Antimicrobial activity of flavonoids from Sedum aizoon L. against Aeromonas in culture medium and in frozen pork

The effects of Quercetin on wound healing in the human umbilical vein endothelial cells

An injury that affects the integrity of the skin, either inside or externally, is called a wound. Damaged tissue is repaired by a set of cellular and molecular mechanisms known as wound healing. Quercetin, a naturally occurring flavonoid, may hasten the healing of wounds. The study's objective was to investigate any potential impacts of quercetin on the wound-healing process. Human umbilical vein endothelial cells (HUVECs) were treated to varying dose ranges of quercetin (5-320 nM) for 24 and 48 h. Cultured cells were evaluated by using the MTT analysis, wound scratch assay and vascular tube formation. Furthermore the gene expression of VEGF and FGF were evaluated by qRT-PCR to determine the effects of quercetin on angiogenezis and wound repair. Positive effects of quercetin on cellular viability were demonstrated by the MTT experiment. In HUVECs quercetin promoted tube formation, migration, and proliferation while also averting wound breakage. Moreover, quercetin increased the expression of the FGF and VEGF genes, which aid in the healing of wounds in HUVECs. Quercetin may be bioactive molecule that successfully speeds up wound healing by regulating the vasculogenezis and healing cells.

Phytochemical Characterization and Bioactivity Evaluation of Extracts Obtained via Ultrasound-Assisted Extraction of Medicinal Plant Phedimus aizoon

Phedimus aizoon has been utilized as a medicinal plant in Asia. However, the production of phytochemical-rich extracts from P. aizoon and the evaluation of their bioactivity are limited. Herein, phytochemical-rich extracts were prepared by ultrasound-assisted extraction of P. aizoon, with a high extraction yield of 16.56%. The extracts contained about 126 mg of phenolics and 31 mg of flavonoids per g of the extracts. The chromatographic analysis (GC-MS and HPLC analyses) identified 19 notable phytochemicals of the extracts from P. aizoon, including pentacosane, hexadecanoic acid, gallic acid, vanillic acid, and quercetin. The gallic acid content of the extracts was relatively high at 2.75 mg/g. The identified compounds are known to have various bioactivities, such as antioxidant, antibacterial, and antifungal activities. In fact, the prepared extracts exhibited antioxidant activity at 24-28% of that of ascorbic acid. In addition, it showed antibacterial activity against both Escherichia coli (Gram-negative bacteria) and Staphylococcus aureus (Gram-positive bacteria). This study highlights that P. aizoon deserves attention as a natural bioactive substance and emphasizes the need for applications of the extracts from P. aizoon.

Influence of flavonoids from Sedum aizoon L. on mitochondrial function of Rhizopus nigricans in strawberry

Rhizopus nigricans (R. nigricans), one of the fungi that grows the fastest, is frequently discovered in postharvest fruits, it's the main pathogen of strawberry root rot. Flavonoids in Sedum aizoon L. (FSAL) is a kind of green and safe natural substance extracted from Sedum aizoon L. which has antifungal activity. In this study, the minimum inhibitory concentration (MIC) of FSAL on R. nigricans and cell apoptosis tests were studied to explore the inhibitory effect of FSAL on R. nigricans. The effects of FSAL on mitochondria of R. nigricans were investigated through the changes of mitochondrial permeability transition pore(mPTP), mitochondrial membrane potential(MMP), Ca2+ content, H2O2 content, cytochrome c (Cyt c) content, the related enzyme activity and related genes of mitochondria. The results showed that the MIC of FSAL on R. nigricans was 1.800 mg/mL, with the addition of FSAL (1.800 mg/mL), the mPTP openness of R. nigricans increased and the MMP reduced. Resulting in an increase in Ca2+ content, accumulation of H2O2 content and decrease of Cyt c content, the activity of related enzymes was inhibited and related genes were up-regulated (VDAC1, ANT) or down-regulated (SDHA, NOX2). This suggests that FSAL may achieve the inhibitory effect of fungi by damaging mitochondria, thereby realizing the postharvest freshness preservation of strawberries. This lays the foundation for the development of a new plant-derived antimicrobial agent.

Quercetin ameliorates advanced glycation end product-induced wound healing impairment and inflammaging in human gingival fibroblasts

Background/purpose

Diabetes mellitus (DM) and periodontal disease are both prevalent and chronic inflammatory disorders that have significant health impact. Many studies have pointed out that advanced glycation end-products (AGEs) in DM induces inflammaging, which is a pre-aging and hyperinflammatory condition, and it has been linked to a greater likelihood in developing periodontitis. Inflammaging in DM has been shown to be driven by AGEs-induced cell senescence, inflammatory cytokines, and oxidative stress, resulting in the degradation of periodontium. Quercetin has shown abilities to decrease inflammation and oxidative stress in a variety of tissues, however, the effect in diabetic periodontitis remains uncertain. Thus, the aim of this study was to investigate its impacts on inflammaging in diabetic periodontitis.

Materials and methods

We examined cell proliferation in human gingival fibroblasts (HGF), wound healing, IL-6 and IL-8 secretions, cellular senescence expression, and the formation of reactive oxygen species (ROS) in response to AGE stimulation with and without Quercetin intervention. Following that, we looked into NF-κβ activity to see if Quercetin mediate its effects via this pro-inflammatory signaling.

Results

Quercetin at 20 μM and below did not have any impact on HGFs' cell proliferation rate. Quercetin intervention improved the AGEs-impaired wound healing, in addition to the attenuation of AGEs-induced ROS in a dose-dependent pattern. Moreover, Quercetin therapy dose-dependently inhibited AGEs-induced cell senescence activity along with its senescence associated secretion phenotype (SASP) secretions such as IL-6 and IL-8. Western blot analysis indicated that Quercetin was able to reverse the phosphorylation of p65 and Iκβ in AGEs-stimulated HGFs, demonstrating it can modulate NF-κβ pathway.

Conclusion

Accumulation of AGEs can elicit inflammaging in HGFs, as seen by increased pro-inflammatory cytokines, cell senescence expression and oxidative stress. The results proposed that Quercetin is able to ameliorate inflammaging in diabetic periodontitis and improve wound healing via the suppression of NF-κβ pathway and hence, may be a promising approach for treatment of diabetes-associated periodontitis.

Biosurfactant from Pseudomonas fragi enhances the competitive advantage of Pseudomonas but reduces the overall spoilage ability of the microbial community in chilled meat

Biosurfactants from Pseudomonas spp. have been reported to exhibit antibacterial and anti-adhesive properties, but their role during meat spoilage remains unclear. In this study, the biosurfactant was isolated from an isolate of Pseudomonas fragi with strong spoilage potential, and its surface tension and emulsification ability were determined. The chemical and microbial characteristics of the biosurfactant-treated meat samples were periodically analyzed. The results demonstrated that the biosurfactant produced by P. fragi could reduce surface tension and showed good emulsification properties. For the in situ spoilage trials, biosurfactant from P. fragi changed the microbial diversity on meat, helping Pseudomonas establish a dominant position in the population. However, biosurfactant treatment caused chicken meat to exhibit a weaker spoilage state, as indicated by the growth of psychrophilic microorganisms, total volatile basic nitrogen (TVBN) and meat color. These results provide practical information for understanding the role of P. fragi biosurfactant during chilled meat storage.

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.

Variation of Microbial Community and Fermentation Quality in Corn Silage Treated with Lactic Acid Bacteria and Artemisia argyi during Aerobic Exposure

Silage, especially whole crop corn silage (WCCS), is an important part of ruminant diets, with its high moisture content and rich nutrient content, which can easily cause contamination by mold and their toxins, posing a great threat to ruminant production, food safety and human health. The objective of this study was to examine effects of lactic acid bacteria (LAB) Lactiplantibacillus (L.) plantarum subsp. plantarum ZA3 and Artemisia argyi (AA) on the fermentation characteristics, microbial community and mycotoxin of WCCS during 60 days (d) ensiling and subsequent 7 d aerobic exposure. The results showed that WCCS treated with LAB and AA both had lower pH value and ammonia nitrogen (NH₃-N) contents, and higher lactic and acetic acids concentration compared with other groups after 60 d ensiling. In addition, for microbial communities, Acetobacter and Enterobacter were inhibited in all AA group, while higher abundance of Lactobacilli was maintained; besides, Candida, Pichia and Kazachstania abundances were decreased in both 6% and 12% AA groups. The content of five kinds of mycotoxins were all significantly lower after 7 d of aerobic exposure. As for the total flavonoid (TF), which is significantly higher in all AA treated groups, it was positively correlated with Paenibacillus, Weissella and Lactobacilli, and negatively with Acetobacter, Enterobacteria, Kazachstania and Pichia.

Ethnobotany and the Role of Plant Natural Products in Antibiotic Drug Discovery

The crisis of antibiotic resistance necessitates creative and innovative approaches, from chemical identification and analysis to the assessment of bioactivity. Plant natural products (NPs) represent a promising source of antibacterial lead compounds that could help fill the drug discovery pipeline in response to the growing antibiotic resistance crisis. The major strength of plant NPs lies in their rich and unique chemodiversity, their worldwide distribution and ease of access, their various antibacterial modes of action, and the proven clinical effectiveness of plant extracts from which they are isolated. While many studies have tried to summarize NPs with antibacterial activities, a comprehensive review with rigorous selection criteria has never been performed. In this work, the literature from 2012 to 2019 was systematically reviewed to highlight plant-derived compounds with antibacterial activity by focusing on their growth inhibitory activity. A total of 459 compounds are included in this Review, of which 50.8% are phenolic derivatives, 26.6% are terpenoids, 5.7% are alkaloids, and 17% are classified as other metabolites. A selection of 183 compounds is further discussed regarding their antibacterial activity, biosynthesis, structure-activity relationship, mechanism of action, and potential as antibiotics. Emerging trends in the field of antibacterial drug discovery from plants are also discussed. This Review brings to the forefront key findings on the antibacterial potential of plant NPs for consideration in future antibiotic discovery and development efforts.

Drug delivery based pharmacological enhancement and current insights of quercetin with therapeutic potential against oral diseases

The heavy burden of oral diseases such as oral cancers, dental caries, periodontitis, etc. and their consequence on the patient's quality of life demonstrated an urgent demand for developing effective therapeutics. Quercetin as a natural derived flavonoid, could be utilized in the therapeutic formulation of various diseases such as diabetes, breast cancer and asthma, owing to its prominent pharmacological values. In the last decade, the applications of quercetin as a natural compound in oral treatment have attracted increasing interest due to its multifunction including antioxidant, antibacterial, anti-inflammatory and antineoplastic activities. Besides, considering the low bioavailability of quercetin, great efforts have been made in its drug delivery systems to address the problem of limited application. Therefore, this review summarized the cutting-edge researches on versatile effects and enhanced bioavailability of quercetin resulting from innovative drug delivery systems, particularly focused on its potential against oral diseases. The application of quercetin would provide novel and promising therapeutic approach for clinical treatment, promoting the development of global dental public health.