Ameliorative effects and molecular mechanisms of vine tea on western diet-induced NAFLD

Coffee pulp improves glucose and lipid metabolism disorder in high-fat diet-induced diabetic mice

Background

Coffee berry extracts are anti-lipogenic and lipolytic. This study aims to investigate the effect and mechanism of coffee pulp on high-fat diet (HFD)-induced glucose and lipid metabolism disorder in mice.

Methods

The type 2 diabetes (T2D) mouse model was established by feeding the C57BL/6 J mice with HFD. Mice were administered with coffee pulp diluted in drinking water before or after the establishment of the T2D mouse model. After treatment, the body weight and fasting blood glucose (FBG) of mice were monitored; the intraperitoneal glucose tolerance test (IPGTT) of mice was performed; plasma insulin was determined by ELISA; serum total cholesterol (TC), triglyceride (TG) and liver TG were determined by biochemical analysis; hematoxylin-eosin (H&E) staining was used to evaluate organ histomorphology. Gene expression of key genes in de novo lipogenesis (DNL) in the liver was examined by quantitative reverse transcription PCR (RT-qPCR).

Results

Mice that consumed coffee pulp after modeling showed reduced FBG and liver TG, improved IPGTT, and alleviated fatty liver. Consuming coffee pulp before modeling prevented HFD-induced blood glucose and plasma TG increases. Mice consuming coffee pulp also had lower body fat and liver TG compared to the model group. qPCR results showed that the expression of transcription factors (Srebp1, PPARγ) and genes (Fasn, CideA, Plin3, Plin4, Plin5) related to DNL and lipid droplets (LD) formation in the liver of mice consuming coffee pulp were significantly lower than those of the control group.

Conclusions

Our study demonstrated that coffee pulp can attenuate HFD-induced disorders of glucose and lipid metabolism, and this effect may be related to the key pathways of lipid synthesis DNL and LD formation pathways in the liver.

Hepatocyte-specific casein kinase 1 epsilon ablation ameliorates metabolic dysfunction-associated steatohepatitis by upregulating TRAF3 in mice

Casein kinase 1 epsilon (CK1ε), a member of the serine/threonine protein kinase family, is known to phosphorylate a broad range of substrates. However, its role in the development of chronic liver diseases remains elusive. This study aimed to investigate the role of CK1ε in the development and progression of metabolic dysfunction-associated steatohepatitis (MASH). Hepatocyte-specific CK1ε knockout (CK1εΔHEP) mice were generated by crossbreeding mice with floxed CK1ε alleles (CK1εfl/fl) and Cre expressing Albumin mice. Mice were fed either a Western diet (WD) or a methionine and choline-deficient (MCD) to induce MASH. CK1εΔHEP was associated with a decreased severity of WD- or MCD-induced MASH, as confirmed by reduced incidence of hepatic lesions and significantly lower levels of alanine aminotransferase, aspartate aminotransferase, and proinflammatory cytokine TNF-α. CK1εΔHEP WD-fed mice exhibited significant amelioration of total cholesterol, triglycerides and de novo lipogenic genes, indicating that CK1ε could influence lipid metabolism. CK1εΔHEP WD-fed mice showed significantly downregulated TRAF3, phosphorylated (p) TAK1, pTBK1, and pAKT levels, thereby affecting downstream MAPK signaling, indicating a potential mechanism for the observed rescue. Finally, pharmacological inhibition of CK1ε with PF670462 improved PA-induced steatohepatitis in vitro and attenuated WD-induced metabolic profile in vivo. In conclusion, CK1ε upregulates TRAF3, which in turn causes TAK1-dependent signaling, amplifies downstream MAPK signaling, modifies p-c-Jun levels, and exacerbates inflammation, all of which are factors in WD-induced MASLD.

Antioxidant effects of Paeoniflorin and relevant molecular mechanisms as related to a variety of diseases: A review

Paeoniflorin (PF), which is the main component of the Paeonia lactiflora Pall extract, is one of the traditional Chinese medicines. The pharmacological effects associated with PF include antioxidant, immunomodulatory, anti-inflammatory, anticancer, antidepressant-like and neuroprotective effects. Our previous studies had revealed that PF protected melanocytes and inhibited photodamage through the suppression of oxidative stress (OS). As OS plays a vital role in the progression of a variety of diseases, the capacity for PF to suppress OS may exert important effects upon them. However, no review exists on these antioxidant effects of PF as related to various diseases. Therefore, in this review we summarized studies involved with examining the antioxidant effects and molecular mechanisms of PF. Through its capacity to inhibit OS, PF has been shown to exert beneficial effects upon several systems including nervous, cardiac/vascular, digestive, and respiratory as well as specific diseases such as diabetes, autoimmune, pregnancy related, ocular, kidney, dermatology, along with suppression of distal flap necrosis, postoperative adhesions, and hearing loss. Such findings provide new insights and directions for future research directed at the development of PF as a natural antioxidant for the treatment of clinical diseases.

Integration of network pharmacology, lipidomics, and transcriptomics analysis to reveal the mechanisms underlying the amelioration of AKT-induced nonalcoholic fatty liver disease by total flavonoids in vine tea

Nonalcoholic fatty liver disease (NAFLD) is the main reason for chronic liver diseases and malignancies. Currently, there is a lack of approved drugs for the prevention or treatment of NAFLD. Vine tea (Ampelopsis grossedentata) has been used as a traditional Chinese beverage for centuries. Vine tea carries out several biological activities including the regulation of plasma lipids and blood glucose, hepato-protective function, and anti-tumor activity and contains the highest content of flavonoids. However, the underlying mechanisms of total flavonoids from vine tea (TF) in the attenuation of NAFLD remain unclear. Therefore, we investigated the interventions and mechanisms of TF in mice with NAFLD using an integrated analysis of network pharmacology, lipidomics, and transcriptomics. Staining and biochemical tests revealed a significant increase in AKT-overexpression-induced (abbreviated as AKT-induced) NAFLD in mice. Lipid accumulation in hepatic intracellular vacuoles was alleviated after TF treatment. In addition, TF reduced the hepatic and serum triglyceride levels in mice with AKT-induced NAFLD. Lipidomics results showed 32 differential lipids in the liver, mainly including triglycerides (TG), diglycerides (DG), phosphatidylcholine (PC), and phosphatidylethanolamine (PE). Transcriptomic analysis revealed that 314 differentially expressed genes were commonly upregulated in the AKT group and downregulated in the TF group. The differential regulation of lipids by the genes Pparg, Scd1, Chpt1, Dgkz, and Pla2g12b was further revealed by network enrichment analysis and confirmed by RT-qPCR. Furthermore, we used immunohistochemistry (IHC) to detect changes in the protein levels of the key proteins PPARγ and SCD1. In summary, TF can improve hepatic steatosis by targeting the PPAR signaling pathway, thereby reducing de novo fatty acid synthesis and modulating the glycerophospholipid metabolism.

Supplementation of Silymarin Alone or in Combination with Salvianolic Acids B and Puerarin Regulates Gut Microbiota and Its Metabolism to Improve High-Fat Diet-Induced NAFLD in Mice

Silymarin, salvianolic acids B, and puerarin were considered healthy food agents with tremendous potential to ameliorate non-alcoholic fatty liver disease (NAFLD). However, the mechanisms by which they interact with gut microbiota to exert benefits are largely unknown. After 8 weeks of NAFLD modeling, C57BL/6J mice were randomly divided into five groups and fed a normal diet, high-fat diet (HFD), or HFD supplemented with a medium or high dose of Silybum marianum extract contained silymarin or polyherbal extract contained silymarin, salvianolic acids B, and puerarin for 16 weeks, respectively. The untargeted metabolomics and 16S rRNA sequencing were used for molecular mechanisms exploration. The intervention of silymarin and polyherbal extract significantly improved liver steatosis and recovered liver function in the mice, accompanied by an increase in probiotics like Akkermansia and Blautia, and suppressed Clostridium, which related to changes in the bile acids profile in feces and serum. Fecal microbiome transplantation confirmed that this alteration of microbiota and its metabolites were responsible for the improvement in NAFLD. The present study substantiated that alterations of the gut microbiota upon silymarin and polyherbal extract intervention have beneficial effects on HFD-induced hepatic steatosis and suggested the pivotal role of gut microbiota and its metabolites in the amelioration of NAFLD.

Dihydromyricetin ameliorates hepatic steatosis and insulin resistance via AMPK/PGC-1α and PPARα-mediated autophagy pathway

BACKGROUND

Dihydromyricetin (DHM), a flavonoid compound of natural origin, has been identified in high concentrations in ampelopsis grossedentata and has a broad spectrum of biological and pharmacological functions, particularly in regulating glucose and lipid metabolism. The objective of this research was to examine how DHM affected nonalcoholic fatty liver disease (NAFLD) and its underlying mechanisms involved in the progression of NAFLD in a rat model subjected to a high-fat diet (HFD). Additionally, the study examines the underlying mechanisms in a cellular model of steatohepatitis using palmitic acid (PA)-treated HepG2 cells, with a focus on the potential correlation between autophagy and hepatic insulin resistance (IR) in the progress of NAFLD.

METHODS

SD rats were exposed to a HFD for a period of eight weeks, followed by a treatment with DHM (at doses of 50, 100, and 200 mg·kg-1·d-1) for additional six weeks. The HepG2 cells received a 0.5 mM PA treatment for 24 h, either alone or in conjunction with DHM (10 µM). The histopathological alterations were assessed by the use of Hematoxylin-eosin (H&E) staining. The quantification of glycogen content and lipid buildup in the liver was conducted by the use of PAS and Oil Red O staining techniques. Serum lipid and liver enzyme levels were also measured. Autophagic vesicle and autolysosome morphology was studied using electron microscopy. RT-qPCR and/or western blotting techniques were used to measure IR- and autophagy-related factors levels.

RESULTS

The administration of DHM demonstrated efficacy in ameliorating hepatic steatosis, as seen in both in vivo and in vitro experimental models. Moreover, DHM administration significantly increased GLUT2 expression, decreased G6Pase and PEPCK expression, and improved IR in the hepatic tissue of rats fed a HFD and in cells exhibiting steatosis. DHM treatment elevated Beclin 1, ATG 5, and LC3-II levels in hepatic steatosis models, correlating with autolysosome formation. The expression of AMPK levels and its downstream target PGC-1α, and PPARα were decreased in HFD-fed rats and PA-treated hepatocytes, which were reversed through DHM treatment. AMPK/ PGC-1α and PPARα knockdown reduced the impact of DHM on hepatic autophagy, IR and accumulation of hepatic lipid.

CONCLUSIONS

Our findings revealed that AMPK/ PGC-1α, PPARα-dependent autophagy pathways in the pathophysiology of IR and hepatic steatosis has been shown, suggesting that DHM might potentially serve as a promising treatment option for addressing this disease.

Research progress on the regulation of oxidative stress by phenolics: the role of gut microbiota and Nrf2 signaling pathway

In recent years, the increase in high-calorie diets and sedentary lifestyles has made obesity a global public health problem. An unbalanced diet promotes the production of proinflammatory cytokines and causes redox imbalance in the body. Phenolics have potent antioxidant activity and cytoprotective ability. They can scavenge free radicals and reactive oxygen species, and enhance the activity of antioxidant enzymes, thus combating the body's oxidative stress. They can also improve the body's inflammatory response, enhance the enzyme activity of lipid metabolism, and reduce the contents of cholesterol and triglyceride. Most phenolics are biotransformed and absorbed into the blood after the action by gut microbiota; these metabolites then undergo phase I and II metabolism and regulate oxidative stress by scavenging free radicals and increasing expression of antioxidant enzymes. Phenolics induce the expression of genes encoding antioxidant enzymes and phase II detoxification enzymes by stimulating Nrf2 to enter the nucleus and bind to the antioxidant response element after uncoupling from Keap1, thereby promoting the production of antioxidant enzymes and phase II detoxification enzymes. The absorption rate of phenolics in the small intestine is extremely low. Most phenolics reach the colon, where they interact with the microbiota and undergo a series of metabolism. Their metabolites will reach the liver via the portal vein and undergo conjugation reactions. Subsequently, the metabolites reach the whole body to exert biological activity by traveling with the systemic circulation. Phenolics can promote the growth of probiotics, reduce the ratio of Firmicutes/Bacteroidetes (F/B), and improve intestinal microecological imbalance. This paper reviews the nutritional value, bioactivity, and antioxidant mechanism of phenolics in the body, aiming to provide a scientific basis for the development and utilization of natural antioxidants and provide a reference for elucidating the mechanism of action of phenolics for regulating oxidative stress in the body. © 2023 Society of Chemical Industry.

Golden bile powder prevents drunkenness and alcohol-induced liver injury in mice via the gut microbiota and metabolic modulation

BACKGROUND

Drunkenness and alcoholic liver disease (ALD) are critical public health issues associated with significant morbidity and mortality due to chronic overconsumption of alcohol. Traditional remedies, such as bear bile powder, have been historically acclaimed for their hepatoprotective properties. This study assessed the efficacy of a biotransformed bear bile powder known as golden bile powder (GBP) in alleviating alcohol-induced drunkenness and ALD.

METHODS

A murine model was engineered to simulate alcohol drunkenness and acute hepatic injury through the administration of a 50% ethanol solution. Intervention with GBP and its effects on alcohol-related symptoms were scrutinized, by employing an integrative approach that encompasses serum metabolomics, network medicine, and gut microbiota profiling to elucidate the protective mechanisms of GBP.

RESULTS

GBP administration significantly delayed the onset of drunkenness and decreased the duration of ethanol-induced inebriation in mice. Enhanced liver cell recovery was indicated by increased hepatic aldehyde dehydrogenase levels and superoxide dismutase activity, along with significant decreases in the serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, triglyceride, and total cholesterol levels (P < 0.05). These biochemical alterations suggest diminished hepatic damage and enhanced lipid homeostasis. Microbiota analysis via 16S rDNA sequencing revealed significant changes in gut microbial diversity and composition following alcohol exposure, and these changes were effectively reversed by GBP treatment. Metabolomic analyses demonstrated that GBP normalized the alcohol-induced perturbations in phospholipids, fatty acids, and bile acids. Correlation assessments linked distinct microbial genera to serum bile acid profiles, indicating that the protective efficacy of GBP may be attributable to modulatory effects on metabolism and the gut microbiota composition. Network medicine insights suggest the prominence of two active agents in GBP as critical for addressing drunkenness and ALD.

CONCLUSION

GBP is a potent intervention for alcohol-induced pathology and offers hepatoprotective benefits, at least in part, through the modulation of the gut microbiota and related metabolic cascades.

Phosphorylation: new star of pathogenesis and treatment in steatotic liver disease

Steatotic liver disease poses a serious threat to human health and has emerged as one of the most significant burdens of chronic liver disease worldwide. Currently, the research mechanism is not clear, and there is no specific targeted drug for direct treatment. Phosphorylation is widely regarded as the most common type of protein modification, closely linked to steatotic liver disease in previous studies. However, there is no systematic review to clarify the relationship and investigate from the perspective of phosphorylation. Phosphorylation has been found to mainly regulate molecule stability, affect localization, transform molecular function, and cooperate with other protein modifications. Among them, adenosine 5'-monophosphate-activated protein kinase (AMPK), serine/threonine kinase (AKT), and nuclear factor kappa-B (NF-kB) are considered the core mechanisms in steatotic liver disease. As to treatment, lifestyle changes, prescription drugs, and herbal ingredients can alleviate symptoms by influencing phosphorylation. It demonstrates the significant role of phosphorylation as a mechanism occurrence and a therapeutic target in steatotic liver disease, which could be a new star for future exploration.

Mechanism of Action and Related Natural Regulators of Nrf2 in Nonalcoholic Fatty Liver Disease

With the acceleration of people's pace of life, non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease in the world, which greatly threatens people's health and safety. Therefore, there is still an urgent need for higher-quality research and treatment in this area. Nuclear factor Red-2-related factor 2 (Nrf2), as a key transcription factor in the regulation of oxidative stress, plays an important role in inducing the body's antioxidant response. Although there are no approved drugs targeting Nrf2 to treat NAFLD so far, it is still of great significance to target Nrf2 to alleviate NAFLD. In recent years, studies have reported that many natural products treat NAFLD by acting on Nrf2 or Nrf2 pathways. This article reviews the role of Nrf2 in the pathogenesis of NAFLD and summarizes the currently reported natural products targeting Nrf2 or Nrf2 pathway for the treatment of NAFLD, which provides new ideas for the development of new NAFLD-related drugs.

Kefir Ameliorates Alcohol-Induced Liver Injury Through Modulating Gut Microbiota and Fecal Bile Acid Profile in Mice

SCOPE

Alcoholic liver disease (ALD) is the leading cause of liver-related deaths worldwide. Kefir has been studied for its properties of anti-obesity, rebuilding intestinal homeostasis, and alleviating non-alcoholic fatty liver disease. However, the possible role of kefir in the prevention or treatment of ALD has not been carefully considered. Here, it evaluated the protective effects of kefir supplementation on alcohol-induced liver injury.

METHODS AND RESULTS

C57BL/6J mice are fed to Lieber-DeCarli liquid diet containing alcohol to build ALD mouse model, followed by oral administration with kefir. Results indicate that kefir treatment improves liver pathological changes, decreases the expression levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and inflammatory markers, and increases antioxidant levels. Kefir supplementation also restores the intestinal barrier and altered microbial composition, indicates as increases of Blautia, Bacteroides, and Parasutterella and decreases in the Firmicutes/Bacteroidetes (F/B) ratio and populations of Psychrobacter, Bacillus, and Monoglobus. Moreover, kefir supplementation decreases the levels of total bile acids (BAs) and primary BAs and increases the secondary/primary BA ratio. Gut microbes play a key role in the conversion of primary to secondary fecal BAs.

CONCLUSION

Kefir can ameliorate ALD through regulating the composition of the gut microbiota.

A comprehensive review of vine tea: Origin, research on Materia Medica, phytochemistry and pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Vine tea is a popular folk tea that has been consumed in China for more than 1200 years. It is often used in ethnic medicine by ethnic groups in southwest China with at least 35 aliases in 10 provinces. In coastal areas, vine tea is mostly used to treat heatstroke, aphtha, aphonia, toothache, etc. In contrast, in the southwest inland regions, vine tea is mostly used to clear away heat and toxic materials, antiphlogosis and relieving sore-throat, lowering blood pressure and lipid levels, and alleviating fatigue. Three main species have been used as the source of vine tea, Nekemias grossedentata, Nekemias cantonensis and Nekemias megalophylla. Among them, the leaves of Nekemias grossedentata were considered as new food resource in complicance with regulations, according to the Food Safety Standards published by the Monitoring and Evaluation Department of the National Health and Family Planning Commission in China.

AIM OF THE STUDY

At present, the comprehensively summary of Materia Medica on the history and source of vine tea is currently unavailable. The current article summed up the Materia Medica, species origin and pharmacological effects of all 3 major species used in vine tea to fill the knowledge gaps. We also aim to provide a reference for future research on historical textual, resource development and medicinal utilization of vine tea.

MATERIALS AND METHODS

Adhering to the literature screening methodology outlined by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), this review encompasses 148 scholarly research papers from three database, paper ancient books, local chronicles and folklore through field investigations. We then comprehensively summarized and discussed research progresses in scientific and application studies of vine tea.

RESULTS

The historical records indicated that vine tea could have been used as early as Southern and Northern Dynasties (AC 420-589). Nekemias grossedentata, Nekemias cantonensis and Nekemias megalophylla, were used to considered as vine tea in the ethnic medicine. The main phytochemicals found in three plants are flavonoids, polyphenols and terpenoids, among which dihydromyricetin (DHM) is the most important and most studied active substance. The key words "Ampelopsis grossedentata" (Synonym of Nekemias grossedentata) and "dihydromyricetin/DHM" showed the highest frequency over the last 27 year based on the research trend analysis. And the ethnopharmacology studies drawn the main activities of vine tea are antioxidant, antibacterial, hepatoprotective, neuroprotective and anti-atherosclerosis activities.

CONCLUSIONS

This review systematically summarized and discussed vine tea from the following five aspects, history, genetic relationship, phytochemistry, research trend and ethnopharmacology. Vine tea has a long historical usage in Chinese ethnic medicine. Its outstanding therapeutic efficacies have attracted extensive attention in other places in the world at present. Nekemias cantonensis and Nekemias megalophylla are quite similar to Nekemias grossedentata in terms of many aspects. However, the current research has a narrow focus on mainly Nekemias grossedentata and DHM. We propose that future studies could be carried out to determine the synergistic effect of multi-components and multi-targets of vine tea including all 3 species to provide valuable knowledge.

Modifying effects of 2,4-D and Glyphosate exposures on gut-liver-adipose tissue axis of diet-induced non-alcoholic fatty liver disease in mice

Nonalcoholic fatty liver disease (NAFLD), which is linked to western diet (WD) intake, affects 30% of the world's population and involves the crosstalk of liver steatosis, hypertrophy/inflammation of adipose tissue and deregulation of gut microbiome. Glyphosate and 2,4-D are some of the most applied herbicides worldwide, and their roles in NAFLD have not been investigated. Thus, the present study evaluated whether glyphosate and 2,4-D, in single or mixed exposure, alter WD-induced NAFLD in a mouse model. Male C57Bl/6 mice (n = 10/group) received a fat (30% lard, 0.02% cholesterol), and sucrose-rich diet (20%) and high sugar solution (23.1 and 18.9 g/L of fructose and glucose) for 6 months. Simultaneously, animals received glyphosate (0.05 or 5 mg/kg/day), 2,4-D (0.02 or 2 mg/kg/day), or their combination (0.05 +0.02 or 5 +2 mg/kg/day) by intragastrical administration (5 ×/week). Doses were based on the Acceptable Daily Intake (ADIs) or No Observed Adverse Effect Level (NOAEL) levels. Herbicide exposures featured differential responses. WD-induced obesity, hypercholesterolemia, and hyperglycemia remained unaltered. Compared to the group receiving only WD, only the concomitant exposure to WD and 2,4-D (2 mg) enhanced the percentage of mice with moderate/severe hepatic inflammation, CD68 macrophage infiltration, and malondialdehyde levels in the liver. In line, this herbicide modulated immune response- (including Cd4, C8b, Cd28, Cxcr3, Cxcr6) and oxidative stress-related (such as Gsta1, Gsta2, Gsta4, Gstm1, Gstm2, Gstm3, Gstm4, Nqo1, Gpx2) genes in the hepatic transcriptome analysis. This exposure also enriched pro-inflammatory Deferribacteres phylum in fecal microbiome. In general, the herbicide mixtures did not feature the same effects attributed to 2,4-D isolated exposure. Our findings indicate that 2,4-D, at a dose within the toxicological limits, was able to induce disturbances in mainly at the liver and gut axes involved in NAFLD development in male mice.

Tetrahydropalmatine ameliorates hepatic steatosis in nonalcoholic fatty liver disease by switching lipid metabolism via AMPK-SREBP-1c-Sirt1 signaling axis

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is becoming a global epidemic without effective treatment currently available. NAFLD is characterized by an increase in hepatic de novo lipogenesis (DNL) and inadequate compensatory enhancement in fatty acid oxidation (FAO), which disturbs lipid homeostasis. In NAFLD, lipid metabolism relies heavily on metabolic reprogramming. Moreover, lipid metabolism plays an essential role in switching between lipogenesis and FAO, which is beneficial for the anti-NAFLD therapy. Our recent study demonstrated that the phytochemical tetrahydropalmatine (THP) has positive efficacy in hepatocellular carcinoma (HCC). However, it remains unclear whether the therapeutic benefits of THP are primarily due to delaying the progression of hepatic steatosis to HCC.

PURPOSE

This work aimed to systemically evaluate the pharmacological functions and underlying mechanisms of THP in NAFLD using both in vitro and in vivo models.

METHODS

NAFLD models were established using high-fat diet (HFD)-fed mice in vivo and palmitic acid- and oleic acid-challenged hepatocytes in vitro. Metabonomics analysis concomitant with biochemical indices and computational biology assays were performed comprehensively to reveal the key link between the treatment of NAFLD and the AMPK-SREBP-1c-Sirt1 signaling axis.

RESULTS

Hepatic metabolomics analysis revealed that THP altered lipid metabolism by enhancing FAO and inhibiting glycolysis, tricarboxylic acid cycle, and urea cycle in HFD-fed mice. Analysis of gene expression showed that THP profoundly suppressed hepatic DNL and promoted FAO. THP supplementation not only significantly decreased body/liver weight gain and serum indices but also ameliorated hepatic steatosis. Simultaneously, impaired lipotoxicity was observed in vivo and in vitro after THP supplementation, protecting against steatosis-driven injury. Metabolic phenotype assays showed that THP promoted switching from glycolysis inhibition to FAO enhancement in steatotic cells, resulting in reprogramming lipid metabolism. Mechanistically, THP accelerated lipid oxidation by activating AMPK-SREBP-1c-Sirt1 axis signaling. Applying molecular docking combined with surface plasmon resonance and cellular thermal shift assay target engagement, as well as siRNA assays, AMPKα was confirmed as a direct molecular target of THP.

CONCLUSION

In summary, THP ameliorates hepatic steatosis in NAFLD by switching lipid metabolism via the AMPK-SREBP-1c-Sirt1 pathway. This work provides an attractive phytochemical component for therapy against hepatic steatosis in NAFLD.

Assessment of Areca Nut Bioactivities in Western Diet-Induced Mice NAFLD Model

The areca nut is often consumed as a chewing food in the Asian region. Our previous study revealed that the areca nut is rich in polyphenols with high antioxidant activity. In this study, we further assessed the effects and molecular mechanisms of the areca nut and its major ingredients on a Western diet-induced mice dyslipidemia model. Male C57BL/6N mice were divided into five groups and fed with a normal diet (ND), Western diet (WD), WD with areca nut extracts (ANE), areca nut polyphenols (ANP), and arecoline (ARE) for 12 weeks. The results revealed that ANP significantly reduced WD-induced body weight, liver weight, epididymal fat, and liver total lipid. Serum biomarkers showed that ANP ameliorated WD-enhanced total cholesterol and non-high-density lipoprotein (non-HDL). Moreover, analysis of cellular signaling pathways revealed that sterol regulatory element-binding protein 2 (SREBP2) and enzyme 3-hydroxy-3-methylglutaryld coenzyme A reductase (HMGCR) were significantly downregulated by ANP. The results of gut microbiota analysis revealed that ANP increased the abundance of beneficial bacterium Akkermansias and decreased the abundance of the pathogenic bacterium Ruminococcus while ARE shown the opposite result to ANP. In summary, our data indicated that areca nut polyphenol ameliorated WD-induced dyslipidemia by increasing the abundance of beneficial bacteria in the gut microbiota and reducing the expressions of SREBP2 and HMGCR while areca nut ARE inhibited this improvement potential.

Regulatory Effects and Molecular Mechanisms of Tea and Its Active Compounds on Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD), the most common chronic liver disease, is a multifactorial disease resulting from the interaction between environment, genetic background, and metabolic stress. Most treatments for NAFLD include dietary intervention and exercise show limited efficacy due to the complex mechanisms involved in NAFLD. Meanwhile, drug therapy is accompanied by serious side effects. The development of high-efficiency natural supplements is a sustainable strategy for the prevention and treatment of NAFLD. As the second most consumed beverage, tea has health benefits that have been widely recognized. Nevertheless, the intervention of tea active compounds in NAFLD has received limited attention. Tea contains abundant bioactive compounds with potential effects on NAFLD, such as catechins, flavonoids, theanine, tea pigments, and tea polysaccharides. We reviewed the intrinsic and environmental factors and pathogenic mechanisms that affect the occurrence and development of NAFLD, and summarized the influences of exercise, drugs, diet, and tea drinking on NAFLD. On this basis, we further analyzed the potential effects and molecular regulatory mechanisms of tea active compounds on NAFLD and proposed future development directions. This review hopes to provide novel insights into the development and application of tea active compounds in the prevention and treatment of NAFLD.

Tianhuang formula reduces the oxidative stress response of NAFLD by regulating the gut microbiome in mice

Background

The gut microbiome affects the occurrence and development of NAFLD, but its mechanism has not yet been fully elucidated. Chinese medicine is a new treatment strategy to improve NAFLD by regulating the gut microbiome. Tianhuang formula (TH) has been proved to have a lipid-lowering effect in which constituents of ginsenoside Rb1, ginsenoside Rg1, ginsenoside Rb, ginsenoside Re, and ginsenoside R1 from Panax notoginseng and berberine, palmatine, and coptisine from Coptis chinensis have low drug permeability, which results in poor intestinal absorption into the human body, and are thus able to come into contact with the gut microflora for a longer time. Therefore, it might be able to influence the gut microbial ecosystem, but it still needs to be investigated.

Method

The characteristics of the gut microbiome were represented by 16S rRNA sequencing, and the metabolites in intestinal contents and liver were discovered by non-targeted metabolomics. Correlation analysis and fermentation experiments revealed the relationship between the gut microbiome and metabolites. Blood biochemical indicators, liver function indicators, and oxidation-related indicators were assayed. H&E staining and Oil Red O staining were used to analyze the characteristics of hepatic steatosis. RT-qPCR and western blotting were used to detect the expression of genes and proteins in liver tissues, and fecal microbial transplantation (FMT) was performed to verify the role of the gut microbiome.

Results

Gut microbiome especially Lactobacillus reduced, metabolites such as 5-Methoxyindoleacetate (5-MIAA) significantly reduced in the liver and intestinal contents, the level of hepatic GSH and SOD reduced, MDA increased, and the protein expression of Nrf2 also reduced in NAFLD mice induced by high-fat diet (HFD). The normal diet mice transplanted with NAFLD mice feces showed oxidative liver injury, indicating that the NAFLD was closely related to the gut microbiome. TH and TH-treated mice feces both can reshape the gut microbiome, increase the abundance of Lactobacillus and the content of 5-MIAA in intestinal contents and liver, and improve oxidative liver injury. This indicated that the effect of TH improving NAFLD was related to the gut microbiome, especially Lactobacillus. 5-MIAA, produced by Lactobacillus, was proved with fermentation experiments in vitro. Further experiments proved that 5-MIAA activated the Nrf2 pathway to improve oxidative stress in NAFLD mice induced by HFD. TH reshaped the gut microbiome, increased the abundance of Lactobacillus and its metabolite 5-MIAA to alleviate oxidative stress, and improved NAFLD.

Conclusion

The study has demonstrated a mechanism by which the gut microbiome modulated oxidative stress in NAFLD mice induced by HFD. The traditional Chinese medicine TH improved NAFLD by regulating the gut microbiome, and its mechanism was related to the “Lactobacillus-5-MIAA-Nrf2” pathway. It provided a promising way for the intervention of NAFLD.

Natural flavonoids: Potential therapeutic strategies for non-alcoholic fatty liver disease

The incidence of non-alcoholic fatty liver disease (NAFLD) is increasing rapidly worldwide; however, there are currently limited treatments for NAFLD. The disease spectrum includes simple fatty liver, non-alcoholic steatohepatitis (NASH), fibrosis, cirrhosis, and progression to hepatocellular carcinoma (NASH-HCC). The therapeutic effects of NAFLD remain controversial. Although researchers have conducted studies on the pathogenesis of NAFLD, its pathogenesis and anti-NAFLD mechanisms have not been fully elucidated. Previous studies have found that flavonoids, as natural substances with extensive pharmacological activity and good therapeutic effects, have excellent antioxidant, anti-inflammatory, metabolic disease improvement, anti-tumor, and other properties and can significantly alleviate NAFLD. Flavonoids could be further developed as therapeutic drugs for NAFLD. In this paper, the pathogenesis of NAFLD and the mechanisms of flavonoids against NAFLD are summarized to provide a theoretical basis for screening flavonoids against non-alcoholic liver injury.

Dietary Polyphenols Alleviate Autoimmune Liver Disease by Mediating the Intestinal Microenvironment: Challenges and Hopes

Autoimmune liver disease is a chronic liver disease caused by an overactive immune response in the liver that imposes a significant health and economic cost on society. Due to the side effects of existing medicinal medications, there is a trend toward seeking natural bioactive compounds as dietary supplements. Currently, dietary polyphenols have been proven to have the ability to mediate gut-liver immunity and control autoimmune liver disease through modulating the intestinal microenvironment. Based on the preceding, this Review covers the many forms of autoimmune liver illnesses, their pathophysiology, and the modulatory effects of polyphenols on immune disorders. Finally, we focus on how polyphenols interact with the intestinal milieu to improve autoimmune liver disease. In conclusion, we suggest that dietary polyphenols have the potential as gut-targeted modulators for the prevention and treatment of autoimmune liver disease and highlight new perspectives and critical issues for future pharmacological applications.

Dihydromyricetin ameliorates diet-induced obesity and promotes browning of white adipose tissue by upregulating IRF4/PGC-1α

BACKGROUND

Promoting the browning of white adipose tissue (WAT) is a promising approach for the treatment of obesity and related comorbidities because it increases energy expenditure. In this study, we investigated whether Dihydromyricetin (DHM), a flavonoid component, could ameliorate diet-induced obesity through promoting the browning of WAT.

METHODS

Male C57BL/6 J mice were received a high-fat diet (HFD) to induce obesity and subsequently were treated with DHM (100 mg/kg/day) or vehicle for 4 weeks. The effects of DHM on weight reduction and metabolic phenotype improvement were observed in the mice. The expression of genes and protein involved in browning of WAT were assessed in inguinal WAT (iWAT) of the mice. Then, the effect of DHM on the inducing browning program was verified in adipocytes differentiated from stromal vascular fraction (SVF) cells of mouse iWAT. Finally, the mechanism by which DHM improves the browning of WAT was explored using RNA-seq and luciferase reporter assay.

RESULTS

We find that DHM reduces body weight, decreases WAT mass, improves glucose and lipid metabolic disorders, and ameliorates hepatic steatosis in diet-induced obese (DIO) mice. Further studies show that DHM induces WAT browning, which is manifested by increased expression of uncoupling protein 1 (UCP1) and peroxisome proliferator-activated receptor gamma coactivator (PGC)-1α and enhanced mitochondrial activity in iWAT and primary adipocytes. In addition, we also find that DHM enhances interferon regulatory factor 4 (IRF4) expression, which is a key transcriptional regulator of PGC-1α.

CONCLUSION

Our findings identify that DHM prevents obesity by inducing the browning of WAT through the upregulation of IRF4/PGC-1α, which may have potential therapeutic implications for the treatment of obesity.

Lactobacillus plantarum 23-1 improves intestinal inflammation and barrier function through the TLR4/NF-κB signaling pathway in obese mice

As a natural active ingredient, lactic acid bacteria have potential anti-inflammatory effects. In this study, male C57BL/6J mice were given a high-fat diet (HFD) to establish an obese mouse model. Lactobacillus plantarum 23-1 (LP23-1) with prebiotic characteristics was intervened for 8 weeks to evaluate its remission effect on obese animals and related mechanisms. The effects of LP23-1 on lipid accumulation and intestinal inflammation in HFD-fed mice were systematically evaluated by detecting lipid accumulation, blood lipid level, pathological changes in the liver and small intestine, oxidative stress and inflammatory cell level, lipid transport-related gene expression, the inflammatory signaling pathway, and intestinal tight junction (TJ) mRNA and protein expression. The results showed that LP23-1 could significantly reduce the body weight and fat index of HFD-fed mice, improve the lipid levels of serum and liver, reduce the histopathological damage to the liver and small intestine, and alleviate oxidative stress and inflammatory response caused by obesity. In addition, reverse transcription-polymerase chain reaction and western blot analysis showed that LP23-1 could regulate the mRNA expression of lipid transport-related genes; activate the TLR4/NF-κB signaling pathway; reduce intestinal inflammation; improve the mRNA and protein expression of intestinal TJ proteins zona occludens-1 (ZO-1), occludin, claudin-1, and Muc2; repair intestinal mucosal injury; and enhance intestinal barrier function. The aforementioned results showed that LP23-1 through the TLR4/NF-κB signaling pathway and intestinal barrier function reduced obesity symptoms. This study provided new insights into the mechanism of LP23-1 in reducing obesity and provided a theoretical basis for developing new functional foods.

Natural Garlic Organosulfur Compounds Prevent Metabolic Disorder of Lipid and Glucose by Increasing Gut Commensal Bacteroides acidifaciens

A number of reports of the effects of garlic on gut microbiota revealed that the active garlic organosulfur compounds (OSCs) are destabilized by the action of alliinase during garlic preparation. In this study, garlic alliinase was deactivated to obtain stable garlic OSCs. Experiments with C57BL/6J mice fed with lipid and glucose metabolic disorder-inducing Western diet (WD) revealed that stable garlic OSCs prevented the disorder by increasing the relative abundance of gut Bacteroides acidifaciens. Molecular analysis indicated that garlic OSCs inhibited dyslipidemia and fatty liver by increasing taurine and subsequently promoting hepatic fatty acid β-oxidation. In parallel, garlic OSCs could meliorate glucose homeostasis by inhibiting dipeptidyl peptidase-4 (DPP-4) and hepatic gluconeogenesis. In vitro bacterial culture experiments revealed that garlic OSCs directly increased the growth of gut Bacteroides acidifaciens. The results of this study demonstrate that the molecular mechanism of the preventive effect of garlic OSCs on the WD-induced metabolic disorder is attributed to the enhanced growth of Bacteroides acidifaciens and the consequent increase in taurine.

The hepatoprotective effects of plant-based foods based on the "gut-liver axis": a prospective review

The importance of the "gut-liver axis" in the pathogenesis of liver diseases has been revealed recently; which promotes the process of developing preventive and therapeutic strategies. However, considering that there are still many challenges in the medical treatment of liver diseases, potential preventive dietary intervention may be a good alternative choice. Plant-based foods have received much attention due to their reported health-promoting effects in targeting multiple pathways involved in the pathogenesis of liver diseases as well as the relative safety for general use. Based on the PubMed and Web of Science databases, this review emphatically summarizes the plant-based foods and their chemical constituents with reported effects to impact the LPS/TLR4 signaling pathway of gut-liver axis of various liver diseases, reflecting their health benefits in preventing/alleviating liver diseases. Moreover, some plant-based foods with potential gut-liver effects are specifically analyzed from the reported studies and conclusions. This review intends to provide readers an overview of the current progress in the field of this research topic. We expect to see more hepatoprotective measures for alleviating the current prevalence of liver diseases.

Lactobacillus paracasei 24 Attenuates Lipid Accumulation in High-Fat Diet-Induced Obese Mice by Regulating the Gut Microbiota

Obesity has become a worldwide public health problem. Lactic acid bacteria have attracted extensive attention for alleviating obesity and fat accumulation. This study aimed to evaluate the alleviating effects of Lactobacillus paracasei 24 (LP24) on lipid accumulation in an obese mouse model induced by a high-fat diet (HFD). The results showed that LP24 treatment significantly reduced body weight and fat deposition in HFD mice, improved blood lipid levels and liver steatosis, reduced liver oxidative stress injury and the inflammatory response, and regulated fat metabolism-related factors. Moreover, LP24 regulated the abundance and diversity of the gut microbiota, reduced the abundance of Firmicutes and the ratio of Firmicutes/Bacteroidetes (F/B), and increased the abundance of Akkermansia. In summary, LP24 regulates lipid metabolism by activating the expression level of related genes and regulating the gut microbiota through the gut-liver axis to attenuate the development of obesity. This study provides a theoretical basis for probiotics to regulate gut microbiota to reduce lipid accumulation.

Recent update on application of dihydromyricetin in metabolic related diseases

As a new type of natural flavonoids, dihydromyricetin (DMY) has attracted more and more attention. It has a series of pharmacological effects, such as anti-inflammatory, anti-tumor, anti-oxidation, antibacterial and so on, and it is almost no toxicity and with excellent safety. Therefore, even if the bioavailability is poor, it is often added to daily food, beverages and even medicines. In recent years, some researchers have found that DMY can treat some diseases by anti-oxidation, anti-inflammation, promoting cell death and regulate the activity of lipid and glucose metabolism. In addition, the mechanism of DMY on these diseases was also related to the signal pathway of AMPK, PI3K/Akt, PPAR and the participation of microRNAs. This review describes the mechanism of DMY in metabolic related diseases from three aspects: metabolic diseases, liver diseases, and cancers, hoping to provide some new ideas for clinical researches.

Involvement of AMP-activated Protein Kinase α/Nuclear Factor (Erythroid-derived 2) Like 2-iniatived Signaling Pathway in Cytoprotective Effects of Wasabi 6-(Methylsulfinyl) Hexyl Isothiocyanate

6-(Methylsulfinyl) hexyl isothiocyanate (6-MSITC) is an active ingredient present in Wasabi, which is a popular pungent spice used in Japanese cuisine. Our previous studies suggested that the primary antioxidant activity of 6-MSITC may link to other biological activity. This study aimed to clarify how the antioxidant activity of 6-MSITC contributes to preventing overloaded lipid stress in hepatic cell model. HepG2 cells were treated with 6-MSITC at defined concentrations and times in normal medium or in combined fatty acids (CFA) medium, and the targeted proteins were detected by Western blotting. The kinetic data revealed that 6-MSITC activated AMP-activated protein kinase α (AMPKα) and nuclear factor (erythroid-derived 2) like 2 (Nrf2), and then enhanced the protein expression of Forkhead box protein O1 (FOXO1) and Sirtuin1 as well as that of the Nrf2 target proteins, NAD(P)H:quinone oxidoreductase 1 (NQO1) and heme oxygenase (HO-1). Furthermore, lipid metabolic stress was mimicked in HepG2 cells by overloading CFA. 6-MSITC significantly alleviated CFA-induced formation of thiobarbituric acid reactive substances and fat accumulation. Signaling analysis data revealed that 6-MSITC enhanced phosphorylation of AMPKα, upregulated the expression of Nrf2, NQO1, heme oxygenase 1, FOXO1, and Siruin1, and downregulated the expression of PPARα. Taken together, our results suggested that the AMPKα/Nrf2-mediated signaling pathways might be involved in the cytoprotective effects of Wasabi 6-MSITC against metabolic lipid stress.

Putative Mechanisms Underlying the Beneficial Effects of Polyphenols in Murine Models of Metabolic Disorders in Relation to Gut Microbiota

The beneficial effects of polyphenols on metabolic disorders have been extensively reported. The interaction of these compounds with the gut microbiota has been the focus of recent studies. In this review, we explored the fundamental mechanisms underlying the beneficial effects of polyphenols in relation to the gut microbiota in murine models of metabolic disorders. We analyzed the effects of polyphenols on three murine models of metabolic disorders, namely, models of a high-fat diet (HFD)-induced metabolic disorder, dextran sulfate sodium (DSS)-induced colitis, and a metabolic disorder not associated with HFD or DSS. Regardless of the model, polyphenols ameliorated the effects of metabolic disorders by alleviating intestinal oxidative stress, improving inflammatory status, and improving intestinal barrier function, as well as by modulating gut microbiota, for example, by increasing the abundance of short-chain fatty acid-producing bacteria. Consequently, polyphenols reduce circulating lipopolysaccharide levels, thereby improving inflammatory status and alleviating oxidative imbalance at the lesion sites. In conclusion, polyphenols likely act by regulating intestinal functions, including the gut microbiota, and may be a safe and suitable therapeutic agent for various metabolic disorders.

Molecular Mechanism Underlying the Regulatory Effect of Vine Tea on Metabolic Syndrome by Targeting Redox Balance and Gut Microbiota

Metabolic syndrome (MS) is a metabolic disorder that arises from the increasing prevalence of obesity. The pathophysiology seems to be largely attributable to the imbalance of lipid and glucose metabolism, redox signaling pathways, and gut microbiota. The increased syndromes, such as type 2 diabetes and cardiovascular disease demands natural therapeutic attention for those at high risk. Vine tea, as a traditional medicinal and edible resource rich in flavonoids, especially for dihydromyricetin (DHM), exhibits promising health benefits on the intervention of MS, but the specific molecular mechanism has not been systematically elucidated. The present article aims to summarize the regulatory effects and biological targets of vine tea or DHM on MS, and analyze the underlying potential molecular mechanisms in cells, animals, and humans, mainly by regulating the redox associated signaling pathways, such as Nrf2, NF-κB, PI3K/IRS2/AKT, AMPK-PGC1α-SIRT1, SIRT3 pathways, and the crosstalk among them, and by targeting several key biomarkers. Moreover, vine tea extract or DHM has a positive impact on the modulation of intestinal microecology by upregulating the ratio of Firmicutes/Bacteroidetes (F/B) and increasing the relative abundance of Akkermansia muciniphila. Therefore, this review updated the latest important theoretical basis and molecular evidence for the development and application of vine tea in dietary functional products or drugs against MS and also imputed the future perspectives to clarify the deep mechanism among vine tea or DHM, redox associated signaling pathways, and gut microbiota.

The Anti-Adiposity Mechanisms of Ampelopsin and Vine Tea Extract in High Fat Diet and Alcohol-Induced Fatty Liver Mouse Models

Ampelopsis grossedentata (AG) is an ancient medicinal plant that is mainly distributed and used in southwest China. It exerts therapeutic effects, such as antioxidant, anti-diabetic, and anti-inflammatory activities, reductions in blood pressure and cholesterol and hepatoprotective effects. Researchers in China recently reported the anti-obesity effects of AG extract in diet-induced obese mice and rats. To verify these findings, we herein investigated the effects of AG extract and its principal compound, ampelopsin, in high-fat diet (HFD)- and alcohol diet-fed mice, olive oil-loaded mice, and differentiated 3T3-L1 cells. The results obtained showed that AG extract and ampelopsin significantly suppressed increases in the weights of body, livers and abdominal fat and also up-regulated the expression of carnitine palmitoyltransferase 1A in HFD-fed mice. In olive oil-loaded mice, AG extract and ampelopsin significantly attenuated increases in serum triglyceride (TG) levels. In differentiated 3T3-L1 cells, AG extract and ampelopsin promoted TG decomposition, which appeared to be attributed to the expression of hormone-sensitive lipase. In alcohol diet-fed mice, AG extract and ampelopsin reduced serum levels of ethanol, glutamic oxaloacetic transaminase (GOT), and glutamic pyruvic transaminase (GPT) and liver TG. An examination of metabolic enzyme expression patterns revealed that AG extract and ampelopsin mainly enhanced the expression of aldehyde dehydrogenase and suppressed that of cytochrome P450, family 2, subfamily e1. In conclusion, AG extract and ampelopsin suppressed diet-induced intestinal fat accumulation and reduced the risk of fatty liver associated with HFD and alcohol consumption.

Dietary ferulic acid and vanillic acid on inflammation, gut barrier function and growth performance in lipopolysaccharide-challenged piglets

Ferulic acid (FA) and vanillic acid (VA) are considered as major phenolic metabolites of cyanidin 3-glucoside, a polyphenol that widely exists in plants that possess a protective effect against oxidative stress and inflammation in our previous study. This study aimed to investigate the effect of FA and VA on inflammation, gut barrier function, and growth performance in a weaned piglet model challenged with lipopolysaccharide (LPS). Thirty-six piglets (PIC 337 × C48, 28 d of age) were randomly allocated into 3 treatments with 6 replicate pens (2 piglets per pen). They were fed with a basal diet or a diet containing 4,000 mg/kg of FA or VA. Dietary supplementation of VA significantly increased average daily gain (ADG) (P < 0.05). Both FA and VA decreased serum levels of thiobarbituric acid reactive substances (TBARS), interlukin (IL)-1β, IL-2, IL-6, and tumor necrosis factor (TNF)-α (P < 0.05), and enhanced the expression of tight junction protein oclaudin (P < 0.05). Analysis of gut microbiota indicated that both FA and VA increased the Firmicutes/Bacteroidetes ratio alongside reducing the relative abundance of the Prevotellaceae family including Prevotella 9 and Prevotella 2 genera, but enriched the Lachoiraceaea family including the Lachnospiraceae FCS020 group (P < 0.05). Moreover, VA reduced the relative abundance of Prevotella 7 and Prevotella 1 but enriched Lachnospira, Eubacterium eligens group, and Eubacterium xylanophilum group (P < 0.05), while FA showed a limited effect on these genera. The results demonstrated that both VA and FA could alleviate inflammation and oxidative stress, but only VA has a significant positive effect on the growth performance of LPS-challenged piglets potentially through modulating gut microbiota.

Effects of novel cellulase (Cel 906) and probiotic yeast fermentation on antioxidant and anti-inflammatory activities of vine tea (Ampelopsis grossedentata)

Vine tea (Ampelopsis grossedentata) is a plant resource with good nutritional and medicinal, and is widely consumed in China. This study aimed to develop a functional vine tea fermentation broth using microbial fermentation and cellulase degradation. First, the most suitable probiotics for vine tea fermentation were screened, and the fermentation conditions were optimized. Then, a new cellulase (Cel 906, MW076177) was added to evaluate the changes in the contents of effective substances and to study its efficacy. The results show that saccharomyces cerevisiae Y-401 was identified as the best strain, the optimal fermentation conditions were a time of 94.60 h, feeding concentration of 115.21 g/L, and temperature of about 34.97°C. The vine tea fermentation broth has a strong inhibitory ability on 2,2'-azinobis3-ethylbenzothiazoline-6-sulfonic acid (ABTS) (99.73%), peroxyl (53.15%), superoxide anion radicals (84.13%), and 1,1-Diphenyl-2-trinitrophenylhydrazine (DPPH) (92.48%). It has a decent inhibitory impact on the cell viability, tyrosinase activity (32.25%), and melanin synthesis (63.52%) of B16-F10 melanoma cells induced by α-MSH. Inflammatory cell recruitment was reduced in a zebrafish inflammation model. Therefore, this vine tea fermented broth has strong antioxidant, anti-melanoma, and anti-inflammatory effects, and has healthcare potential as a probiotic tea.

The spleen-strengthening and liver-draining herbal formula treatment of non-alcoholic fatty liver disease by regulation of intestinal flora in clinical trial

OBJECTIVE

As a metabolic disease, one important feature of non-alcoholic fatty liver disease (NAFLD) is the disturbance of the intestinal flora. Spleen-strengthening and liver-draining formula (SLF) is a formula formed according to the theory of "One Qi Circulation" (Qing Dynasty, 1749) of Traditional Chinese Medicine (TCM), which has shown significant therapeutic effect in patients with NAFLD in a preliminary clinical observation. In this study, we aim to explore the mechanism of SLF against NAFLD, especially its effect on glucolipid metabolism, from the perspective of intestinal flora.

METHODS

A prospective, randomized, controlled clinical study was designed to observe the efficacy and safety of SLF in the treatment of NAFLD. The study participants were randomly and evenly divided into control group and treatment group (SLF group). The control group made lifestyle adjustments, while the SLF group was treated with SLF on top of the control group. Both groups were participated in the study for 12 consecutive weeks. Furthermore, the feces of the two groups were collected before and after treatment. The intestinal flora of each group and healthy control (HC) were detected utilizing 16S rRNA gene sequencing.

RESULTS

Compared with the control group, the SLF group showed significant improvements in liver function, controlled attenuation parameter (CAP), and liver stiffness measurement (LSM), meanwhile, patients had significantly lower lipid and homeostasis model assessment of insulin resistance (HOMA-IR) with better security. Intestinal flora 16S rRNA gene sequencing results indicated reduced flora diversity and altered species abundance in patients with NAFLD. At the phylum level, Desulfobacterota levels were reduced. Although Firmicutes and Bacteroidetes did not differ significantly between HC and NAFLD, when grouped by alanine transaminase (ALT) and aspartate transaminase (AST) levels in NAFLD, Firmicutes levels were significantly higher in patients with ALT or AST abnormalities, while Bacteroidetes was significantly lower. Clinical correlation analysis showed that Firmicutes positively correlated with gender, age, ALT, AST, LSM, and Fibroscan-AST (FAST) score, while the opposite was true for Bacteroidetes. At the genus level, the levels of Alistipes, Bilophila, Butyricimonas, Coprococcus, Lachnospiraceae_NK4A136 group Phascolarctobacterium, Ruminococcus, UCG-002, and UCG-003 were reduced, whereas abundance of Tyzzerella increased. There was no statistically significant difference in Firmicutes and Bacteroidota levels in the SLF group before and after treatment, but both bacteria tended to retrace. At the genus level, Coprococcus (Lachnospiraceae family), Lachnospiraceae_NK4A136 group (Lachnospiraceae family), and Ruminococcus (Ruminococcaceae family) were significantly higher in the SLF group after treatment, and there was also a tendency for Bilophila (Desulfovibrionaceae family) to be back-regulated toward HC.

CONCLUSIONS

SLF can improve liver function and glucolipid metabolism in patients with NAFLD and lower down liver fat content to some extent. SLF could be carried out by regulating the disturbance of intestinal flora, especially Coprococcus, Lachnospiraceae_NK4A136 group, and Ruminococcus genus.

Purslane (Portulacae oleracea L.) attenuates cadmium-induced hepatorenal and colonic damage in mice: Role of chelation, antioxidant and intestinal microecological regulation

BACKGROUND

Cadmium (Cd) is a representative pernicious metal, which has high biological toxicity. Its precaution through dietary administration is considered an important strategy. Considering that Portulaca oleracea L. (Por.L) has antioxidant, anti-inflammatory and other high medicinal value, and purslane insoluble dietary fiber (PIDF) has good binding property to metal ions, they could be good methods for Cd-induced biotoxicity therapy.

PURPOSE

To investigate the beneficial effects of Por.L or PIDF against Cd-induced subchronic toxicity and identify its underlying mechanisms.

STUDY DESIGN AND METHODS

C57BL/6 male mice (n = 12) were received 100 mg l^-1 CdCl₂ in water for 8 weeks. Mice were divided into four groups: Control, Cd-treated, 8% Por.L + Cd, and 8% PIDF + Cd. Histological evaluation, inductively coupled plasma-mass spectrometry, western blotting analysis, quantitative real time-PCR, gas chromatography-mass spectrometry and 16S rDNA analysis were used in the study.

RESULTS

Por.L treatment was able to inhibit inflammation and accumulation of Cd, enhance the activity of antioxidant enzymes, increase beneficial bacterial species of Akkermansia and Faecalibaculum and suppress the production of inflammatory cytokines in the colon, such as TNF-α, IL-6, IL-1β and IFN-γ. PIDF mainly relieved the toxicity of Cd by increasing the production of short chain fatty acids with anti-inflammatory functions and repressing the liver and kidney inflammation mediated by the TLR4/ MyD88/NF-κB pathway.

CONCLUSION

Our study has demonstrated that the antagonistic-Cd effects of Por.L might be mediated via chelation, antioxidation, regulation of intestinal microecology. Thus, our study provides a novel insight into Por.L as a promising function food for the anti-Cd biotoxicity. Por.L supplement could be considered as a potential coping strategy to alleviate hazardous effects in Cd-exposed humans.

Hepatocyte-Specific Deficiency of BAP31 Amplified Acetaminophen-Induced Hepatotoxicity via Attenuating Nrf2 Signaling Activation in Mice

Liver-specific deficiency of B-cell receptor-associated protein 31 knockout mice (BAP31-LKO) and the littermates were injected with acetaminophen (APAP), markers of liver injury, and the potential molecular mechanisms were determined. In response to APAP overdose, serum aspartate aminotransferase and alanine aminotransferase levels were increased in BAP31-LKO mice than in wild-type controls, accompanied by enhanced liver necrosis. APAP-induced apoptosis and mortality were increased. Hepatic glutathione was decreased (1.60 ± 0.31 μmol/g tissue in WT mice vs. 0.85 ± 0.14 μmol/g tissue in BAP31-LKO mice at 6 h, p < 0.05), along with reduced glutathione reductase activity and superoxide dismutase; while malondialdehyde was significantly induced (0.41 ± 0.03 nmol/mg tissue in WT mice vs. 0.50 ± 0.05 nmol/mg tissue in BAP31-LKO mice for 6 h, p < 0.05). JNK signaling activation and APAP-induced hepatic inflammation were increased in BAP31-LKO mice. The mechanism research revealed that BAP31-deficiency decreased Nrf2 mRNA stability (half-life of Nrf2 mRNA decreased from ~1.3 h to ~40 min) and miR-223 expression, led to reduced nuclear factor erythroid 2-related factor 2 (Nrf2) signaling activation and antioxidant genes induction. BAP31-deficiency decreased mitochondrial membrane potentials, reduced mitochondria-related genes expression, and resulted in mitochondrial dysfunction in the liver. Conclusions: BAP31-deficiency reduced the antioxidant response and Nrf2 signaling activation via reducing Nrf2 mRNA stabilization, enhanced JNK signaling activation, hepatic inflammation, and apoptosis, amplified APAP-induced hepatotoxicity in mice.

Angelica Polysaccharide Antagonizes 5-FU-Induced Oxidative Stress Injury to Reduce Apoptosis in the Liver Through Nrf2 Pathway

Oxidative stress induced by chemotherapeutic agents causes hepatotoxicity. 5-Fluorouracil (5-FU) has been found to have a variety of side effects, but its toxic effect on the liver and the mechanism are still unclear. Angelica polysaccharide (ASP), the main active ingredient of Dang Gui, has antioxidative stress effects. In this study, we investigated the antagonistic effects of ASP on 5-FU-induced injury in the mouse liver and human normal liver cell line MIHA and the possible mechanism. Our results show that ASP inhibited 5-FU-induced the decrease in Bcl-2 protein and the increase in Bax protein. ASP alleviated 5-FU-induced the increase in alanine aminotransferase (ALT), triglyceride (TG), and aspartate aminotransferase (AST) content; hepatic steatosis; and liver fibrosis. ASP restored 5-FU-induced swelling of mitochondria and the endoplasmic reticulum. 5-FU promoted the expression of Keap1 and increased the binding to NF-E2-related factor 2 (Nrf2) to reduce the nuclear translocation of Nrf2, thereby weakening the transcriptional activity of Nrf2 to inhibit the expression of HO-1; reducing the activity of GSH, SOD, and CAT to increase ROS content; and aggravating DNA damage (indicated by the increase in 8-OHdG). However, ASP reversed these reactions. In conclusion, ASP attenuated the 5-FU-induced Nrf2 pathway barrier to reduce oxidative stress injury and thereby inhibit the disorder of lipid anabolism and apoptosis. The study provides a new protectant for reducing the hepatic toxicity caused by 5-FU and a novel target for treating the liver injury.

Extracts of Vine Tea Improve Diet-Induced Non-Alcoholic Steatohepatitis Through AMPK-LXRα Signaling

Chinese vine tea can improve glucose and lipid metabolic disorders. However, its protective effects in non-alcoholic steatohepatitis (NASH) and its underlying molecular mechanisms remain unclear. Liver X receptor α (LXRα) inhibition and adenosine monophosphate-(AMP)-activated protein kinase (AMPK) activation can enhance control of NASH. AMPK activators have also been shown to inactivate LXRα. Here, the anti-NASH effects of vine tea extract (VTE) dosed at 1 g.100 g^-1 diet were investigated using NASH mice challenged with a methionine and choline-deficient l-amino acid diet (MCDD) and a high-fat diet (HFD). Pharmacological mechanisms of VTE were explored using TUNEL staining, AMPK inhibition, Western blot, reporter assays, qRT-PCR analyses, and immunofluorescence. VTE treatment improved fatty liver in HFD-induced mice, while it alleviated the progression of NASH including protecting against liver lipid accumulation, steatosis, endoplasmic reticulum stress, apoptosis, inflammation, and functional injury in MCDD-fed mice. VTE reduced the action of hepatic lipogenic genes, F4/80, pro-inflammatory cytokines, CHOP, and cleaved Caspase-3 expression, while promoting expression of fatty acid oxidation genes CPT1α, ß. VTE also enhanced AMPK and blocked LXRα signaling in mouse livers. In vitro results indicated that VTE increased AMPK phosphorylation and reduced LXRα activity in HepG2 cells. Conversely, the antagonistic effect of VTE on LXRα was decreased through AMPK inhibition. Our data suggests that VTE may improve diet-induced NASH, which involves the pharmacological modulation of the AMPK-LXRα signaling pathway.

Similarities and Differences: A Comparative Review of the Molecular Mechanisms and Effectors of NAFLD and AFLD

Non-alcoholic fatty liver disease (NAFLD) and alcoholic fatty liver disease (AFLD) are the most prevalent metabolic liver diseases globally. Due to the complex pathogenic mechanisms of NAFLD and AFLD, no specific drugs were approved at present. Lipid accumulation, oxidative stress, insulin resistance, inflammation, and dietary habits are all closely related to the pathogenesis of NAFLD and AFLD. However, the mechanism that promotes disease progression has not been fully elucidated. Meanwhile, the gut microbiota and their metabolites also play an important role in the pathogenesis and development of NAFLD and AFLD. This article comparatively reviewed the shared and specific signaling pathways, clinical trials, and potential intervention effectors of NAFLD and AFLD, revealing their similarities and differences. By comparing the shared and specific molecular regulatory mechanisms, this paper provides mutual reference strategies for preventing and treating NAFLD, AFLD, and related metabolic diseases. Furthermore, it provides enlightenment for discovering novel therapies of safe and effective drugs targeting the metabolic liver disease.

Caveolin-1 Alleviates Acetaminophen-Induced Fat Accumulation in Non-Alcoholic Fatty Liver Disease by Enhancing Hepatic Antioxidant Ability via Activating AMPK Pathway

Non-alcoholic fatty liver disease (NAFLD) is an independent risk factor for acute liver injury caused by overuse of acetaminophen (APAP). Caveolin-1 (CAV1), a regulator of hepatic energy metabolism and oxidative stress, was found to have a protective effect against NAFLD in our previous study. However, it remains unclear whether CAV1 has a protective effect against APAP-induced hepatotoxicity in NAFLD. The aim of this study was to determine whether CAV1 inhibits oxidative stress through the AMPK/Nrf2/HO-1 pathway to protect the liver from fat accumulation exacerbated by APAP in NAFLD. In this study, seven-week-old C57BL/6 male mice (18–20 g) were raised under similar conditions for in vivo experiment. In vitro, L02 cells were treated with A/O (alcohol and oleic acid mixture) for 48 h, and APAP was added at 24 h for further incubation. The results showed that the protein expression of the AMPK/Nrf2 pathway was enhanced after CAV1 upregulation. The effects of CAV1 on fat accumulation, ROS, and the AMPK/Nrf2 anti-oxidative pathway were reduced after the application of CAV1-siRNA. Finally, treatment with compound C (an AMPK inhibitor) prevented CAV1 plasmid-mediated alleviation of oxidative stress and fat accumulation and reduced the protein level of Nrf2 in the nucleus, demonstrating that the AMPK/Nrf2/HO-1 pathway was involved in the protective effect of CAV1. These results indicate that CAV1 exerted a protective effect against APAP-aggravated lipid deposition and hepatic injury in NAFLD by inhibiting oxidative stress. Therefore, the upregulation of CAV1 might have clinical benefits in reducing APAP-aggravated hepatotoxicity in NAFLD.

Dietary Polyphenols to Combat Nonalcoholic Fatty Liver Disease via the Gut-Brain-Liver Axis: A Review of Possible Mechanisms

Polyphenols are a group of micronutrients widely existing in plant foods including fruits, vegetables, and teas that can improve nonalcoholic fatty liver disease (NAFLD). In this review, the existing knowledge of dietary polyphenols for the development of NAFLD regulated by intestinal microecology is discussed. Polyphenols can influence the vagal afferent pathway in the central and enteric nervous system to control NAFLD via gut-brain-liver cross-talk. The possible mechanisms involve in the alteration of microbial community structure, effects of gut metabolites (short-chain fatty acids (SCFAs), bile acids (BAs), endogenous ethanol (EnEth)), and stimulation of gut-derived hormones (ghrelin, cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1), and leptin) based on the targets excavated from the gut-brain-liver axis. Consequently, the communication among the intestine, brain, and liver paves the way for new approaches to understand the underlying roles and mechanisms of dietary polyphenols in NAFLD pathology.

Bilberry Anthocyanins Ameliorate NAFLD by Improving Dyslipidemia and Gut Microbiome Dysbiosis

Non-alcoholic fatty liver disease (NAFLD) is a manifestation of metabolic syndrome closely linked to dyslipidemia and gut microbiome dysbiosis. Bilberry anthocyanins (BA) have been reported to have preventive effects against metabolic syndrome. This study aimed to investigate the protective effects and mechanisms of BA in a Western diet (WD)-induced mouse model. The results revealed that supplementation with BA attenuated the serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), low-density lipoprotein cholesterol (LDL-c), fat content in liver, 2-thiobarbituric acid reactive substances (TBARS) and α-smooth muscle actin (α-SMA) caused by WD. Furthermore, gut microbiota characterized by 16S rRNA sequencing revealed that BA reduced remarkably the ratio of Firmicutes/Bacteroidetes (F/B) and modified gut microbiome. In particular, BA increased the relative abundance of g_Akkermansia and g_Parabacteroides. Taken together, our data demonstrated that BA might ameliorate WD-induced NAFLD by attenuating dyslipidemia and gut microbiome dysbiosis.