Ameliorative Effect of Chitosan Oligosaccharides on Hepatic Encephalopathy by Reshaping Gut Microbiota and Gut-Liver Axis

In vitro fermentation characteristics of polysaccharide from Scrophularia ningpoensis and its effects on type 2 diabetes mellitus gut microbiota

Background

Increasing evidence has shown a close relation between the pathogenesis of type 2 diabetes mellitus (T2DM), which is a global health problem with multifactorial etiopathogenesis, and gut microbiota.

Methods

During in-vitro fermentation of Scrophularia ningpoensis (known as Xuanshen) polysaccharide (SNP) by T2DM gut microbiota, effects of SNP on the gas content, production of short-chain fatty acids (SCFAs), metabolite profile and microbiota composition were studied.

Results

Analysis of chemical compositions indicates that the total sugar content of SNP was found to be as high as 87.35 ± 0.13% (w/w). SNP treatment significantly improved the gas volume and composition in T2DM fecal matter. Moreover, intestinal flora degraded SNP to produce SCFAs, thus regulating SCFA production and composition. Metabolomic analysis implied that SNP shows potential to regulate the five gut metabolites (L-valine, L-leucine, L-isoleucine, L-alanine, and xylitol) in T2DM fecal matter. Furthermore, dysbiosis of gut microbiota induced by T2DM was reversed by SNP. The evidence includes decreasing Firmicutes/Bacteroidota ratio at phylum level promoting proliferation of the bacterial abundance of Dorea, Parabacteroides, Faecalibacterium, and Lachnospira and decreased bacterial abundance of Escherichia-Shigella. Based on these findings, the action mechanism of SNP against T2DM was clarified by reshaping microbiota and regulating intestinal metabolites, and a novel target was provided for interventions of T2DM.

Low molecular fucoidan alleviated alcohol-induced liver injury in BALB/c mice by regulating the gut microbiota-bile acid-liver axis

Fucoidan has attracted significant attention owing to its remarkable bioactivities, but the effect of molecular weight (Mw) on its activities in the context of alcoholic liver diseases (ALD) is poorly understood. In this study, low Mw fucoidan (OSLF) was prepared, and its protective effect against alcohol-induced liver injury was assessed in a mouse model. OSLF increased weight gain and colon length, improved lipid disorders, and reduced oxidative stress in mice exposed to alcohol, alleviating liver injury. OSLF alleviated inflammation in the liver by inhibiting alcohol-activated NF-κB and MAPK pathways. The underlying mechanism can be attributed to the improvement of alcohol-induced dysbiosis of the gut microbiota, including a decrease in Proteobacteria and Bacteroidetes and an increase in microbiota diversity, as well as the abundances of Parabacteroides, Bacteroides, and Faecalibaculum. Metabolomics results showed that OSLF improved alcohol-induced abnormalities of microbiota metabolites, primarily involving amino acid metabolism and short chain fatty acids production. In addition, OSLF ameliorated bile acid metabolism in the gut and regulated the expression of bile acid-associated genes in the liver, affecting bile acid synthesis, regulation, and transport. It suggested that OSLF had the potential for the management of ALD by regulating the gut microbiota-bile acid-liver axis.

Protective effects of Tinospora cordifolia miers extract against hepatic and neurobehavioral deficits in thioacetamide-induced hepatic encephalopathy in rats via modulating hyperammonemia and glial cell activation

ETHNOPHARMACOLOGICAL RELEVANCE

Tinospora cordifolia (TC) a potential medicinal herb, has been ethnobotanically used as an eco-friendly supplement to manage various diseases, including cerebral fever. Earlier studies have shown that TC exhibits diverse beneficial effects, including hepatoprotective and neuroprotective effects. However, the effects of TC remain unexplored in animal models of encephalopathy including hepatic encephalopathy (HE).

AIM OF THE STUDY

To evaluate the effects of TC stem extract against thioacetamide (TAA)-induced behavioural and molecular alterations in HE rats.

METHODS AND MATERIALS

The extract was preliminarily screened through phytochemical and HR-LC/MS analysis. Animals were pre-treated with TC extract at doses 30 and 100 mg/kg, orally. Following 7 days of TC pre-treatment, HE was induced by administering TAA (300 mg/kg, i. p. thrice). Behavioural assessments were performed after 56 h of TAA first dose. The animals were then sacrificed to assess biochemical parameters in serum, liver and brain. Liver tissue was used for immunoblotting and histological studies to evaluate inflammatory and fibrotic signalling. Moreover, brain tissue was used to evaluate brain edema, activation of glial cells (GFAP, IBA-1) and NF-κB/NLRP3 downstream signalling via immunoblotting and immunohistochemical analysis in cortex and hippocampus.

RESULTS

The pre-treatment with TC extract effective mitigated TAA-induced behavioural alterations, lowered serum LFT (AST, ALT, ALP, bilirubin) and oxidative stress markers in liver and brain. TC treatment significantly modulated hyperammonemia, cerebral edema and preserved the integrity of BBB proteins in HE animals. TC treatment attenuated TAA-induced histological changes, tissue inflammation (pNF-κB (p65), TNF-α, NLRP3) and fibrosis (collagen, α-SMA) in liver. In addition, immunoblotting analysis revealed TC pre-treatment inhibited fibrotic proteins such as vimentin, TGF-β1 and pSmad2/3 in the liver. Our study further showed that TC treatment downregulated the expression of MAPK/NF-κB inflammatory signalling, as well as GFAP and IBA-1 (glial cell markers) in cortex and hippocampus of TAA-intoxicated rats. Additionally, TC-treated animals exhibited reduced expression of caspase3/9 and BAX induced by TAA.

CONCLUSION

This study revealed promising insights on the protective effects of TC against HE. The findings clearly demonstrated that the significant inhibition of MAPK/NF-κB signalling and glial cell activation could be responsible for the observed beneficial effects of TC in TAA-induced HE rats.

Pharmacodynamic study of chitosan in combination with salvianolic acid B in the treatment of CC14 -induced liver fibrosis in mice

Liver fibrosis is a chronic liver lesion caused by excessive deposition of the extracellular matrix after liver damage, resulting in fibrous scarring of liver tissue. The progression of liver fibrosis is partially influenced by the gut microbiota. Chitosan can play a therapeutic role in liver fibrosis by regulating the gut microbiota based on the 'gut-liver axis' theory. Salvianolic acid B can inhibit the development of liver fibrosis by inhibiting the activation of hepatic stellate cells and reducing the production of extracellular matrix. In this study, the therapeutic effect of chitosan in combination with salvianolic acid B on liver fibrosis was investigated in a mouse liver fibrosis model. The results showed that the combination of chitosan and salvianolic acid B was better than the drug alone, improving AST/ALT levels and reducing the expression of α-SAM, COL I, IL-6 and other related genes. It improved the structure of gut microbiota and increased the abundance of beneficial bacteria such as Lactobacillus. The above results could provide new ideas for the clinical treatment of liver fibrosis.