Gut microbiota as an emerging therapeutic avenue for the treatment of non-alcoholic fatty liver disease

Exploring the therapeutic potential of silymarin-based herbal remedy (prebiotic) and probiotic blend in a mouse model of NAFLD: Insights into gut microbiota modulation and liver health

Non-alcoholic fatty liver disease (NAFLD) is a significant consequence of metabolic dysfunction, often associated with changes in the intestinal microbiota. Prebiotics and probiotics have shown promise in NAFLD management. This study evaluated a silymarin-based herbal remedy with piperine and fulvic acid, alongside a probiotic blend of Bifidobacterium adolescentis, Bifidobacterium bifidum, Lactobacillus casei, and Lactobacillus rhamnosus. Using a NAFLD mouse model induced by a high-fat and high-fructose diet, we assessed biochemical parameters, liver function, glucose levels, and conducted histological analysis. Stool samples underwent 16S rRNA metagenomic analysis to explore changes in microbiota composition. Mice on the high-fat diet exhibited elevated lipids, liver enzymes, and glucose, with reduced high-density lipoprotein levels (with p value < 0.001). Treatment, particularly with F3 (silymarin-piperine-fulvic acid herbal remedy and probiotic blend), significantly reduced hepatic fat accumulation and improved gut microbiota composition. This study highlights the potential of silymarin-based therapy combined with probiotics in attenuating NAFLD progression.

Hovenia dulcis: a Chinese medicine that plays an essential role in alcohol-associated liver disease

Globally, alcohol-associated liver disease (ALD) has become an increased burden for society. Disulfirams, Benzodiazepines (BZDs), and corticosteroids are commonly used to treat ALD. However, the occurrence of side effects such as hepatotoxicity and dependence, impedes the achievement of desirable and optimal therapeutic efficacy. Therefore, there is an urgent need for more effective and safer treatments. Hovenia dulcis is an herbal medicine promoting alcohol removal clearance, lipid-lowering, anti-inflammatory, and hepatoprotective properties. Hovenia dulcis has a variety of chemical components such as dihydromyricetin, quercetin and beta-sitosterol, which can affect ALD through multiple pathways, including ethanol metabolism, immune response, hepatic fibrosis, oxidative stress, autophagy, lipid metabolism, and intestinal barrier, suggesting its promising role in the treatment of ALD. Thus, this work aims to comprehensively review the chemical composition of Hovenia dulcis and the molecular mechanisms involved in the process of ALD treatment.

Deciphering the role of gut metabolites in non-alcoholic fatty liver disease

Perturbations in microbial abundance or diversity in the intestinal lumen leads to intestinal inflammation and disruption of intestinal membrane which eventually facilitates the translocation of microbial metabolites or whole microbes to the liver and other organs through portal vein. This process of translocation finally leads to multitude of health disorders. In this review, we are going to focus on the mechanisms by which gut metabolites like SCFAs, tryptophan (Trp) metabolites, bile acids (BAs), ethanol, and choline can either cause the development/progression of non-alcoholic fatty liver disease (NAFLD) or serves as a therapeutic treatment for the disease. Alterations in some metabolites like SCFAs, Trp metabolites, etc., can serve as biomarker molecules whereas presence of specific metabolites like ethanol definitely leads to disease progression. Thus, proper understanding of these mechanisms will subsequently help in designing of microbiome-based therapeutic approaches. Furthermore, we have also focussed on the role of dysbiosis on the mucosal immune system. In addition, we would also compile up the microbiome-based clinical trials which are currently undergoing for the treatment of NAFLD and non-alcoholic steatohepatitis (NASH). It has been observed that the use of microbiome-based approaches like prebiotics, probiotics, symbiotics, etc., can act as a beneficial treatment option but more research needs to be done to know how to manipulate the composition of gut microbes.

Gut firmicutes: Relationship with dietary fiber and role in host homeostasis

Firmicutes and Bacteroidetes are the predominant bacterial phyla colonizing the healthy human gut. Accumulating evidence suggests that dietary fiber plays a crucial role in host health, yet most studies have focused on how the dietary fiber affects health through gut Bacteroides. More recently, gut Firmicutes have been found to possess many genes responsible for fermenting dietary fiber, and could also interact with the intestinal mucosa and thereby contribute to homeostasis. Consequently, the relationship between dietary fiber and Firmicutes is of interest, as well as the role of Firmicutes in host health. In this review, we summarize the current knowledge regarding the molecular mechanism of dietary fiber degradation by gut Firmicutes and explain the communication pathway of the dietary fiber-Firmicutes-host axis, and the beneficial effects of dietary fiber-induced Firmicutes and their metabolites on health. A better understanding of the dialogue sustained by the dietary fiber-Firmicutes axis and the host could provide new insights into probiotic therapy and novel dietary interventions aimed at increasing the abundance of Firmicutes (such as Faecalibacterium, Lactobacillus, and Roseburia) to promote health.

In-silico, in-vitro and ex-vivo evidence of combining silymarin phytopharmaceutical with piperine, and fulvic acid for enhancing its solubility and permeability

Non-alcoholic fatty liver disease is one of the leading causes of death worldwide. Even if with such a high mortality there is no definite treatment approved. Thus, there is a need to develop a formulation which can have multiple pharmacological activities. Herbal drugs are among the most promising compounds that act by different pharmacological actions. For increasing the bio-activity of Silymarin we had isolated five active biomarker molecules from silymarin extract (as a Phytopharmaceutical) in our previous work. It possesses lower bioavailability due to poor solubility, lesser permeability and first pass metabolism effect. Therefore, from the literature we had screened two bioavailability enhancers i.e. piperine and fulvic acid for overcoming the drawbacks associated with silymarin. Hence, in this study we had first explored the ADME-T parameters and then evaluated their in-silico activity for different enzymes involved in inflammation and fibrosis. Interestingly, it was found that besides the bioavailability enhancing property, piperine and fulvic acid also shown anti-inflammatory and anti-fibrotic action, particularly more activity was demonstrated by fulvic acid than piperine. Furthermore, the concentration of the bioavailability enhancers i.e. 20% FA and 10% PIP were optimized by QbD assisted solubility studies. Moreover, the percentage release and apparent permeability coefficient of the optimized formulation was found to be 95% and 90%, respectively as compared to 6.54*106 and 1.63*106 respectively by SM suspension alone. Furthermore, it was found that plain rhodamine solution penetrated only up to 10 um whereas, formulation penetrated up to 30 um. Thus, combining these three, can not only increase the bioavailability of silymarin, but might also, increase the physiological action synergistically.

Decoding the bidirectional relationship between gut microbiota and COVID-19

From late 2019, whole world has been facing COVID-19 pandemic which is caused by SARS-CoV-2 virus. This virus primarily attacks the respiratory tract and enter host cell by binding with angiotensin 2 converting enzyme receptors present on alveoli of the lungs. Despite its binding in the lungs, many patients have reported gastrointestinal symptoms and indeed, RNA of the virus have been found in faecal sample of patients. This observation gave a clue of the involvement of gut-lung axis in this disease development and progression. From several studies reported in past two years, intestinal microbiome has shown to have bidirectional link with lungs i.e., gut dysbiosis increases the tendency of infection with COVID-19 and coronavirus can also cause perturbations in intestinal microbial composition. Thus, in this review we have tried to figure out the mechanisms by which disturbances in the gut composition can increase the susceptibility to COVID-19. Understanding these mechanisms can play a crucial role in decreasing the disease outcomes by manipulating the gut microbiome using prebiotics, probiotics, or combination of two. Even, faecal microbiota transplantation can also show better results, but intensive clinical trials need to be done first.

Dihydromyricetin Protects Against Ethanol-Induced Toxicity in SH-SY5Y Cell Line: Role of GABAA Receptor

Toxicity induced by binge alcohol drinking, particularly in adolescent and young adults, is of major medical and social consequence. Recently, we reported that butyrate, a short chain fatty acid, can protect against ethanol (ETOH)-induced toxicity in an in vitro model. In this study, we sought to evaluate the potential effectiveness of dihydromyricetin (DHM), a natural bioactive flavonoid, alone or in combination with butyrate in the same model. Exposure of SH-SY5Y cells for 24 h to 500 mM ETOH resulted in approximately 40% reduction in cell viability, which was completely prevented by 0.1 μM DHM. Combinations of DHM and butyrate provided synergistic protection against alcohol toxicity. Whereas butyrate effect was shown to be mediated primarily through fatty acid receptor 3 activation, DHM protection appears to be mediated primarily via benzodiazepine receptor site of GABA_A receptor. This is based on the finding that DHM's effect could be completely prevented by pretreatment with flumazenil, a selective antagonist at this site, but not by bicuculline, a selective antagonist at the actual GABA_A receptor binding site. These findings suggest potential utility of DHM alone or in combination with butyrate against ETOH-induced toxicity.

Intestinal Dysbiosis, the Tryptophan Pathway and Nonalcoholic Steatohepatitis

Non-alcoholic fatty liver disease (NAFLD) progresses from simple steatosis to steatohepatitis (NASH), which may then progress to the development of cirrhosis and hepatocarcinoma. NASH is characterized by both steatosis and inflammation. Control of inflammation in NASH is a key step for the prevention of disease progression to severe sequalae. Intestinal dysbiosis has been recognized to be an important causal factor in the pathogenesis of NASH, involving both the accumulation of lipids and aggravation of inflammation. The effects of gut dysbiosis are mediated by adverse shifts of various intestinal commensal bacterial genera and their associated metabolites such as butyrate, tryptophan, and bile acids. In this review, we focus on the roles of tryptophan and its metabolites in NASH in association with intestinal dysbiosis and discuss possible therapeutic implications.

Sodium Butyrate Protects Against Ethanol-Induced Toxicity in SH-SY5Y Cell Line

Alcohol use disorder (AUD), brought about by excessive alcohol use, is associated with damages to several organs including the brain. Chronic excessive use of alcohol can compromise intestinal integrity, leading to changes in gut microbiota (GM) composition known as dysbiosis. Dysbiosis, by disruption of the gut-brain axis (GBA), further exacerbates the deleterious effects of alcohol. One of the fermentation by-products of GM is butyrate (BUT), a short-chain fatty acid (SCFA) that plays an important role in maintaining homeostasis of the GBA. Alcohol metabolism results in formation of acetaldehyde, a highly reactive compound that reacts with dopamine in the brain to form toxic adducts such as salsolinol. Recent studies indicate potential neuro-protective effects of BUT against various toxicants including salsolinol. Here, we sought to investigate whether BUT can also protect against alcohol toxicity. Pretreatment of neuroblastoma-derived SH-SY5Y cells with 500 mM ethanol (ETOH) for 24 h resulted in approximately 40% reduction in cell viability, which was totally blocked by 10 µM of either BUT or AR 420,626 (AR), a selective fatty acid 3 receptor (FA3R) agonist. The neuro-protective effects of both BUT and AR were significantly (80%) attenuated by beta-hydroxy butyrate (BHB), a selective FA3R antagonist. Interestingly, combination of BUT and AR resulted in synergistic protection against ETOH, which was totally blocked by BHB. These findings suggest potential utility of butyrate and/or FA3R agonists against ETOH-induced toxicity.