewed interest in botanical insecticides as viable pest control tools. Amid rising demand for sustainable crop protection, this study screens Cerrado plants traditionally used in medicine to pinpoint bioactive compounds that could replace synthetic pesticides. These products have complex chemical compositions, with compounds acting synergistically through multiple mechanisms, including oral (ingestion of allelochemicals) and topical (contact of allelochemicals on epidermis) toxicity. This study evaluated the oral and topical toxicity of aqueous leaf extracts from Anemopaegma arvense (AEAa), Coussarea hydrangeifolia (AECh), Tapirira guianensis (AETg), and Duguetia furfuracea (AEDf) on Plutella xylostella. In the oral toxicity test, first-instar larvae were fed treated diets until pupation, with biological parameters monitored until adulthood. The extracts caused an average of 45% larval mortality, reduced pupal duration, and lowered egg production. In the topical toxicity test, only the extract from T. guianensis showed significant effect (p = 0.0171), causing 30% mortality in third-instar larvae. The other extracts showed no significant topical toxicity, and AECh showed no lethal or sublethal effects at all. Phytochemical screening was assessed by quantitative spectrophotometric assays, and semi-quantitative classical colorimetric tests. Major compound classes identified were tannins, flavonoids, triterpenoids, coumarins, and alkaloids. These findings highlight the potential of the evaluated plant extracts for pest control, particularly via ingestion, while also underscoring the need for further studies to better understand their efficacy and mechanisms of action. Full article

Antioxidants, such as stilbenes, anthocyanidins, coumarins, tannins and flavonoids, are often based on oxygen-containing redox systems and tend to feature several hydroxyl groups in their chemical structures. From a synthetic perspective, oxygen atoms are prone to bioisosteric replacement with sulfur and, notably, selenium. The main objective of this narrative literature review is to explore if and how bioisosteric substitution of oxygen with sulfur or selenium can enhance the biological activity of natural products. This replacement boosts the biological activity of the resulting molecules considerably as they now combine the redox and antioxidant properties of the original flavonoids and other natural products with the specific redox behavior of sulfur and selenium. Besides sequestering free radicals and peroxides, they may, for instance, also catalyze the removal of oxidative stressors, capture free metal ions and even provide scope for selenium supplementation. Since these molecules resemble their natural counterparts, they also exhibit considerable selectivity inside the body and a good pharmacokinetic profile. Still, the synthesis of such hybrid molecules integrating sulfur and selenium into flavonoids and other natural products is a challenge and requires innovative synthetic strategies and approaches. Full article