The Chinese medicine Chai Hu Li Zhong Tang protects against non-alcoholic fatty liver disease by activating AMPKα

Targeting AMPK related signaling pathways: A feasible approach for natural herbal medicines to intervene non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a metabolic disease characterized by abnormal deposition of lipid in hepatocytes. If not intervened in time, NAFLD may develop into liver fibrosis or liver cancer, and ultimately threatening life. NAFLD has complicated etiology and pathogenesis, and there are no effective therapeutic means and specific drugs. Currently, insulin sensitizers, lipid-lowering agents and hepatoprotective agents are often used for clinical intervention, but these drugs have obvious side effects, and their effectiveness and safety need to be further confirmed. Adenosine monophosphate (AMP)-activated protein kinase (AMPK) plays a central role in maintaining energy homeostasis. Activated AMPK can enhance lipid degradation, alleviate insulin resistance (IR), suppress oxidative stress and inflammatory response, and regulate autophagy, thereby alleviating NAFLD. Natural herbal medicines have received extensive attention recently because of their regulatory effects on AMPK and low side effects. In this article, we reviewed the biologically active natural herbal medicines (such as natural herbal medicine formulas, extracts, polysaccharides, and monomers) that reported in recent years to treat NAFLD via regulating AMPK, which can serve as a foundation for subsequent development of candidate drugs for NAFLD.

Application and mechanism of Chinese herb medicine in the treatment of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a chronic liver condition closely associated with metabolic syndrome, with its incidence rate continuously rising globally. Recent studies have shown that the development of NAFLD is associated with insulin resistance, lipid metabolism disorder, oxidative stress and endoplasmic reticulum stress. Therapeutic strategies for NAFLD include lifestyle modifications, pharmacological treatments, and emerging biological therapies; however, there is currently no specific drug to treat NAFLD. However Chinese herb medicine (CHM) has shown potential in the treatment of NAFLD due to its unique therapeutic concepts and methods for centuries in China. This review aims to summarize the pathogenesis of NAFLD and some CHMs that have been shown to have therapeutic effects on NAFLD, thus enriching the scientific connotation of TCM theories and facilitating the exploration of TCM in the treatment of NAFLD.

Traditional Chinese medicine and plant-derived natural products in regulating triglyceride metabolism: Mechanisms and therapeutic potential

The incidence of cardiometabolic disease is increasing globally, with a trend toward younger age of onset. Among these, atherosclerotic cardiovascular disease is a leading cause of mortality worldwide. Despite the efficacy of traditional lipid-lowering drugs, such as statins, in reducing low-density lipoprotein cholesterol levels, a significant residual risk of cardiovascular events remains, which is closely related to unmet triglyceride (TG) targets. The clinical application of current TG-lowering Western medicines has certain limitations, necessitating alternative or complementary therapeutic strategies. Traditional Chinese medicine (TCM) and plant-derived natural products, known for their safety owing to their natural origins and diverse biological activities, offer promising avenues for TG regulation with potentially fewer side effects. This review systematically summarises the mechanisms of TG metabolism and subsequently reviews the regulatory effects of TCM and plant-derived natural products on TG metabolism, including the inhibition of TG synthesis (via endogenous and exogenous pathways), promotion of TG catabolism, regulation of fatty acid absorption and transport, enhancement of lipophagy, modulation of the gut microbiota, and other mechanisms. In conclusion, through a comprehensive analysis of recent studies, this review consolidates the multifaceted regulatory roles of TCM and plant-derived natural products in TG metabolism and elucidates their potential as safer, multi-target therapeutic agents in managing hypertriglyceridemia and mitigating cardiovascular risk, thereby providing a basis for new drug development.

Polysaccharide of Atractylodes macrocephala Koidz alleviate lipopolysaccharide-stimulated liver inflammation injury of goslings through miR-223/NLRP3 axis

Lipopolysaccharide (LPS) infection could cause severe liver inflammation and lead to liver damage, even death. Previous studies have shown that polysaccharide of Atractylodes macrocephala Koidz (PAMK) could protect liver from inflammation caused by LPS in mice. However, whether PAMK could alleviate liver inflammatory injury in other animals with LPS is still unknown. For evaluating whether PAMK could alleviate liver inflammatory injury in goslings with LPS, a total of 80 healthy 1-day old Magang goslings were randomly divided into 4 groups (control group, PAMK group, LPS group, and PAMK+LPS group). Goslings in control group and LPS group were fed with basal diet, and goslings in PAMK group and PAMK+LPS group were fed basal diet supplemented with 400 mg/kg PAMK to the end of trial. On 24 d of age, goslings in the control group and PAMK group were intraperitoneal injected 0.5 mL normal saline, and goslings in LPS and PAMK+LPS groups were intraperitoneal injected with LPS at 5 mg/kg BW. The serum and liver samples were collected for further analysis after treatment of LPS at 6, 12, 24, and 48 h. Furthermore, the hepatocytes were extracted from goose embryo to measure the expression of the key genes of miR-223/NLRP3 axis. The results showed that PAMK pretreatment could maintain normal cell morphology of liver, alleviate the enhanced levels of biochemical indexes ALT and AST, decrease the levels of IL-1β and IL-18, increase the relative mRNA expression of miR-223, and decrease the expression of NLRP3, Caspase-1, and cleaved Caspase-1 in liver and hepatocytes of goslings induced by LPS. These results indicated that PAMK could relieve inflammatory liver tissue damage after LPS treatment and downregulate the level of inflammation factors via miR-223/NLRP3 axis, thus playing a liver protective role in liver inflammation injury in goslings.

Adipose-derived mesenchymal stem cell-secreted extracellular vesicles alleviate non-alcoholic fatty liver disease via delivering miR-223-3p

Increasing studies have identified the potential of mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) in non-alcoholic fatty liver disease (NAFLD) treatment. Hence, we further focused on the potential of adipose-derived MSC (ADSC)-EVs in NAFLD by delivering miR-223-3p. The uptake of isolated ADSC-EVs by hepatocytes was assessed, and the expression of miR-223-3p in ADSC-EVs and hepatocytes was characterized. It was established that miR-223-3p, enriched in ADSC-EVs, could be delivered by ADSC-EVs into hepatocytes. Using co-culture system and gain-of-function approach, we evaluated the effect of ADSC-EVs carrying miR-223-3p on lipid accumulation and liver fibrosis in pyrrolizidine alkaloids (PA)-induced hepatocytes and a high-fat diet-induced NAFLD mouse model. Bioinformatics websites and dual-luciferase reporter gene assay were performed to determine the interactions between miR-223-3p and E2F1, which was further validated by rescue experiments. ADSC-EVs containing miR-223-3p displayed suppressive effects on lipid accumulation and liver fibrosis through E2F1 inhibition, since E2F1 was demonstrated as a target gene of miR-223-3p. The protective role of ADSC-EVs by delivering miR-223-3p was then confirmed in the mouse model. Collectively, this study elucidated that ADSC-EVs delayed the progression NAFLD through the delivery of anti-fibrotic miR-223-3p and subsequent E2F1 suppression, which may suggest miR-223-3p-loaded ADSC-EVs to be a potential therapeutic approach for NAFLD.

Primary Broiler Hepatocytes for Establishment of a Steatosis Model

Fatty liver hemorrhage syndrome (FLHS) in chickens is characterized by steatosis and bleeding in the liver, which has caused huge losses to the poultry industry. This study aimed to use primary cultured broiler hepatocytes to establish a steatosis model to explore the optimal conditions for inducing steatosis by incubating the cells with a fat emulsion. Primary hepatocytes were isolated from an AA broiler by a modified two-step in situ perfusion method. Hepatocytes were divided into an untreated control group and a fat emulsion group that was incubated with 2.5, 5, 10, or 20% fat emulsion for different times to determine the optimal conditions for inducing steatosis of primary hepatocytes. Incubation of the cells with 10% fat emulsion resulted in cell viability at 48 h of 67%, which was higher than the control group and met the requirements of the model. In the second experiment, steatosis was induced by incubating hepatocytes with 10% fat emulsion for 48 h. In consequence, the apoptosis rate decreased (p > 0.05) and the concentration of ALT (p < 0.001), AST (p < 0.01), and TG (p < 0.05) increased significantly; the expression level of SREBP-1c (p < 0.05) increased, and the expression levels of PPARα (p < 0.001), CPT1 (p < 0.001), and CPT2 (p < 0.05) were lower in the fat emulsion group than in the control group. In conclusion, the induction condition was selected as 10% fat emulsion incubation for 48 h, and we successfully established a fatty liver degeneration model for broilers.

Therapeutic potential of traditional Chinese medicine for the treatment of NAFLD: a promising drug Potentilla discolor Bunge

Nonalcoholic fatty liver disease (NAFLD) is characterized by excessive accumulation of hepatic lipids and metabolic stress-induced liver injury. There are currently no approved effective pharmacological treatments for NAFLD. Traditional Chinese medicine (TCM) has been used for centuries to treat patients with chronic liver diseases without clear disease types and mechanisms. More recently, TCM has been shown to have unique advantages in the treatment of NAFLD. We performed a systematic review of the medical literature published over the last two decades and found that many TCM formulas have been reported to be beneficial for the treatment of metabolic dysfunctions, including Potentilla discolor Bunge (PDB). PDB has a variety of active compounds, including flavonoids, terpenoids, organic acids, steroids and tannins. Many compounds have been shown to exhibit a series of beneficial effects for the treatment of NAFLD, including anti-oxidative and anti-inflammatory functions, improvement of lipid metabolism and reversal of insulin resistance. In this review, we summarize potential therapeutic effects of TCM formulas for the treatment of NAFLD, focusing on the medicinal properties of natural active compounds from PDB and their underlying mechanisms. We point out that PDB can be classified as a novel candidate for the treatment and prevention of NAFLD.

Danning tablets alleviate high fat diet-induced obesity and fatty liver in mice via modulating SREBP pathway

ETHNOPHARMACOLOGICAL RELEVANCE

The traditional Chinese formula Danning tablets exhibit wide clinical applications in liver and gallbladder diseases, and currently it is reported to be effective on fatty liver disease in clinical trials. However, the underlying mechanisms remain elusive.

AIM OF THE STUDY

The purpose of the present study was to assess the effects and potential pharmacological mechanisms of Danning tablet against high fat diet (HFD)-induced obesity, fatty liver, and related metabolic disorders in mice.

MATERIALS AND METHODS

C57BL/6 J male mice were treated with HFD for 12 weeks to trigger obesity and fatty liver condition. Then those mice were randomly divided into 5 groups, namely HFD, Danning tablet (0.75, 1.5 or 3 g/kg bodyweight) or lovastatin (30 mg/kg bodyweight) for extra 6 weeks' treatment of HFD. Food intake and bodyweight were recorded each week. In the last week, before the mice were sacrificed, fasting blood glucose levels and insulin levels were measured. Furthermore, insulin and glucose tolerance tests were performed. Blood and hepatic lipid levels were examined, the lipid metabolism-associated gene expressions and protein levels in the liver or adipose tissues were assayed after sacrificing all mice.

RESULTS

Our results demonstrated that a high dose of Danning tablet (3 g/kg) treatment mitigated body weight gain, reduced blood and hepatic cholesterol and triglyceride levels. The morphology analysis showed that Danning tablets could reduce lipid accumulation in both liver and brown adipose tissue. Moreover, Danning tablets could improve fasting blood glucose levels and ameliorate glucose and insulin tolerance in HFD-induced obese mice. Furthermore, qRT-PCR analysis revealed that the mRNA expressions of SREBP-1 and SREBP-2 as well as their target genes were remarkedly down-regulated in the liver and adipose tissue of diet-induced obesity (DIO) mice after treating those mice with Danning tablets.

CONCLUSION

Our results indicated that Danning tablets could improve the obesity-induced metabolic associated fatty liver disease (MAFLD) and related metabolic disorders. The potential mechanism may probably involve the regulation of the SREBP pathway.

Bupleuri radix extract ameliorates impaired lipid metabolism in high-fat diet-induced obese mice via gut microbia-mediated regulation of FGF21 signaling pathway

BACKGROUND

Obesity and its comorbidities are associated with abnormal lipid metabolism and gut microbiota dysbiosis. Bupleuri Radix is a medicinal plant used in traditional Chinese medicine with the prevention and treatment of obesity-related diseases. In this study, we aim to validate the regulation of Bupleuri Radix Extract (BupE) on lipid metabolism in obese mice, and try to find out the potential active components and reveal the underlying mechanisms.

METHODS

Ingredients in BupE, their circulating metabolites in mice and fecal biotransformation products were analyzed by ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS). Western blotting, RT-PCR and ELISA were used for tests of objective genes and proteins. 16 s rRNA sequencing was performed to examine intestinal bacteria composition and microbes' functional changes were predicted with PICRUSt software. An absolute quantification method was set up via the construction of recombinant plasmid for the assays of intestinal flora. Specific microbial strains were cultured in anaerobic conditions and oral administrated to mice for intestinal mono-colonization.

RESULTS

BupE attenuated obesity, liver steatosis, and dyslipidemia in HFD-fed mice by up-regulating the expression of FGF21 in liver and white adipose tissue (WAT) as well as the downstream proteins of FGF21 signal pathway including β-klotho, GLUT1 and PGC-1α, etc. UPLC/Q-TOF-MS fingerprints showed no compounds from BupE or their metabolites or biotransformation products were detected in rodent serum samples. High-throughput pyrosequencing data indicated that BupE reversed obesity-induced constructional and functional alterations of intestinal flora. Two bacterial strains, Bacteroides acidifaciens (B. acidifaciens) and Ruminococcus gnavus (R. gnavus), were separated and identified from the feces of obese mice and by intestinal mono-colonization they were verified to intervene in the anti-obesity effects of BupE on mice.

CONCLUSION

These data suggest that BupE protects against diet-induced obesity and counteracts metabolic syndrome features consistent with a mechanism involving the gut-liver axis that boosts hepatic FGF21 secretion and consequent down-stream proteins expression relating to lipid metabolism. And in this gut-liver axis, intestinal microbes such as B.acidifaciens and R.gnavus play an indispensable role.

Lack of Augmenter of Liver Regeneration Disrupts Cholesterol Homeostasis of Liver in Mice by Inhibiting the AMPK Pathway

It is well known that excessive cholesterol accumulation within hepatocytes deteriorates nonalcoholic fatty liver disease (NAFLD). Augmenter of liver regeneration (ALR) has been reported to alleviate NAFLD through anti-apoptosis; however, whether ALR could protect liver from cholesterol-induced NAFLD remains unclear. Mice with heterozygous deletion of Gfer (the gene for ALR, Gfer ^+/-) were generated, and liver steatosis was induced by either choline-deficient ethionine-supplemented, methionine choline-deficient diet for 4 weeks, or high-fat diet for 16 weeks. The results showed that Gfer ^+/- mice developed a more severe fatty liver phenotype than Gfer ^+/+ mice. The livers of Gfer ^+/- mice exhibited a higher concentration of cholesterol and low-density lipoprotein compared with the normal mice. Transcriptome-based analysis predicts low-density lipoprotein receptor (LDLR) primarily involved in the metabolic pathway. The experiments further indicate that cholesterol accumulation within hepatocytes is closely associated with enhancing the expression of LDLR and activation of sterol regulatory element binding protein 2 (SREBP2). Because adenosine monophosphate-activated protein kinase (AMPK) is a critical regulator of SREBP2 activation, we measured whether the activity of AMPK was regulated by ALR. We found that knockdown of ALR expression inhibited the phosphorylation of LKB1, an upstream activator of AMPK, followed by AMPK inactivation and SREBP2 maturation/nuclear translocation, leading to extensive cholesterol accumulation. Meanwhile, cellular oxidative stress increased as a result of ALR knockdown, indicating that ALR might also have a role in suppressing reactive oxygen species production. Conclusion: Our results confirm that ALR regulates cholesterol metabolism and alleviates hepatic steatosis probably through the LKB1-AMPK-SREBP2-LDLR pathway in vivo and in vitro, providing a putative mechanism for combating fatty liver disease.

Nonalcoholic Fatty Liver Disease: Pathogenesis and Treatment in Traditional Chinese Medicine and Western Medicine

Nonalcoholic Fatty Liver Disease (NAFLD) is one of the most important causes of liver disease worldwide and probably destined to become the leading cause of end-stage liver disease in the coming decades, affecting both adults and children. Faced with the severe challenges for the prevention and control of NAFLD, this article discusses the understanding and mechanism of NAFLD from Chinese and Western medicine. Moreover, the progress regarding its treatment in both Chinese and Western medicine is also summarized. Both Chinese medicine and Western medicine have their own characteristics and clinical efficacy advantages in treating diseases. The purpose of this article is to hope that Chinese and Western medicine have complementary advantages, complementing each other to improve clinical NAFLD therapy prevention and treatment methods to receive more and more attention throughout the global medical community.

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

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

Apigenin reduces the excessive accumulation of lipids induced by palmitic acid via the AMPK signaling pathway in HepG2 cells

In recent years, increasing attention has been paid to diseases caused by excessive accumulation of lipids in the liver with therapeutic agents derived from natural products offering an alternative treatment to conventional therapies. Among these therapeutic agents, apigenin, a natural flavonoid, has been proven to exert various beneficial biological effects. In the present study, the antiadipogenic effects of apigenin in HepG2 cells was investigated. It was demonstrated that the treatment of cells with different concentrations of apigenin for 24 h significantly decreased the palmitic acid-induced increases in total cholesterol (TC) and triglyceride (TG) levels as well as intracellular lipid accumulation. In addition, apigenin increased the phosphorylated-AMP-activated protein kinase (AMPK) levels but decreased the expression levels of 3-hydroxy-3-methylglutaryl CoA reductase, sterol regulatory element-binding protein (SREBP)-1, fatty acid synthase, and SREBP-2 in a concentration-dependent manner. The present findings suggested that apigenin might improve lipid metabolism by activating the AMPK/SREBP pathway to reduce lipid accumulation in the liver.

Protective effect and mechanism of Qiwei Tiexie capsule on 3T3-L1 adipocytes cells and rats with nonalcoholic fatty liver disease by regulating LXRα, PPARγ, and NF-κB-iNOS-NO signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Qiwei Tiexie capsule (QWTX) is a representative prescription of Tibetan medicine, which is widely used for long-term treatment of chronic liver disease and nonalcoholic fatty liver disease (NAFLD).

AIM OF THE STUDY

This study explored the effects and mechanism of QWTX on 3T3-L1 adipocytes and NAFLD.

MATERIALS AND METHODS

The 3T3-L1 preadipocytes and NAFLD rat model were used in the study. In 3T3-L1 cells, the cytotoxicity of QWTX was tested by CKK-8, and glucose uptake and fat acid oxidation were assessed by 2-deoxy-D-[³H] glucose and [1-¹⁴C] palmitic acid, respectively. The expression levels of carnitine palmitoyltransferase-1 (CPT-1), liver X receptor α (LXRα), peroxisome proliferator-activated receptor (PPAR) γ, inducible nitric oxide synthase (iNOS), ikappa B α (IκBα), and AKT were determined by PCR and western blot. NAFLD was established by the administration of fat emulsion and sucrose for 9 weeks. The effects of QWTX on lipid metabolism, liver function, and hepatic morphology were observed in NAFLD rats by HE and transmission electron microscope. Serum level of nitric oxide (NO) and fee fatty acid (FFA), superoxide dismutase (SOD) and malondialdehyde (MDA) contents in the liver, as well as the expression levels of Cytochrome P450 2E1 (CYP2E1), NF-κB, monocyte chemoattractant protein 1 (MCP-1), CPT-1, LXRα, PPARα, PPARβ/δ, PPARγ, and iNOS were all detected.

RESULTS

QWTX showed no cell cytotoxicity in 3T3-L1 preadipocyte cells, and increased the ¹⁴CO₂ production rate to 4.15, which indicated the reducing the fatty accumulation. In NAFLD, QWTX attenuated liver steatosis, fat vacuoles and inflammation from the HE staining and electron micrograph tests. For the oxidative stress biomarkers, serum FFA level was reduced and serum NO level was enhanced after QWTX treatment. In liver tissue, SOD was decreased and MDA was significantly increased in NAFLD, and both of them were restored by QWTX. NF-κB and CYP2E1 were also upregulated in NAFLD, while downregulated by QWTX. Downregulation of LXRα, PPARγ and iNOS by QWTX were both observed in the 3T3-L1 adipocytes and NAFLD model.

CONCLUSIONS

QWTX protected the liver injury in differentiated 3T3-L1 adipocytes and NAFLD by regulating the LXRα, PPARγ, and NF-κB-iNOS-NO signal pathways.