Hyperoside attenuates non-alcoholic fatty liver disease in rats via cholesterol metabolism and bile acid metabolism

Gut microbiota regulates hepatic ketogenesis and lipid accumulation in ketogenic diet-induced hyperketonemia by disrupting bile acid metabolism

The ketogenic diet (KD) induces prolonged hyperketonemia, characterized by elevated circulating level of β-hydroxybutyrate. However, the KD can negatively affect host metabolic health by altering the gut microbial community. Despite this, the regulatory effect of the gut microbiota on hepatic ketogenesis and triacylglycerol (TAG) accumulation during a KD remains poorly understood. Here, we hypothesized that the commensal bacterium regulates hepatic lipid metabolism in association with KD-induced hyperketonemia. The KD disrupts the remodeling of the gut microbiota following antibiotic-induced depletion. The capacity for ketogenesis and the severity of TAG accumulation in the liver closely correlated with changes in the gut microbial composition and the up-regulation of hepatic farnesoid X receptor (FXR), peroxisome proliferator-activated receptor alpha (PPARα), and diacylglycerol O-acyltransferase 2 (DGAT2), which were modulated by bile acid metabolism through the gut-liver axis. The commensal bacterium Clostridium perfringens type A is particularly implicated in prolonged hyperketonemia, exacerbating hepatic ketogenesis and steatosis by disrupting secondary bile acid metabolism. The increased conversion of deoxycholic acid to 12-ketolithocholic acid represents a critical microbial pathway during C. perfringens colonization. These findings illuminate the adverse effects of the gut microbiota on hepatic adaptation to a KD and highlight the regulatory role of C. perfringens in ketonic states.

Quercetin alleviates metabolic-associated fatty liver disease by tuning hepatic lipid metabolism, oxidative stress and inflammation

The natural flavonoid quercetin, which exhibits a range of biological activities, has been implicated in liver disease resistance in recent research. In vivo study attesting to quercetin's protective effect against metabolic-associated fatty liver disease (MAFLD) is inadequate, however. Here, our investigation explored the potential benefits of quercetin in preventing MAFLD in C57BL/6 mice fed a high-fat diet (HFD). The results revealed that quercetin ameliorated the aberrant enhancement of body and liver weight. The hepatic histological anomalie induced by MAFLD were also mitigated by quercetin. HFD-induced imbalance in serum LDL, HDL, AST, ALT, TG, and LDH was mitigated by quercetin. Mechanically, we found that quercetin improved lipid metabolism by reducing lipogenesis proteins including ACC, FASN, and SREBP-1c and enhancing β-oxidation proteins including PPARα and CPT1A. In vitro study demonstrated that quercetin regulated hepatic lipid metabolism by targeting SREBP-1c and PPARα. Additionally, quercetin enhanced the antioxidant capacity in HFD-treated mice by downregulating Nrf2 and HO-1 expressions and upregulating SOD and GPX1 expressions. The hyper-activation of inflammation was also restored by quercetin via eliminating the phosphorylation of IκBα and NF-κB p65. Collectively, our observations highlight that quercetin exerts hepatoprotective properties in MAFLD mice by regulating hepatic lipid metabolism, oxidative stress and inflammatory response.

GSK621 ameliorates lipid accumulation via AMPK pathways and reduces oxidative stress in hepatocytes in vitro and in obese mice in vivo

INTRODUCTION

Metabolic-dysfunction-associated fatty liver disease (MAFLD) represents a broad spectrum of liver lipid metabolism disorders associated with metabolic homeostasis, inflammation, oxidative stress, and fibrogenesis. The incidence of MAFLD has increased in recent years, but there is a lack of effective treatment strategies. GSK621 shows potential as a novel adenosine-monophosphate-activated protein kinase (AMPK) agonist; however, its function in lipid metabolism has not yet been confirmed.

OBJECTIVES

This study aimed to determine the effects of GSK621 on liver lipid accumulation in vitro and vivo and explore the underlying mechanism of these effects.

METHODS

The function of GSK621 in lipid deposition was investigated in vitro with HepG2 cells and normal mouse liver cells (AML12), and in vivo using C57BL/6 J mice fed with a high-fat diet (60 % fat) for 8 weeks to establish a model of MAFLD, followed by GSK621 treatment for a further 8 weeks.

RESULTS

GSK621 treatment significantly improved hepatocyte steatosis via the AMPK-carnitine palmitoyl transferase 1 (CPT1A) pathway and decreased levels of reactive oxygen species (ROS) in cells, accompanied by elevated expression of antioxidative stress proteins. MAFLD mice showed significant improvements in liver steatosis after GSK621 treatment, as well as increased expression of liver proteins related to the AMPK pathway and antioxidative stress.

CONCLUSION

GSK621 can improve hepatocytes steatosis in vitro and vivo via the AMPK-CPT1A pathway by increasing lipid metabolism and augmenting expression of antioxidant-stress-related proteins to reduce ROS deposition.

Advances in flavonoid bioactivity in chronic diseases and bioavailability: transporters and enzymes

Flavonoids, abundant in the human diet, have been extensively studied for their therapeutic bioactivities. Recent research has made significantly advances in our understanding of the biological activities of flavonoids, demonstrating their therapeutic effects for various chronic diseases. However, the generally low bioavailability of flavonoids limits their effectiveness. Therefore, it is essential to explore the pharmacokinetics of flavonoids, paying particular attention to the roles of transporters and metabolizing enzymes. This paper reviews recent studies on the bioactivity of flavonoids, highlighting the importance of transporters and metabolic enzymes in their pharmacokinetics.

Hyperoside modulates bile acid and fatty acid metabolism, presenting a potentially promising treatment for non-alcoholic fatty liver disease

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) is a multifactorial chronic condition that requires a systematic approach for effective management. Multi-effect therapeutic drugs derived from traditional Chinese medicine are increasingly being recognized as promising alternatives for NAFLD intervention. Hyperoside, a natural flavone glycoside found in Cuscuta chinensis Lam, Forsythia suspensa, and Crataegus pinnatifida Bge, has been shown to effectively mitigate NAFLD in rats. However, the underlying mechanism through which hyperoside alleviates NAFLD remains unclear.

OBJECTIVE

This study aims to explore the specific mechanisms by which hyperoside intervenes in the progression of NAFLD.

METHODS

In this study, a high-fat diet was used to induce the NAFLD model in rats. An integrated analysis, including mass spectrometry-based lipidomics, TMT-based proteomics, 16S rRNA sequencing, and bile acid-targeted metabolomics, was employed to identify significantly altered metabolites and proteins. Western blotting, molecular docking, and isothermal titration calorimetry were conducted to analyze the direct targets of action.

RESULTS

The results indicate that hyperoside activates farnesoid X receptor (FXR), promoting fatty acid oxidation and the efflux of bile acids from the liver. Additionally, hyperoside inhibits hepatic ATP citrate lyase (ACLY) and works synergistically with activated FXR to suppress de novo lipogenesis. Hyperoside also inhibits intestinal microbes linked to bile-salt hydrolase (BSH) activity, which enhances the production of ileal bile acids (BAs), particularly conjugated BAs, thus reducing the liver toxicity of endogenous BAs.

CONCLUSION

Our findings suggest that hyperoside alleviates NAFLD by modulating fatty acid and bile acid metabolism through FXR and ACLY, suggesting its potential as a multi-effect candidate drug for the treatment of NAFLD.

Deficiency of β-arrestin2 ameliorates MASLD in mice by promoting the activation of TAK1/AMPK signaling

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a liver manifestation of metabolic syndrome characterized by excessive hepatic lipid accumulation and lipid metabolism disorders. It has become the most common chronic liver disease worldwide. β-arrestin2 is a multifunctional scaffold protein that is among the most important regulatory molecules, and it exerts key roles in regulating various cellular processes, such as immune response, cellular collagen production, and inflammation. In the current study, we aimed to explore the function of β-arrestin2 in the development and progression of MASLD. Firstly, we observed that the expression of β-arrestin2 was upregulated in liver samples from patients with MASLD. Then, the western diet (WD) combined with CCl4 injection-induced MASLD was established in wild-type mice, and showed that liver β-arrestin2 expression was also gradually increased, and positively correlated with the degree of lipid metabolism disorder during MASLD progression. Ulteriorly, β-arrestin2 knockout (Arrb2 KO) mice were utilized to induce the MASLD model and found that β-arrestin2 deficiency significantly ameliorated lipid accumulation and inflammatory response in the liver of MASLD mice. Furthermore, the in vitro depletion and overexpression experiments showed that increased β-arrestin2 aggravated lipid accumulation via inhibiting the activation of the TAK1/AMPK pathway, which may be mediated by competitively binding to TAB1 with TAK1. These findings suggest that β-arrestin2 is essential to regulate intrahepatic lipid metabolism. Here, we provide a novel insight in understanding of the expression and function of β-arrestin2 in MASLD, demonstrating that it may be a potential therapeutic target for MASLD treatment.

Crosstalk Between Bile Acids and Intestinal Epithelium: Multidimensional Roles of Farnesoid X Receptor and Takeda G Protein Receptor 5

Bile acids and their corresponding intestinal epithelial receptors, the farnesoid X receptor (FXR), the G protein-coupled bile acid receptor (TGR5), play crucial roles in the physiological and pathological processes of intestinal epithelial cells. These acids and receptors are involved in the regulation of intestinal absorption, signal transduction, cellular proliferation and repair, cellular senescence, energy metabolism, and the modulation of gut microbiota. A comprehensive literature search was conducted using PubMed, employing keywords such as bile acid, bile acid receptor, FXR (nr1h4), TGR5 (gpbar1), intestinal epithelial cells, proliferation, differentiation, senescence, energy metabolism, gut microbiota, inflammatory bowel disease (IBD), colorectal cancer (CRC), and irritable bowel syndrome (IBS), with a focus on publications available in English. This review examines the diverse effects of bile acid signaling and bile receptor pathways on the proliferation, differentiation, senescence, and energy metabolism of intestinal epithelial cells. Additionally, it explores the interactions between bile acids, their receptors, and the microbiota, as well as the implications of these interactions for host health, particularly in relation to prevalent intestinal diseases. Finally, the review highlights the importance of developing highly specific ligands for FXR and TGR5 receptors in the context of metabolic and intestinal disorders.

The non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio as a predictor of NAFLD prevalence and steatosis severity

Altered lipid metabolism is a crucial jeopardy cause for developing non-alcoholic fatty liver disease (NAFLD). Among various lipid metrics, the ratio of non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol (NHHR) has recently emerged as a promising indicator showing significant potential in predicting the prevalence of NAFLD. This study aimed to provide novel insights for the prevention of NAFLD by examining the relationship between NHHR and the prevalence of NAFLD. To identify the connection between NHHR and NAFLD, this study utilized descriptive analysis, multivariate logistic regression, and restricted cubic spline regression to investigate data collected by the National Health and Nutrition Examination Survey performed from 2017 to 2020. Furthermore, the connection between NHHR and the controlled attenuation parameter (CAP) was assessed using multiple linear regression, smoothed curve fitting, and threshold effect analysis. The NAFLD group showed higher NHHR levels than the non-NAFLD group (2.990 vs 2.240, P < 0.001). Multiple logistic and linear regression analyses indicated significant positive associations between NHHR and its quartiles with both the prevalence of NAFLD and CAP levels. Additionally, NHHR was positively associated with the prevalence of NAFLD in a linear dose-response relationship. Furthermore, smoothed curve fitting demonstrated a positive relationship between NHHR and CAP, with a threshold effect at an inflection point of 3.398. Higher NHHR levels were significantly associated with the prevalence of NAFLD and steatosis, and maintaining NHHR in the appropriate range may reduce these conditions.

LC-HRMS profiling of Dendrobium huoshanense aqueous extract and its therapeutic effects on nonalcoholic fatty liver disease in mice through the TLR2-NF-κB and AMPK-SREBP1-SIRT1 signaling pathways

Dendrobium huoshanense (DH) belongs to the Dendrobium genus of the Orchidaceae family and is a herbaceous plant that protects the liver and nourishes the Yin according to traditional Chinese Medicine (TCM) theory. This research aimed to determine the therapeutic effect and mechanisms of DH on a nonalcoholic fatty liver disease (NAFLD) mouse model and its chemical composition. For pharmacological research, the pathological damage and lipid accumulation in liver tissues were evaluated using HE and oil red staining, respectively. The differential proteins between the model and DHH groups were screened using 4D label-free quantitative proteomics, and the proteomic results were verified using Western blot. The potential mechanism was validated by metabolomic analysis. The main active ingredients in a DH aqueous extract were identified using UHPLC-Q Exactive HF HRMS. Pathological staining results showed that DH can reverse liver pathological damage and lipid accumulation in the NAFLD model. Quantitative proteomics revealed that the differential proteins were mainly associated with liver lipid deposition (LAL, AMPK, TM7SF2, SBCAD, and SIRT1), insulin resistance (GYS1, GYS2, PYGL, FoxO1, and PPAR-γ), and inflammation (TLR2 and MAPKAPK). Western blot verified the above-mentioned results. Metabolomic analysis also indicated that the DH aqueous extract ameliorated NAFLD in mice by affecting cholesterol metabolism and AMPK signaling pathway, proving its significant therapeutic effects on the NAFLD model. Sixty-five compounds were identified from DH aqueous extract by analyzing the precise molecular weight and MS/MS fragmentation pathway. The pharmacological mechanism of DH in treating NAFLD mainly involved the TLR2-NF-κB and AMPK-SREBP1-SIRT1 signaling pathways.

Comparative effects of aerobic and resistance exercise on bile acid profiles and liver function in patients with non-alcoholic fatty liver disease

OBJECTIVE

Our research aims to explore the effects of different exercise on liver function and bile acid in patients with non-alcoholic fatty liver disease (NAFLD), to identify the most beneficial exercise modalities for patients with NAFLD.

DESIGN

Participants were randomly divided into four groups: control group, aerobic training group, resistance training group, and aerobic training combined with resistance training group. Participants underwent assessments of body shape, blood lipid, glucose levels and liver function biochemical parameters. Their bile acid levels were measured using the LC-MS/MS system. Changes in these parameters before and after the intervention and differences between groups were analyzed.

RESULTS

Participants in the AT group showed significant improvements in liver function parameters. Additionally, levels of total bile acids and ursodeoxycholic acid significantly increased. The RT group and AT + RT group also showed improvements in body shape and liver function parameters, but the improvements in these groups were not as pronounced as those in the AT group.

CONCLUSIONS

Aerobic exercise is the most beneficial modality for young patients with NAFLD, as it significantly improves body shape and liver function while also reducing blood lipid and glucose levels.

TRIAL REGISTRATION

Clinical trial number NCT06338449, registered on March 22, 2024.

A study of correlation of the dietary index for gut microbiota with non-alcoholic fatty liver disease based on 2007-2018 National Health and Nutrition Examination Survey

Objective

To explore the correlation of dietary index for gut microbiota (DI-GM) with non-alcoholic fatty liver disease (NAFLD).

Methods

Data of 6,711 participants were extracted from the National Health and Nutrition Examination Survey (NHANES) during 2007-2018. A weighted logistic regression analysis was employed for assessment of the correlation of DI-GM with NAFLD, and a restricted cubic spline (RCS) analysis was implemented to examine potential non-linear associations. Subgroup analyses were conducted to identify particularly susceptible groups. Additionally, the synergistic effects of different DI-GM components on NAFLD risk was assessed by weighted quantile sum (WQS) regression.

Results

The DI-GM exhibited statistically significant correlation with NAFLD [OR (95%CI):0.91 (0.85, 0.98), p = 0.015]. The results of the RCS analysis indicated a linear correlation of DI-GM and NAFLD (p = 0.810 for non-linearity). Further stratified analyses indicated that the negative correlation of DI-GM with NAFLD were significant and consistent for all subgroups. The results of WQS regression revealed that soybean (27%), refined grains (17%), coffee (16%), and red meat (9%) had the highest contribution weights to NAFLD.

Conclusion

As an important tool for assessment of the influences of diet on gut microbiota, DI-GM is negatively correlated with NAFLD risk factors. Soybean, refined grains, coffee, and red meat are key factors influencing NAFLD. The direct correlation of DI-GM with NAFLD shall be explored and the effectiveness of prevention and treatment of NAFLD shall be evaluated by improving DI-GM scores via dietary interventions.

Sanye tablet regulates gut microbiota and bile acid metabolism to attenuate hepatic steatosis

ETHNOPHARMACOLOGICAL RELEVANCE

Sanye Tablet (SYT), a patent traditional Chinese prescription, is commonly used in treating type 2 diabetes mellitus and hyperlipidemia. Both clinical and animal studies suggest that SYT effectively regulates lipid metabolism. However, its mode of action on hepatic steatosis has yet to be fully elucidated.

AIM OF STUDY

This study investigates the lipid-regulating effects and underlying mechanism of SYT in high-fat diet (HFD)-induced hepatic steatosis mice.

MATERIAL AND METHODS

The inhibitory effects of SYT on developing hepatic steatosis were investigated in HFD-fed C57BL/6N mice. Biochemical markers, including total cholesterol (TC) and triglycerides (TG), were measured using specific kits. Hepatic histological alterations were determined by Hematoxylin and Eosin (H&E) and Oil Red O staining. Hepatic, fecal, and systemic bile acids (BAs) profiles were detected by UPLC-MS. mRNA and protein levels of BAs synthesis-related enzymes and critical nodes of farnesoid X receptor (FXR)/fibroblast growth factor 15 (FGF15)/fibroblast growth factor receptor 4 (FGFR4) signaling were detected. Fecal microbial composition was analyzed by 16S rRNA gene sequencing and the antimicrobial activity of SYT was further evaluated in vitro.

RESULTS

SYT alleviated HFD-induced hepatic steatosis by decreasing TG and TC levels, relieving hepatocyte ballooning, and promoting hepatic BAs synthesis. Moreover, SYT significantly increased the levels of taurine-conjugated BAs in the liver and feces, which in turn inhibited the FXR/FGF15/FGFR4 signaling. Consequently, the hepatic BAs synthesis-related enzyme expression was promoted to reduce lipid accumulation. Notably, SYT remodeled the gut microbiota composition of HFD-fed mice, especially inhibiting the growth of bile salt hydrolase (BSH)-producing bacteria, such as Lactobacillus murinus, Lactobacillus johnsonii, and Enterococcus faecalis.

CONCLUSION

The findings illustrated that SYT prevented hepatic steatosis by improving hepatic lipid accumulation, which is reflected in modulating the gut-liver axis. SYT corrects BAs profile, restores perturbed FXR/FGF15/FGFR4 signaling and promotes hepatic BAs synthesis, which is associated with modulation on certain BSH-producing bacteria.

Environmental concentrations of N-nitrosodiethylamine (NDEA) disturb the Ca2 + and K+ homeostasis in the gills and epidermis of mosquitofish (Gambusia affinis)

N-nitrosodiethylamine (NDEA), a nitrogenous disinfection by-product, is notorious for its ubiquitous presence in the environment and its carcinogenic properties. However, its impact on ion homeostasis in aquatic organisms remains underexplored. In the present study, we investigated the effects of NDEA on ion homeostasis in mosquitofish exposed to varying concentrations for 30 days. Calcium and potassium fluxes were monitored using noninvasive micro-test technology (NMT), and ATPase activities and gene expressions related to ion transport and immune responses were assessed. Principal component analysis was conducted to identify the organs most sensitive to different NDEA exposure levels. The results revealed that NDEA exposure inhibited transport enzyme activities and affected the expression of ion transport- and immune-related genes. Among all tested tissues, the gills exhibited the highest overall sensitivity (0.443) to NDEA exposure, underscoring their essential functions in ion transport and calcium regulation. These findings underscore the critical role of ion homeostasis in NDEA-induced toxicity and highlight the importance of understanding tissue-specific responses in assessing the ecological risks posed by N-nitrosamines in aquatic environments.

Clinical application of bile acid profile combined with lipid indices in metabolic dysfunction-associated steatotic liver disease

OBJECTIVE

This study aims to investigate the diagnostic potential of bile acid profiles combined with lipid parameters in metabolic dysfunction-associated steatotic liver disease (MASLD).

METHOD

This study employed LC-MS technology to analyze the serum bile acid profiles of 186 male patients with MASLD and 80 male non-MASLD patients. According to whether the serum samples exhibit dyslipidemia, the subjects were divided into four groups. Subsequently, a series of analyses were conducted, including univariate analysis, the Spearman correlation test, multinomial logistic regression, restricted cubic spline regression, and ROC curve analysis.

RESULT

The bile acid profiles of serum samples with dyslipidemia exhibit significant differences compared to those of normal serum samples. The bile acids, which include total deoxycholic acid (DCA), secondary bile acids (SBA), unconjugated bile acids (UCBA), 12α-hydroxylated bile acids (12HBA), total bile acids (TBA), primary bile acids (PBA)/SBA, and glycine-conjugated bile acids (GCBA)/taurine-conjugated bile acids (TCBA), demonstrate a non-linear correlation with the logarithmic ratio of triglycerides (TG) to high-density lipoprotein cholesterol (HDL-C). The ROC analysis indicates that, in populations with normal lipid levels, bile acid indicators such as GLCA and 12HBA demonstrate a superior ability to distinguish between MASLD and non-MASLD compared to populations with abnormal lipid levels and the overall population. Their diagnostic performance significantly surpasses that of existing MASLD diagnostic models.

CONCLUSION

The combination of bile acid profiles and lipid indicators holds significant diagnostic potential in MASLD.

Integrating bioinformatics and metabolomics to identify potential biomarkers of hypertensive nephropathy

Hypertensive nephropathy (HN), caused by long-term poorly controlled hypertension, is the second common cause of end-stage renal disease after diabetes mellitus, but the pathogenesis of HN is unclear. The purpose of this study was to identify the biological pathways involved in the progression of HN and bile acid (BA)-related biomarkers, and to analyze the role of bile acids in HN. Download gene microarray data from Gene Expression Omnibus. Differentially expressed genes (DEGs) associated with HN were identified, and then DEGs were subjected to Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis. A protein-protein interaction (PPI) network was established using DEGs to identify BA-related hub genes in combination with bile acid identical targets. An animal model of early hypertensive nephropathy was established using SHR and the concentrations of 39 bile acids were measured quantitatively in the renal cortex to screen for significantly different concentrations and to analyze the correlation between bile acid concentrations and blood pressure. A total of 398 DEGs were screened. The results of enrichment analysis identified multiple biological pathways associated with hypertension, nephropathy and bile acids. Combining PPI network and bile acid-related targets, three BA-related hub genes (APOE, ALB, SERPINA1) were identified. Quantitative analysis of bile acids revealed significant differences in the concentrations of seven bile acids (DCA, CDCA, UDCA, UCA, CA, TDCA, TCDCA). The concentrations of these bile acids showed a positive correlation with blood pressure values in SHR, with CA, DCA and TDCA showing a stronger correlation and specificity with blood pressure in SHR. Three BA-related hub genes (APOE, ALB, SERPINA1) may be involved in the early stages of HN. The concentrations of multiple bile acids were significantly elevated in the early stages of HN, with CA, DCA and TDCA being more correlated and specific with blood pressure and having higher diagnostic value. These BA-related hub genes and BAs may be involved in disease progression in the early stages of HN.

Innovative strategy for full-scale polar components explicition and ultrasonic-assisted optimization of Astragalus membranaceus flower

Traditional extraction under merely one specific solvent was confronted with incomplete phytochemical unscramble problem. In view of this, in order to obtain the overall chemical understanding, we attempted to use Astragalus membranaceus flower, an abundant exploitable resource, to screen a novel extraction mixing scheme via gradient solvents based on the ions' quantity detected in UHPLC-Q-TOF-MS/MS approach. Samples were firstly extracted by different concentration ethanol, and then, six mixing schemes were investigated and one scheme with maximum detected ions was screened out. After identification procedures based on an comprehensive reference database, 136 components covered 54 flavonoids were accurately identified, indicating that flavonoids may played a critical role in Astragalus membranaceus flower. Through the Box-Behnken Design optimization, 29.79 mg/g of flavonoids were extracted under ethanol concentration of 35 %, solid-liquid ratio of 1:50, extraction time of 50 min. The experiments showed that the established mixing scheme could obtain more comprehensive ingredients compared to orthodox extraction, further guide the optimization of significative ingredients scientifically. The present paper could promote the development of Astragalus membranaceus flower.

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.

Liver diseases: epidemiology, causes, trends and predictions

As a highly complex organ with digestive, endocrine, and immune-regulatory functions, the liver is pivotal in maintaining physiological homeostasis through its roles in metabolism, detoxification, and immune response. Various factors including viruses, alcohol, metabolites, toxins, and other pathogenic agents can compromise liver function, leading to acute or chronic injury that may progress to end-stage liver diseases. While sharing common features, liver diseases exhibit distinct pathophysiological, clinical, and therapeutic profiles. Currently, liver diseases contribute to approximately 2 million deaths globally each year, imposing significant economic and social burdens worldwide. However, there is no cure for many kinds of liver diseases, partly due to a lack of thorough understanding of the development of these liver diseases. Therefore, this review provides a comprehensive examination of the epidemiology and characteristics of liver diseases, covering a spectrum from acute and chronic conditions to end-stage manifestations. We also highlight the multifaceted mechanisms underlying the initiation and progression of liver diseases, spanning molecular and cellular levels to organ networks. Additionally, this review offers updates on innovative diagnostic techniques, current treatments, and potential therapeutic targets presently under clinical evaluation. Recent advances in understanding the pathogenesis of liver diseases hold critical implications and translational value for the development of novel therapeutic strategies.

From gut to liver: Exploring the crosstalk between gut-liver axis and oxidative stress in metabolic dysfunction-associated steatotic liver disease

Non-alcoholic fatty liver disease (NAFLD), now recognized as metabolic dysfunction-associated steatotic liver disease (MASLD), represents a significant and escalating global health challenge. Its prevalence is intricately linked to obesity, insulin resistance, and other components of the metabolic syndrome. As our comprehension of MASLD deepens, it has become evident that this condition extends beyond the liver, embodying a complex, multi-systemic disease with hepatic manifestations that mirror the broader metabolic landscape. This comprehensive review delves into the critical interplay between the gut-liver axis and oxidative stress, elucidating their pivotal roles in the etiology and progression of MASLD. Our analysis reveals several key findings: (1) Bile acid dysregulation can trigger oxidative stress through enhanced ROS production in hepatocytes and Kupffer cells, leading to mitochondrial dysfunction and lipid peroxidation; (2) Gut microbiota dysbiosis disrupts intestinal barrier function, allowing increased translocation of endotoxins like LPS, which activate inflammatory pathways through TLR4 signaling and promote oxidative stress via NADPH oxidase activation; (3) The redox-sensitive transcription factors NF-κB and Nrf2 serve as crucial mediators in the gut-liver axis, with NF-κB regulating inflammatory responses and Nrf2 orchestrating antioxidant defenses; (4) Oxidative stress-induced damage to intestinal barrier function creates a destructive feedback loop, further exacerbating liver inflammation and disease progression. These findings highlight the complex interrelationship between gut-liver axis dysfunction and oxidative stress in MASLD pathogenesis, suggesting potential therapeutic targets for disease management.

The bile acid profile

As a large and structurally diverse family of small molecules, bile acids play a crucial role in regulating lipid, glucose, and energy metabolism. In the human body, bile acids share a similar chemical structure with many isomers, exhibit little difference in polarity, and possess various physiological activities. The types and contents of bile acids present in different diseases vary significantly. Therefore, comprehensive and accurate detection of the content of various types of bile acids in different biological samples can not only provide new insights into the pathogenesis of diseases but also facilitate the exploration of novel strategies for disease diagnosis, treatment, and prognosis. The detection of disease-induced changes in bile acid profiles has emerged as a prominent research focus in recent years. Concurrently, targeted metabolomics methods utilizing high-performance liquid chromatography-mass spectrometry (HPLC-MS) have progressively established themselves as the predominant technology for the separation and detection of bile acids. Bile acid profiles will increasingly play an important role in diagnosis and guidance in the future as the relationship between disease and changes in bile acid profiles becomes clearer. This highlights the growing diagnostic value of bile acid profiles and their potential to guide clinical decision-making. This review aims to explore the significance of bile acid profiles in clinical diagnosis from four perspectives: the synthesis and metabolism of bile acids, techniques for detecting bile acid profiles, changes in bile acid profiles associated with diseases, and the challenges and future prospects of applying bile acid profiles in clinical settings.

Flavonoids for gastrointestinal tract local and associated systemic effects: A review of clinical trials and future perspectives

BACKGROUND

Flavonoids are naturally occurring dietary phytochemicals with significant antioxidant effects aside from several health benefits. People often consume them in combination with other food components. Compiling data establishes a link between bioactive flavonoids and prevention of several diseases in animal models, including cardiovascular diseases, diabetes, gut dysbiosis, and metabolic dysfunction-associated steatotic liver disease (MASLD). However, numerous clinical studies have demonstrated the ineffectiveness of flavonoids contradicting rodent models, thereby challenging the validity of using flavonoids as dietary supplements.

AIM OF REVIEW

This review provides a clinical perspective to emphasize the effective roles of dietary flavonoids as well as to summarize their specific mechanisms in animals briefly.

KEY SCIENTIFIC CONCEPTS OF REVIEW

First, this review offers an in-depth elucidation of the metabolic processes of flavonoids within human, encompassing the small, large intestine, and the liver. Furthermore, the review provides a comprehensive overview of the various functions of flavonoids in the gastrointestinal tract, including hindering the breakdown and assimilation of macronutrients, such as polysaccharides and lipids, regulating gut hormone secretion as well as inhibition of mineral iron absorption. In the large intestine, an unabsorbed major portion of flavonoids interact with the gut flora leading to their biotransformation. Once absorbed and circulated in the bloodstream, bioactive flavonoids or their metabolites exert numerous beneficial systemic effects. Lastly, we examine the protective effects of flavonoids in several metabolic disorders, including endothelial dysfunction, MASLD, cardiovascular disease, obesity, hyperlipidemia, and insulin resistance. In conclusion, this review outlines the safety and future prospects of flavonoids in the field of health, especially in the prevention of metabolic syndrome (MetS).

Gastrointestinal absorption and its regulation of hawthorn leaves flavonoids

Hawthorn leave flavonoids (HLF) are widely used as an herb or dietary supplements for cardio-cerebrovascular diseases. However, its gastrointestinal absorption behavior and mechanism have not been disclosed. In this study, gastrointestinal absorption and its regulation of 4''-O-glucosylvitexin (GLV), 2''-O-rhamnosylvitexin (RHV), vitexin (VIT), rutin (RUT) and hyperoside (HP) in HLF were investigated using in vitro, in situ and in vivo models. Apparent permeability coefficient (Papp) of five flavonoids were (2.18 ± 0.15) ×10-7~(3.83 ± 0.22) ×10-7 cm·sec-1 across the Caco-2 cells. GLV, RHV, VIT and RUT demonstrated similar and poor absorption in rat stomach (absorption percentage per hour (A), (1.78 ± 0.14 ~ 5.69 ± 0.51)%·h-1) and small intestine (absorption rate ([Formula: see text], (0.012 ± 0.006 ~ 0.055 ± 0.003) h-1), extent (A, (1.28 ± 0.14 ~ 2.82 ± 0.19)% ·h-1) and potential (Papp, (0.31 ± 0.05 ~ 1.41 ± 0.08)×10-7 cm·sec-1)), while HP showed relatively better absorption (Papp, (2.55 ± 0.15 ~ 4.27 ± 0.36)×10-7 cm·sec-1) in rat small intestine. Absorption of five flavonoids exhibited dose-dependence, pH-dependence and region-selectivity. Meanwhile, these flavonoids were excreted via intestine, secreted via bile and metabolized by intestinal microflora. Their absorption was significantly increased by absorption enhancers (cow bile salt and sodium dodecyl sulphate), transporter regulators (verapamil hydrochloride, digoxin and rifampicin). GLV and RHV exhibited enterohepatic circulation after oral administration of HLF. In conclusion, flavonoids in HLF were absorbed via passive diffusion accompanied with active transport, intestinal microflora metabolism, bile secretion and intestinal efflux. They belong to BCS class III ("like" drugs with high solubility and low permeability) and displayed poor oral bioavailability.

Caveolin-1 mitigates the advancement of metabolic dysfunction-associated steatotic liver disease by reducing endoplasmic reticulum stress and pyroptosis through the restoration of cholesterol homeostasis

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most prevalent chronic liver disease worldwide, which has the potential to advance to fibrosis. CAV1 has the effects of improving liver lipid deposition in MASLD, however, the potential mechanism is largely unknown. Here, we establish a MASLD mouse model in CAV1 knockout (KO) mice and perform transcriptome analysis on livers from mice to investigate the effects of CAV1 in MASLD progression. In addition, we evaluated the expression of CAV1 in human liver samples, and also conducted assays in vitro to investigate the molecular role of CAV1 in MASLD progression. The results illustrate that the expression of liver CAV1 in the decreases during MASLD progression, which aggravates the accumulation of cholesterol in the liver, leading to more severe endoplasmic reticulum (ER) stress and pyroptosis. Mechanistically, CAV1 regulates the expression of FXR/NR1H4 and its downstream cholesterol transporter, ABCG5/ABCG8, suppressing ER stress and alleviating pyroptosis. Our study confirms CAV1 is a crucial regulator of cholesterol homeostasis in MASLD and plays an important role in disease progression.

Repeated Injection of Xylazine Causes Liver Injury Through the PPAR Signaling Pathway in Rats

With the gradual emergence of xylazine as a street drug, incidents of xylazine poisoning are now occurring worldwide. However, it remains unknown whether long-term exposure to xylazine causes nonalcoholic fatty liver disease (NAFLD). In the present study, the rats were injected with xylazine intraperitoneally for 28 consecutive days, and then serum and liver tissues were collected for analysis. Weight loss was observed in the 40 mg/kg group and elevated levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were observed. Histopathologic examination showed hepatic steatosis, necrosis, and fibrosis. By mRNA sequencing, 192 upregulated genes and 277 downregulated genes were found in the 40 mg/kg group, and the PPAR signaling pathway was ranked first in the KEGG pathway analysis. Four genes in the PPAR signaling pathway, Fabp5, Acox2, and Cpt2, were also verified in the 40 mg/kg group by RT-qPCR analysis and western blot. Our results demonstrated that long-term injection of xylazine causes NAFLD and the PPAR signaling pathway plays a core role in the process of xylazine-associated liver injury.

Potential mechanism of perillaldehyde in the treatment of nonalcoholic fatty liver disease based on network pharmacology and molecular docking

Non-alcoholic fatty liver disease (NAFLD) is one of the most common chronic metabolic liver diseases worldwide. Perillaldehyde (4-propyl-1-en-2-ylcyclohexene-1-aldehyde, PA) is a terpenoid compound extracted from Perilla, which has effective pharmacological activities such as anti-inflammatory, antidepressant, and anticancer. This study aimed to explore the pharmacological effects of PA in intervening with NAFLD and reveal its potential mechanisms. Firstly, we identified the core targets of PA intervention therapy for NAFLD through network pharmacology and molecular docking techniques. After that, in vitro animal experiments such as H&E and Masson staining, immunofluorescence, immunohistochemistry, and Western blot were conducted to validate the results network effectively pharmacology predicted. Network pharmacology analysis suggested that PPAR-α may be the core target of PA intervention in NAFLD. H&E and Masson staining showed that after low-dose (50 mg/kg) PA administration, there was a noticeable improvement in fat deposition in the livers of NAFLD mice, and liver tissue fibrosis was alleviated. Immunohistochemical and immunofluorescence analysis showed that low dose (50 mg/kg) PA could reduce hepatocyte apoptosis, decrease the content of pro-apoptosis protein Bax, and increase the expression of anti-apoptosis protein Bcl-2 in NAFLD mice. Western blot results confirmed that low-dose (50 mg/kg) PA could increase the expression of PPAR-α and inhibit the expression of NF-κB in NAFLD mice. Our study indicated that PA could enhance the activity of PPAR-α and reduce the level of NF-κB in NAFLD mice, which may positively affect the prevention of NAFLD.

Medium chain triglycerides alleviate non-alcoholic fatty liver disease through bile acid-mediated FXR signaling pathway: A comparative study with common vegetable edible oils

With the global epidemic trend of obesity, non-alcoholic fatty liver disease (NAFLD) has become a significant cause of chronic liver disease, seriously affecting human health. Medium-chain triglycerides (MCT) with a fatty acid chain length varying between 6 and 10 carbon atoms (most sources from coconut and palm kernel oils), which exhibited activities to improve lipid metabolism, prevent cardiovascular diseases, and enhance immunity. However, the efficacy differences and potential mechanisms between MCT and traditional long-chain vegetable oils (palm oil, PA; high oleic peanut oil, OA) in obesity-induced NAFLD were still unclear. The present study treated obesity-induced NAFLD mice with different dietary lipids for 16 weeks. The results showed that MCT supplements significantly improved abnormal elevation of weight gain and blood lipids and reduced hepatic lipid accumulation to a greater extent than PA and OA. Furthermore, bile acid profiling results indicated that MCT significantly changed the composition of bile acids in the liver, reduced the concentrations of cholic acid (CA), deoxycholic acid (DCA), β-muricholic acid (β-MCA), and ursodeoxycholic acid (UDCA) and increased the concentrations of chenodeoxycholic Acid (CDCA), taurochenodeoxycholic acid （TCDCA), hyodeoxycholic acid (HDCA), and taurohyodeoxycholic acid (THDCA). Mechanistically, MCT supplement upregulated FXR signal and inhibited the expression of key genes for triglyceride synthesis in the liver, thereby reducing hepatic lipid accumulation. In summary, MCT exerted a superior effect on PA and OA in improving obesity-induced NAFLD. These results provided new evidence for the application of MCT in treating NAFLD.

Bile acid disorders and intestinal barrier dysfunction are involved in the development of fatty liver in laying hens

The pathogenesis of fatty liver is highly intricate. The role of the gut-liver axis in the development of fatty liver has gained increasing recognition in recent years. This study was conducted to explore the role of bile acid signaling and gut barrier in the pathogenesis of fatty liver. A total of 100 "Jing Tint 6" laying hens, 56-week-old, were used and fed basal diets until 60 weeks of age. At the end of the experiment, thirty individuals were selected based on the degree of hepatic steatosis. The hens with minimal hepatic steatosis (< 5 %) were chosen as healthy controls, while those with severe steatosis (> 33 %) in the liver were classified as the fatty liver group. Laying hens with fatty liver and healthy controls showed significant differences in body weight, liver index, abdominal fat ratio, feed conversion ratio (FCR), albumin height, Haugh unit, and biochemical indexes. The results of bile acid metabolomics revealed a clear separation in hepatic bile acid profiles between the fatty liver group and healthy controls, and multiple secondary bile acids were decreased in the fatty liver group, indicating disordered bile acid metabolism. Additionally, the mRNA levels of farnesoid X receptor (FXR) and genes related to bile acid transport were significantly decreased in both the liver and terminal ileum of hens with fatty liver. Moreover, the laying hens with fatty liver exhibited significant decreases in ileal crypt depth, the number of goblet cells, and the mRNA expression of tight junction-related proteins, alongside a significant increase in ileal permeability. Collectively, these findings suggest that disordered bile acids, suppressed FXR-mediated signaling, and impaired intestinal barrier function are potential factors promoting the development of fatty liver. These insights indicate that regulating bile acids and enhancing intestinal barrier function may become new preventive and therapeutic strategies for fatty liver in the near future.

Rutin ameliorates HCD-induced cholesterol metabolism disorder in zebrafish larvae revealed by transcriptome and metabolome analysis

Changes in modern lifestyles have led to an increase in obesity rates. Excessive lipid accumulation leads to abnormal cholesterol metabolism, and maintaining a balanced cholesterol metabolism is essential for the normal functioning of cells and the body. Rutin belongs to the group of flavonoids with hypolipidemic, anti-inflammatory and antioxidant effects. The aim of this study was to investigate the role of rutin in cholesterol metabolism disorders induced by a high cholesterol diet in zebrafish larvae. The trial was divided into five groups: Normal diet (ND), 5 % high cholesterol diet (HCD), 5 % high cholesterol diet with 80 μg/g ezetimibe diet (EZE), 5 % high cholesterol diet with 5 % rutin diet (RL-HCD), and 5 % high cholesterol diet with 10 % rutin diet (RH-HCD). Zebrafish larvae at 5 dpf were randomly divided into five groups and continuously fed different diets for 10 days, after 10 days zebrafish samples were collected for subsequent experiments. Body length, body width, oil red O, and Nile red staining were measured to detect biochemical indexes, analyze inflammatory response and lipid accumulation. Vascular endothelial injury was assessed by stereofluorescence microscopy and ELISA. In order to study the protective effect of rutin in zebrafish with cholesterol metabolism disorder induced by HCD, RNA-seq and LC-MS/MS nontargeted metabolomics were employed. The results indicate that HCD led to an increase in the body length and width of zebrafish. The HCD group induced an increase in body length and width, lipid accumulation, and exacerbated inflammation. Additionally, vascular damage and abnormal expression of endothelial cell markers were observed. Rutin lowered lipid levels in zebrafish fed an HCD, reduced inflammation, and protected endothelial cells. The RNA-seq and metabolomic analysis combined demonstrated that rutin effectively ameliorates the disorder of cholesterol metabolism in vivo by reducing cholesterol synthesis and promoting cholesterol transport.

Integrative analysis of non12-hydroxylated bile acid revealed the suppressed molecular map of alternative pathway in nonalcoholic steatohepatitis mice

Bile acids (BAs) are significantly altered in the liver and serum of patients with nonalcoholic steatohepatitis (NASH). However, the underlying mechanisms of these changes, particularly BA alternative pathways (BAP) responsible for non12-OH BAs, remain unclear. RNA-seq data were initially analyzed to reveal the changes of gene expression in NASH patients. Targeted metabolomics were conducted on plasma from NASH mice induced by high-fat or western diet with CCl4 for 10-24 weeks. Liver tissues were examined using proteomics, RT-qPCR, and western blotting. An integrated approach was then employed to analyze protein interactions and network correlations. Analysis of RNA-seq data revealed the inhibition of CYP7B1 in NASH patients, indicating the dysregulation of BAP. In NASH mouse models, dysregulation of BA circulation was observed by increased plasma total BA (TBA) levels and decreased liver TBA, with liver swelling and histopathological changes. Targeted metabolomics revealed suppressed levels of non12-OH BAs, which inversely correlated with increased liver injury markers. The reduced mRNA and protein expression of Fxr and upregulation of Lxr signaling in livers suggested the suppressed BAP was modulated by Fxr-Lxr signaling. Moreover, BAP interactions predominantly implicated multiple metabolism disruptions, involving 7 hub proteins (Hk1, Acadsb, Pklr, Insr, Ldlr, Cyp27a1, and Cyp7b1), offering promising therapeutic targets for NASH. We presented the metabolic and proteomic map of BAP and its regulatory network in NASH progression. Therapeutic targeting of BAP or its co-regulatory proteins holds promise for NASH treatment and metabolic syndrome management.

Investigating the tamoxifen/high-fat diet synergy: a promising paradigm for nonalcoholic steatohepatitis induction in a rat model

Non-alcoholic steatohepatitis (NASH) is a severe liver condition characterized by excessive fat deposition, ballooning, and lobular inflammation. This investigation was conducted to estimate the capability of concomitant tamoxifen administration (TAM) with a high fat diet (HFD) to induce a reliable NASH model that mimics human NASH features. Rats were administered TAM (25 mg/kg/day p.o.) and consumed HFD for 5 weeks. A time-course investigation was conducted to determine the optimal time for NASH development. Liver function indices, hepatic lipid profile factors, oxidative stress biomarkers, and inflammatory mediators were estimated. Additionally, macroscopic and microscopic changes were examined. Compared with the time-matched control group receiving vehicle alone, TAM/HFD significantly impaired liver function indices represented as marked elevation in ALT, AST, and ALP serum levels. TAM/HFD significantly increased lipid profile factors including high TG and TC hepatic levels. Additionally, TAM/HFD remarkably raised hepatic levels of TNF-α and IL-17 and significantly decreased IL-10. The combination also increases the oxidative status evidenced by high content of MDA as well as low activity of GPx and SOD. Accordingly, the combination of TAM and HFD for 5 weeks collaboratively promotes NASH development by initiating compromised hepatocyte functionality, elevated lipid levels, oxidative stress, and liver inflammation.

Effects of dietary protein level on liver lipid deposition, bile acid profile and gut microbiota composition of growing pullets

The current study investigated the effects of dietary crude protein (CP) level on the liver lipid metabolism, gut microbiota, and bile acids (BA) profiles of growing pullets. Roman growing pullets (N = 180, 13-wk-old) were divided into 3 treatments groups with 6 replicates in each group and 10 hens in each replicate and provided 3 different dietary CP level diet treatments. The diet treatments included: a high-protein diet (15.5% CP, HP group), a medium-protein diet (14.5% CP, MP group), and a low-protein diet (13.5% CP, LP group). Compared with HP group, LP group significantly increased the lipid contents in the body (such as Breast intramuscular fat [BIMF], Leg intramuscular fat [LIMF], Percentage of abdominal fat [PAF], liver triglyceride [TG] and liver cholesterol [TC]), and the lipid metabolism-related parameters in serum (such as cholesterol (TC), high density lipoprotein cholesterol [HDL-C], low density lipoprotein cholesterol [LDL-C], very low density lipoprotein [VLDL]), and the mRNA expression of lipid metabolism-related genes (such as fatty acid synthase [FAS], CCAAT/enhancer binding protein β [C/EBPβ], and fatty acid translocase [FAT/CD6]) (P < 0.05). In addition, LP group significantly reduced the contents of lithocholic acid (LCA), isoLCA, and ursodesoxycholic acid (UDCA), and increased the deoxycholic acid (DCA) content compared with HP group (P < 0.05). The effects of LCA on lipid deposition were confirmed in chicken preadipocyte cell line (CPI), in which LCA supplementation significantly decreased the relative expression of PPARγ, FAS, acyl-CoA carboxylase (ACC) and SREBP-1c (P < 0.05). Correlation analysis further revealed a significant association between BA profiles and lipid metabolism-related parameters. Furthermore, 16S rRNA gene sequencing indicated that dietary protein level can significantly affect the richness, diversity, and composition of cecal microbiota in growing pullets. LP group significantly increased the abundance of Bacteroidetes and significantly decreased the abundance of Firmicutesa compared with the HP group. In summary, low protein diet in growing pullets influence the liver lipid metabolism through changing the gut microbiota and liver BA metabolism.

Exploratory Role of Flavonoids on Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) in a South Italian Cohort

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most recent definition for steatotic liver disease associated with metabolic syndrome. The results of recent metabolic and observational studies suggest a potential beneficial effect of food-derived flavonoids in some chronic diseases, including MASLD. The study aims to evaluate the protective role of diet flavonoids in subjects with and without MASLD belonging to a cohort living in the South of Italy.

METHODS

The study cohort comprised 1297 participants assessed in the NUTRIHEP cohort (2015-2018), divided into two groups, based on presence or absence of MASLD.

RESULTS

The results indicated statistically significant flavonoid consumption, showing a protective role against MASLD, at an optimal concentration of 165 mg/day, with an OR value of 0.63, (p = 0.001, 95% C.I.: 0.47; 0.83 t). The OR remained almost unchanged when the intake increased from 165 mg per day to 185 mg per day.

CONCLUSIONS

In conclusion, our study results show a protective role of flavonoids against MASLD. Consuming only 165 mg of flavonoids daily can activate this protective function, reducing the risk of MASLD.

Zhi-Kang-Yin formula attenuates high-fat diet-induced metabolic disorders through modulating gut microbiota-bile acids axis in mice

BACKGROUND

Metabolic disorders have become one of the global medical problems. Due to the complexity of its pathogenesis, there is still no effective treatment. Bile acids (BAs) and gut microbiota (GM) have been proved to be closely related to host metabolism, which could be important targets for metabolic disorders. Zhi-Kang-Yin (ZKY) is a traditional Chinese medicine (TCM) formula developed by the research team according to theory of TCM and has been shown to improve metabolism in clinic. However, the underlying mechanisms are unclear.

AIM OF THE STUDY

This study aimed to investigate the potential mechanisms of the beneficial effect of ZKY on metabolism.

METHODS

High-fat diet (HFD)-fed mice were treated with and without ZKY. The glucose and lipid metabolism-related indexes were measured. BA profile, GM composition and hepatic transcriptome were then investigated to analyze the changes of BAs, GM, and hepatic gene expression. Moreover, the relationship between GM and BAs was identified with functional gene quantification and ex vivo fermentation experiment.

RESULTS

ZKY reduced weight gain and lipid levels in both liver and serum, attenuated hepatic steatosis and improved glucose tolerance in HFD-fed mice. BA profile detection showed that ZKY changed the composition of BAs and increased the proportion of unconjugated BAs and non-12-OH BAs. Hepatic transcriptomic analysis revealed fatty acid metabolism and BA biosynthesis related pathways were regulated. In addition, ZKY significantly changed the structure of GM and upregulated the gene copy number of bacterial bile salt hydrolase. Meanwhile, ZKY directly promoted the growth of Bifidobacterium, which is a well-known bile salt hydrolase-producing genus. The ex vivo co-culture experiment with gut microbiota and BAs demonstrated that the changes of BAs profile in ZKY group were mediated by ZKY-shifted GM, which led to increased expression of genes associated with fatty acid degradation in the liver.

CONCLUSION

Our study indicated that the effect of ZKY on improving metabolism is associated with the modulation of GM-BAs axis, especially, by upregulating the abundance of bile salt hydrolase-expression bacteria and increasing the levels of unconjugated BAs. This study indicates that GM-BAs axis might be an important pathway for improving metabolic disorders by ZKY.

Gypensapogenin A-Liposomes Efficiently Ameliorates Hepatocellular Lipid Accumulation via Activation of FXR Receptor

Non-alcoholic fatty liver disease (NAFLD) is one of the most common metabolic diseases encountered in clinical practice, which is characterized by the excessive accumulation of triglycerides (steatosis), and a variety of metabolic abnormalities including lipid metabolism and bile acid metabolism are closely related to NAFLD. In China, Gynostemma pentaphyllum is used as functional food and Chinese medicine to treat various diseases, especially NAFLD, for a long time. However, the active components that exert the main therapeutic effects and their mechanisms remain unclear. In this study, Gypensapogenin A was isolated from the total saponins of G. pentaphyllum and prepared as a liposomal delivery system. Gypensapogenin A liposomes could activate FXR, inhibit the expression of CYP7A1 and CYP8B1, increase the expression of CYP27A1, modulate the ratio of CA and CDCA, decrease the content of CA, and increase the content of CDCA, thus forming a virtuous cycle of activating FXR to play a role in lowering blood lipid levels.

Bioprotective Role of Phytocompounds Against the Pathogenesis of Non-alcoholic Fatty Liver Disease to Non-alcoholic Steatohepatitis: Unravelling Underlying Molecular Mechanisms

Non-alcoholic fatty liver disease (NAFLD), with a global prevalence of 25%, continues to escalate, creating noteworthy concerns towards the global health burden. NAFLD causes triglycerides and free fatty acids to build up in the liver. The excessive fat build-up causes inflammation and damages the healthy hepatocytes, leading to non-alcoholic steatohepatitis (NASH). Dietary habits, obesity, insulin resistance, type 2 diabetes, and dyslipidemia influence NAFLD progression. The disease burden is complicated due to the paucity of therapeutic interventions. Obeticholic acid is the only approved therapeutic agent for NAFLD. With more scientific enterprise being directed towards the understanding of the underlying mechanisms of NAFLD, novel targets like lipid synthase, farnesoid X receptor signalling, peroxisome proliferator-activated receptors associated with inflammatory signalling, and hepatocellular injury have played a crucial role in the progression of NAFLD to NASH. Phytocompounds have shown promising results in modulating hepatic lipid metabolism and de novo lipogenesis, suggesting their possible role in managing NAFLD. This review discusses the ameliorative role of different classes of phytochemicals with molecular mechanisms in different cell lines and established animal models. These compounds may lead to the development of novel therapeutic strategies for NAFLD progression to NASH. This review also deliberates on phytomolecules undergoing clinical trials for effective management of NAFLD.

Farnesoid X receptor: From Structure to Function and Its Pharmacology in Liver Fibrosis

The farnesoid X receptor (FXR), a ligand-activated transcription factor, plays a crucial role in regulating bile acid metabolism within the enterohepatic circulation. Beyond its involvement in metabolic disorders and immune imbalances affecting various tissues, FXR is implicated in microbiota modulation, gut-to-brain communication, and liver disease. The liver, as a pivotal metabolic and detoxification organ, is susceptible to damage from factors such as alcohol, viruses, drugs, and high-fat diets. Chronic or recurrent liver injury can culminate in liver fibrosis, which, if left untreated, may progress to cirrhosis and even liver cancer, posing significant health risks. However, therapeutic options for liver fibrosis remain limited in terms of FDA-approved drugs. Recent insights into the structure of FXR, coupled with animal and clinical investigations, have shed light on its potential pharmacological role in hepatic fibrosis. Progress has been achieved in both fundamental research and clinical applications. This review critically examines recent advancements in FXR research, highlighting challenges and potential mechanisms underlying its role in liver fibrosis treatment.

Role of FXR in the development of NAFLD and intervention strategies of small molecules

Non-alcoholic fatty liver disease (NAFLD) remains a prevailing etiological agent behind hepatocyte diseases like chronic liver disease. The spectrum of processes involved in NAFLD stages includes hepatic steatosis, non-alcoholic fatty liver, and non-alcoholic steatohepatitis (NASH). Without intervention, the progression of NASH can further deteriorate into cirrhosis and ultimately, hepatocellular carcinoma. The cardinal features that characterize NAFLD are insulin resistance, lipogenesis, oxidative stress and inflammation, extracellular matrix deposition and fibrosis. Due to its complex pathogenesis, existing pharmaceutical agents fail to take a curative or ameliorative effect on NAFLD. Consequently, it is imperative to identify novel therapeutic targets and strategies for NAFLD, ideally to improve the aforementioned key features in patients. As an enterohepatic regulator of bile acid homeostasis, lipid metabolism, and inflammation, FarnesoidX receptor (FXR) is an important pharmacological target for the treatment of NAFLD. Manipulating FXR to regulate lipid metabolic signaling pathways is a potential mechanism to mitigate NAFLD. Therefore, elucidating the modulatory character of FXR in regulating lipid metabolism in NAFLD has the potential to yield groundbreaking perspectives for drug design. This review details recent advances in the regulation of lipid depletion in hepatocytes and investigates the pivotal function of FXR in the progress of NAFLD.

Increase in bile acids after sleeve gastrectomy improves metabolism by activating GPBAR1 to increase cAMP in mice with nonalcoholic fatty liver disease

BACKGROUND

Bile acids (BAs) concentration can affect metabolic improvement caused by bariatric surgery and BA concentrations increase in patients after sleeve gastrectomy (SG). Here, how BAs after SG affect metabolism in nonalcoholic fatty liver disease (NAFLD) was studied.

METHODS

Mice were given high-fat diet (HFD) to induce NAFLD and received SG surgery. Hepatic and fecal BA concentrations in mice were detected by liquid chromatography-tandem mass spectrometry method. BA-related genes were detected by quantitative real-time polymerase chain reaction. G protein BA receptor 1 (GPBAR1) expression was identified using western blot analysis. NAFLD mice after SG received GPBAR1 inhibitor Triamterene. The weight of mice and mice liver was detected. Mouse liver tissue was observed by hematoxylin-eosin and Oil Red O staining. Triglyceride (TG), nonesterified fatty acid (NEFA), and cyclic adenosine monophosphate (cAMP) levels in mouse liver tissue were analyzed by metabolic assay and enzyme-linked immune sorbent assay.

RESULTS

SG boosted increase in hepatic total/conjugated BAs and related genes and GPBAR1 expression, and attenuated increase in fecal total BAs/muricholic acid in HFD-induced mice and increased fecal taurine-BAs in HFD-induced mice. Triamterene (72 mg/kg) reversed the inhibitory role of SG in HFD-induced increase of body weight, lipid accumulation, inflammatory cell infiltration, and increase of hepatic weight and TG/NEFA content, and counteracted the positive role of SG in HFD-induced increase of hepatic cAMP concentration in mice.

CONCLUSIONS

BAs improve metabolism via activating GPBAR1 to increase cAMP in NAFLD mice after SG.

A Current Understanding of FXR in NAFLD: The multifaceted regulatory role of FXR and novel lead discovery for drug development

The global prevalence of nonalcoholic fatty liver disease (NAFLD) has reached 30 %, with an annual increase. The incidence of NAFLD-induced cirrhosis is rapidly rising and has become the leading indicator for liver transplantation in the US. However, there are currently no US Food and Drug Administration-approved drugs for NAFLD. Increasing evidence underscores the close association between NAFLD and bile acid metabolism disorder, highlighting the feasibility of targeting the bile acid signaling pathway for NAFLD treatment. The farnesoid X receptor (FXR) is an endogenous receptor for bile acids that exhibits favorable effects in ameliorating the metabolic imbalance of bile acids, lipid disorders, and disruption of intestinal homeostasis, all of which are key characteristics of NAFLD, making FXR a promising therapeutic target for NAFLD. The present review provides a comprehensive overview of the diverse mechanisms through which FXR improves NAFLD, with particular emphasis on its involvement in regulating bile acid homeostasis and the recent advancements in drug development targeting FXR for NAFLD treatment.

Discovery and validation of COX2 as a target of flavonoids in Apocyni Veneti Folium: Implications for the treatment of liver injury

ETHNOPHARMACOLOGICAL RELEVANCE

Apocyni Veneti Folium (AVF), a popular traditional Chinese medicine (TCM), is known for its effects in soothing the liver and nerves and eliminating heat and water. It is relevant from an ethnopharmacological perspective. Pharmacological research has confirmed its benefits on antihypertension, antihyperlipidemia, antidepression, liver protection, immune system boosting, antiaging, and diabetic vascular lesions. Previous studies have shown that flavonoids, the active ingredients, have a hepatoprotective effect. However, the exact mechanism has not been clarified.

AIM OF THE STUDY

This study aimed to identify the active flavonoids in AVF and their corresponding targets for liver injury. Multiple methods were introduced to confirm the targets.

MATERIAL AND METHODS

AVF compounds were analyzed using liquid chromatography-mass spectrometry (LC-MS). Then, network pharmacology was utilized to screen potential hepatoprotection targets of the compounds. An enzyme activity assay was performed to determine the effect of the compounds on the targets. Biolayer interferometry (BLI) was applied to confirm the direct interaction between the compounds and the targets.

RESULTS

A total of 71 compounds were identified by LC-MS and 19 compounds and 112 shared targets were screened using network pharmacology. These common targets were primarily involved in the TNF signaling pathway, cancer pathways, hepatitis B, drug responses, and negative regulation of the apoptotic process. Flavonoids were the primary pharmacological substance basis of AVF. The cyclooxygenase 2 (COX2) protein was one of the direct targets of flavonoids in AVF. The enzyme activity assay and BLI-based intermolecular interactions demonstrated that the compounds astragalin, isoquercitrin, and hyperoside exhibited stronger inhibition of enzyme activity and a higher affinity with COX2 compared to epigallocatechin, quercetin, and catechin.

CONCLUSIONS

COX2 was preliminarily identified as a target of flavonoids, and the mechanism of the hepatoprotective effect of AVF might be linked to flavonoids inhibiting the activity of COX2. The findings can establish the foundation for future research on the traditional hepatoprotective effect of AVF on the liver and for clinical studies on liver disorders.

Dapagliflozin ameliorates hepatic steatosis via suppressing LXRα-mediated synthesis of lipids and bile acids

Nonalcoholic fatty liver disease (NAFLD) prevalence is rising globally with no pharmacotherapies approved. Hepatic steatosis is closely associated with progression and prognosis of NAFLD. Dapagliflozin, kind of sodium-glucose cotransporter 2 (SGLT2) inhibitor, was found to improve NAFLD in clinical trials, while the underlying mechanism remains poorly elucidated. Here, we reported that dapagliflozin effectively mitigated liver injury and relieved lipid metabolism disorders in vivo. Further investigation showed that dapagliflozin markedly suppressed Liver X Receptor α (LXRα)-mediated synthesis of de novo lipids and bile acids (BAs). In AML12 cells, our results proved dapagliflozin decreased lipid contents via inhibiting the expression of LXRα and downstream liposynthesis genes. Proteosome inhibitor MG132 eliminated the effect of dapagliflozin on LXRα-mediated signaling pathway, which suggested that dapagliflozin downregulated LXRα expression through increasing LXRα degradation. Knockdown of LXRα with siRNA abolished the reduction of lipogenesis from dapagliflozin treatment, indicating that LXRα might be the pivotal target for dapagliflozin to exhibit the aforementioned benefits. Furthermore, the data showed that dapagliflozin reversed gut dysbiosis induced by BAs disruption and altered gut microbiota profile to reduce intestinal lipids absorption. Together, our study deciphered a novel mechanism by which dapagliflozin relieved hepatic steatosis and highlighted the potential benefit of dapagliflozin in treating NAFLD.

Examining the Pathogenesis of MAFLD and the Medicinal Properties of Natural Products from a Metabolic Perspective

Metabolic-associated fatty liver disease (MAFLD), characterized primarily by hepatic steatosis, has become the most prevalent liver disease worldwide, affecting approximately two-fifths of the global population. The pathogenesis of MAFLD is extremely complex, and to date, there are no approved therapeutic drugs for clinical use. Considerable evidence indicates that various metabolic disorders play a pivotal role in the progression of MAFLD, including lipids, carbohydrates, amino acids, and micronutrients. In recent years, the medicinal properties of natural products have attracted widespread attention, and numerous studies have reported their efficacy in ameliorating metabolic disorders and subsequently alleviating MAFLD. This review aims to summarize the metabolic-associated pathological mechanisms of MAFLD, as well as the natural products that regulate metabolic pathways to alleviate MAFLD.

The Reduced Gut Lachnospira Species Is Linked to Liver Enzyme Elevation and Insulin Resistance in Pediatric Fatty Liver Disease

The objective of this study was to investigate gut dysbiosis and its metabolic and inflammatory implications in pediatric metabolic dysfunction-associated fatty liver disease (MAFLD). This study included 105 children and utilized anthropometric measurements, blood tests, the Ultrasound Fatty Liver Index, and fecal DNA sequencing to assess the relationship between gut microbiota and pediatric MAFLD. Notable decreases in Lachnospira spp., Faecalibacterium spp., Oscillospira spp., and Akkermansia spp. were found in the MAFLD group. Lachnospira spp. was particularly reduced in children with MAFLD and hepatitis compared to controls. Both MAFLD groups showed a reduction in flavone and flavonol biosynthesis sequences. Lachnospira spp. correlated positively with flavone and flavonol biosynthesis and negatively with insulin levels and insulin resistance. Body weight, body mass index (BMI), and total cholesterol levels were inversely correlated with flavone and flavonol biosynthesis. Reduced Lachnospira spp. in children with MAFLD may exacerbate insulin resistance and inflammation through reduced flavone and flavonol biosynthesis, offering potential therapeutic targets.

Natural Products in the Modulation of Farnesoid X Receptor Against Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a global health concern with a high prevalence and increasing economic burden, but official medicine remains unavailable. Farnesoid X receptor (FXR), a nuclear receptor member, is one of the most promising drug targets for NAFLD therapy that plays a crucial role in modulating bile acid, glucose, and lipid homeostasis, as well as inhibits hepatic inflammation and fibrosis. However, the rejection of the FXR agonist, obecholic acid, by the Food and Drug Administration for treating hepatic fibrosis raises a question about the functions of FXR in NAFLD progression and the therapeutic strategy to be used. Natural products, such as FXR modulators, have become the focus of attention for NAFLD therapy with fewer adverse reactions. The anti-NAFLD mechanisms seem to act as FXR agonists and antagonists or are involved in the FXR signaling pathway activation, indicating a promising target of FXR therapeutic prospects using natural products. This review discusses the effective mechanisms of FXR in NAFLD alleviation, and summarizes currently available natural products such as silymarin, glycyrrhizin, cycloastragenol, berberine, and gypenosides, for targeting FXR, which can facilitate development of naturally targeted drug by medicinal specialists for effective treatment of NAFLD.

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.

Identification of commensal gut bacterial strains with lipogenic effects contributing to NAFLD in children

Gut microbiota is known to have a significant impact on nonalcoholic fatty liver disease (NAFLD), particularly in children with obesity. However, the specific functions of microbiota at the strain level in this population have not been fully elucidated. In this study, we successfully isolated and identified several commensal gut bacterial strains that were dominant in children with obesity and NAFLD. Among these, four novel isolates were found to have significant lipogenic effects in vitro. These strains exhibited a potential link to hepatocyte steatosis by regulating the expression of genes involved in lipid metabolism and inflammation. Moreover, a larger cohort analysis confirmed that these identified bacterial strains were enriched in the NAFLD group. The integrated analysis of these strains effectively distinguished NASH from NAFL. These four strains might serve as potential biomarkers in children with NAFLD. These findings provided new insights into the exploration of therapeutic targets for NAFLD.

Low intake of ruminant trans fatty acids ameliorates the disordered lipid metabolism in C57BL/6J mice fed a high-fat diet

Currently, the health benefits of ruminant trans fatty acids (R-TFA) are still controversial. Our previous investigations indicated that R-TFA at higher dosages (1.3% and 4% E) caused disordered lipid metabolism in mice; however, through collecting R-TFA intake data in 9 provinces of China, it was suggested that, in 2021, the range of R-TFA intake for Chinese residents was about 0.053-0.307 g d-1. Based on the 2022 Nutritional Dietary Guidelines for Chinese Residents, the recommended daily energy supply from R-TFA was about 0.11%-0.15% E. However, the health effects of R-TFA at a lower dosage are still unknown; therefore, our current research aims to further explore the effects of R-TFA on health. Through in vivo experiments, it was shown that R-TFA (0.15% E) decreased body weight gain and serum cholesterol levels in C57BL/6J mice fed a high-fat diet, while it had no significant effect on mice fed a low-fat diet. Besides, hepatic histopathology analysis suggested that R-TFA (0.15% E) ameliorated the degree of hepatic steatosis and reduced intrahepatocyte lipid droplet accumulation in C57BL/6J mice fed a high-fat diet. Through lipidomics analysis, we further screened 8 potential lipid metabolites that participate in regulating the dysregulation of lipid metabolism. Finally, it was suggested that R-TFA (0.15% E) down-regulated the expression of genes related to inflammation and cholesterol synthesis while up-regulated the expression of genes related to cholesterol clearance, which might partially explain the salutary effect of R-TFA (0.15% E) in ameliorating the hepatic steatosis and improving disordered lipid metabolism in mice fed a high-fat diet. Our current research will provide a reference for the intake of R-TFA and, furthermore, give some insights into understanding the health effects of R-TFA.

Pharmacological modulation of cholesterol 7α-hydroxylase (CYP7A1) as a therapeutic strategy for hypercholesterolemia

Despite the availability of many therapeutic options, the prevalence of hypercholesterolemia remains high. There exists a significant unmet medical need for novel drugs and/or treatment combinations to effectively combat hypercholesterolemia while minimizing adverse reactions. The modulation of cholesterol 7α-hydroxylase (CYP7A1) expression via perturbation of the farnesoid X receptor (FXR) - dependent pathways, primarily FXR/small heterodimer partner (SHP) and FXR/ fibroblast growth factor (FGF)-19/ fibroblast growth factor receptor (FGFR)-4 pathways, presents as a potential option to lower cholesterol levels. This paper provides a comprehensive review of the important role that CYP7A1 plays in cholesterol homeostasis and how its expression can be exploited to assert differential control of bile acid synthesis and cholesterol metabolism. Additionally, the paper also summarizes the current therapeutic options for hypercholesterolemia, and positions modulators of CYP7A1 expression, namely FGFR4 inhibitors and FXR antagonists, as emerging and distinct pharmacological agents to complement and diversify the treatment regime. Their mechanistic and clinical considerations are also extensively described to interrogate the benefits and risks associated with using FXR-mediating agents, either singularly or in combination with recognised agents such as statins to target hypercholesterolemia.

Therapeutic Role of Polyphenol Extract from Prunus cerasifera Ehrhart on Non-Alcoholic Fatty Liver

Prunus cerasifera Ehrhart (P. cerasifera) flourishes uniquely in the arid landscapes of Xinjiang, China. Preliminary studies have revealed the therapeutic potential of its polyphenol extract (PPE) in mitigating liver lipid accumulation in mice fed a high-fat diet. We established a mouse model that was subjected to a continuous high-fat diet for 24 weeks and administered PPE to investigate the effects of PPE on cholesterol and BA metabolism in NAFLD mice. The results showed that PPE administration (200 and 400 mg/kg/day, BW) led to a reduction in liver TC, an increase in liver T-BAs, and normalization of the disrupted fecal BA profile. Concurrently, it decreased levels of lipotoxic BAs and inhibited hepatic cholesterol synthesis (evidenced by reduced HMGCR activity) and intestinal cholesterol absorption (indicated by lower ACAT2 levels) while enhancing intestinal cholesterol efflux (via LXRα, ABCA1, ABCG5, and ABCG8) and stimulating hepatic BA synthesis (CYP7A1, CYP27A1) and secretion (BSEP). PPE thus led to a significant reduction in lipotoxic BAs metabolized by gut microbiota and a downregulation of the BA secretion pathway under its influence. Our findings reveal the therapeutic effect of PPE on NAFLD mice via regulating cholesterol and BA metabolism, providing a theoretical basis for exploring the potential functions of P. cerasifera.