Flavonoids with antibacterial and antioxidant potentials from the stem bark of Uapaca heudelotti

Unveiling the Potential of Protein-Based Sustainable Antibacterial Materials

The surge in bacterial growth and the escalating resistance against a multitude of antibiotic drugs have burgeoned into an alarming global threat, necessitating urgent and innovative interventions. In response to this peril, scientists have embarked on the development of advanced biocompatible antibacterial materials, aiming to counteract not only bacterial infections but also the pervasive issue of food spoilage resulting from microbial proliferation. Protein-based biopolymers and their meticulously engineered composites are at the forefront of this endeavor. Their potential in combating this severe global concern presents an approach that intersects the domains of biomedicine and environmental science. The present review article delves into the intricate extraction processes employed to derive various proteins from their natural sources, unraveling the complex biochemical pathways that underpin their antibacterial properties. Expanding on the foundational knowledge, the review also provides a comprehensive synthesis of functionalized proteins modified to enhance their antibacterial efficacy, unveiling a realm of possibilities for tailoring solutions to specific biomedical and environmental applications. The present review navigates through their antibacterial applications; from wound dressings to packaging materials with inherent antibacterial properties, the potential applications underscore the versatility and adaptability of these materials. Moreover, this comprehensive review serves as a valuable roadmap, guiding future research endeavors in reshaping the landscape of natural antibacterial materials on a global scale.

Dietary flavonoids-microbiota crosstalk in intestinal inflammation and carcinogenesis

Colorectal cancer (CRC) is currently the third leading cancer and commonly develops from chronic intestinal inflammation. A strong association was found between gut microbiota and intestinal inflammation and carcinogenic risk. Flavonoids, which are abundant in vegetables and fruits, can inhibit inflammation, regulate gut microbiota, protect gut barrier integrity, and modulate immune cell function, thereby attenuating colitis and preventing carcinogenesis. Upon digestion, about 90% of flavonoids are transported to the colon without being absorbed in the small intestine. This phenomenon increases the abundance of beneficial bacteria and enhances the production of short-chain fatty acids. The gut microbe further metabolizes these flavonoids. Interestingly, some metabolites of flavonoids play crucial roles in anti-inflammation and anti-tumor effects. This review summarizes the modulatory effect of flavonoids on gut microbiota and their metabolism by intestinal microbe under disease conditions, including inflammatory bowel disease, colitis-associated cancer (CAC), and CRC. We focus on dietary flavonoids and microbial interactions in intestinal mucosal barriers as well as intestinal immune cells. Results provide novel insights to better understand the crosstalk between dietary flavonoids and gut microbiota and support the standpoint that dietary flavonoids prevent intestinal inflammation and carcinogenesis.

Kaempferol: Antimicrobial Properties, Sources, Clinical, and Traditional Applications

Flavonoids are a category of plant-derived compounds which exhibit a large number of health-related effects. One of the most well-known and studied flavonoids is kaempferol, which can be found in a wide variety of herbs and plant families. Apart from their anticarcinogenic and anti-inflammatory effects, kaempferol and its associated compounds also exhibit antibacterial, antifungal, and antiprotozoal activities. The development of drugs and treatment schemes based on these compounds is becoming increasingly important in the face of emerging resistance of numerous pathogens as well as complex molecular interactions between various drug therapies. In addition, many of the kaempferol-containing plants are used in traditional systems all over the world for centuries to treat numerous conditions. Due to its variety of sources and associated compounds, some molecular mechanisms of kaempferol antimicrobial activity are well known while others are still under analysis. This paper thoroughly documents the vegetal and food sources of kaempferol as well as the most recent and significant studies regarding its antimicrobial applications.

Chemical Constituents from Uapaca guineensis (Phyllanthaceae), and the Computational Validation of Their Antileishmanial and Anti-inflammatory Potencies

From the chemical investigations of the root bark of Uapaca guineensis, nine distinct compounds (1–9) have been isolated and characterized as lupeol, betulin, betulinic acid, β-amyryl acetate, physcion, quercetin, rutin, β-sitosterol, and β-sitosterol-3-O-β-D-glucopyranoside, respectively. The structures of all the isolated compounds have been established using their NMR data as well as the comparison of those data with the ones reported in the literature. Interestingly, to the best of our knowledge, except for the lupane-type triterpenoids (1–3) and compounds 4 and 9, all the other compounds are reported for the first time from this genus. Since the plant is widely used for the treatment of skin diseases, leishmaniasis and inflammatory diseases, the antileishmanial and anti-inflammatory potencies of all the isolated compounds have been computationally validated through their ability to inhibit the receptors 1QCC and 2XOX (for the antileishmanial studies) and 6Y3C and 1CX2 (for the anti-inflammatory studies). Furthermore, the ADMET studies of compounds have been done to evaluate their drug-likeness. Results demonstrate that all the isolated compounds showed a better affinity for both receptors’ binding sites than the standard drugs miltefosine and aspirin. Moreover, the compounds would not cause addiction when used as lead molecules whereas, aspirin is predicted to violate the BBB over a long term of usage as a drug. This study gives additional information on the chemistry of U. guineensis and its classification as a potential source of good leads for the development of potent antileishmanial and anti-inflammatory drugs.

Gb_ANR-47 Enhances the Resistance of Gossypium barbadense to Fusarium oxysporum f. sp. vasinfectum (FOV) by Regulating the Content of Proanthocyanidins

Anthocyanidin reductase (ANR) is an important regulator of flavonoid metabolism, and proanthocyanidins, the secondary metabolites of flavonoids, play an important role in the response of plants to pathogenic stress. Therefore, in this study, the expression analysis of the ANR gene family of Gossypium barbadense after inoculation with Fusarium oxysporum f. sp. vasinfectum (FOV) was performed at different time points. It was found that Gb_ANR-47 showed significant differences in the disease-resistant cultivar 06-146 and the susceptible cultivar Xinhai 14, as well as in the highest root expression. It was found that the expression of Gb_ANR-47 in the resistant cultivar was significantly higher than that in the susceptible cultivar by MeJA and SA, and different amounts of methyl jasmonate (MeJA) and salicylic acid (SA) response elements were found in the promoter region of Gb_ANR-47. After silencing GbANR-47 in 06-146 material by VIGS technology, its resistance to FOV decreased significantly. The disease severity index (DSI) was significantly increased, and the anthocyanin content was significantly decreased in silenced plants, compared to controls. Our findings suggest that GbANR-47 is a positive regulator of FOV resistance in Gossypium barbadense. The research results provide an important theoretical basis for in-depth analysis of the molecular mechanism of GbANR-47 and improving the anti-FOV of Gossypium barbadense.

Chemical aspects of polyphenol-protein interactions and their antibacterial activity

The hunt for novel antibiotics has become a global public health imperative due to the rise in multidrug-resistant microorganisms, untreatable infection cases, overuse, and inefficacy of modern antibiotics. Polyphenols are getting much attention in research due to their multiple biological effects; their use as antimicrobial agents is attributed to their activity and that microbes have a hard time developing resistance to these natural compounds. Polyphenols are secondary metabolites produced in higher plants. They are known to possess various functional properties in the human body. Polyphenols also exhibit antibacterial activities against foodborne pathogens. Their antibacterial mechanism is based on inhibiting bacterial biofilm formation or inactivating enzymes. This review focused on polyphenol-protein interactions and the creation of this complex as a possible antibacterial agent. Also, different phenolic interactions on bacterial proteins, efflux pump, cell membrane, bacterial adhesion, toxins, and other bacterial proteins will be explored; these interactions can work in a synergic combination with antibiotics or act alone to assure bacterial inhibition. Additionally, our review will focus on polyphenol-protein interaction as a possible strategy to eradicate bacteria because polyphenols have shown a robust enzyme-inhibitory characteristic and a high tendency to complex with proteins, a response that neutralizes any bactericidal potential.

The antibacterial activity of natural-derived flavonoids

Flavonoids, a wide variety of phenolic secondary metabolites, are found in almost all plant families in the leaves, stems, roots, flowers, and seeds. Flavonoids could exert antibacterial activity via damaging the cytoplasmic membrane, inhibiting energy metabolism, and inhibiting the synthesis of nucleic acids, so flavonoids are considered constitutive antibacterial substances. This review aims to outline the recent advances of natural-derived flavonoids, including flavonoid glycosides with antibacterial potential to provide novel antibacterial lead hits/candidates, covering articles published between January 2016 and July 2021.

Flavonoids from Marine-Derived Actinobacteria as Anticancer Drugs

Flavonoids represent a large diverse group of natural products that are used as a traditional medicine against various infectious diseases. They possess many biological activities including antimicrobial, antioxidant, anti-inflammatory, anti-cancer and anti-diabetic activities. Commercially, flavonoids are mainly obtained from plants, however, several challenges are faced during their extraction. Microorganisms have been known as natural sources of a wide range of bioactive compounds including flavonoids. Actinobacteria are the most prolific group of microorganisms for the production of bioactive secondary metabolites, thus facilitating the production of flavonoids. The screening programs for bioactive compounds revealed the potential application of actinobacteria to produce flavonoids with interesting biological activities, especially anticancer activities. Since marine actinobacteria are recognized as a potential source of novel anticancer agents, they are highly expected to be potential producers of anticancer flavonoids with unusual structures and properties. In this review, we highlight the production of flavonoids by actinobacteria through classical fermentation, engineering of plant biosynthetic genes in a recombinant actinobacterium and the de novo biosynthesis approach. Through these approaches, we can control and improve the production of interesting flavonoids or their derivatives for the treatment of cancer.

Evaluation of Essential Oils and Extracts of Rose Geranium and Rose Petals as Natural Preservatives in Terms of Toxicity, Antimicrobial, and Antiviral Activity

Essential oils (EOs) and extracts of rose geranium (Pelargonium graveolens) and petals of rose (Rosa damascena) have been fully characterized in terms of composition, safety, antimicrobial, and antiviral properties. They were analyzed against Escherichia coli, Salmonella enterica serovar Typhimurium, Staphylococcus aureus, Aspergillus niger, and Adenovirus 35. Their toxicity and life span were also determined. EO of P. graveolens (5%) did not retain any antibacterial activity (whereas at 100% it was greatly effective against E. coli), had antifungal activity against A. niger, and significant antiviral activity. Rose geranium extract (dilutions 25−90%) (v/v) had antifungal and antibacterial activity, especially against E. coli, and dose-dependent antiviral activity. Rose petals EO (5%) retains low inhibitory activity against S. aureus and S. Typhimurium growth (about 20−30%), antifungal activity, and antiviral activity for medium to low virus concentrations. Rose petals extract had significant antibacterial activity at dilutions of 25−90%, especially against E. coli and S. Typhimurium, antifungal, and the most potent antiviral activity. None of the EOs and extracts were toxic in dilutions of up to 5% and 90%, respectively. Finally, all materials had a life span of more than eight weeks. These results support the aspect that rose petals and rose geranium EOs, and extracts, have beneficial antimicrobial and antiviral properties and they can be used as natural preservatives.