Regulating the Imbalance of Gut Microbiota by Smilax china L. Polyphenols to Alleviate Dextran Sulfate Sodium-induced Inflammatory Bowel Diseases

Gut Microbiota and Tryptophan Metabolism in Pathogenesis of Ischemic Stroke: A Potential Role for Food Homologous Plants

SCOPE

The intestinal flora is involved in the maintenance of human health and the development of diseases, and is closely related to the brain. As an essential amino acid, tryptophan (TRP) participates in a variety of physiological functions in the body and affects the growth and health of the human body. TRP catabolites produced by the gut microbiota are important signaling molecules for microbial communities and host-microbe interactions, and play an important role in maintaining health and disease pathogenesis.

METHODS AND RESULTS

The review first demonstrates the evidence of TRP metabolism in stroke and the relationship between gut microbiota and TRP metabolism. Furthermore, the review reveals that food homologous plants (FHP) bioactive compounds have been shown to regulate various metabolic pathways of the gut microbiota, including the biosynthesis of valine, leucine, isoleucine, and vitamin B6 metabolism. The most notable metabolic alteration is in TRP metabolism.

CONCLUSION

The interaction between gut microbiota and TRP metabolism offers a plausible explanation for the notable bioactivities of FHP in the treatment of ischemic stroke (IS). This review enhances the comprehension of the underlying mechanisms associated with the bioactivity of FHP on IS.

Natural Products on Inflammatory Bowel Disease: Role of Gut Microbes

Inflammatory bowel disease (IBD) refers to long-term medical conditions that involve inflammation of the digestive tract, and the global incidence and prevalence of IBD are on the rise. Gut microbes play an important role in maintaining the intestinal health of the host, and the occurrence, development, and therapeutic effects of IBD are closely related to the structural and functional changes of gut microbes. Published studies have shown that the natural products from traditional Chinese medicine have direct or indirect regulatory impacts on the composition and metabolism of the gut microbes. In this review, we summarize the research progress of several groups of natural products, i.e., flavonoids, alkaloids, saponins, polysaccharides, polyphenols, and terpenoids, for the therapeutic activities in relieving IBD symptoms. The role of gut microbes and their intestinal metabolites in managing the IBD is presented, with focusing on the mechanism of action of those natural products. Traditional Chinese medicine alleviated IBD symptoms by regulating gut microbes, providing important theoretical and practical basis for the treatment of variable inflammatory intestinal diseases.

Research progress of treating hyperuricemia in rats and mice with traditional Chinese medicine

Hyperuricemia (HUA) is a common chronic metabolic disease caused by abnormal purine metabolism and uric acid excretion. Despite extensive research on HUA, no clear treatment has been found so far. Improving purine metabolism and promoting uric acid excretion is crucial for the effective treatment of HUA. In recent years, traditional Chinese medicine and traditional Chinese medicine prescriptions have shown good effects in treating HUA. This article summarizes the latest progress in treating HUA in rats and mice using traditional Chinese medicine and prescriptions, elaborates on the pathogenesis of HUA, explores the application of commonly used traditional Chinese medicine treatment methods and prescriptions, and discusses the previous pharmacological mechanisms. In general, our research indicates that traditional Chinese medicine can effectively relieve the symptoms related to elevated uric acid levels in HUA rats and mice. However, further exploration and research are needed to verify its efficacy, safety, and feasibility.

Smilax China L. polysaccharide prevents HFD induced-NAFLD by regulating hepatic fat metabolism and gut microbiota

BACKGROUND

The increasing incidence of nonalcoholic fatty liver disease (NAFLD) has urged the development of new therapeutics. NAFLD is intimately linked to gut microbiota due to the hepatic portal system, and utilizing natural polysaccharides as prebiotics has become a prospective strategy for preventing NAFLD. Smilax china L. polysaccharide (SCP) possesses excellent hepatoprotective and anti-inflammatory activity. However, its protective effects on NAFLD remains unclear.

PURPOSE

The goal of this study was to explore the protective effects of SCP on high-fat diet (HFD)-induced NAFLD mice by regulating hepatic fat metabolism and gut microbiota.

METHODS

Extraction and isolation from Smilax china L. rhizome to obtain SCP. C57BL/6 J mice were distributed to six groups: Control (normal chow diet), HFD-fed mice were assigned to HFD, simvastatin (SVT), and low-, medium-, high-doses of SCP for 12 weeks. The body, liver, and different adipose tissues weights were detected, and lipids in serum and liver were assessed. RT-PCR and Western blot were used to detect the hepatic fat metabolism-related genes and proteins. Gut microbiota of cecum contents was profiled through 16S rRNA gene sequencing.

RESULTS

SCP effectively reversed HFD-induced increase weights of body, liver, and different adipose tissues. Lipid levels of serum and liver were also significantly reduced after SCP intervention. According to the results of RT-PCR and western blot analysis, SCP treatment up-regulated the genes and proteins related to lipolysis were up-regulated, while lipogenesis-related genes and proteins were down-regulated. Furthermore, the HFD-induced dysbiosis of intestinal microbiota was similarly repaired by SCP intervention, including enriching beneficial bacteria and depleting harmful bacteria.

CONCLUSION

SCP could effectively prevent HFD-induced NAFLD, might be considered as a prebiotic agent due to its excellent effects on altering hepatic fat metabolism and maintaining gut microbiota homeostasis.

The antagonism mechanism of astilbin against cadmium-induced injury in chicken lungs via Treg/Th1 balance signaling pathway

The purpose of this study was to investigate the effect of Treg/Th1 imbalance in cadmium-induced lung injury and the potential protective effect of astilbin against cadmium-induced lung injury in chicken. Cadmium exposure significantly decreased T-AOC and GSH-Px levels and SOD activity in the chicken lung tissues. In contrast, it significantly increased the MDA and NO levels. These results indicate that cadmium triggers oxidative stress in lungs. Histopathological analysis revealed that cadmium exposure further induced infiltration of lymphocytes in the chicken lungs, indicating that cadmium causes pulmonary damage. Further analysis revealed that cadmium decreased the expression of IL-4 and IL-10 but increased those of IL-17, Foxp3, TNF-α, and TGF-β, indicating that the exposure of cadmium induced the imbalance of Treg/Th1. Moreover, cadmium adversely affected chicken lung function by activating the NF-kB pathway and inducing expression of genes downstream to these pathways (COX-2, iNOS), associated with inflammatory injury in the lung tissue. Astilbin reduced cadmium-induced oxidative stress and inflammation in the lungs by increasing antioxidant enzyme activities and restoring Treg/Th1 balance. In conclusion, our results suggest that astilbin treatment alleviated the effects of cadmium-mediated lung injury in chickens by restoring the Treg/Th1 balance.

Diet-derived circulating antioxidants and risk of inflammatory bowel disease: a Mendelian randomization study and meta-analysis

Background

Previous studies have shown conflicting results regarding the impact of circulating antioxidants on the risk of inflammatory bowel disease (IBD). In this study, our intent was to investigate the causal relationship between circulating antioxidants and IBD using Mendelian randomization (MR).

Methods

Instrumental variables for absolute circulating antioxidants (ascorbate, retinol, lycopene, and β-carotene) and circulating antioxidant metabolites (α-tocopherol, γ-tocopherol, ascorbate, and retinol) were screened from published studies. We obtained outcome data from two genome-wide association study (GWAS) databases, including the international inflammatory bowel disease genetics consortium (IIBDGC, 14,927 controls and 5,956 cases for Crohn's disease (CD), 20,464 controls and 6,968 cases for ulcerative colitis (UC), and 21,770 controls and 12,882 cases for IBD) and the FinnGen study (375,445 controls and 1,665 cases for CD, 371,530 controls and 5,034 cases for UC, and 369,652 controls and 7,625 cases for IBD). MR analysis was performed in each of the two databases and those results were pooled using meta-analysis to assess the overall effect of exposure on each phenotype. In order to confirm the strength of the findings, we additionally conducted a replication analysis using the UK Biobank.

Results

In the meta-analysis of the IIBDGC and FinnGen, we found that each unit increase in absolute circulating level of retinol was associated with a 72% reduction in the risk of UC (OR: 0.28, 95% CI: 0.10 to 0.78, P=0.015). The UC GWAS data from the UK Biobank also confirmed this causal relationship (OR: 0.99, 95% CI: 0.97 to 1.00, P=0.016). In addition, there was suggestive evidence that absolute retinol level was negatively associated with IBD (OR: 0.41, 95% CI: 0.18 to 0.92, P=0.031). No other causal relationship was found.

Conclusion

Our results provide strong evidence that the absolute circulating level of retinol is associated with a reduction in the risk of UC. Further MR studies with more instrumental variables on circulating antioxidants, especially absolute circulating antioxidants, are needed to confirm our results.

Smilax china Polyphenols Stimulate Browning via [Formula: see text]3-Adrenergic Receptor/AMP-Activated Protein Kinase [Formula: see text] Signaling Pathway in 3T3-L1 Adipocytes

The aim of this study is to investigate the molecular mechanism of Smilax china L. polyphenols (SCLPs) in enhancing lipid metabolism and stimulating browning to reduce lipid accumulation in 3T3-L1 adipocytes. SCLP treatment obviously decreased lipid content in a dose-dependent manner (10-40 μg/mL) in adipocytes. SCLP treatment cooperated with noradrenalin to increase lipolysis. SCLPs reduced the gene expressions of C/EBP[Formula: see text] and Ap2 and enhanced the expressions of ACO, CPT, pHSL/HSL, ATGL, and PKA in adipocytes. Furthermore, SCLPs increased mRNA and protein expressions of brown adipocyte-specific factors (UCP-1, PRDM16, PGC-1α, and PPARγ) and mRNA expressions of beige adipocyte-specific markers (CD137, Tbx1, and Tmem26) in 3T3-L1 adipocytes, as well as mitochondrial biogenesis genes (Nrf1 and Tfam). In addition, according to the immunofluorescence staining, the mitochondria number was increased by SCLP. Moreover, β3-AR or AMPK agonist synergistic SCLPs enhanced the expressions of UCP-1, PRDM16, and PGC-1α. While β3-AR or AMPK antagonist significantly decreased the expressions of these brown adipocyte-specific factors, SCLP treatment inhibited the effect of antagonist to improve the expression of UCP-1, PRDM16, and PGC-1α. These results indicated that SCLPs may regulate lipid metabolism and stimulate browning via the β3-AR/AMPKα signaling pathway. Thus, SCLPs likely have potential therapeutic effects on obesity.