Dihydroartemisinin protects against alcoholic liver injury through alleviating hepatocyte steatosis in a farnesoid X receptor-dependent manner

Progress of mitochondrial and endoplasmic reticulum-associated signaling and its regulation of chronic liver disease by Chinese medicine

The endoplasmic reticulum (ER) is connected to mitochondria through mitochondria-associated ER membranes (MAMs). MAMs provide a framework for crosstalk between the ER and mitochondria, playing a crucial role in regulating cellular calcium balance, lipid metabolism, and cell death. Dysregulation of MAMs is involved in the development of chronic liver disease (CLD). In CLD, changes in MAMs structure and function occur due to factors such as cellular stress, inflammation, and oxidative stress, leading to abnormal interactions between mitochondria and the ER, resulting in liver cell injury, fibrosis, and impaired liver function. Traditional Chinese medicine has shown some research progress in regulating MAMs signaling and treating CLD. This paper reviews the literature on the association between mitochondria and the ER, as well as the intervention of traditional Chinese medicine in regulating CLD.

Dihydroartemisinin ameliorates the liver steatosis in metabolic associated fatty liver disease mice by attenuating the inflammation and oxidative stress and promoting autophagy

PURPOSE

To explore the effect and potential mechanism of dihydroartemisinin (DHA) on metabolism-related fatty liver disease.

METHODS

A metabolic associated fatty liver disease (MAFLD) mice model was induced with continuous supplies of high-fat diet. DHA was intraperitoneally injected into mice. The weight of mice was monitored. The concentrations of total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) in serum were detected by an automatic biochemical analyzer. The liver tissues were stained by hematoxylin and eosin and oil red O. The level of inflammation, oxidative stress, and autophagy was assessed by reverse transcription polymerase chain reaction, biochemical examination, Western blot and transmission electron microscope assays.

RESULTS

DHA treatment reduced theMAFLD-enhanced the level of weight gain, the concentrations of TC, TG, LDL and malonaldehyde, while increasedthe MAFLD-decreased the concentrations of HDL and superoxide dismutase. DHA ameliorated the MAFLD-aggravated pathological changes and the number of lipid droplets. Low dose of DHA declined the MAFLD-induced the enhancement of the expression of inflammatory factor. DHA treatment increased the MAFLD-enhanced the level of autophagy related protein, while decreased the MAFLD-reduced the protein level of p62. The increased level of autophagy was confirmed by transmission electron microscope.

CONCLUSIONS

DHA can improve liver steatosis in MAFLD mice by inhibiting inflammation and oxidative stress and promoting autophagy.

Morinda citrifolia Extract Prevents Alcoholic Fatty Liver Disease by Improving Gut Health

Alcoholic liver disease (ALD) is a major chronic liver disease. Chronic alcohol consumption induces dysbiosis, disruption of gut barrier function, oxidative stress, inflammation, and changes in lipid metabolism, thereby leading to ALD. In this study, we investigated whether the commercial Morinda citrifolia extract Nonitri can ameliorate ALD symptoms through the gut-liver axis. We used mice chronically administered EtOH and found a marked increase in serum endotoxin levels and biomarkers of liver pathology. Moreover, the EtOH-treated group showed significantly altered gut microbial composition particularly that of Alistipes, Bacteroides, and Muribaculum and disrupted gut barrier function. However, Nonitri improved serum parameters, restored the microbial proportions, and regulated levels of zonula occludens1, occludin, and claudin1. Furthermore, Nonitri suppressed inflammation by inhibiting endotoxin-triggered toll-like receptor 4-signaling pathway and fat deposition by reducing lipogenesis through activating AMP-activated protein kinase in the liver. Furthermore, Pearson's correlation analysis showed that gut microbiota and ALD-related markers were correlated, and Nonitri regulated these bacteria. Taken together, our results indicate that the hepatoprotective effect of Nonitri reduces endotoxin levels by improving gut health, and inhibits fat deposition by regulating lipid metabolism.

Network Pharmacology-Based Exploration on the Intervention of Qinghao Biejia Decoction on the Inflammation-Carcinoma Transformation Process of Chronic Liver Disease via MAPK and PI3k/AKT Pathway

Chronic liver disease(CLD) is a slow-developing and long-term disease that can cause serious damage to the liver. Thus far, it has been associated with viral hepatitis, non-alcoholic fatty liver disease(NAFLD), alcoholic liver disease(ALD), hepatic fibrosis(HF), liver cirrhosis (LC), and liver cancer. Qinghao Biejia Decoction (QBD) is a classic ancient Chinese herbal prescription with strong immune-enhancing, anti-inflammatory, and anti-tumor effects. In this study, we used a network pharmacology approach to investigate the molecular mechanisms of QBD in the inflammation-carcinoma transformation process of chronic liver disease. Two key drug targets, MAPK1 and PIK3CA, were screened using network pharmacology and molecular docking techniques, revealing dihydroartemisinin, artesunate, 12-O-Nicotinoylisolineolone, caffeic acid, and diincarvilone A as active ingredients involved in QBD mechanisms. The main signaling pathways involved were the PI3K-AKT signaling pathway and MAPK signaling pathway. In summary, our results indicated that QBD affects the inflammatory transformation of chronic liver disease through MAPK1 and PIK3CA and signaling pathways MAPK and PI3K/AKT. These data provide research direction for investigating the mechanisms underlying the inflammation-carcinoma transformation process in QBD for chronic liver disease.

Transcriptomic Analysis Reveals Lactobacillus reuteri Alleviating Alcohol-Induced Liver Injury in Mice by Enhancing the Farnesoid X Receptor Signaling Pathway

Alcoholic liver disease (ALD) is caused by alcohol abuse and can progress to hepatitis, cirrhosis, and even hepatocellular carcinoma. Previous studies suggested that Lactobacillus reuteri (L. reuteri) ameliorates ALD, but the exact mechanisms are not fully known. This study created an ALD model in mice, and the results showed L. reuteri significantly alleviating lipid accumulation in the mice. Transcriptome sequencing showed the L. reuteri treatment group had the most enriched metabolic pathway genes. We then studied the farnesoid X receptor (FXR) metabolic pathway in the mice liver tissue. Western blot analysis showed that FXR and carbohydrate response element binding protein (ChREBP) were upregulated and sterol regulatory element binding transcription factor 1 (Srebf1) and Cluster of differentiation (CD36) were downregulated in the L. reuteri-treated group. Subsequently, we administered FXR inhibitor glycine-β-muricholic acid (Gly-β-MCA) to mice, and the results show that Gly-β-MCA could reduce the therapeutic effect of L. ruteri. In conclusion, our study shows L. reuteri improved liver lipid accumulation in mice via the FXR signaling regulatory axis and may be a viable treatment option for ALD.

Dihydroartemisinin promoted FXR expression independent of YAP1 in hepatocellular carcinoma

Loss of FXR, one of bile acid receptors, enlarged livers. Yes-associated protein 1 (YAP1), a dominant oncogene, promotes hepatocellular carcinoma (HCC). However, the relationship between FXR and YAP1 was unspecified in bile acid homeostasis in HCC. Here, we used TIMER2.0, the Cancer Genome Atlas (TCGA) Database, and Kaplan-Meier Plotter Database and discovered that FXR was positively correlated with better prognosis in liver cancer patients. Our previous research showed that dihydroartemisinin (DHA) inhibited cell proliferation in HepG2 and HepG22215 cells. However, the relationship of YAP1 and the bile acid receptor FXR remains elusive during DHA treatment. Furthermore, we showed that DHA improved FXR and reduced YAP1 in the liver cancer cells and mice. Additionally, the expression of nucleus protein FXR was enhanced in Yap1^LKO mice with liver cancer. DHA promoted the expression level of whole and nuclear protein FXR independent of YAP1 in Yap1^LKO mice with liver cancer. DHA declined cholesterol 7α-hydroxylase, but not sterol 27-hydroxylase, and depressed cholic acid and chenodeoxycholic acid of liver tissue in Yap1^LKO mice with liver cancer. Generally, our results suggested that DHA improved FXR and declined YAP1 to suppress bile acid metabolism. Thus, we suggested that FXR acted as a potential therapeutic target in HCC.

Dihydroartemisinin alleviates steatosis and inflammation in nonalcoholic steatohepatitis by decreasing endoplasmic reticulum stress and oxidative stress

Nonalcoholic steatohepatitis (NASH) is a severely inflammatory subtype of nonalcoholic fatty liver. Endoplasmic reticulum stress (ERS) and oxidative stress (OS) cause metabolic abnormalities, promote liver steatosis and inflammation, and are central to the development of NASH. Dihydroartemisinin (DHA) is a compound extracted from Artemisia annua that is often used in the treatment of malaria. Recent studies have shown that DHA also has a wide range of pharmacological effects, acting on various organs throughout the body to exert anti-inflammatory, antioxidant, and anti-fibrotic effects. In this study, we demonstrated in vitro that the anti-inflammatory effect of DHA is effective against NASH and reduces liver steatosis. DHA treatment decreased the synthesis of lipids, such as cholesterol and free fatty acids, and the expression of nuclear factor kappa-B. This is accomplished by inhibiting the unfolded protein response and reducing the production of reactive oxygen species, thereby inhibiting OS and ERS. This study reveals DHA's therapeutic effect and potential mechanism in NASH, implying that DHA could be a new and promising candidate for NASH therapy.

Anti-malarial drug: the emerging role of artemisinin and its derivatives in liver disease treatment

Artemisinin and its derivatives belong to a family of drugs approved for the treatment of malaria with known clinical safety and efficacy. In addition to its anti-malarial effect, artemisinin displays anti-viral, anti-inflammatory, and anti-cancer effects in vivo and in vitro. Recently, much attention has been paid to the therapeutic role of artemisinin in liver diseases. Several studies suggest that artemisinin and its derivatives can protect the liver through different mechanisms, such as those pertaining to inflammation, proliferation, invasion, metastasis, and induction of apoptosis and autophagy. In this review, we provide a comprehensive discussion of the underlying molecular mechanisms and signaling pathways of artemisinin and its derivatives in treating liver diseases. Further pharmacological research will aid in determining whether artemisinin and its derivatives may serve as promising medicines for the treatment of liver diseases in the future.

Dihydroartemisinin regulates lipid droplet metabolism in hepatic stellate cells by inhibiting lncRNA-H19-induced AMPK signal

Activation of hepatic stellate cells (HSCs) is a central event in the pathogenesis of liver fibrosis and is often accompanied by the disappearance of lipid droplets (LDs). Although interference with LD metabolism can effectively reverse the activation of HSCs, there is currently no effective therapy for liver fibrosis. Our previous evidence indicates that long non-coding RNA (lncRNA)-H19 plays an essential role in LD metabolism of HSC. In this study, we investigated the potential molecular mechanism of dihydroartemisinin (DHA) inhibits LD metabolism and liver fibrosis by regulating H19-AMPK pathway. We found that DHA restores LDs content in activated HSCs via reducing the transcription of H19 driven by hypoxia inducible factor 1 subunit alpha (HIF1α) and inhibiting the lipid oxidation signal mediated by AMP-activated protein kinase (AMPK) phosphorylation. In vivo experiments, we have proved that DHA reduced the deposition of extracellular matrix (ECM) and reduce the level of liver fibrosis in CCl₄-induced liver fibrosis of mice. In summary, our results emphasize the importance of H19 in liver fibrosis and the potential of DHA to regulate H19 to treat liver fibrosis, providing a new direction for the prevention and treatment of liver fibrosis.

The pathophysiological function of non-gastrointestinal farnesoid X receptor

Farnesoid X receptor (FXR) influences bile acid homeostasis and the progression of various diseases. While the roles of hepatic and intestinal FXR in enterohepatic transport of bile acids and metabolic diseases were reviewed previously, the pathophysiological functions of FXR in non-gastrointestinal cells and tissues have received little attention. Thus, the roles of FXR in the liver, immune system, nervous system, cardiovascular system, kidney, and pancreas beyond the gastrointestinal system are reviewed herein. Gain of FXR function studies in non-gastrointestinal tissues reveal that FXR signaling improves various experimentally-induced metabolic and immune diseases, including non-alcoholic fatty liver disease, type 2 diabetes, primary biliary cholangitis, sepsis, autoimmune diseases, multiple sclerosis, and diabetic nephropathy, while loss of FXR promotes regulatory T cells production, protects the brain against ischemic injury, atherosclerosis, and inhibits pancreatic tumor progression. The downstream pathways regulated by FXR are diverse and tissue/cell-specific, and FXR has both ligand-dependent and ligand-independent activities, all of which may explain why activation and inhibition of FXR signaling could produce paradoxical or even opposite effects in some experimental disease models. FXR signaling is frequently compromised by diseases, especially during the progressive stage, and rescuing FXR expression may provide a promising strategy for boosting the therapeutic effect of FXR agonists. Tissue/cell-specific modulation of non-gastrointestinal FXR could influence the treatment of various diseases. This review provides a guide for drug discovery and clinical use of FXR modulators.

Improving glucose and lipids metabolism: drug development based on bile acid related targets

Bariatric surgery is one of the most effective treatment options for severe obesity and its comorbidities. However, it is a major surgery that poses several side effects and risks which impede its clinical use. Therefore, it is urgent to develop alternative safer pharmacological approaches to mimic bariatric surgery. Recent studies suggest that bile acids are key players in mediating the metabolic benefits of bariatric surgery. Bile acids can function as signaling molecules by targeting bile acid nuclear receptors and membrane receptors, like FXR and TGR5 respectively. In addition, the composition of bile acids is regulated by either the hepatic sterol enzymes such as CYP8B1 or the gut microbiome. These bile acid related targets all play important roles in regulating metabolism. Drug development based on these targets could provide new hope for patients without the risks of surgery and at a lower cost. In this review, we summarize the most updated progress on bile acid related targets and development of small molecules as drug candidates based on these targets.

A Perspective Of Intestinal Immune-Microbiome Interactions In Alcohol-Associated Liver Disease

Uncovering the intricacies of the gut microbiome and how it interacts with the host immune system has opened up pathways in the search for the treatment of disease conditions. Alcohol-associated liver disease is a major cause of death worldwide. Research has shed light on the breakdown of the protective gut barriers, translocation of gut microbes to the liver and inflammatory immune response to microbes all contributing to alcohol-associated liver disease. This knowledge has opened up avenues for alternative therapies to alleviate alcohol-associated liver disease based on the interaction of the commensal gut microbiome as a key player in the regulation of the immune response. This review describes the relevance of the intestinal immune system, the gut microbiota, and specialized and non-specialized intestinal cells in the regulation of intestinal homeostasis. It also reflects how these components are altered during alcohol-associated liver disease and discusses new approaches for potential future therapies in alcohol-associated liver disease.

HIF-1α-upregulated lncRNA-H19 regulates lipid droplet metabolism through the AMPKα pathway in hepatic stellate cells

Activation of hepatic stellate cells (HSCs) is a central event in the pathogenesis of liver fibrosis and is characterized by the disappearance of lipid droplets. Although the exogenous supplementation of lipid droplet content can effectively reverse the activation of HSCs, the underlying molecular mechanisms are largely unknown. In our current study, we sought to investigate the role of lncRNA-H19 in the process of lipid droplets disappearance and to further examine the underlying molecular mechanisms. We found that the lncRNA-H19 level was increased in CCl₄-induced fibrotic liver, which activated HSCs. Further research showed that hypoxia inducible factor-1α (HIF-1α) significantly increased lncRNA-H19 expression by binding to the lncRNA-H19 promoter at two hypoxia response element (HRE) sites located at 492-499 and 515-522 bp. Importantly, lncRNA-H19 knockdown markedly inhibited HSC activation and alleviated liver fibrosis, indicating that lncRNA-H19 may be a potential target for anti-fibrosis therapeutic approaches. Moreover, lncRNA-H19 knockdown could reverse the lipid droplet phenotype of activated HSCs, inhibiting the phosphorylated AMPKα-mediated lipid oxidation signaling pathway. The AMPK agonist AICAR promoted AMPKα phosphorylation and abrogated lipid droplets restoration in HSCs transfected with the lncRNA-H19 knockdown plasmid. Experimental molecular analysis showed that lncRNA-H19 triggered AMPKα to interact with LKB1 and resulted in AMPKα phosphorylation, which accelerating lipid droplets degradation and lipid oxidation. Taken together, our results highlighted the role of lncRNA-H19 in the metabolism of lipid droplets in HSCs, and revealed a new molecular target for alleviating liver fibrosis.

Evaluation of the hepatoprotective effect of Yigan mingmu oral liquid against acute alcohol-induced liver injury in rats

Background

Yigan mingmu oral liquid (YGMM) is a herbal medicine based on a famous Chinese herbal formula that has been used for sore eyes for more than 400 years. Eye health is closely associated with the liver based on TCM. This study aimed to investigate the hepatoprotective effect of YGMM against acute liver injury induced by alcohol in rats.

Methods

Experimental rats were administered with silymarin and YGMM through the gastric gavage during the entire experiment. Starting from the 11th day, the rats were administered orally with 14 ml/kg Red Star Erguotou Liquor, a popular brand, at 4 h after the dose of silymarin (100 mg/kg) and YGMM (1, 2.5 and 5 ml/kg in low, middle and high dosage group, respectively) once a day for 4 weeks except for the rats in the normal group. Biochemical parameters, including ALT, AST, TB, TG, T-SOD, GSH, and MDA were detected to evaluate the protective effect of YGMM. Pathological changes were observed through histopathological examination.

Results

Treatment with YGMM exhibited a significant protective effect by reversing the biochemical parameters (ALT, AST, TB, TG, and GSH) and histopathological changes. Histopathological examination by Oil Red O Staining Solution showed that lipid droplets were significantly reduced in the silymarin and YGMM groups (p < 0.001) when compared to alcohol group.

Conclusions

YGMM exhibits a significant hepatoprotective activity against acute liver injury induced by alcohol in rats.

Nerve growth factor induced farnesoid X receptor upregulation modulates autophagy flux and protects hepatocytes in cholestatic livers

Upregulation of nerve growth factor (NGF) in parenchymal hepatocytes has been shown to exert hepatoprotective function during cholestatic liver injury. However, the modulatory role of NGF in regulation of liver autophagy remains unclear. This study aimed to scrutinize the regulatory role of NGF in hepatic expression of farnesoid X receptor (FXR), a bile acid (BA)-activated nuclear receptor, and to determine its cytoprotective effect on BA-induced autophagy and cytotoxicity. Livers of human hepatolithiasis and bile duct ligation (BDL)-induced mouse cholestasis were used for histopathological and molecular detection. The regulatory roles of NGF in autophagy flux and FXR expression, as well as its hepatoprotection against BA cytotoxicity were examined in cultured hepatocytes. FXR downregulation in human hepatolithiasis livers showed positive correlation with hepatic NGF levels. NGF administration upregulated hepatic FXR levels, while neutralization of NGF decreased FXR expression in BDL-induced cholestatic mouse livers. In vitro studies demonstrated that NGF upregulated FXR expression, increased cellular LC3 levels, and exerted hepatoprotective effect in cultured primary rat hepatocytes. Conversely, autophagy inhibition abrogated NGF-driven cytoprotection under BA exposure, suggesting involvement of NGF-modulated auophagy flux. Although FXR agonistic GW4064 stimulation did not affect auophagic LC3 levels, FXR activity inhibition significantly potentiated BA-induced cytotoxicity and increased cellular p62/SQSTM1 and Rab7 protein in SK-Hep1 hepatocytes. Moreover, FXR gene silencing abolished the protective effect of NGF under BA exposure. These findings support that NGF modulates autophagy flux via FXR upregulation and protects hepatocytes against BA-induced cytotoxicity. NGF/FXR axis is a novel therapeutic target for treatment of cholestatic liver diseases.

Dihydroartemisinin attenuates alcoholic fatty liver through regulation of lipin-1 signaling

Alcoholic liver disease (ALD) is generated from excessive alcohol consumption, characterized by hepatic steatosis. Mechanistically, excessive hepatic lipid accumulation was attributed to the aberrant lipin-1 signaling during the development of alcoholic steatosis in rodent species and human. Dihydroartemisinin (DHA) has been recently identified to relieve hepatocytes necrosis and prevent from hepatic steatosis in alcohol-induced liver diseases; however, the role of DHA in ALD has not been elucidated completely. Therefore, this study was aimed to further identify the potential mechanisms of pharmacological effects of DHA on ALD. Results demonstrated that DHA regulated the expression and nucleocytoplasmic shuttling of lipin-1 in mice with chronic ethanol exposure. Results confirmed that the disruption of lipin-1 signaling abolished the suppression of DHA on alcohol-induced hepatic steatosis. Interestingly, DHA also significantly improved liver injury, and inflammation mediated by lipin-1 signaling in chronic alcohol-fed mice. in vivo experiments further consolidated the concept that DHA protected against hepatocyte lipoapoptosis dependent on the regulation of nucleocytoplasmic shuttling of lipin-1 signaling, resulting in attenuated ratio of Lpin1 β/α. Obvious increases in cell apoptosis were observed in alcohol-treated lipin1β-overexpressed mice. Although DHA attenuated cell apoptosis, overexpression of lipin-1β neutralized DHA action. DHA ameliorated activation of endoplasmic reticulum stress through inhibiting activation of JNK and CHOP, which was abrogated by overexpression of lipin-1β. In summary, DHA significantly improved liver injury, steatosis and hepatocyte lipoapoptosis in chronic alcohol-fed mice via regulation of lipin-1 signaling.

Gallic acid protects against ethanol-induced hepatocyte necroptosis via an NRF2-dependent mechanism

Alcoholic liver disease (ALD), featured by excessive hepatocyte death and inflammation, is a prevalent disease that causes heavy health burdens worldwide. Hepatocyte necroptosis is a central event that promotes inflammation in ALD. At molecular levels, inhibition of nuclear factor (erythroid - derived 2) - like 2 (NRF2) was an important trigger for cell necroptosis. The protective effects of gallic acid (GA) on liver diseases caused by multiple factors have been elucidated, however, the role of GA in ALD remained unclear. Therefore, this study was aimed to investigate the anti-ALD effects of GA and further reveal the molecular mechanisms. Results showed that GA could effectively recover cell viability and reduce the release of aspartate transaminase, alanine transaminase, and lactic dehydrogenase by ethanol-stimulated hepatocytes. More importantly, GA limited hepatocyte necroptosis under ethanol stimulation, which was characterized by reduced expression of distinct necroptotic signals receptor-interacting protein 1 (RIP1) and RIP3 and release of high mobility group box protein 1. Mechanistically, GA could induce NRF2 expression in ethanol-incubated hepatocytes, which was a molecular basis for GA to suppress ethanol-induced hepatocyte necroptosis. In conclusion, this study demonstrated that GA improved ethanol-induced hepatocyte necroptosis in vitro. Further, NRF2 activation might be requisite for GA to exert its protective effects.

Chemistry and Pharmacology of GPBAR1 and FXR Selective Agonists, Dual Agonists, and Antagonists

In the recent years, bile acid receptors FXR and GPBAR1 have attracted the interest of scientific community and companies, as they proved promising targets for the treatment of several diseases, ranging from liver cholestatic disorders to metabolic syndrome, inflammatory states, nonalcoholic steatohepatitis (NASH), and diabetes.Consequently, the development of dual FXR/GPBAR1 agonists, as well as selective targeting of one of these receptors, is considered a hopeful possibility in the treatment of these disorders. Because endogenous bile acids and steroidal ligands, which cover the same chemical space of bile acids, often target both receptor families, speculation on nonsteroidal ligands represents a promising and innovative strategy to selectively target GPBAR1 or FXR.In this review, we summarize the most recent acquisition on natural, semisynthetic, and synthetic steroidal and nonsteroidal ligands, able to interact with FXR and GPBAR1.

Molecular mechanism and research progress on pharmacology of traditional Chinese medicine in liver injury

CONTEXT

Liver disease is a common threat to human health, caused by a variety of factors that damage the liver. Recent studies have shown that active ingredients (for example: flavonoids, saponins, acids, phenols, and alkaloids) from Traditional Chinese Medicine (TCM) can have hepatoprotective benefits, which represents an attractive source of drug discovery for treating liver injury.

OBJECTIVE

We reviewed recent contributions on the chemically induced liver injury, immunological liver damage, alcoholic liver injury, and drug-induced liver injury, in order to summarize the research progress in molecular mechanism and pharmacology of TCM, and provides a comprehensive overview of new TCM treatment strategies for liver disease.

MATERIALS AND METHODS

Relevant literature was obtained from scientific databases such as Pubmed, Web of Science. and CNKI databases on ethnobotany and ethnomedicines (from January 1980 to the end of May 2018). The experimental studies involving the antihepatic injury role of the active agents from TCM and the underlying mechanisms were identified. The search terms included 'liver injury' or 'hepatic injury', and 'traditional Chinese medicine', or 'herb'.

RESULTS

A number of studies revealed that the active ingredients of TCM exhibit potential therapeutic benefits against liver injury, while the underlying mechanisms appear to contribute to the regulation of inflammation, oxidant stress, and pro-apoptosis signaling pathways.

DISCUSSION AND CONCLUSIONS

The insights provided in this review will help further exploration of botanical drugs in the development of liver injury therapy via study on the effective components of TCM.

Update on FXR Biology: Promising Therapeutic Target?

Farnesoid X receptor (FXR), a metabolic nuclear receptor, plays critical roles in the maintenance of systemic energy homeostasis and the integrity of many organs, including liver and intestine. It regulates bile acid, lipid, and glucose metabolism, and contributes to inter-organ communication, in particular the enterohepatic signaling pathway, through bile acids and fibroblast growth factor-15/19 (FGF-15/19). The metabolic effects of FXR are also involved in gut microbiota. In addition, FXR has various functions in the kidney, adipose tissue, pancreas, cardiovascular system, and tumorigenesis. Consequently, the deregulation of FXR may lead to abnormalities of specific organs and metabolic dysfunction, allowing the protein as an attractive therapeutic target for the management of liver and/or metabolic diseases. Indeed, many FXR agonists have been being developed and are under pre-clinical and clinical investigations. Although obeticholic acid (OCA) is one of the promising candidates, significant safety issues have remained. The effects of FXR modulation might be multifaceted according to tissue specificity, disease type, and/or energy status, suggesting the careful use of FXR agonists. This review summarizes the current knowledge of systemic FXR biology in various organs and the gut–liver axis, particularly regarding the recent advancement in these fields, and also provides pharmacological aspects of FXR modulation for rational therapeutic strategies and novel drug development.

Protection by the Total Flavonoids from Rosa laevigata Michx Fruit against Lipopolysaccharide-Induced Liver Injury in Mice via Modulation of FXR Signaling

We previously reported the effects of the total flavonoids (TFs) from Rosa laevigata Michx fruit against carbon tetrachloride-induced liver damage, non-alcoholic fatty liver disease, and liver ischemia-reperfusion injury. However, there have been no papers reporting the role of R. laevigata TFs against lipopolysaccharide (LPS)-induced liver injury. In this paper, liver injury in mice was induced by LPS, and R. Laevigata extract was intragastrically administered to the mice for 7 days. Biochemical parameters in serum and liver tissue were examined, and pathological changes were observed by transmission electron microscopy, hematoxylin and eosin (H&E) and Oil Red O staining. The results showed that the TFs markedly reduced serum ALT (alanine transferase), AST (aspartate transaminase), TG (total triglyceride), and TC (total cholesterol) levels and relative liver weights and improved liver pathological changes. In addition, the TFs markedly decreased tissue MDA (malondialdehyde) level and increased the levels of SOD (superoxide dismutase) and GSH-Px (glutathione peroxidase). A mechanistic study showed that the TFs significantly increased the expression levels of Nrf2 (nuclear erythroid factor2-related factor 2), HO-1 (heme oxygenase-1), NQO1 (NAD(P)H dehydrogenase (quinone 1), GCLC (glutamate-cysteine ligase catalytic subunit), and GCLM (glutamate-cysteine ligase regulatory subunit) and decreased Keap1 (Kelch-like ECH-associated protein 1) level by activating FXR (farnesoid X receptor) against oxidative stress. Furthermore, the TFs markedly suppressed the nuclear translocation of NF-&kappa;B (nuclear factor-kappa B) and subsequently decreased the expression levels of IL (interleukin)-1&beta;, IL-6, HMGB-1 (high -mobility group box 1), and COX-2 (cyclooxygenase-2) by activating FXR and FOXO3a (forkhead box O3) against inflammation. Besides, the TFs obviously reduced the expression levels of SREBP-1c (sterol regulatory element-binding proteins-1c), ACC1 (acetyl-CoA carboxylase-1), FASN (fatty acid synthase), and SCD1 (stearoyl-coenzyme A desaturase 1), and improved CPT1 (carnitine palmitoyltransferase 1) level by activating FXR to regulate lipid metabolism. Our results suggest that TFs exhibited protective effect against LPS-induced liver injury by altering FXR-mediated oxidative stress, inflammation, and lipid metabolism, and should be developed as an effective food and healthcare product for the therapy of liver injury in the future.

Novel natural product therapeutics targeting both inflammation and cancer

Inflammation is recently recognized as one of the hallmarks of human cancer. Chronic inflammatory response plays a critical role in cancer development, progression, metastasis, and resistance to chemotherapy. Conversely, the oncogenic aberrations also generate an inflammatory microenvironment, enabling the development and progression of cancer. The molecular mechanisms of action that are responsible for inflammatory cancer and cancer-associated inflammation are not fully understood due to the complex crosstalk between oncogenic and pro-inflammatory genes. However, molecular mediators that regulate both inflammation and cancer, such as NF-κB and STAT have been considered as promising targets for preventing and treating these diseases. Recent works have further demonstrated an important role of oncogenes (e.g., NFAT1, MDM2) and tumor suppressor genes (e.g., p53) in cancer-related inflammation. Natural products that target these molecular mediators have shown anticancer and anti-inflammatory activities in preclinical and clinical studies. Sesquiterpenoids (STs), a class of novel plant-derived secondary metabolites have attracted great interest in recent years because of their diversity in chemical structures and pharmacological activities. At present, we and other investigators have found that dimeric sesquiterpenoids (DSTs) may exert enhanced activity and binding affinity to molecular targets due to the increased number of alkylating centers and improved conformational flexibility and lipophilicity. Here, we focus our discussion on the activities and mechanisms of action of STs and DSTs in treating inflammation and cancer as well as their structure-activity relationships.

Oroxylin A inhibits ethanol-induced hepatocyte senescence via YAP pathway

OBJECTIVES

Oroxylin A, a natural flavonoid isolated from Scutellaria baicalensis, has been reported to have anti-hepatic injury effects. However, the effects of oroxylin A on alcoholic liver disease (ALD) remains unclear. The aim of this study was to elucidate the effects of oroxylin A on ALD and the potential mechanisms.

MATERIALS AND METHODS

Male ICR mice and human hepatocyte cell line LO₂ were used. Yes-associated protein (YAP) overexpression and knockdown were achieved using plasmid and siRNA technique. Cellular senescence was assessed by analyses of the senescence-associated β-galactosidase (SA-β-gal), senescence marker p16, p21, Hmga1, cell cycle and telomerase activity.

RESULTS

Oroxylin A alleviated ethanol-induced hepatocyte damage by suppressing activities of supernatant marker enzymes. We found that oroxylin A inhibited ethanol-induced hepatocyte senescence by decreasing the number of SA-β-gal-positive LO₂ cells and reducing the expression of senescence markers p16, p21 and Hmga1 in vitro. Moreover, oroxylin A affected the cell cycle and telomerase activity. Of importance, we revealed that YAP pharmacological inhibitor verteporfin or YAP siRNA eliminated the effect of oroxylin A on ethanol-induced hepatocyte senescence in vitro, and this was further supported by the evidence in vivo experiments.

CONCLUSION

Therefore, these aggregated data suggested that oroxylin A relieved alcoholic liver injury possibly by inhibiting the senescence of hepatocyte, which was dependent on its activation of YAP in hepatocytes.

Gugulipid causes hypercholesterolemia leading to endothelial dysfunction, increased atherosclerosis, and premature death by ischemic heart disease in male mice

For proper cholesterol metabolism, normal expression and function of scavenger receptor class B type I (SR-BI), a high-density lipoprotein (HDL) receptor, is required. Among the factors that regulate overall cholesterol homeostasis and HDL metabolism, the nuclear farnesoid X receptor plays an important role. Guggulsterone, a bioactive compound present in the natural product gugulipid, is an antagonist of this receptor. This natural product is widely used globally as a natural lipid-lowering agent, although its anti-atherogenic cardiovascular benefit in animal models or humans is unknown. The aim of this study was to determine the effects of gugulipid on cholesterol homeostasis and development of mild and severe atherosclerosis in male mice. For this purpose, we evaluated the impact of gugulipid treatment on liver histology, plasma lipoprotein cholesterol, endothelial function, and development of atherosclerosis and/or ischemic heart disease in wild-type mice; apolipoprotein E knockout mice, a model of atherosclerosis without ischemic complications; and SR-B1 knockout and atherogenic–diet-fed apolipoprotein E hypomorphic (SR-BI KO/ApoER61^h/h) mice, a model of lethal ischemic heart disease due to severe atherosclerosis. Gugulipid administration was associated with histological abnormalities in liver, increased alanine aminotransferase levels, lower hepatic SR-BI content, hypercholesterolemia due to increased HDL cholesterol levels, endothelial dysfunction, enhanced atherosclerosis, and accelerated death in animals with severe ischemic heart disease. In conclusion, our data show important adverse effects of gugulipid intake on HDL metabolism and atherosclerosis in male mice, suggesting potential and unknown deleterious effects on cardiovascular health in humans. In addition, these findings reemphasize the need for rigorous preclinical and clinical studies to provide guidance on the consumption of natural products and regulation of their use in the general population.

Interaction between autophagy and senescence is required for dihydroartemisinin to alleviate liver fibrosis

Autophagy and cellular senescence are stress responses essential for homeostasis. Therefore, they may represent new pharmacologic targets for drug development to treat diseases. In this study, we sought to evaluate the effect of dihydroartemisinin (DHA) on senescence of activated hepatic stellate cells (HSCs), and to further elucidate the underlying mechanisms. We found that DHA treatment induced the accumulation of senescent activated HSCs in rat fibrotic liver, and promoted the expression of senescence markers p53, p16, p21 and Hmga1 in cell model. Importantly, our study identified the transcription factor GATA6 as an upstream molecule in the facilitation of DHA-induced HSC senescence. GATA6 accumulation promoted DHA-induced p53 and p16 upregulation, and contributed to HSC senescence. By contrast, siRNA-mediated knockdown of GATA6 dramatically abolished DHA-induced upregulation of p53 and p16, and in turn inhibited HSC senescence. Interestingly, DHA also appeared to increase autophagosome generation and autophagic flux in activated HSCs, which was underlying mechanism for DHA-induced GATA6 accumulation. Autophagy depletion impaired GATA6 accumulation, while autophagy induction showed a synergistic effect with DHA. Attractively, p62 was found to act as a negative regulator of GATA6 accumulation. Treatment of cultured HSCs with various autophagy inhibitors, led to an inhibition of DHA-induced p62 degradation, and in turn, prevented DHA-induced GATA6 accumulation and HSC senescence. Overall, these results provide novel implications to reveal the molecular mechanism of DHA-induced senescence, by which points to the possibility of using DHA based proautophagic drugs for the treatment of liver fibrosis.