Molecular Mechanism Underlying the Regulatory Effect of Vine Tea on Metabolic Syndrome by Targeting Redox Balance and Gut Microbiota

Ethanol extract of propolis relieves exercise-induced fatigue via modulating the metabolites and gut microbiota in mice

Background

Propolis, a natural mixture rich in bioactive compounds, has shown the potential to relieve exercise-induced fatigue. However, the underlying mechanism remains unclear. This study aimed to explore the anti-fatigue effects of ethanol extract of propolis (EEP) and its potential mechanisms.

Methods

Male C57BL/6 mice aged 6-8 weeks were subjected to swim training with or without EEP supplementation (400 mg/kg.bw) for 3 weeks, followed by a exhaustive swimming test to simulate exercise-induced fatigue. The exhaustion time and fatigue-related biochemical indices were measured to assess the anti-fatigue effects. The anti-fatigue mechanism of EEP was further investigated using untargeted serum metabolomics and 16S rRNA gene sequencing of the gut microbiota.

Results

The results showed that supplementation with EEP significantly increased the exhaustive swimming time of the mice by 27.64%, with no significant effects on body weight, food intake, or viscera and muscle index among the 3 groups. Biochemical analysis indicated that EEP effectively alleviated fatigue-related biochemical indices caused by excessive exercise, including liver glycogen (LG), muscle glycogen (MG), blood lactate (BLA), blood urea nitrogen (BUN), lactate dehydrogenase (LDH), interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor-alpha (TNF-α), superoxide dismutase (SOD), total antioxidant capacity (T-AOC), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA). Serum metabolomics analysis revealed that EEP reversed the levels of 6 key metabolites (Gamma-Aminobutyric acid, pipecolic acid, L-isoleucine, sucrose, succinic acid, and L-carnitine), which are involved in 7 metabolic pathways related to energy metabolism, amino acid metabolism, and carbohydrate metabolism. 16S rRNA sequencing analysis of the cecal contents showed that EEP altered the composition and structure of the gut microbiota, increasing the abundance of butyrate-producing bacteria and reducing the abundance of harmful bacteria. Correlation analysis revealed that specific bacterial genera were closely related to certain differential metabolites and biochemical indices.

Conclusion

Our study showed that EEP significantly increased exercise endurance in mice and exerted anti-fatigue effects by modulating key metabolites and the gut microbiota.

Dihydromyricetin Alleviated Acetaminophen-Induced Acute Kidney Injury via Nrf2-Dependent Anti-Oxidative and Anti-Inflammatory Effects

Acute kidney injury (AKI) is a common side effect of acetaminophen (APAP) overdose. Dihydromyricetin (DHM) is the most abundant flavonoid in rattan tea, which has a wide range of pharmacological effects. In the current study, APAP-induced AKI models were established both in vivo and in vitro. The results showed that DHM pretreatment remarkably alleviated APAP-induced AKI by promoting antioxidant capacity through the nuclear factor erythroid-related factor 2 (Nrf2) signaling pathway in vivo. In addition, DHM reduced ROS production and mitochondrial dysfunction, thereby alleviating APAP-induced cytotoxicity in HK-2 cells. The way in which DHM improved the antioxidant capacity of HK-2 cells was through promoting the activation of the Nrf2-mediated pathway and inhibiting the expression levels of inflammation-related proteins. Furthermore, Nrf2 siRNA partially canceled out the protective effect of DHM against the cytotoxicity caused by APAP in HK-2 cells. Altogether, the protective effect of DHM on APAP-induced nephrotoxicity was related to Nrf2-dependent antioxidant and anti-inflammatory effects.

Molecular Mechanism of Vine Tea Dihydromyricetin Extract on Alleviating Glucolipid Metabolism Disorder in db/db Mice: Based on Liver RNA-Seq and TLR4/MyD88/NF-κB Pathway

The primary active compound in vine tea is dihydromyricetin (DMY), which has a longstanding history as a dietary supplement and traditional ethnic medicine. However, the precise molecular mechanism by which vine tea dihydromyricetin extract (VDMY) regulates glucolipid metabolic disorder remains unclear. In this study, we first assessed the effect of VDMY on various physiological parameters in db/db mice, followed by RNA sequencing (RNA-seq) to identify key signaling pathways affected by VDMY in liver tissues. We also examined the impact of VDMY on the liver's TLR4/MyD88/NF-κB and FOXO1 pathways using Western blotting. Our results showed that VDMY significantly reduced fasting blood glucose (FBG), total cholesterol (TC), triglycerides (TGs), and low-density lipoprotein cholesterol (LDL-C), while increasing high-density lipoprotein cholesterol (HDL-C) levels. Additionally, VDMY enhanced the liver's antioxidant capacity by upregulating superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH), while lowering malondialdehyde (MDA), alanine aminotransferase (ALT), and aspartate aminotransferase (AST), thus alleviating liver damage. RNA-seq analysis further revealed that VDMY influenced multiple biological processes, including transcription, glycolysis, gluconeogenesis, and redox reactions, suggesting that its effects may be mediated through the TLR4/MyD88/NF-κB and FOXO1 pathways. Additionally, Western blot analysis revealed that VDMY effectively downregulated the expressions of TLR4, MyD88, NF-κB, and FOXO1 proteins in the liver of db/db mice, indicating that VDMY could target these pathways to intervene glucolipid metabolism dysfunction.

Supplementation of Ampelopsis grossedentata extract contributes to the improvement of intestinal health in swine

Introduction

Ampelopsis grossedentata (vine tea), a high polyphenol content antioxidant plant resource, is renowned for its medicinal benefits. This study aimed to investigate the effects of Ampelopsis grossedentata extract (AGE) on anti-inflammatory and antioxidant ability, enhancement of intestinal immunity, improvement of intestinal structure, and regulation of gut microbiota in swine.

Methods

A total of 135 weaned piglets were randomly divided into three groups: a control group, a low-dose group, and a high-dose group. Pigs were weighed and blood was collected on days 36, 85, and 154. The feed intake was recorded daily to calculate growth performance parameters. On day 154, five to six pigs in each group were randomly selected and euthanized to obtain a small intestine to investigate the effects of AGE on anti-inflammatory and antioxidant abilities and gut microbiota.

Results

The results showed that 500 mg/kg AGE increased the expression of anti-inflammatory and immune cytokines (IL-10, IgG, and IgA) (p < 0.05, p < 0.01) and decreased the expression of proinflammatory cytokines (IL-1β) (p < 0.05) in serum. Additionally, 500 mg/kg AGE enhanced the antioxidant capacity by increasing the GSH-Px, CAT, and SOD (p < 0.05, p < 0.01).

Discussion

A total of 500 mg/kg AGE significantly increased the abundance of gut microbiota, enhanced the gut barrier, and modulated gut immunity. During the piglet phase, 500 mg/kg AGE increased the relative abundance of Prevotella (p < 0.05). During the growing-finishing phase, 500 mg/kg AGE increased the relative abundance of unclassified_f__Lachnospiraceae and Bacteroides (p < 0.05, p < 0.01). Overall, we recommended 500 mg/kg AGE as a routine addition dose for swine to improve porcine growth performance and intestinal health.

Therapeutic potential of dietary nutrients and medicinal foods against metabolic disorders: Targeting Akkermansia muciniphila

As one of the most attractive next‐generation probiotics, mucin‐degrading Akkermansia muciniphila has emerged as an essential and integral factor in maintaining human health and affecting pathological outcomes. Its abundance is inversely associated with various metabolic diseases (e.g., obesity and type 2 diabetes), cardiovascular diseases, and intestinal inflammation. Supplementing A. muciniphila to restore the gut microbiota ecosystem is a promising approach for treating metabolic disorders. However, the direct utilization of this probiotic is limited by technological and regulatory hurdles, such as the in vitro bulk culture of A. muciniphila and the need for expensive animal‐derived materials. Therefore, enrichment of A. muciniphila using nutraceutical supplements is a feasible strategy. Dietary supplements, especially medicinal herbs, offer a vast and valuable resource as potential prebiotics for promoting the growth of A. muciniphila in the gut, ensuring reliable safety and efficacy. In this study, we first systemically reviewed the dietary substances and medicinal foods known to promote A. muciniphila from over 100 literature sources, aiming to establish a candidate basis for future exploration of prebiotics targeting A. muciniphila. Furthermore, we summarized and discussed the major regulatory factors and mechanisms responsible for the beneficial effect of A. muciniphila on metabolic disorders, hoping to open up exciting directions for in‐depth research on the pharmacological mechanism of A. muciniphila and pave the way for its clinical therapeutics.

The Molecular Mechanism Underlying the Therapeutic Effect of Dihydromyricetin on Type 2 Diabetes Mellitus Based on Network Pharmacology, Molecular Docking, and Transcriptomics

Type 2 diabetes mellitus (T2DM) is a chronic and complex disease, and traditional drugs have many side effects. The active compound dihydromyricetin (DHM), derived from natural plants, has been shown in our previous study to possess the potential for reducing blood glucose levels; however, its precise molecular mechanism remains unclear. In the present study, network pharmacology and transcriptomics were performed to screen the molecular targets and signaling pathways of DHM disturbed associated with T2DM, and the results were partially verified by molecular docking, RT-PCR, and Western blotting at in vivo levels. Firstly, the effect of DHM on blood glucose, lipid profile, and liver oxidative stress in db/db mice was explored and the results showed that DHM could reduce blood glucose and improve oxidative stress in the liver. Secondly, GO analysis based on network pharmacology and transcriptomics results showed that DHM mainly played a significant role in anti-inflammatory, antioxidant, and fatty acid metabolism in biological processes, on lipoprotein and respiratory chain on cell components, and on redox-related enzyme activity, iron ion binding, and glutathione transferase on molecular functional processes. KEGG system analysis results showed that the PI3K-Akt signaling pathway, IL17 signaling pathway, HIF signaling pathway, MAPK signaling pathway, AGE-RAGE signaling pathway in diabetic complications, and TNF signaling pathway were typical signaling pathways disturbed by DHM in T2DM. Thirdly, molecular docking results showed that VEGFA, SRC, HIF1A, ESR1, KDR, MMP9, PPARG, and MAPK14 are key target genes, five genes of which were verified by RT-PCR in a dose-dependent manner. Finally, Western blotting results revealed that DHM effectively upregulated the expression of AKT protein and downregulated the expression of MEK protein in the liver of db/db mice. Therefore, our study found that DHM played a therapeutic effect partially by activation of the PI3K/AKT/MAPK signaling pathway. This study establishes the foundation for DHM as a novel therapeutic agent for T2DM. Additionally, it presents a fresh approach to utilizing natural plant extracts for chemoprevention and treatment of T2DM.

The Interaction between Oxidative Stress Biomarkers and Gut Microbiota in the Antioxidant Effects of Extracts from Sonchus brachyotus DC. in Oxazolone-Induced Intestinal Oxidative Stress in Adult Zebrafish

Oxidative stress is a phenomenon caused by an imbalance between the production and accumulation of reactive oxygen species in cells and tissues that eventually leads to the production of various diseases. Here, we investigated the antioxidant effects of the extract from Sonchus brachyotus DC. (SBE) based on the 0.2% oxazolone-induced intestinal oxidative stress model of zebrafish. Compared to the model group, the treatment group alleviated oxazolone-induced intestinal tissue damage and reduced the contents of malondialdehyde, reactive oxygen species, IL-1β, and TNF-α and then increased the contents of superoxide dismutase, glutathione peroxidase, and IL-10. The 16s rDNA gene sequencing findings demonstrated that SBE could increase the relative abundance of Fusobacteriota, Actinobacteriota, and Firmicutes and decrease the relative abundance of Proteobacteria. Based on the correlation analysis between the oxidative stress biomarkers and intestinal flora, we found that the trends of oxidative stress biomarkers were significantly correlated with intestinal microorganisms, especially at the genus level. The correlations of MDA, IL-1β, and TNF-α were significantly negative with Shewanella, while SOD, GSH-Px, and IL-10 were significantly positive with Cetobacterium, Gemmobacter, and Flavobacterium. Consequently, we concluded that the antioxidant effect of SBE was realized through the interaction between oxidative stress biomarkers and gut microbiota.