Therapeutic Potential of Natural Plants Against Non-Alcoholic Fatty Liver Disease: Targeting the Interplay Between Gut Microbiota and Bile Acids

A novel EndMT inhibitor, xanthotoxin, attenuates non-alcoholic fatty liver disease by acting as TGFβR2 antagonist

BACKGROUND

Endothelial-to-mesenchymal transition (EndMT) has emerged as a key process contributing to the pathology of non-alcoholic fatty liver disease (NAFLD). Thus, identifying EndMT inhibitors may help impede NAFLD progression.

PURPOSE

Our research aims to identify potent natural EndMT inhibitors and explore their therapeutic potential and mechanisms of action in NAFLD.

METHODS

A natural compound library was employed to screen potential EndMT inhibitors. High-fat diet (HFD)-induced ApoE-/- mice and free fatty acid (FFA)-treated human hepatic sinusoidal endothelial cells (HHSECs) were employed as animal and cellular models of NAFLD. EndMT was evaluated by western blotting, qRT-PCR, immunofluorescence staining, tube formation, wound healing, and transwell assays. LC-MS/MS was applied to screen for altered secreted proteins during EndMT. Molecular docking, CETSA, and SPR assays were employed to validate the combination of xanthotoxin with TGFβR2.

RESULTS

Xanthotoxin was identified as a novel EndMT inhibitor. Further investigation revealed that xanthotoxin ameliorates NAFLD in ApoE-/- mice. By inhibiting EndMT, xanthotoxin improves endothelial dysfunction, reduces the pro-NAFLD factor ANGPTL2 secretion, and increases the anti-NAFLD factor SOD2 secretion, thus reducing hepatocyte steatosis, inflammation, and hepatic stellate cell fibrosis. Additional studies demonstrated that xanthotoxin binds to TGFβR2 and acts as its antagonist to block EndMT. In mice, EC-specific overexpression of TGFβR2 negated xanthotoxin's therapeutic impact on NAFLD.

CONCLUSION

This study reveals for the first time that xanthotoxin attenuates NAFLD by acting as a TGFβR2 antagonist to inhibit EndMT. These findings highlight the significant therapeutic potential of xanthotoxin in NAFLD treatment.

Characteristics of serum bile acid profiles among individuals with metabolic dysfunction-associated steatotic liver disease

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) has become the predominant chronic liver condition globally. Bile acid (BA) metabolism contributes significantly to MASLD progression. In this multicenter clinical study, we aimed to characterize serum BA profiles in patients with MASLD and identify specific alterations compared to healthy controls.

METHODS

All MASLD cases were sourced from the gastroenterology outpatient departments of Shanghai Baoshan Hospital of Integrated Chinese and Western Medicine, Shanghai Baoshan District Songnan Community Health Service Center, and Lianyungang Oriental Hospital between June 2015 and December 2019. The data were analyzed using SPSS version 26.0, with a p-value of less than 0.05 considered significant.

RESULTS

A total of 215 participants (35.3% women) with MASLD and 49 controls (44.9% women), aged 18-65 years, were included. MASLD patients showed higher levels of serum total BA (TBA), cholic acid (CA), chenodeoxycholic acid (CDCA), and ursodeoxycholic acid (UDCA) (p < 0.05, p < 0.01) when compared to controls. Furthermore, women patients with MASLD demonstrated notably higher levels of lithocholic acid (LCA), glycolithocholic acid (GLCA), and taurolithocholic acid (TLCA) than men patients with MASLD (p < 0.025, p < 0.01). Compared to women, men exhibited a higher proportion of primary to secondary BAs. Additionally, in men patients with MASLD, the serum concentrations of CA, CDCA, glycocholic acid (GCA), glycochenodeoxycholic acid (GCDCA), and taurochenodeoxycholic acid (TCDCA) exhibited significant negative correlations with ALT levels, while deoxycholic acid (DCA) and TLCA showed negative correlations with BMI.

CONCLUSIONS

Patients with MASLD exhibited notable variations in BA profiles, including sex-specific differences. This study provides corresponding evidence on the association between BAs and MASLD.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, NO: ChiCTR-OOC-15006157, registration date: March 25, 2015.

Xiaohua Funing decoction ameliorates non-alcoholic fatty liver disease by modulating the gut microbiota and bile acids

Introduction

The gut microbiota and bile acids (BAs) have emerged as factors involved in the development of non-alcoholic fatty liver disease (NAFLD). Xiaohua Funing decoction (XFD) is a traditional Chinese medicine formula used for the treatment of NAFLD. Previous studies have indicated that XFD protects liver function, but the underlying mechanism remains unclear.

Methods

In this study, a Wistar rat model of NAFLD (Mod) was established via a high-fat diet. The effects of obeticholic acid (OCA) and XFD on Mod rats were subsequently evaluated. Wistar rats in the control (Con) group were fed a standard diet. There were eight rats in each group, and the treatment lasted for 12 weeks. Furthermore, metagenomic sequencing and BA metabolomic analyses were performed.

Results

Compared to the Con group, the Mod group presented significant differences in body and liver weights; serum total cholesterol (TC) and triglyceride (TG) levels; and liver TG, TC, and bile salt hydrolase levels (p < 0.05 or p < 0.01). Importantly, OCA and XFD administration normalized these indicators (p < 0.05 or p < 0.01). Pathology of the liver and white fat steatosis was observed in the Mod group, but steatosis was significantly alleviated in the OCA and XFD groups (p < 0.05 or p < 0.01). The abundances of Bacteroidales_bacterium, Prevotella_sp., bacterium_0.1xD8-71, and unclassified_g_Turicibacter in the Mod group were significantly different from those in the Con group (p < 0.05 or p < 0.01), whereas the abundance of Bacteroidales_bacterium was greater in the XFD group. A total of 17, 24, and 24 differentially abundant BAs were detected in the feces, liver, and serum samples from the Mod and Con groups, respectively (p < 0.05 or p < 0.01). In the feces, liver, and serum, XFD normalized the levels of 16, 23, and 14 BAs, respectively, including glycochenodeoxycholic acid, deoxycholic acid, murideoxycholic acid, lithocholic acid, 23-nordeoxycholic acid, and 3β-ursodeoxycholic acid. In addition, glycochenodeoxycholic acid was identified as a potential biomarker of NAFLD.

Discussion

In summary, our experiments revealed that XFD regulates the gut microbiota and BAs, providing beneficial effects on liver lipid accumulation in NAFLD.

Yellow tea polysaccharides protect against non-alcoholic fatty liver disease via regulation of gut microbiota and bile acid metabolism in mice

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a major clinical and global public health issue, with no specific pharmacological treatment available. Currently, there is a lack of approved drugs for the clinical treatment of NAFLD. Large-leaf yellow tea polysaccharides (YTP) is a natural biomacromolecule with excellent prebiotic properties and significant therapeutic effects on multiple metabolic diseases. However, the specific mechanisms by which YTP regulates NAFLD remain unclear.

PURPOSE

This study aims to explore the prebiotic effects of YTP and the potential mechanisms by which it inhibits hepatic cholesterol accumulation in NAFLD mice.

METHODS

The effects of YTP on lipid accumulation were evaluated in NAFLD mice through obesity trait analysis and bile acids (BAs) metabolism assessment. Additionally, fecal microbiota transplantation (FMT) was performed, and high-throughput sequencing was employed to investigate the mechanisms underlying YTP's regulatory effects on gut microbiota and BA metabolism.

RESULTS

Our study demonstrated that YTP altered the constitution of colonic BA, particularly increasing the levels of conjugated BA and non-12OH BA, which suppressed ileum FXR receptors and hepatic BA reabsorption, facilitated BA synthesis, and fecal BA excretion. The modifications were characterized by a decrease in the levels of FXR, FGF15, FGFR4, and ASBT proteins, and an increase in the levels of Cyp7a1 and Cyp27a1 proteins. YTP might affect enterohepatic circulation and by the activated the hepatic FXR-SHP pathway. Meanwhile, YTP reshaped the intestinal microbiome structure by decreasing BSH-producing genera and increasing taurine metabolism genera. The correlation analysis implied that Muribaculaceae, Pseudomonas, acterium_coprostanoligenes_group, Clostridiales, Lachnospiraceae_NK4A136_group, Delftia, Dubosiella, and Romboutsia were strongly correlated with specific BA monomers.

CONCLUSIONS

YTP modulates bile salt hydrolase-related microbial genera to activate alternative bile acid synthesis pathways, thereby inhibiting NAFLD progression. These results suggest that YTP may serve as a potential probiotic formulation, offering a feasible dietary intervention for NAFLD.

Plant miR6262 Modulates the Expression of Metabolic and Thermogenic Genes in Human Hepatocytes and Adipocytes

BACKGROUND

Edible plants have been linked to the mitigation of metabolic disturbances in liver and adipose tissue, including the decrease of lipogenesis and the enhancement of lipolysis and adipocyte browning. In this context, plant microRNAs could be key bioactive molecules underlying the cross-kingdom beneficial effects of plants. This study sought to explore the impact of plant-derived microRNAs on the modulation of adipocyte and hepatocyte genes involved in metabolism and thermogenesis.

METHODS

Plant miR6262 was selected as a candidate from miRBase for the predicted effect on the regulation of human metabolic genes. Functional validation was conducted after transfection with plant miRNA mimics in HepG2 hepatocytes exposed to free fatty acids to mimic liver steatosis and hMADs cells differentiated into brown-like adipocytes.

RESULTS

miR6262 decreases the expression of the predicted target RXRA in the fatty acids-treated hepatocytes and in brown-like adipocytes and affects the expression profile of critical genes involved in metabolism and thermogenesis, including PPARA, G6PC, SREBF1 (hepatocytes) and CIDEA, CPT1M and PLIN1 (adipocytes). Nevertheless, plant miR6262 mimic transfections did not decrease hepatocyte lipid accumulation or stimulate adipocyte browning.

CONCLUSIONS

these findings suggest that plant miR6262 could have a cross-kingdom regulation relevance through the modulation of human genes involved in lipid and glucose metabolism and thermogenesis in adipocytes and hepatocytes.

Toxicity assessment of Cucurbita pepo cv Dayangua and its effects on gut microbiota in mice

BACKGROUND

Cucurbita pepo cv Dayangua (CPD) is an edible plant with diverse pharmacological properties. The current research on CPD has primarily focused on initial investigations of its chemical composition and pharmacological effects, and no comprehensive toxicity assessment has been conducted to date.

METHODS

In the present study, the toxicity of CPD was evaluated through both acute and sub-chronic oral toxicity tests in mice. 16S rDNA sequencing was used to analyze the composition of the gut microbiota of mice at different time points to observe the effect of CPD on these microbial communities.

RESULTS

In the acute toxicity test, CPD exhibited low toxicity, with a median lethal dose (LD50) > 2000 mg/kg. The sub-chronic toxicity test indicated that CPD administration at doses of 200, 400, and 600 mg/kg did not cause mortality or significant organ damage in mice. Furthermore, analysis of the gut microbiota after gavage administration of CPD at 400 and 600 mg/kg revealed an improved abundance of some beneficial gut bacteria.

CONCLUSIONS

In summary, no acute or sub-chronic toxic effects were observed in mice following the oral administration of CPD. CPD did not affect the structure and diversity of the gut microbiota and may contribute to an increase in the number of beneficial gut bacteria.

Components from Curcuma longa (Turmeric) Against Hepatobiliary Diseases Based on Gut-Liver Axis: Pharmacotherapeutic Properties and Potential Clinical Applications

Turmeric is widely used worldwide, and there are many examples of its use in treating hepatobiliary diseases. The gut-liver axis is a bidirectional relationship between gut microorganisms and the liver that is closely related to the pathogenesis of hepatobiliary diseases. This review systematically summarizes the components of turmeric. It links the studies on turmeric affecting gut microorganisms to its effects on liver and biliary diseases to explain the potential mechanism of turmeric's regulation of the gut-liver axis. Besides, ethnopharmacology, phytochemicals, and clinical adverse events associated with turmeric have been researched. Furthermore, turmeric is a safe agent with good clinical efficacy and without apparent toxicity at a certain amount. By summarizing the influence of turmeric on the liver by regulating the gut-liver axis, especially the gut microbiota, it provides a preclinical basis for using turmeric as a safe and effective therapeutic agent for the prevention and treatment of hepatobiliary diseases based on the gut-liver axis. However, more efforts should be made to exploit its clinical application further.

Plant miR8126-3p and miR8126-5p Decrease Lipid Accumulation through Modulation of Metabolic Genes in a Human Hepatocyte Model That Mimics Steatosis

Plant-based food interventions are promising therapeutic approaches for non-alcoholic fatty liver disease (NAFLD) treatment, and microRNAs (miRNAs) have emerged as functional bioactive components of dietary plants involved in cross-kingdom communication. Deeper investigations are needed to determine the potential impact of plant miRNAs in NAFLD. This study aimed to identify plant miRNAs that could eventually modulate the expression of human metabolic genes and protect against the progression of hepatic steatosis. Plant miRNAs from the miRBase were used to predict human target genes, and miR8126-3p and miR8126-5p were selected as candidates for their potential role in inhibiting glucose and lipid metabolism-related genes. Human HepG2 cells were transfected with plant miRNA mimics and then exposed to a mixture of oleic and palmitic acids to mimic steatosis. miR8126-3p and miR8126-5p transfections inhibited the expression of the putative target genes QKI and MAPKAPK2, respectively, and had an impact on the expression profile of key metabolic genes, including PPARA and SREBF1. Quantification of intrahepatic triglycerides revealed that miR8126-3p and miR8126-5p attenuated lipid accumulation. These findings suggest that plant miR8126-3p and miR8126-5p would induce metabolic changes in human hepatocytes eventually protecting against lipid accumulation, and thus, they could be potential therapeutic tools for preventing and alleviating lipid accumulation.

Compound Chinese medicine (F1) improves spleen deficiency diarrhea by protecting the intestinal mucosa and regulating the intestinal flora

Compound Chinese medicine (F1) is a traditional prescription in Chinese medicine that is commonly used to treat spleen deficiency diarrhea (SDD). It has demonstrated remarkable effectiveness in clinical practice. However, the precise mechanism by which it exerts its antidiarrheal effect is still unclear. This study aimed at investigating the antidiarrheal efficacy and mechanism of F1 on senna-induced secretory diarrhea (SDD). Senna was utilized to induce the development of a mouse model of senna-induced secretory diarrhea (SDD) in order to observe the rate of diarrhea, diarrhea index, blood biochemistry, and histopathological changes in the small intestine. Additionally, the levels of sodium and hydrogen exchange protein 3 (NHE3) and short-chain fatty acids (SCFAs) were determined using enzyme-linked immunosorbent assay (ELISA). The impact of F1 on the senna-induced SDD mouse models was evaluated by monitoring changes in the gut microbiota through 16S rRNA (V3-V4) sequencing. The results demonstrated that F1, a traditional Chinese medicine, effectively increased the body weight of SDD mice and reduced the incidence of diarrhea and diarrhea index. Additionally, F1 restored liver and kidney function, reduced the infiltration of inflammatory cells in intestinal tissue, and promoted the growth of intestinal villi. Furthermore, F1 was found to enhance the expression of NHE3 and SCFAs. It also increased the abundance of Firmicutes and Lactobacillus species, while decreasing the abundance of Proteobacteria and Shigella.

Discussion on treatment of liver fibrosis with traditional Chinese medicine from the perspective of gut microbiota

Liver fibrosis is the key stage of various chronic liver diseases, and its occurrence and development are closely related to the imbalance of the gut microbiota. In terms of treatment, there is still a lack of ideal chemical drugs, but traditional Chinese medicine has shown unique clinical efficacy in the treatment of hepatic fibrosis. In recent years, research on the regulation of the gut microbiota by traditional Chinese medicine has attracted widespread attention in the academic community. The primary target of the active ingredients of traditional Chinese medicine compound in hepatic fibrosis may be the gut microbiota, or they exert biological effects through the intestinal flora medium and the characteristic reconstruction of the gut microbiota. From the perspective of the "gut-liver axis", the therapetuic effect of traditional Chinese medicine on liver fibrosis is closely connected with regulating the intestinal flora and "treating the liver and spleen together". Based on the viewpoint of the gut-liver axis, this paper discusses the anti-hepatic fibrosis effects of traditional Chinese medicine and its active ingredients by regulating the gut microbiota, with an aim to provide a new research perspective for the therapetuic effect of traditional Chinese medicine on hepatic fibrosis.

Biosynthetic Pathways of Dimeric Natural Products Containing Bisanthraquinone and Related Xanthones

Many dimeric natural products containing bisanthraquinone and related xanthones with diverse structures and versatile bioactivities have been isolated over the years. However, the complicated biosynthetic pathways of such natural products, which have remained elusive until recently, negatively impact their mass bioproduction and biosynthetic structural modification for drug discovery. In this concept, we summarize the recent progress in gene cluster mining and biosynthetic pathway elucidation of natural products containing bisanthraquinone and related xanthones. These pioneering works may pave the way for further biosynthetic pathway elucidation and structure modification of dimeric natural products through gene and protein engineering.

Male zooid extracts of Antheraea pernyi ameliorates non-alcoholic fatty liver disease and intestinal dysbacteriosis in mice induced by a high-fat diet

The male zooid of Antheraea pernyi (A. pernyi) accumulates several nutrients and physiological activity-related substances for reproduction. Some components in the extracts of the male zooid of A. pernyi (EMZAP) have several functions, such as protecting the liver, enhancing immunity, antiatheroscloresis, anti-aging, and antitumor effects. In this study, we investigated the ameliorating effects on high-fat diet (HFD)-induced non-alcoholic fatty liver disease (NAFLD). The EMZAP treatment could ameliorate NAFLD and effectively decrease the serum total cholesterol, triglyceride and low-density lipoprotein levels and a significant increase in serum high-density lipoprotein levels was observed. Additionally, the EMZAP treatment reduced the levels of liver-function enzymes and pro-inflammatory cytokines (i.e., IL-6, IL-8, TNF-α, TGF-β₁) and also the oxidative stress indices and regulated the expression of genes associated with fatty acid metabolism (SREBP-1c, PPARα, ACOX-1, CPT-1) in the liver to prevent the development of NAFLD. Furthermore, EMZAP enhanced the diversity and richness of the beneficial intestinal microbes, suggesting its potential as a dietary supplement and functional food to combat NAFLD induced by HFD.

Nuciferine Protects Against High-Fat Diet-Induced Hepatic Steatosis via Modulation of Gut Microbiota and Bile Acid Metabolism in Rats

Our previous study showed that nuciferine (NF) attenuated non-alcoholic fatty liver disease (NAFLD), which is attributed to a high-fat diet (HFD) through reinforcing intestinal barrier functions, regulating lipid metabolism, and improving inflammation. To clarify whether other mechanisms contribute to the anti-NAFLD efficacy of NF, the present study investigated the influence of NF on bile acid (BA) metabolism and gut microbiota in HFD-fed rats. The data demonstrated that NF changed the composition of colonic BA, particularly elevating conjugated BA and non-12OH BA levels. As shown by downregulated protein levels of FXR, FGF15, FGFR4, and ASBT and upregulated protein levels of CYP7A1 and CYP27A1, NF inhibited ileal FXR signaling, promoted BA synthesis, suppressed BA reabsorption, and facilitated fecal BA excretion. NF might affect hepatic FXR signaling, BA conjugation, and enterohepatic circulation by the changed mRNA levels of Fxr, Shp, Baat, Bacs, Bsep, Ntcp, Ibabp, and Ostα/β. Meanwhile, NF regulated the gut microbiota, characterized by decreased BSH-producing genus, 7α-dehydroxylation genus, and increased taurine metabolism-related genus. Spearman rank correlation analysis implied that Colidextribacter, Adlercreutzia, Family_XIII_AD3011_group, Lachnospiraceae_UCG-010, Eisenbergiella, and UCG-005 were robustly associated with particular BA monomers. In conclusion, our experiment results suggested that NF could exert a mitigating effect on NAFLD via regulating BA metabolism and modulating the gut microbiota.