The Potential Effect of Chinese Herbal Formula Hongqijiangzhi Fang in Improving NAFLD: Focusing on NLRP3 Inflammasome and Gut Microbiota

Effects of plant natural products on metabolic-associated fatty liver disease and the underlying mechanisms: a narrative review with a focus on the modulation of the gut microbiota

Metabolic-associated fatty liver disease (MAFLD) is a chronic liver disease characterized by the excessive accumulation of fat in hepatocytes. However, due to the complex pathogenesis of MAFLD, there are no officially approved drugs for treatment. Therefore, there is an urgent need to find safe and effective anti-MAFLD drugs. Recently, the relationship between the gut microbiota and MAFLD has been widely recognized, and treating MAFLD by regulating the gut microbiota may be a new therapeutic strategy. Natural products, especially plant natural products, have attracted much attention in the treatment of MAFLD due to their multiple targets and pathways and few side effects. Moreover, the structure and function of the gut microbiota can be influenced by exposure to plant natural products. However, the effects of plant natural products on MAFLD through targeting of the gut microbiota and the underlying mechanisms are poorly understood. Based on the above information and to address the potential therapeutic role of plant natural products in MAFLD, we systematically summarize the effects and mechanisms of action of plant natural products in the prevention and treatment of MAFLD through targeting of the gut microbiota. This narrative review provides feasible ideas for further exploration of safer and more effective natural drugs for the prevention and treatment of MAFLD.

A herb mixture to ameliorate non-alcoholic fatty liver in rats fed a high-fat diet

This study was performed to investigate the effects of an herb extract mixture (HM) in ameliorating non-alcoholic fatty liver disease (NAFLD). The HM contained equal amounts of 70% ethanol extracts from Zingiber officinale, Centella asiatica, and Boehmeria nivea. In vitro, the HM significantly inhibited lipid accumulation in oleic acid-stimulated HepG2 cells. We further evaluated the anti-NAFLD activities of the HM in vivo in an animal model. Rats were fed two different amounts of the HM (50 and 200 mg/kg body weight) along with a high-fat diet for 6 weeks. HM supplementation reduced liver weight; epididymal, peri-renal, and intra-abdominal fat content; and serum triglyceride, total cholesterol, and low-density lipoprotein cholesterol levels as well as increased high-density lipoprotein cholesterol levels in a dose-dependent manner. Histological evaluation of liver specimens further demonstrated that administration of HM significantly prevented hepatic lipid accumulation and subsequent development of hepatic steatosis. These findings suggest that HM can be used as an alternative nutraceutical for ameliorating NAFLD.

The interplay between herbal medicines and gut microbiota in metabolic diseases

Globally, metabolic diseases are becoming a major public health problem. Herbal medicines are medicinal materials or preparations derived from plants and are widely used in the treatment of metabolic diseases due to their good curative effects and minimal side effects. Recent studies have shown that gut microbiota plays an important role in the herbal treatment of metabolic diseases. However, the mechanisms involved are still not fully understood. This review provides a timely and comprehensive summary of the interactions between herbal medicines and gut microbiota in metabolic diseases. Mechanisms by which herbal medicines treat metabolic diseases include their effects on the gut microbial composition, the intestinal barrier, inflammation, and microbial metabolites (e.g., short-chain fatty acids and bile acids). Herbal medicines can increase the abundance of beneficial bacteria (e.g., Akkermansia and Blautia), reduce the abundance of harmful bacteria (e.g., Escherichia-Shigella), protect the intestinal barrier, and alleviate inflammation. In turn, gut microbes can metabolize herbal compounds and thereby increase their bioavailability and bioactivity, in addition to reducing their toxicity. These findings suggest that the therapeutic effects of herbal medicines on metabolic diseases are closely related to their interactions with the gut microbiota. In addition, some methods, and techniques for studying the bidirectional interaction between herbal medicines and gut microbiota are proposed and discussed. The information presented in this review will help with a better understanding of the therapeutic mechanisms of herbal medicines and the key role of gut microbiota.

Fufang Zhenzhu Tiaozhi Capsule Prevents Intestinal Inflammation and Barrier Disruption in Mice With Non-Alcoholic Steatohepatitis

Nonalcoholic steatohepatitis (NASH) has become a major cause of liver transplantation and liver-associated death. Targeting the gut-liver axis is a potential therapy for NASH. The Fufang Zhenzhu Tiaozhi (FTZ) capsule, a traditional Chinese medicine commonly used in clinical practice, has recently emerged as a promising drug candidate for metabolic diseases such as NASH. The present study aimed to investigate whether FTZ exerts an anti-NASH effect by targeting the gut-liver axis. Mice were fed with a high-fat diet (HFD) for 20 weeks to induce NASH. HFD-fed mice were daily intragastrically administrated with FTZ at 10 weeks after tbe initiation of HFD feeding. The mRNA levels of genes associated with the intestinal tight junction, lipid metabolism, and inflammation were determined by the q-PCR assay. Hepatic pathology was evaluated by H&E staining. The gut microbiota was analyzed by 16S rRNA gene sequencing. FTZ attenuated HFD-induced obesity, insulin resistance, and hepatic steatosis in mice. FTZ treatment decreased the elevated levels of serum aminotransferases and liver triglyceride in NASH mice. Furthermore, FTZ treatment reduced hepatic inflammatory cell infiltration and fibrosis in mice. In addition, FTZ attenuated the intestinal inflammatory response and improved intestinal barrier function. Mechanistically, FTZ-treated mice showed a different gut microbiota composition compared with that in HFD-fed mice. Finally, we identified eight differential metabolites that may contribute to the improvement of NASH with FTZ treatment. In summary, FTZ ameliorates NASH by inhibiting gut inflammation, improving intestinal barrier function, and modulating intestinal microbiota composition.

Mechanisms of traditional Chinese medicine in modulating gut microbiota metabolites-mediated lipid metabolism

ETHNOPHARMACOLOGICAL RELEVANCE

The gut microbiome plays an important role in advancing the process of host lipid metabolism directly or indirectly. Traditional Chinese medicine (TCM) can improve the intestinal environment by intervening with gut microbiota metabolites to potentially regulate lipid levels. However, the underlying mechanisms remain unclear. Therefore, we examined the current databases to search for studies related to influence of TCM on the gut microbiota metabolites-mediated lipid metabolism.

AIM OF THE STUDY

This paper aims to review the TCM that could regulate lipid metabolism mediated by microbial metabolites and their pharmacological targets and provides perspectives for future investigation.

METHODS

Electronic databases including PubMed, Web of Science, EMBASE, the Cochrane Library, Chinese Biological Medicine Database, and China National Knowledge Infrastructure were searched up to April 2021 to identify eligible studies.

RESULTS

A total of 30 active compounds, five Chinese herbal formulae, and three proprietary Chinese medicines were included in this review. We found that TCM can effectively improve lipid metabolism by increasing short chain fatty acids (SCFA) levels, regulating bile acid (BA) metabolism, reducing the production of trimethylamine N-oxide (TMAO), alleviating the release of inflammatory factors, and altering branched-chain amino acids (BCAA) biosynthesis. This process is accompanied by changes in the structure of the gut microbiota, blood lipids, and expression of lipid metabolism genes.

CONCLUSION

In summary, studies on the regulation of lipid metabolism by microbial metabolites in TCM will provide a new approach for better management of dyslipidemia, which may facilitate future clinical treatments.

Herbal therapy for ameliorating nonalcoholic fatty liver disease via rebuilding the intestinal microecology

The worldwide prevalence of nonalcoholic fatty liver disease (NAFLD) is increasing, and this metabolic disorder has been recognized as a severe threat to human health. A variety of chemical drugs have been approved for treating NAFLD, however, they always has serious side effects. Chinese herbal medicines (CHMs) have been widely used for preventing and treating a range of metabolic diseases with satisfactory safety and effective performance in clinical treatment of NAFLD. Recent studies indicated that imbanlance of the intestinal microbiota was closely associated with the occurrence and development of NAFLD, thus, the intestinal microbiota has been recognized as a promising target for treatment of NAFLD. In recent decades, a variety of CHMs have been reported to effectively prevent or treat NAFLD by modulating intestinal microbiota to further interfer the gut-liver axis. In this review, recent advances in CHMs for the treatment of NAFLD via rebuilding the intestinal microecology were systematically reviewed. The key roles of CHMs in the regulation of gut microbiota and the gut-liver axis along with their mechanisms (such as modulating intestinal permeability, reducing the inflammatory response, protecting liver cells, improving lipid metabolism, and modulating nuclear receptors), were well summarized. All the knowledge and information presented here will be very helpful for researchers to better understand the applications and mechanisms of CHMs for treatment of NAFLD.

Effects of wogonoside on the inflammatory response and oxidative stress in mice with nonalcoholic fatty liver disease

CONTEXT

Wogonoside has many pharmacological activities, but whether it has a protective effect against non-alcoholic fatty liver disease (NAFLD) has not been reported.

OBJECTIVE

This study investigates the protective effect of wogonoside against NAFLD in mice and its potential mechanism.

MATERIALS AND METHODS

C57BL/6 mice were randomly divided into control group, NAFLD group and low-, medium- and high-dose wogonoside groups (5, 10 and 20 mg/kg, respectively) (n= 12). Mice in the control group were fed with the standard diet, and those in NAFLD group and low-, medium- and high-dose wogonoside groups were fed with a high-fat diet. The different doses of wogonoside were administered by gavage once a day for 12 weeks.

RESULTS

Compared with those in NAFLD group, the liver mass, liver index and the LDL, TG, TC, IL-2, IL-6, TNF-α, MDA and NF-κB p65 levels were decreased, and the SOD and GSH-Px activities, and HDL, IκBα, Nrf2 and HO-1 contents were increased in wogonoside groups. Compared with those in the NAFLD group, wogonoside (5, 10 and 20 mg/kg) reduced AST (132.21 ± 14.62, 115.70 ± 11.32 and 77.94 ± 8.86 vs. 202.35 ± 19.58 U/L) and ALT (104.37 ± 11.92, 97.53 ± 10.12 and 56.74 ± 6.33 vs. 154.66 ± 14.23 U/L) activities in the serum.

DISCUSSION AND CONCLUSIONS

Wogonoside has a protective effect against NAFLD in mice, which may be related to its anti-inflammation and inhibition of oxidative stress, suggesting that wogonoside may be a potential therapeutic agent for the treatment of NAFLD.

Metabolomic Analysis Identifies Glycometabolism Pathways as Potential Targets of Qianggan Extract in Hyperglycemia Rats

Qianggan formula, a designed prescription according to the Traditional Chinese Medicine (TCM) theory, is widely used in treating chronic liver diseases, and indicated to prevent blood glucose increase in patients via unknown mechanisms. To unravel the effects and underlying mechanisms of Qianggan formula on hyperglycemia, we administrated Qianggan extract to high fat and high sucrose (HFHS) diet rats. Results showed that four-week Qianggan extract intervention significantly decreased serum fasting blood glucose, hemoglobin A1c, and liver glycogen levels. Gas chromatography-mass spectrometry (GC-MS) approach was employed to explore metabolomic profiles in liver and fecal samples. By multivariate and univariate statistical analysis (variable importance of projection value > 1 and p value < 0.05), 44 metabolites (18 in liver and 30 in feces) were identified as significantly different. Hierarchical cluster analysis revealed that most differential metabolites had opposite patterns between pair-wise groups. Qianggan extract restored the diet induced metabolite perturbations. Metabolite sets enrichment and pathway enrichment analysis revealed that the affected metabolites were mainly enriched in glycometabolism pathways such as glycolysis/gluconeogenesis, pentose phosphate pathway, fructose, and mannose metabolism. By compound-reaction-enzyme-gene network analysis, batches of genes (e.g. Hk1, Gck, Rpia, etc) or enzymes (e.g. hexokinase and glucokinase) related to metabolites in enriched pathways were obtained. Our findings demonstrated that Qianggan extract alleviated hyperglycemia, and the effects might be partially due to the regulation of glycometabolism related pathways.

Chinese Medicinal Herbs Targeting the Gut-Liver Axis and Adipose Tissue-Liver Axis for Non-Alcoholic Fatty Liver Disease Treatments: The Ancient Wisdom and Modern Science

Non-alcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases worldwide. The pathogenesis of NAFLD is complex. Frontline western medicines only ameliorate the symptoms of NAFLD. On the contrary, the uniqueness of Chinese medicine in its interpretation of NAFLD and the holistic therapeutic approach lead to a promising therapeutic efficacy. Recent studies reveal that the gut-liver axis and adipose tissue-liver axis play important roles in the development of NAFLD. Interestingly, with advanced technology, many herbal formulae are found to target the gut-liver axis and adipose tissue-liver axis and resolve the inflammation in NAFLD. This is the first review summarizes the current findings on the Chinese herbal formulae that target the two axes in NAFLD treatment. This review not only demonstrates how the ancient wisdom of Chinese medicine is being interpreted by modern pharmacological studies, but also provides valuable information for the further development of the herbal-based treatment for NAFLD.