A structure-activity relationship study of flavonoids as inhibitors of E. coli by membrane interaction effect

Antimicrobial Activity of Leaf Aqueous Extract of Schinus polygamus (Cav.) Cabrera against Pathogenic Bacteria and Spoilage Yeasts

The antimicrobial activity of an aqueous extract of the leaves of Schinus polygamus (cav.) Cabrera against microorganisms of food importance was evaluated. First, the leaf aqueous extract of Schinus polygamus was characterized, quantifying hydroxycinnamic acids and phenolic compounds. Then, a battery of strains was tested, including Escherichia coli ATCC 25922, Salmonella Typhimurium ATCC 14028, and Listeria monocytogenes ATCC 13932. Also, we tested wine spoilage yeasts such as Brettanomyces bruxellensis LAMAP2480, B. bruxellensis LAMAP1359, B. bruxellensis CECT1451, and Pichia guilliermondii NPCC1051. Tests were conducted using the kinetic curve of growth and cell viability counts. The results indicate that with 10% v/v of concentrated extract, it is possible to observe growth inhibition of all microorganisms studied, with statistically significant differences during the whole measurement time (70 h for bacteria and 145 h for yeast).

Efficacy of Annona glabra extract against acute hepatopancreatic necrosis disease in white-leg shrimp (Penaeus vannamei)

This study aims to investigate the use of pond apple (Annona glabra) compounds as a novel strategy to prevent and treat acute hepatopancreatic necrosis disease (AHPND) as well as to better understand the mechanism of health improvement in shrimp. The A. glabra leaf extracts were extracted using various solvents and examined for in vitro and in vivo activity against Vibrio parahaemolyticus strains. In comparison with ethanol and water extracts, methanol extract showed the strongest bactericidal effect (MBC/MIC ratio of 2.50 ± 1.00), with minimal inhibitory concentration (MIC) of 0.023 ± 0.012 mg ml-1 and minimum bactericidal concentration (MBC) of 0.065 ± 0.062 mg ml-1. White leg shrimp (P. vannamei, body weight 10.37 ± 0.27 g) fed A. glabra methanol extracts-containing diets (AMEDs) at 1 %, 1.5 %, and 2.0 % demonstrated no deleterious effects on survival and were significantly increased in length and weight after 30 days of feeding. The level of total haemocyte, hyaline haemocyte on day 15 and granulocyte on day 30 remarkably increased (p < 0.05) in shrimps fed AMEDs groups compared to those in the control group. The finding demonstrates that granulocyte was induced time dependently. In particular, the survival rate of V. parahaemolyticus challenged shrimps under medication with AMEDs at 1.5 % and 2.0 % was significantly higher (p < 0.05) than that of the control group. The decrease in bacterial load of Vibrio spp. and V. parahaemolyticus was obviously recorded in hepatopancreas shrimp given AMEDs 1.5 % and 2.0 % and may be linked to herb characteristics such as antibacterial activity, enhancing innate immunity, and its potential to maintain the integrity of hepatopancreatic tissue. Our findings suggest that A. glabra extract might be used as a health enhancer in commercial farmed shrimp.

Mechanisms of polyphenols on quality control of aquatic products in storage: A review

Aquatic products are easily spoiled during storage due to oxidation, endogenous enzymes, and bacteria. At the same time, compared with synthetic antioxidants, based on the antibacterial and antioxidant mechanism of biological agents, the development of natural, nontoxic, low-temperature, better-effect green biological preservatives is more acceptable to consumers. The type and molecular structure of polyphenols affect their antioxidant and antibacterial effectiveness. This review will describe how they achieve their antioxidant and antibacterial effects. And the recent literature on the mechanism and application of polyphenols in the preservation of aquatic products was updated and summarized. The conclusion is that in aquatic products, polyphenols alleviate lipid oxidation, protein degradation and inhibit the growth and reproduction of microorganisms, so as to achieve the effect of storage quality control. And put forward suggestions on the application of the research results in aquatic products. We hope to provide theoretical support for better exploration of the application of polyphenols and aquatic product storage.

Production of kojic acid by Aspergillus flavus OL314748 using box-Behnken statistical design and its antibacterial and anticancer applications using molecular docking technique

Kojic acid is a wonderful fungal secondary metabolite that has several applications in the food, medical, and agriculture sectors. Many human diseases become resistant to normal antibiotics and normal treatments. We need to search for alternative treatment sources and understand their mode of action. Aspergillus flavus ASU45 (OL314748) was isolated from the caraway rhizosphere as a non-aflatoxin producer and identified genetically using 18S rRNA gene sequencing. After applying the Box-Behnken statistical design to maximize KA production, the production raised from 39.96 to 81.59 g/l utilizing (g/l) glucose 150, yeast extract 5, KH2PO4 1, MgSO4.7H2O 2, and medium pH 3 with a coefficient (R2) of 98.45%. Extracted KA was characterized using FTIR, XRD, and a scanning electron microscope. Crystalized KA was an effective antibacterial agent against six human pathogenic bacteria (Bacillus cereus, Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia, Serratia marcescens, and Serratia plymuthica). KA achieves high inhibition activity against Bacillus cereus, K. pneumonia, and S. plymuthica at 100 μg/ml concentration by 2.75, 2.85, and 2.85 compared with chloramphenicol which gives inhibition zones 1, 1.1, and 1.6, respectively. Crystalized KA had anticancer activity versus three types of cancer cell lines (Mcf-7, HepG2, and Huh7) and demonstrated high cytotoxic capabilities on HepG-2 cells that propose strong antitumor potent of KA versus hepatocellular carcinoma. The antibacterial and anticancer modes of action were illustrated using the molecular docking technique. Crystalized kojic acid from a biological source represented a promising microbial metabolite that could be utilized as an alternative antibacterial and anticancer agent effectively.

Differential Effects of Soy Isoflavones on the Biophysical Properties of Model Membranes

The effects that the main soy isoflavones, genistein and daidzein, have upon the biophysical properties of a model lipid bilayer composed of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) or DOPC with cholesterol (4 to 1 mol ratio) have been investigated by transbilayer water permeability, differential scanning calorimetry, and confocal Raman microspectroscopy. Genistein is found to increase water permeability, decrease phase transition temperature, reduce enthalpy of transition, and induce packing disorder in the DOPC membrane with an increasing concentration. On the contrary, daidzein decreases water permeability and shows negligible impact on thermodynamic parameters and packing disorder at comparable concentrations. For a cholesterol-containing DOPC bilayer, both genistein and daidzein exhibit an overall less pronounced effect on transbilayer water permeability. Their respective differential abilities to modify the physical and structural properties of biomembranes with varying lipid compositions signify a complex and sensitive nature to isoflavone interactions, which depends on the initial state of bilayer packing and the differences in the molecular structures of these soy isoflavones, and provide insights in understanding the interactions of these molecules with cellular membranes.

Discovery of an adjuvant that resensitizes polymyxin B-resistant bacteria

Infections caused by antibiotic-resistant bacteria are a major threat to health, increasing mortality rates and straining health systems worldwide. Adjuvants targeted to beta-lactamase function are able to resensitize bacteria to beta-lactam antibiotics, but there is comparatively little research into the use of adjuvants against other resistance phenotypes. In this study, we performed a high-throughput screen of 74 natural products to identify adjuvants that synergized with antibiotics to eradicate resistant Gram-negative bacteria. From this, we identified six adjuvant hits which restored growth inhibition when combined with the relevant antibiotic, and pursued a lead candidate, perforone, which possessed selective adjuvant activity in combination with polymyxin B against polymyxin-resistant Escherichia coli cells. These results suggest that pairing adjuvants with antibiotics could be a useful general intervention against resistant bacteria, helping to mitigate the effects of antimicrobial resistance.

Terminalia petiolaris A.Cunn ex Benth. Extracts Have Antibacterial Activity and Potentiate Conventional Antibiotics against β-Lactam-Drug-Resistant Bacteria

Terminalia petiolaris A. Cunn. Ex Benth. (genus: Terminalia, family: Combretaceae) is native to Australia. Terminalia spp. have traditionally been used to treat various ailments, including bacterial infections. Solvents of varying polarity were used to extract compounds from leaves of this species, and the extracts were tested against a panel of bacteria, including antibiotic-resistant strains. The methanolic and water extracts showed substantial inhibitory activity against several bacteria, including antibiotic-resistant strains in both disc diffusion and liquid dilution assays. Combining these extracts with selected conventional antibiotics enhanced the inhibition of bacterial growth for some combinations, while others showed no significant interaction. In total, two synergistic, twenty-five additive, twenty-three non-interactive and one antagonistic interaction were observed. The methanolic and ethyl acetate plant extracts were found to be non-toxic in Artemia franciscana nauplii toxicity assays. A liquid chromatography-mass spectrometry metabolomics analysis identified several flavonoid compounds, including miquelianin, trifolin and orientin, which might contribute to the observed activities. The potential modes of these active extracts are further discussed in this study.

Antibacterial Activity and Transcriptomic Analysis of Hesperetin against Alicyclobacillus acidoterrestris Vegetative Cells

The aim of this research was to investigate the antimicrobial characteristics and mechanism of hesperetin against Alicyclobacillus acidoterrestris vegetative cells. The results presented show that hesperetin had effective antimicrobial activity on Alicyclobacillus acidoterrestris vegetative cells, minimum inhibition concentration (MIC) of 0.0625 g/L, and minimum bacterial concentration (MBC) greater than 2 g/L. Moreover, treatment of hesperetin caused significant damage to cell integrity, preventing the growth of Alicyclobacillus acidoterrestris vegetative cells, enhancing the leakage of nucleic acid and proteins, and destroying the vegetative cell morphology. To further investigate the mechanism, transcriptomic analysis was carried out, and 3056 differentially expressed genes (DEGs) were detected. Gene ontology (GO) enrichment analysis revealed that hesperetin inhibits Alicyclobacillus acidoterrestris by affecting the intracellular nitrogen metabolism and amino acid metabolism. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis explained that hesperetin was also able to prevent the growth of Alicyclobacillus acidoterrestris by affecting the processes of nutrient transport, energy metabolism, and flagella motility. These results provide new insights into the antimicrobial effects and mechanism of hesperetin against Alicyclobacillus acidoterrestris, which provides a new method for inactive Alicyclobacillus acidoterrestris in the juice industry.

Regional variation in the antibacterial activity of a wild plant, wild garlic (Allium ursinum L.)

Antibacterial activity is a common and highly studied property of plant secondary metabolites. Despite the extensive literature focusing on identifying novel antibacterial metabolites, little work has been undertaken to examine variation in levels of antibacterial activity in any plant species. Here, we used large-scale sampling of leaves of the antibacterial plant, wild garlic (Allium ursinum L.), assembling a set of tissue extracts from 168 plants, with 504 leaves collected and analysed. We assayed extracts for antibacterial activity against Bacillus subtilis and used LC-MS to carry out a chemometric analysis examining variation in individual metabolites, comparing them with several ecological parameters. We found that allicin was the only metabolite which was positively related to antibacterial activity. Soil temperature was a key determinant of variability in the concentrations of many foliar metabolites, however, neither allicin concentrations nor antibacterial activity was related to any of our measured ecological parameters, other than roadside proximity. We suggest that the synthesis of allicin precursors may be largely independent of growing conditions. This may be to ensure that allicin is synthesised rapidly and in sufficiently high concentrations to effectively prevent herbivory and pest damage. This finding contrasts with flavonoids which were found to vary greatly between plants and across sites. Our findings suggest that key biologically active metabolites are constrained in their concentration range compared to other compounds in the metabolome. This has important implications for the development of wild garlic as a health supplement or animal feed additive.

Obtaining polyphenolic extracts from pomegranate peel (Punica granatum) to evaluate the bactericide and antioxidant activity

Pomegranate (Punica granatum) contains secondary metabolites with antioxidant and bactericide activity; however, the study of the peel in the endemic varieties of Mexico has not been deepened. The polyphenols extraction of peel pomegranate endemic to the state of Michoacan, Mexico could be used in the formlulation of healthy food due contains antioxidant compounds or could be used like drugs due contains antibactericide compunds.In this work 3 varieties of pomegranate were analyzed; Wonderful, Apaseo and Tecozautla harvested in 2017 and 2018, carrying out a physicochemical characterization to establish the ripening, application of an experimental design of response surface for drying the peel and extracting polyphenols using two solvents (acetone and ethanol) by the Soxhlet method. As a result, the pomegranates were in the correct ripening, in the drying an optimal point of operation was found without affecting the metabolites (36 h at 55 °C) and in the extraction, the bactericide and antioxidant activity was evaluated observing that in the ketone extracts the best results were obtained in the Apaseo variety being; ABTS•+ technique of 150.78 ET mM/g, DPPH• 109.8 ET mM/g and 11.82 EAG mg/g in dry extract. For the bactericide activity measured by inhibition halos in S. aureus and E. coli it was had; 20.03 mm and 14.05 mm respectively for the Apaseo variety, which is why it is convenient to extract polyphenols under this method in peel of Mexican pomegranate varieties.

pH-Responsive Cobalt(II)-Coordinated Assembly Containing Quercetin for Antimicrobial Applications

The development of novel drug delivery systems (DDSs) with promising antibacterial properties is essential for facing the emergency of increasing resistance to antimicrobial agents. The antibacterial features of quercetin and its metal complexes have been broadly investigated. However, several drawbacks affect their activity and effectiveness. In this work, we propose a DDS based on a pH-responsive cobalt(II)-coordinated assembly containing quercetin and polyacrylic acid. This system is suggested to trigger the release of the model drug in a pH-dependent mode by exploiting the localized acidic environment at the bacterial infection sites under anaerobic conditions. The delivery system has been designed by accurately examining the species and the multiple equilibria occurring in solution among the assembly components. The formation of cobalt(II) complexes with quercetin in the absence or presence of the pH-responsive polyacrylic acid was investigated in buffered aqueous solution at pH 7.4 using spectrophotometric (UV-Vis) and calorimetric (ITC) techniques. The determined binding affinities and thermodynamic parameters that resulted are essential for the development of a DDS with improved binding and release capabilities. Furthermore, the affinity of the polymer-cobalt(II) complex toward the model antimicrobial flavonoid was explored at the solid-liquid interface by quartz crystal microbalance (QCM-D) experiments, which provided marked evidence for drug loading and release under pH control.

Natural Flavonoids Quercetin and Kaempferol Targeting G2/M Cell Cycle-Related Genes and Synergize with Smac Mimetic LCL-161 to Induce Necroptosis in Cholangiocarcinoma Cells

Cholangiocarcinoma (CCA) is an aggressive cancer associated with a very poor prognosis and low survival rates, primarily due to late-stage diagnosis and low response rates to conventional chemotherapy. Therefore, there is an urgent need to identify effective therapeutic strategies that can improve patient outcomes. Flavonoids, such as quercetin and kaempferol, are naturally occurring compounds that have attracted significant attention for their potential in cancer therapy by targeting multiple genes. In this study, we employed network pharmacology and bioinformatic analysis to identify potential targets of quercetin and kaempferol. The results revealed that the target genes of these flavonoids were enriched in G2/M-related genes, and higher expression of G2/M signature genes was significantly associated with shorter survival in CCA patients. Furthermore, in vitro experiments using CCA cells demonstrated that quercetin or kaempferol induced cell-cycle arrest in the G2/M phase. Additionally, when combined with a Smac mimetic LCL-161, an IAP antagonist, quercetin or kaempferol synergistically induced RIPK1/RIPK3/MLKL-mediated necroptosis in CCA cells while sparing non-tumor cholangiocyte cells. These findings shed light on an innovative therapeutic combination of flavonoids, particularly quercetin and kaempferol, with Smac mimetics, suggesting great promise as a necroptosis-based approach for treating CCA and potentially other types of cancer.

"Medicine food homology" plants promote periodontal health: antimicrobial, anti-inflammatory, and inhibition of bone resorption

"Medicine food homology" (MFH) is a term with a lengthy history. It refers to the fact that a lot of traditional natural products have both culinary and therapeutic benefits. The antibacterial, anti-inflammatory and anticancer effects of MFH plants and their secondary metabolites have been confirmed by numerous research. A bacterially generated inflammatory illness with a complicated pathophysiology, periodontitis causes the loss of the teeth's supporting tissues. Several MFH plants have recently been shown to have the ability to prevent and treat periodontitis, which is exhibited by blocking the disease's pathogens and the virulence factors that go along with them, lowering the host's inflammatory reactions and halting the loss of alveolar bone. To give a theoretical foundation for the creation of functional foods, oral care products and adjuvant therapies, this review has especially explored the potential medicinal benefit of MFH plants and their secondary metabolites in the prevention and treatment of periodontitis.

Targeted bacteria-mediated therapy of mouse colorectal cancer using baicalin, a natural glucuronide compound, and E. coli overexpressing β-glucuronidase

The side effects of common chemotherapeutic drugs that damage healthy tissues account for one of the most important problems in cancer research that needs careful addressing. Bacterial-Directed Enzyme Prodrug Therapy (BDEPT) is a promising strategy that uses bacteria to direct a converting enzyme to the tumor site and activate a systemically injected prodrug selectively within the tumor; so that the side effects of the therapy would significantly decrease. In this study, we evaluated the efficacy of baicalin, a natural compound, as a glucuronide prodrug in association with an engineered strain of Escherichia coli DH5α harboring the pRSETB-lux/βG plasmid in a mouse model of colorectal cancer. E. coli DH5α-lux/βG was designed to emit luminescence and overexpress the β-glucuronidase. Unlike the non-engineered bacteria, E. coli DH5α-lux/βG showed the ability to activate baicalin, and the cytotoxic effects of baicalin on the C26 cell line were increased in the presence of E. coli DH5α-lux/βG. Analyzing the tissue homogenates of mice bearing C26 tumors inoculated with E. coli DH5α-lux/βG indicated the specific accumulation and multiplication of bacteria in the tumor tissues. While both baicalin and E. coli DH5α-lux/βG could inhibit tumor growth as monotherapy, an enhanced inhibition was observed when animals were subjected to combination therapy. Moreover, no significant side effects were observed after histological investigation. The results of this study indicate that baicalin has the capability of being used as a suitable prodrug in the BDEPT, however further research is required before it can be applied in the clinic.

Dietary (poly)phenols mitigate inflammatory bowel disease: Therapeutic targets, mechanisms of action, and clinical observations

Inflammatory bowel diseases (IBD), which include Crohn's disease and ulcerative colitis, are a rapidly growing public health concern worldwide. These diseases are heterogeneous at the clinical, immunological, molecular, genetic, and microbial level, but characteristically involve a disrupted immune-microbiome axis. Shortcomings in conventional treatment options warrant the need for novel therapeutic strategies to mitigate these life-long and relapsing disorders of the gastrointestinal tract. Polyphenols, a diverse group of phytochemicals, have gained attention as candidate treatments due to their array of biological effects. Polyphenols exert broad anti-inflammatory and antioxidant effects through the modulation of cellular signaling pathways and transcription factors important in IBD progression. Polyphenols also bidirectionally modulate the gut microbiome, supporting commensals and inhibiting pathogens. One of the primary means by which gut microbiota interface with the host is through the production of metabolites, which are small molecules produced as intermediate or end products of metabolism. There is growing evidence to support that modulation of the gut microbiome by polyphenols restores microbially derived metabolites critical to the maintenance of intestinal homeostasis that are adversely disrupted in IBD. This review aims to define the therapeutic targets of polyphenols that may be important for mitigation of IBD symptoms, as well as to collate evidence for their clinical use from randomized clinical trials.

Phenolic Compounds in Bacterial Inactivation: A Perspective from Brazil

Phenolic compounds are natural substances that are produced through the secondary metabolism of plants, fungi, and bacteria, in addition to being produced by chemical synthesis. These compounds have anti-inflammatory, antioxidant, and antimicrobial properties, among others. In this way, Brazil represents one of the most promising countries regarding phenolic compounds since it has a heterogeneous flora, with the presence of six distinct biomes (Cerrado, Amazon, Atlantic Forest, Caatinga, Pantanal, and Pampa). Recently, several studies have pointed to an era of antimicrobial resistance due to the unrestricted and large-scale use of antibiotics, which led to the emergence of some survival mechanisms of bacteria to these compounds. Therefore, the use of natural substances with antimicrobial action can help combat these resistant pathogens and represent a natural alternative that may be useful in animal nutrition for direct application in food and can be used in human nutrition to promote health. Therefore, this study aimed to (i) evaluate the phenolic compounds with antimicrobial properties isolated from plants present in Brazil, (ii) discuss the compounds across different classes (flavonoids, xanthones, coumarins, phenolic acids, and others), and (iii) address the structure-activity relationship of phenolic compounds that lead to antimicrobial action.

Elicitation of Fruit Fungi Infection and Its Protective Response to Improve the Postharvest Quality of Fruits

Fruit diseases brought on by fungus infestation leads to postharvest losses of fresh fruit. Approximately 30% of harvested fruits do not reach consumers’ plates due to postharvest losses. Fungal pathogens play a substantial part in those losses, as they cause the majority of fruit rots and consumer complaints. Understanding fungal pathogenic processes and control measures is crucial for developing disease prevention and treatment strategies. In this review, we covered the presented pathogen entry, environmental conditions for pathogenesis, fruit’s response to pathogen attack, molecular mechanisms by which fungi infect fruits in the postharvest phase, production of mycotoxin, virulence factors, fungal genes involved in pathogenesis, and recent strategies for protecting fruit from fungal attack. Then, in order to investigate new avenues for ensuring fruit production, existing fungal management strategies were then assessed based on their mechanisms for altering the infection process. The goal of this review is to bridge the knowledge gap between the mechanisms of fungal disease progression and numerous disease control strategies being developed for fruit farming.

Antimicrobial Activity of Quercetin, Naringenin and Catechin: Flavonoids Inhibit Staphylococcus aureus-Induced Hemolysis and Modify Membranes of Bacteria and Erythrocytes

Search for novel antimicrobial agents, including plant-derived flavonoids, and evaluation of the mechanisms of their antibacterial activities are pivotal objectives. The goal of this study was to compare the antihemolytic activity of flavonoids, quercetin, naringenin and catechin against sheep erythrocyte lysis induced by α-hemolysin (αHL) produced by the Staphylococcus aureus strain NCTC 5655. We also sought to investigate the membrane-modifying action of the flavonoids. Lipophilic quercetin, but not naringenin or catechin, effectively inhibited the hemolytic activity of αHL at concentrations (IC₅₀ = 65 ± 5 µM) below minimal inhibitory concentration values for S. aureus growth. Quercetin increased the registered bacterial cell diameter, enhanced the fluidity of the inner and surface regions of bacterial cell membranes and raised the rigidity of the hydrophobic region and the fluidity of the surface region of erythrocyte membranes. Our findings provide evidence that the antibacterial activities of the flavonoids resulted from a disorder in the structural organization of bacterial cell membranes, and the antihemolytic effect of quercetin was related to the effect of the flavonoid on the organization of the erythrocyte membrane, which, in turn, increases the resistance of the target cells (erythrocytes) to αHL and inhibits αHL-induced osmotic hemolysis due to prevention of toxin incorporation into the target membrane. We confirmed that cell membrane disorder could be one of the direct modes of antibacterial action of the flavonoids.

Biophysical studies of the interaction of hRSV Non-Structural 1 protein with natural flavonoids and their acetylated derivatives by spectroscopic techniques and computational simulations

Human respiratory syncytial virus (hRSV) infections are one of the most causes of acute lower respiratory tract infections in children and elderly. The development of effective antiviral therapies or preventive vaccines against hRSV is not available yet. Thus, it is necessary to search for protein targets to combat this viral infection, as well as potential ways to block them. Non-Structural 1 (NS1) protein is an important factor for viral replication success since reduces the immune response by interacting with proteins in the type I interferon pathway. The influence of NS1 on the cell's immune response denotes the potential of its inhibition, being a possible target of treatment against hRSV infection. Here, it was studied the interaction of hRSV NS1 with natural flavonoids chrysin, morin, kaempferol, and myricetin and their mono-acetylated chrysin and penta-acetylated morin derivatives using spectroscopic techniques and computational simulations. The fluorescence data indicate that the binding affinities are on the order of 10⁵ M^-1, which are directly related to the partition coefficient of each flavonoid with Pearson's correlation coefficients of 0.76-0.80. The thermodynamic analysis suggests that hydrophobic interactions play a key role in the formation of the NS1/flavonoid complexes, with positive values of enthalpy and entropy changes. The computational approach proposes that flavonoids bind in a region of NS1 formed between the C-terminal α3-helix and the protein core, important for its biological function, and corroborate with experimental data revealing that hydrophobic contacts are important for the binding. Therefore, the present study provides relevant molecular details for the development of a possible new strategy to fight infections caused by hRSV.

Antibacterial activity and action mechanism of flavonoids against phytopathogenic bacteria

As the most difficult to control in plant disease, phytopathogenic bacteria cause huge losses to agricultural products and economy worldwide. However, the commercially available bactericides are few and enhance pathogen resistance. To alleviate this situation, 50 flavonoids were evaluated for their antibacterial activities and mechanism of action against two intractable plant bacterial pathogens. The results of bioassays showed that most of the flavonoids exhibited moderate inhibitory effects against Xanthomonas oryzae (Xo) and Xanthomonas axonopodis pv citri (Xac). Remarkably, kaempferol showed excellent antibacterial activity against Xo in vitro (EC₅₀ = 15.91 μg/mL) and quercetin showed the best antibacterial activity against Xac in vitro (EC₅₀ = 14.83 μg/mL), which was better than thiodiazole copper (EC₅₀ values against Xo and Xac were 16.79 μg/mL, 59.13 μg/mL, respectively). Subsequently, in vivo antibacterial activity assay further demonstrated kaempferol exhibited a stronger control effect on bacterial infections than thiodiazole copper. Then, the preliminary antibacterial mechanism of kaempferol was investigated by ultrastructural observations, transcriptomic, qRT-PCR analysis and biochemical index determination. These results showed that kaempferol mainly exerted bacteriostatic effects at the molecular level by affecting bacterial energy metabolism, reducing pathogenicity, and leading to disruption of cellular integrity, leakage of contents and cell death eventually.

A review of plant antipathogenic constituents: Source, activity and mechanism

Green prevention and control of plant pathogens is a development direction of sustainable and low-carbon agriculture given the limitation of traditional chemicals. Plant-derived antipathogenic constituents (PAPCs) exhibit the advantages of being environmental benign and a broad spectrum of target pathogens over traditional chemicals. Here, we review the research advances on plant sources, chemical compositions, activities of antipathogenic constituents in the past 20 years. Reported PAPCs are classified into categories of phenols, flavonoids, terpenoids, alkaloids and antimicrobial peptides. Angiosperms, gymnosperms and some lower plants are the main plant source of detected PAPCs. The PAPCs act on pathogens through multiple pathways including destroying cell structures, blocking key composition synthesis and inhibiting cell metabolism. The development trends of PAPCs are finally prospected. This review serves as a comprehensive review on the study of plant antipathogenic constituents and a key reference for forecasting the source, characteristic and activity of PAPC.

Anti-Candida albicans Activity of Ononin and Other Secondary Metabolites from Platonia Insignis MART

Candida albicans is a human pathogen that is part of the healthy microbiome. However, it is often associated with opportunistic fungal infections. The treatment of these infections is challenging because prolonged exposure to antifungal drugs can culminate in fungal resistance during therapy, and there is a limited number of available drugs. Therefore, this study investigated the antifungal activity of ononin by in silico and in vitro assays, and in Tenebrio molitor as an alternative in vivo model of infection caused by C. albicans. Ononin is an isoflavone glycoside derived from formononetin that has various biological activities. According in silico evaluation, ononin showed the best electron affinity in molecular docking with CaCYP51, with a binding free energy of -10.89 kcal/mol, superior to that of the antifungal drugs fluconazole and posaconazole. The ononin + CaCYP51 complex formed hydrogen bonds with Tyr132, Ser378, Phe380, and Met508, as well as hydrophobic connections with Tyr118, Leu121, Phe126, Leu131, Ile304, and Leu309, and interactions with the heme group. Ononin exerted anti-Candida albicans activity, with MIC between 3.9 and 7.8 µg/mL, and inhibited young and mature biofilms, with a reduction in cell density and metabolic activity of 50 to 80%. The compound was not cytotoxic to sheep red blood cells at concentrations up to 1000 µg/mL. Larvae of the mealworm T. molitor were used as an alternative in vivo model of C. albicans infection. Ononin was able to prolong larval survival at concentrations of 0.5, 1, and 5 mg/kg, and was not toxic up to a concentration of 20 mg/kg. Moreover, ononin reduced the fungal charge in treated animals. In conclusion, our results suggest that ononin has anti-Candida albicans activity and is a potential candidate for the development of new therapeutic alternatives.

Antimicrobial activities and mechanisms of extract and components of herbs in East Asia

Antibacterial drugs face increasing challenges due to drug resistance and adverse reactions, which has created a pressing need for the discovery and development of novel antibacterial drugs. Herbs have played an important role in the treatment of infectious diseases. This review aims to summarize, analyze and evaluate the antibacterial activities and mechanisms of components from popular herbs in East Asia. In this review, we have searched and summarized the scientific papers published during the past twenty-year period from electronic databases such as PubMed, ScienceDirect, and Web of Science. These herbs and their components, including alkaloids, flavonoids, essential oils, terpenes, organic acids, coumarins and lignans, display potential antimicrobial effects. Herbal medicine formulas (HMFs) usually show stronger antibacterial activity than single herbs. Herbs and HMFs bring forth antibacterial activities by damaging cell membranes and walls, inhibiting nucleic acid and protein synthesis, and increasing intracellular osmotic pressure. These herbs and their components can be developed as potential and promising novel antibacterial herbal products.

Harnessing the Role of Bacterial Plasma Membrane Modifications for the Development of Sustainable Membranotropic Phytotherapeutics

Membrane-targeted molecules such as cationic antimicrobial peptides (CAMPs) are amongst the most advanced group of antibiotics used against drug-resistant bacteria due to their conserved and accessible targets. However, multi-drug-resistant bacteria alter their plasma membrane (PM) lipids, such as lipopolysaccharides (LPS) and phospholipids (PLs), to evade membrane-targeted antibiotics. Investigations reveal that in addition to LPS, the varying composition and spatiotemporal organization of PLs in the bacterial PM are currently being explored as novel drug targets. Additionally, PM proteins such as Mla complex, MPRF, Lpts, lipid II flippase, PL synthases, and PL flippases that maintain PM integrity are the most sought-after targets for development of new-generation drugs. However, most of their structural details and mechanism of action remains elusive. Exploration of the role of bacterial membrane lipidome and proteome in addition to their organization is the key to developing novel membrane-targeted antibiotics. In addition, membranotropic phytochemicals and their synthetic derivatives have gained attractiveness as popular herbal alternatives against bacterial multi-drug resistance. This review provides the current understanding on the role of bacterial PM components on multidrug resistance and their targeting with membranotropic phytochemicals.

Evaluation of antibacterial activity of compounds isolated from the peel of Newhall navel orange

Fifteen compounds including one flavanone hesperitin (1), two cinnamic acid derivatives as (E)-4-hydroxycinnamic acid (2) and (E)-ferulic acid (3), eight polymethoxyflavones (PMFs) (4-11), and four hydroxylated PMFs (12-15) isolated from orange peel were subjected to antibacterial evaluation. Compounds 1-3 exhibited wide-spectrum antibacterial effects against four test strains involving Bacillus subtilis, Staphylococcus aureus, Xanthomonas citri subsp. citri (Xcc), and Meticillin-resistant Staphylococcus aureus (MRSA) with minimum inhibitory concentrations (MICs) ranging from 0.0312 to 0.125 mg/mL. In contrast, all PMFs showed weak antibacterial activity against these four strains with MICs being equal to or more than 0.125 mg/mL. Hydroxylated PMFs demonstrated better antibacterial effect against Xcc relative to PMFs. In addition, the synergistic effect against Xcc was obtained when compounds 1 and 3 were combined. Furthermore, the scanning electron microscopy (SEM) results of Xcc treated with both compounds 2 and 3 showed shrunken and rough surface morphologies, indicative of the cell membrane damage.

Antibiofilm activity of phytochemicals against Enterococcus faecalis: A literature review

Enterococcus faecalis is a leading causative pathogen of recalcitrant infections affecting heart valves, urinary tract, surgical wounds and dental root canals. Its robust biofilm formation, production of virulence factors and antibiotic resistance contribute significantly to its pathogenicity in persistent infections. The decreased effectiveness of most of antibiotics in preventing and/or eradicating E. faecalis biofilms mandates the discovery of alternative novel antibiofilm agents. Phytochemicals are potential sources of antibiofilm agents due to their antivirulence activity, diversity of chemical structure and multiple mechanisms of action. In this review, we describe the phenotypic and genetic attributes that contribute to antimicrobial tolerance of E. faecalis biofilms. We illuminate the benefits of implementing the phytochemicals to tackle microbial pathogens. Finally, we report the antibiofilm activity of phytochemicals against E. faecalis, and explain their mechanisms of action. These compounds belong to different chemical classes such as terpenes, phenylpropenes, flavonoids, curcuminoids and alkaloids. They demonstrate the ability to inhibit the formation of and/or eradicate E. faecalis biofilms. However, the exact mechanisms of action of most of these compounds are not fully understood. Therefore, the future studies should elucidate the underlying mechanisms in detail.

Recent Advancements in Enhancing Antimicrobial Activity of Plant-Derived Polyphenols by Biochemical Means

Plants are a reservoir of phytochemicals, which are known to possess several beneficial health properties. Along with all the secondary metabolites, polyphenols have emerged as potential replacements for synthetic additives due to their lower toxicity and fewer side effects. However, controlling microbial growth using these preservatives requires very high doses of plant-derived compounds, which limits their use to only specific conditions. Their use at high concentrations leads to unavoidable changes in the organoleptic properties of foods. Therefore, the biochemical modification of natural preservatives can be a promising alternative to enhance the antimicrobial efficacy of plant-derived compounds/polyphenols. Amongst these modifications, low concentration of ascorbic acid (AA)–Cu (II), degradation products of ascorbic acid (DPAA), Maillard reaction products (MRPs), laccase–mediator (Lac–Med) and horse radish peroxidase (HRP)–H2O2 systems standout. This review reveals the importance of plant polyphenols, their role as antimicrobial agents, the mechanism of the biochemical methods and the ways these methods may be used in enhancing the antimicrobial potency of the plant polyphenols. Ultimately, this study may act as a base for the development of potent antimicrobial agents that may find their use in food applications.

Chronic Inflammation in Non-Healing Skin Wounds and Promising Natural Bioactive Compounds Treatment

Chronic inflammation is one of the hallmarks of chronic wounds and is tightly coupled to immune regulation. The dysregulation of the immune system leads to continuing inflammation and impaired wound healing and, subsequently, to chronic skin wounds. In this review, we discuss the role of the immune system, the involvement of inflammatory mediators and reactive oxygen species, the complication of bacterial infections in chronic wound healing, and the still-underexplored potential of natural bioactive compounds in wound treatment. We focus on natural compounds with antioxidant, anti-inflammatory, and antibacterial activities and their mechanisms of action, as well as on recent wound treatments and therapeutic advancements capitalizing on nanotechnology or new biomaterial platforms.

Bioactive Compounds in Ficus Fruits, Their Bioactivities, and Associated Health Benefits: A Review

Bioactive compounds are secondary metabolites synthesized by plants for maintaining homeostasis; however, they also modulate metabolic processes and demonstrate valuable effects in the human body. The fig was cherished as food and for its pharmaceutical properties. The presence of a wide range of biologically active compounds such as carotenoids, flavonoids, phenols, and vitamin C is obligated for their functional properties as well as their technological capability as a dietary supplement is responsible for most health impacts. Owing to the rich and diversified composition of biologically active compounds these compounds possess different biological properties such as antioxidant, anti-inflammatory, antidiabetic, antimicrobial, and hepatoprotective activity that implies those bioactive substances might be used in the creation of novel culinary and medicinal products. Fig fruit should be widely recognized as a natural functional product. This systematic and comprehensive review gives the notion of developing figs species as a viable and innovative component for its varied food and nonfood applications as a remarkable and primitive source of medication and nourishment.

Chemical Characterization, Antioxidant and Antimicrobial Properties of Different Types of Tissue of Cedrus brevifolia Henry Extracts

This study aimed to determine the chemical composition of different types of tissue of Cedrus brevifolia Henry (Pinaceae) methanolic extracts, namely needles, twigs, branches, and bark. Cedrus brevifolia is a narrow endemic coniferous tree species of Cyprus, growing in a sole population in the mountainous area of Paphos Forest. Chemical analysis of the extracts was performed using liquid chromatography combined with time-of-flight high-resolution mass spectrometry (LC/Q-TOF/HRMS). The majority of the 36 compounds tentatively identified belonged to the flavonoids family. The extract of needles was the richest extract in terms of secondary metabolites. The extracts were studied for their antioxidant activity using the DPPH free radical scavenging assay. Additionally, the antibacterial activity was evaluated by determining both the minimum inhibitory concentration and the minimum bactericidal concentration against Staphylococcus aureus and Escherichia coli. All extracts demonstrated antioxidant property, while bark gave the highest antioxidant capacity (IC₅₀ value of 0.011 mg/mL) compared to the other tissues. Antibacterial activity was observed against both types of bacteria, with the extract of branches presenting the strongest activity against S. aureus (MIC, 0.097 mg/mL and MBC, 0.195 mg/mL). This is the first time that extracts of needles, twigs, branches, and bark of C. brevifolia are compared regarding their chemical composition as well as their antimicrobial and antioxidant properties.

Antibacterial Effects of Flavonoids and Their Structure-Activity Relationship Study: A Comparative Interpretation

According to the latest report released by the World Health Organization, bacterial resistance to well-known and widely available antibacterial drugs has become a significant and severe global health concern and a grim challenge to tackle in order to cure infections associated with multidrug-resistant pathogenic microorganisms efficiently. Consequently, various strategies have been orchestrated to cure the severe complications related to multidrug-resistant bacteria effectively. Some approaches involved the retardation of biofilm formation and multidrug-resistance pumps in bacteria as well as the discovery of new antimicrobial agents demonstrating different mechanisms of action. In this regard, natural products namely alkaloids, terpenoids, steroids, anthraquinone, flavonoids, saponins, tannins, etc., have been suggested to tackle the multidrug-resistant bacterial strains owing to their versatile pharmacological effects. Amongst these, flavonoids, also known as polyphenolic compounds, have been widely evaluated for their antibacterial property due to their tendency to retard the growth of a wide range of pathogenic microorganisms, including multidrug-resistant bacteria. The hydroxylation of C5, C7, C3′, and C4′; and geranylation or prenylation at C6 have been extensively studied to increase bacterial inhibition of flavonoids. On the other hand, methoxylation at C3′ and C5 has been reported to decrease flavonoids’ antibacterial action. Hence, the latest information on the antibacterial activity of flavonoids is summarized in this review, with particular attention to the structure–activity relationship of this broad class of natural compounds to discover safe and potent antibacterial agents as natural products.

Flavonoid mediated selective cross-talk between plants and beneficial soil microbiome

Plants generate a wide variety of organic components during their different growth phases. The majority of those compounds have been classified as primary and secondary metabolites. Secondary metabolites are essential in plants' adaptation to new changing environments and in managing several biotic and abiotic stress. It also invests some of its photosynthesized carbon as secondary metabolites to establish a mutual relationship with soil microorganisms in that specific niche. As soil harbors both pathogenic and beneficial microorganisms, it is essential to identify some specific metabolites that can discriminate beneficial and pathogenic ones. Thus, a detailed understanding of metabolite's architectures that interact with beneficial microorganisms could open a new horizon of ecology and agricultural research. Flavonoids are used as classic examples of secondary metabolites in this study to demonstrate recent developments in understanding and realizing how these valuable metabolites can be controlled at different levels. Most of the research was focused on plant flavonoids, which shield the host plant against competitors or predators, as well as having other ecological implications. Thus, in the present review, our goal is to cover a wide range of functional and signalling activities of secondary metabolites especially, flavonoids mediated selective cross-talk between plant and its beneficial soil microbiome. Here, we have summarized recent advances in understanding the interactions between plant species and their rhizosphere microbiomes through root exudates (flavonoids), with a focus on how these exudates facilitate rhizospheric associations.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s11101-022-09806-3.

Cissus quadrangularis L: A comprehensive multidisciplinary review

ETHNOPHARMACOLOGICAL RELEVANCE

Cissus quadrangularis L. is a perennial herb of the Vitaceae family and is utilized comprehensively as a medicinal herb in most tropical regions by various names. This herb is documented to possess a wide-ranging ethnomedicinal uses in malaria, fever, epilepsy, gout, piles, skin diseases, colic, etc. AIM OF THE REVIEW: A organized summary of the botany, traditional uses, phytochemistry, pharmacology, toxicology, available marketed formulations and filed patents were presented to explore the future therapeutic potential and scientific potential of this herb.

MATERIALS AND METHODS

For a review of the literature, various databases were searched, including PubMed, EMBASE, and Scopus etc. From, total 408 records of this herb, we have screened 155 articles consist of desired information and available as full text. Present manuscript is structured from comprehensive information on this herb from screened 155 records. Plant taxonomy was confirmed to the database "The Plant List".

RESULTS

Phytochemical assessment as a whole indicated the presence of flavonoids, triterpenoids, alkaloids, saponins, iridoids, stilbenes, vitamins, steroids, and glycosides. A toxicity study revealed that its LD₅₀ value is above 3000 mg/kg in animals indicating its safety. A variety of pharmacological studies of aerial parts of this herb by different extracts have demonstrated analgesic, anti-inflammatory, anticonvulsant, antimicrobial, anticancer, anti-osteoporotic activity and other bone-related disorders to justify its name as Hadjod. Still, the herb has been utilized in clinical practice and several patents were filed in India and US for its antiosteoporotic property.

CONCLUSION

The studies on Cissus quadrangularis Linn. are extensive, but gaps still remain. The molecular mechanism, structure-activity relationship, potential synergistic and antagonistic effects of these components needs to be further elucidated. These findings suggest the need for further research on this herb for the management of several other chronic ailments.

Antibacterial and anti-Trichomonas Vaginalis effects of Rosa Damascena mill petal oil (a persian medicine product), aqueous and hydroalcoholic extracts

Background

Oils in traditional medicine are important products and used routinely for therapeutic purposes. Rose oil (Rosa damascene Mill), a product of Persian medicine, is advised for the treatment of Infectious diseases related to the female genitourinary tract. In the present study, R. damascena petal oil, aqueous, and hydroalcoholic extracts were evaluated for their in vitro antibacterial and anti-Trichomonas vaginalis effects.

Methods

Anti-trichomonas activity evaluation of extracts and oil were assayed by the Homocytometery method. Their antibacterial effects against Escherichia coli, methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, and clinically isolated Group B Streptococcus were assayed by broth microdilution in 96-well plates.

Results

The MIC of hydroalcoholic and aqueous extracts ranged from 25-50 and 25-100 mg/ml, respectively. Rose oil at all administered doses failed to show any antibacterial activity.

Conclusion

All extracts and oil concentrations showed some degree of growth inhibition activity on T. vaginalis; however, hydroalcoholic extract was more efficient.

The effect of hesperidin, chrysin, and naringenin on the number of somatic cell count in mastitis in dairy cows after multiple intramammary administration

Hesperidin (HE), chrysin (CH) and naringenin (NA) are flavonoids, being the most important group of polyphenols, and show anti-inflammatory properties which have been demonstrated on various models. Polyphenols have a lot of biological properties, such as antioxidative, antiviral, immunomodulatory and anticancer activities. However, the effect on mastitis has not been yet described. This research aimed to analyze the tolerability of selected polyphenols after multiple intramammary administrations (IMM) as well as to investigate their potential impact on somatic cell count (SCC) in mastitis dairy cows. The study was performed on 12 Polish Holstein Black-White cows in their 4th – to 6th lactation. Only animals with inflammation in one-quarter of the udder were selected. The selection was based on SCC and clinical assessment. The experiment was performed with multiple IMM administrations with each of these polyphenols in dairy cows affected with mastitis. Polyphenols were administered at a dose of 30 mg/quarter/day. Milk samples for SCC, blood plasma samples for pharmacokinetics and blood hematology and biochemistry (selected blood parameters were tested) were collected at baseline, treatment period and within the recovery period. Positive effects concerning the number of SCC in milk of mastitic cows were confirmed for all tested polyphenols.

Phytochemicals: A Promising Weapon in the Arsenal against Antibiotic-Resistant Bacteria

The extensive usage of antibiotics and the rapid emergence of antimicrobial-resistant microbes (AMR) are becoming important global public health issues. Many solutions to these problems have been proposed, including developing alternative compounds with antimicrobial activities, managing existing antimicrobials, and rapidly detecting AMR pathogens. Among all of them, employing alternative compounds such as phytochemicals alone or in combination with other antibacterial agents appears to be both an effective and safe strategy for battling against these pathogens. The present review summarizes the scientific evidence on the biochemical, pharmacological, and clinical aspects of phytochemicals used to treat microbial pathogenesis. A wide range of commercial products are currently available on the market. Their well-documented clinical efficacy suggests that phytomedicines are valuable sources of new types of antimicrobial agents for future use. Innovative approaches and methodologies for identifying plant-derived products effective against AMR are also proposed in this review.

Dermal Drug Delivery of Phytochemicals with Phenolic Structure via Lipid-Based Nanotechnologies

Phenolic compounds are a large, heterogeneous group of secondary metabolites found in various plants and herbal substances. From the perspective of dermatology, the most important benefits for human health are their pharmacological effects on oxidation processes, inflammation, vascular pathology, immune response, precancerous and oncological lesions or formations, and microbial growth. Because the nature of phenolic compounds is designed to fit the phytochemical needs of plants and not the biopharmaceutical requirements for a specific route of delivery (dermal or other), their utilization in cutaneous formulations sets challenges to drug development. These are encountered often due to insufficient water solubility, high molecular weight and low permeation and/or high reactivity (inherent for the set of representatives) and subsequent chemical/photochemical instability and ionizability. The inclusion of phenolic phytochemicals in lipid-based nanocarriers (such as nanoemulsions, liposomes and solid lipid nanoparticles) is so far recognized as a strategic physico-chemical approach to improve their in situ stability and introduction to the skin barriers, with a view to enhance bioavailability and therapeutic potency. This current review is focused on recent advances and achievements in this area.

Flavonoid-Coated Gold Nanoparticles as Efficient Antibiotics against Gram-Negative Bacteria-Evidence from In Silico-Supported In Vitro Studies

Flavonoids are a class of bioactive plant-derived natural products that exhibit a broad range of biological activities, including antibacterial ones. Their inhibitory activity toward Gram-positive bacterial was found to be superior to that against Gram-negative ones. In the present study, a number of flavonoid-coated gold nanoparticles (GNPs) were designed to enhance the antibacterial effects of chrysin, kaempferol, and quercetin against a number of Gram-negative bacteria. The prepared GNPs were able to conjugate to these three flavonoids with conjugation efficiency ranging from 41% to 80%. Additionally, they were able to exert an enhanced antibacterial activity in comparison with the free flavonoids and the unconjugated GNPs. Quercetin-coated GNPs were the most active nano-conjugates and were able to penetrate the cell wall of E. coli. A number of in silico experiments were carried out to explain the conjugation efficiency and the antibacterial mechanisms of these flavonoids as follows: (i) these flavonoids can efficiently bind to the glutathione linker on the surface of GNPs via H-bonding; (ii) these flavonoids, particularly quercetin, were able to increase the bacterial membrane rigidity, and hence decrease its functionality; (iii) these flavonoids can inhibit E. coli's DNA gyrase (Gyr-B) with IC50 values ranging from 0.9 to 3.9 µM. In conclusion, these bioactive flavonoid-based GNPs are considered to be very promising antibiotic candidates for further development and evaluation.

Overview of the Antioxidant and Anti-Inflammatory Activities of Selected Plant Compounds and Their Metal Ions Complexes

Numerous plant compounds and their metal-ion complexes exert antioxidative, anti-inflammatory, anticancer, and other beneficial effects. This review highlights the different bioactivities of flavonoids, chromones, and coumarins and their metal-ions complexes due to different structural characteristics. In addition to insight into the most studied antioxidative properties of these compounds, the first part of the review provides a comprehensive overview of exogenous and endogenous sources of reactive oxygen and nitrogen species, oxidative stress-mediated damages of lipids and proteins, and on protective roles of antioxidant defense systems, including plant-derived antioxidants. Additionally, the review covers the anti-inflammatory and antimicrobial activities of flavonoids, chromones, coumarins and their metal-ion complexes which support its application in medicine, pharmacy, and cosmetology.

Biological importance, therapeutic benefit and analytical aspects of bioactive flavonoid pectolinarin in the nature

BACKGROUNDS

Plants and their derived products have been used in the traditional system of medicine for the treatment of various forms of human disorders since very ancient time. In the traditional system of medicine and modern allopathic medicine, numerous phytoconstituents have been used for the preparation of various types of formulation. Flavonoidal class phytochemicals are the main active phytoconstituents of plants, fruit, vegetables and beverages. Flavonoidal class phytochemicals are more referred as "nutraceuticals" due to their important pharmacological activities in the mammalian body.

METHODS

In order to understand the health beneficial effects of flavonoidal class chemical, present work summarized the health beneficial aspects of pectolinarin. Present work summarized the medicinal importance, pharmacological activities and analytical aspects of pectolinarin with various experimental models and advance analytical methods. However, all the collected scientific information's have been analyzed in the present work for their health beneficial potential.

RESULTS

From the analysis of all the collected scientific information in the present work it was found that pectolinarin is an important phytochemical found to be present in the numerous medicinal plants but especially found in Cirsium japonicum which is an important medicinal herb of Korea, China and Japan. Pharmacological activities data analysis signified the health beneficial potential of pectolinarin for their anti-rheumatoid arthritis, analgesic, anti-inflammatory, hepatoprotective, anti-diabetic, anti-tumor, anti-dengue, antiviral, neuroprotective and antidepressant activity. However effectiveness of pectolinarin in central nervous system, bone, liver and cancerous disorders have been also reported in the literature. Analysis of present scientific information revealed the health beneficial potential of pectolinarin in the modern medicine due to their numerous pharmacological activities in different part of biological systems. Due to their biological importance in food and human health, a better understanding of their biological activities indicates their potentials as therapeutic agents.

CONCLUSION

Scientific data of the present work signified the biological potential and therapeutic benefit of pectolinarin.

In vitroassessment of green polyhydroxybutyrate/chitosan blend loaded with kaempferol nanocrystals as a potential dressing for infected wounds

Despite the major medical advancements in recent decades, treating infected wounds successfully remains a challenge. In this research, a functional blend of Polyhydroxybutyrate (PHB) and Chitosan (Cs) was developed for wound infection mitigation with tailored biological and physicochemical properties. Water insoluble kaempferol (KPF) was pre-formulated to water soluble KPF nanocrystals (KPF-NCs) with fine particle size of 145 ± 11 nm, and high colloidal stability (-31 ± 0.4 mV) to improve its drug transdermal delivery. PHB-Cs-KPF-NCs (1:2 ratio) film owned the best physical properties in terms of high breathability, thermal stability and mechanical strength (33 ± 1 MPa). Besides, XRD and FTIR findings indicated the interaction between Cs, PHB and KPF, reducing the film crystallinity. The scanning electron microscopy of the film displayed a highly interconnected porous morphology. KPF-NCs were integrated in PHB-Cs matrix with a marked encapsulation efficiency of 96.6%. The enhanced drug-loading film showed a sustain release pattern of KPF-NCs over 48 h. Interestingly, the developed blend possessed an impressive blood clotting capacity within 20 min. Furthermore, we presented a new naturally-sourced mixture of Cs+KPF-NCs with powerful antibacterial effects against MDRStaphylococcus aureusandAcentibacter baumanniiat very low concentrations. The membrane evidenced a remarkable antibacterial naturein vitrowith almost 100% cell viability reduction against the study strains after 48 h. By virtue of these advantages, this green blend is highly proposed for optimal wound care.

Nonaqueous Polyethylene Glycol as a Safer Alternative to Ethanolic Propolis Extracts with Comparable Antioxidant and Antimicrobial Activity

We compared the chemical composition, antioxidant and antimicrobial activity of two propolis extracts: one obtained with nonaqueous polyethylene glycol, PEG 400 (PgEP), and the other obtained with ethanol (EEP). We analyzed the total phenolic content (TPC) and the concentrations of ten markers of propolis antioxidant activity with HPLC-UV: caffeic acid, p-coumaric acid, trans-ferulic acid, trans-cinnamic acid, kaempferol, apigenin, pinocembrin, chrysin, CAPE, and galangin. Antioxidant activity was tested using DPPH and FRAP assay, and antimicrobial activity was assessed through minimum inhibitory concentrations (MICs) and minimum biofilm eradication concentration (MBEC) determination. Maceration gave the yield of propolis of 25.2 ± 0.08% in EEP, and 21.5 ± 0.24% in PgEP. All ten markers of antioxidant activity were found in both extracts, with all marker concentrations, except kaempferol, higher in EEP. There was no significant difference between the TPC and antioxidant activity of the PgEP and the EEP extract; TPC of PgEP was 16.78 ± 0.23 mg/mL, while EEP had TPC of 15.92 ± 0.78 mg/mL. Both extracts had antimicrobial activity against most investigated pathogens and Staphylococcus aureus, Acinetobacter baumannii, and Escherichia coli biofilms. EEP was more effective against all tested susceptible pathogens, except E. coli, possibly due to higher content of kaempferol in PgEP relative to other polyphenols. Nonaqueous PEG 400 could be used for propolis extraction. It gives extracts with comparable concentrations of antioxidants and has a good antioxidant and antimicrobial activity. It is a safe excipient, convenient for pediatric and veterinary formulations.

Applications of Fruit Polyphenols and Their Functionalized Nanoparticles Against Foodborne Bacteria: A Mini Review

The ingestion of contaminated water and food is known to cause food illness. Moreover, on assessing the patients suffering from foodborne disease has revealed the role of microbes in such diseases. Concerning which different methods have been developed for protecting food from microbes, the treatment of food with chemicals has been reported to exhibit an unwanted organoleptic effect while also affecting the nutritional value of food. Owing to these challenges, the demand for natural food preservatives has substantially increased. Therefore, the interest of researchers and food industries has shifted towards fruit polyphenols as potent inhibitors of foodborne bacteria. Recently, numerous fruit polyphenols have been acclaimed for their ability to avert toxin production and biofilm formation. Furthermore, various studies have recommended using fruit polyphenols solely or in combination with chemical disinfectants and food preservatives. Currently, different nanoparticles have been synthesized using fruit polyphenols to curb the growth of pathogenic microbes. Hence, this review intends to summarize the current knowledge about fruit polyphenols as antibacterial agents against foodborne pathogens. Additionally, the application of different fruit extracts in synthesizing functionalized nanoparticles has also been discussed.

Extraction optimization of bioactive compounds from ora-pro-nobis (Pereskia aculeata Miller) leaves and their in vitro antioxidant and antihemolytic activities

Ora-pro-nobis (Pereskia aculeata Miller) is a non-conventional food plant common in Brazil. The objective of this study was to optimize the extraction of bioactive phenolic compounds from ora-pro-nobis leaves by employing solvent mixtures. Ten extracts were obtained with water, ethanol, acetone, and their binary and ternary mixtures, evaluating the chemical composition, antioxidant activity and bioactivities in vitro. The response surface methodology was applied to model the results and calculate the optimal solvent composition, which is 60% water, 40% ethanol and 0% acetone. The optimized extract is rich in phenolic compounds (64 mg GAE/g) and proteins (823 mg/g) and presents antioxidant activity (in intracellular media as well) and inhibits lipid peroxidation (32%) along with hypotonic hemolysis (H₅₀ = 0.339%), it does not present toxicity in vitro against cancer and normal cells. This is the first report of chicoric, caffeoyl-hexaric and coumaroyl-hexaric acids and some glycosylate derivatives of flavonols in ora-pro-nobis leaves.

The Interactions between Polyphenols and Microorganisms, Especially Gut Microbiota

This review presents the comprehensive knowledge about the bidirectional relationship between polyphenols and the gut microbiome. The first part is related to polyphenols' impacts on various microorganisms, especially bacteria, and their influence on intestinal pathogens. The research data on the mechanisms of polyphenol action were collected together and organized. The impact of various polyphenols groups on intestinal bacteria both on the whole "microbiota" and on particular species, including probiotics, are presented. Moreover, the impact of polyphenols present in food (bound to the matrix) was compared with the purified polyphenols (such as in dietary supplements) as well as polyphenols in the form of derivatives (such as glycosides) with those in the form of aglycones. The second part of the paper discusses in detail the mechanisms (pathways) and the role of bacterial biotransformation of the most important groups of polyphenols, including the production of bioactive metabolites with a significant impact on the human organism (both positive and negative).