The effect of capillarisin on glycochenodeoxycholic acid-induced apoptosis and heme oxygenase-1 in rat primary hepatocytes

Discovery of 5,7-Dimethoxy-2-(3,4,5-trimethoxyphenoxy)-chromen-4-one with Lipid Lowering Effects in Hepatocytes

The population with nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) is increasing. However, no medicine is indicated for treating these diseases clinically nowadays. Therefore, there is an urgent need to develop a new drug to overcome NAFLD and NASH. Capillarisin, a 2-phenoxychromone originating from Artemisia capillaris Thunb., is well-known for its liver-protective effects. As a result, a series of 2-phenoxychromones was prepared and evaluated for its protective activity against lipid droplet formation in oleic acid (OA)-treated Huh7 cells by means of high-content screening. In the light of the results, the compounds with trimethoxy groups on the phenyl ring possessed better inhibitory properties against lipid accumulation in Huh7 cells, compared to other functional groups on the same ring. Nonetheless, the compounds with a hydroxy group at the C-5 position of the chromone exhibited apparent cytotoxicity. Finally, the active compound, 5,7-dimethoxy-2-(3,4,5-trimethoxyphenoxy)-chromen-4-one (7e), with an IC₅₀ value of 32.2 ± 2.1 μM against lipid accumulation and no significant cytotoxicity, reduced the accumulation of lipid droplets by up-regulating peroxisome proliferator-activated receptor gamma coactivator 1α (PGC1α) to facilitate the catabolism of fat, which shows promise for further optimization to manage NAFLD and NASH.

Bile acids as regulatory molecules and potential targets in metabolic diseases

Bile acids are important hydroxylated steroids that are synthesized in the liver from cholesterol for intestinal absorption of lipids and other fatty-nutrient. They also display remarkable and immense functions such as regulating immune responses, managing the apoptosis of cells, participating in glucose metabolism, and so on. Some bile acids were used for the treatment or prevention of diseases such as gallstones, primary biliary cirrhosis, and colorectal cancer. Meanwhile, the accumulation of toxic bile acids leads to apoptosis, necrosis, and inflammation. Alteration of bile acids metabolism, as well as the gut microbiota that interacted with bile acids, contributes to the pathogenesis of metabolic diseases. Therefore, the purpose of this review is to summarize the current functions and pre-clinical or clinical applications of bile acids, and to further discuss the alteration of bile acids in metabolic disorders as well as the manipulation of bile acids metabolism as potential therapeutic targets.

The Study on the Mechanism of Hugan Tablets in Treating Drug-Induced Liver Injury Induced by Atorvastatin

Atorvastatin is a widely used lipid-lowering drug in the clinic. Research shows that taking long-term atorvastatin has the risk of drug-induced liver injury (DILI) in most patients. Hugan tablets, a commonly used drug for liver disease, can effectively lower transaminase and protect the liver. However, the underlying mechanism of Hugan tablets alleviating atorvastatin-induced DILI remains unclear. To address this problem, comprehensive chemical profiling and network pharmacology methods were used in the study. First, the strategy of "compound-single herb-TCM prescription" was applied to characterize the ingredients of Hugan tablets. Then, active ingredients and potential targets of Hugan tablets in DILI treatment were screened using network pharmacology, molecular docking, and literature research. In the end, the mechanism of Hugan tablets in treating atorvastatin-induced DILI was elucidated. The results showed that Hugan tablets can effectively alleviate DILI induced by atorvastatin in model rats, and 71 compounds were characterized from Hugan tablets. Based on these compounds, 271 potential targets for the treatment of DILI were predicted, and 10 key targets were chosen by characterizing protein-protein interactions. Then, 30 potential active ingredients were screened through the molecular docking with these 10 key targets, and their biological activity was explained based on literature research. Finally, the major 19 active ingredients of Hugan tablets were discovered. In addition, further enrichment analysis of 271 targets indicated that the PI3K-Akt, TNF, HIF-1, Rap1, and FoxO signaling pathways may be the primary pathways regulated by Hugan tablets in treating DILI. This study proved that Hugan tablets could alleviate atorvastatin-induced DILI through multiple components, targets, and pathways.

Artemisia scoparia and Metabolic Health: Untapped Potential of an Ancient Remedy for Modern Use

Botanicals have a long history of medicinal use for a multitude of ailments, and many modern pharmaceuticals were originally isolated from plants or derived from phytochemicals. Among these, artemisinin, first isolated from Artemisia annua, is the foundation for standard anti-malarial therapies. Plants of the genus Artemisia are among the most common herbal remedies across Asia and Central Europe. The species Artemisia scoparia (SCOPA) is widely used in traditional folk medicine for various liver diseases and inflammatory conditions, as well as for infections, fever, pain, cancer, and diabetes. Modern in vivo and in vitro studies have now investigated SCOPA's effects on these pathologies and its ability to mitigate hepatotoxicity, oxidative stress, obesity, diabetes, and other disease states. This review focuses on the effects of SCOPA that are particularly relevant to metabolic health. Indeed, in recent years, an ethanolic extract of SCOPA has been shown to enhance differentiation of cultured adipocytes and to share some properties of thiazolidinediones (TZDs), a class of insulin-sensitizing agonists of the adipogenic transcription factor PPARγ. In a mouse model of diet-induced obesity, SCOPA diet supplementation lowered fasting insulin and glucose levels, while inducing metabolically favorable changes in adipose tissue and liver. These observations are consistent with many lines of evidence from various tissues and cell types known to contribute to metabolic homeostasis, including immune cells, hepatocytes, and pancreatic beta-cells. Compounds belonging to several classes of phytochemicals have been implicated in these effects, and we provide an overview of these bioactives. The ongoing global epidemics of obesity and metabolic disease clearly require novel therapeutic approaches. While the mechanisms involved in SCOPA's effects on metabolic, anti-inflammatory, and oxidative stress pathways are not fully characterized, current data support further investigation of this plant and its bioactives as potential therapeutic agents in obesity-related metabolic dysfunction and many other conditions.

Advances in the Study of the Potential Hepatotoxic Components and Mechanism of Polygonum multiflorum

The roots of Polygonum multiflorum (PM) (He Shou Wu in Chinese) are one of the most commonly used tonic traditional Chinese medicines (TCMs) in China. PM is traditionally valued for its antiaging, liver- and kidney-tonifying, and hair-blackening effects. However, an increasing number of hepatotoxicity cases induced by PM attract the attention of scholars worldwide. Thus far, the potential liver injury compounds and the mechanism are still uncertain. The aim of this review is to provide comprehensive information on the potential hepatotoxic components and mechanism of PM based on the scientific literature. Moreover, perspectives for future investigations of hepatotoxic components are discussed. This study will build a new foundation for further study on the hepatotoxic components and mechanism of PM.

Natural products for the prevention and treatment of cholestasis: A review

Cholestasis is a common manifestation of decreased bile flow in various liver diseases. It results in fibrosis and even cirrhosis without proper treatment. It is believed that a wide range of factors, including transporter dysfunction, oxidative stress, inflammatory damage, and immune disruption, can cause cholestasis. In recent years, natural products have drawn much attention for specific multiple-target activities in diseases. Many attempts have been made to investigate the anticholestatic effects of natural products with advanced technology. This review summarizes recent studies on the biological activities and mechanisms of recognized compounds for cholestasis treatment. Natural products, including various flavonoids, phenols, acids, quinones, saponins, alkaloids, glycosides, and so on, function as comprehensive regulators via ameliorating oxidative stress, inflammation, and apoptosis, restoring bile acid balance with hepatic transporters, and adjusting immune disruption. Moreover, in this progress, nuclear factor erythroid 2-related factor 2, reactive oxygen species production, heme oxygenase-1, NF-κB, cholesterol 7 alpha-hydroxylase, and farnesoid X receptors are thought as main targets for the activity of natural products. Therefore, this review presents the detailed mechanisms that include multiple targets and diverse signalling pathways. Natural products are the valuable when seeking novel therapeutic agents to treat cholestatic liver diseases.

Capillarisin blocks prostate-specific antigen expression on activation of androgen receptor in prostate carcinoma cells

BACKGROUND

Capillarisin (Cap), an active ingredient of Artemisia capillaris extracts, has known for its anti-inflammatory, antioxidant, and anticancer properties. Functions of Cap in prostate cancer are not clear. We investigate effects of Cap on downregulation of prostate specific antigen (PSA) via modulation of androgen receptor (AR) in prostate carcinoma cells.

METHODS

Cell proliferation was measured by water-soluble tetrazolium-1 (WST-1) cell proliferation assays. The PSA and AR expressions were assessed by immunoblotting and RT-qPCR assays. Effects of Cap on PSA expressions were determined by ELISA, immunoblotting, and reporter assays. Co-immunoprecipitation and immunoblotting assays were used to define the effects of Cap on dissociation of AR-heat shock protein 90 (Hsp90) interaction.

RESULTS

Cap inhibited LNCaP cell growth in a dose- and/or time-dependent way without inducing poly ADP-Ribose Polymerase (PARP) cleavage. Cap not only effectively suppressed AR and PSA protein expressions, but also attenuated activations of synthetic androgen (R1881) on PSA promoter activity dose- and time-dependently. The Cap pretreatment abrogated effects of R1881 on AR activity by reducing AR translocation to the nucleus. Immunoblotting assays indicated that Cap promoted a degradation of AR proteins dose-dependently in either cycloheximide pretreated-LNCaP cells or AR-ectopic expressed PC-3 cells. Pretreatment of MG132, a proteasome inhibitor, attenuated effect of Cap on AR degradation. Cap lessened AR stability by dissociation of AR-Hsp90 interaction.

CONCLUSIONS

Our results indicated that Cap inhibited growth of LNCaP cells. Cap effectively suppressed androgen activation on AR-mediated transactivation, which is AR-dependent through AR degradation and dissociation of AR-Hsp90 in prostate carcinoma cells.

Effect of quercetin 7-rhamnoside on glycochenodeoxycholic acid-induced L-02 human normal liver cell apoptosis

Quercetin 7-rhamnoside (Q7R) is one of the main flavonoid components of Hypericum japonicum. However, whether Q7R is one of the active ingredients responsible for the hepatopreventive effects of Hypericum japonicum has not yet been ascertained. Thus, the aim of the present study was to elucidate whether Q7R attenuates apoptosis induced by glycochenodeoxycholic acid (GCDC) in vitro, and to elucidate the mechanisms involved. L-02 human normal liver cells were pre-incubated with 0, 50, 100 and 200 µM Q7R for 30 min and then exposed to 100 µM GCDC for the indicated periods of time. Methylthiazolyldiphenyl-tetrazolium bromide (MTT) was performed to examine cell viability. Apoptosis was evaluated by Hoechst 33258 staining and Annexin V-FITC/PI double staining. Intracellular reactive oxygen species (ROS) were detected by flow cytometry using the oxidation-sensitive fluorescent probe, DCFH-DA. The assay for glutathione (GSH) was performed using a GSH detection kit. Intracellular Ca2+ concentration was evaluated using a confocal laser scanning microscope with Fluo-3 as the Ca2+ probe and mitochondrial membrane potential (Δψm) was measured by rhodamine 123 (Rh123) fluorescence. Q7R attenuated the GCDC-induced reduction in cell viability and the high apoptotic rate. Moreover, Q7R protected the L-02 cells from ROS overproduction, GSH depletion, intracellular Ca2+ accumulation and Δψm decrease induced by GCDC. These results suggest that Q7R attenuates L-02 cell injury induced by GCDC, possibly by inhibiting the overproduction of ROS, GSH depletion, intracellular Ca2+ accumulation and Δψm decrease, thereby minimizing L-02 cell apoptosis.

Positive effect of curcumin on inflammation and mitochondrial dysfunction in obese mice with liver steatosis

Obesity contributes to the increased risk of liver- related morbidity and mortality. The accumulation of macrophages in adipose tissue in an inflammatory state is a hallmark of obesity-induced hepatic steatosis. In this study, we reveal the role of curcumin in the molecular mechanisms underlying inflammatory events in a model consisting of obese mice with hepatic steatosis. Obese mice fed with curcumin experienced significant weight loss and significantly reduced serum triglyceride (TG) levels. The adipose tumor necrocis factor-α, interleukin-6 (IL-6) and monocyte chemotactic protein-1 levels were significantly higher in obese mice compared to mice fed with curcumin. Compared to the obese mice, curcumin decreased the number of F4/80-positive macrophages in epididymal adipose and liver tissue. The induction of signal transducer and activator of transcription 3 phosphorylation by curcumin resulted in the downregulation of the suppressor of cytokine signaling 3 in the liver of obese mice. Curcumin decreased hepatic TG in obese mice by downregulating the gene expression of sterol regulatory element-binding protein-1c in the liver. The hepatic expression of several mitochondrial biogenesis genes decreased in the obese mice, including mitochondrial DNA (mtDNA), nuclear respiratory factor 1 (NRF1) and mitochondrial transcription factor A (Tfam), which are responsible for the lower mitochondrial respiratory chain (MRC) complex I activity and adenosine triphosphate production. By contrast, obese mice treated with curcumin showed normalized mtDNA, NRF1 and Tfam gene expression, reduced hepatic nuclear factor-κB activities and levels of thiobarbituric acid reactive substances (TBARS) and restored mitochondrial oxidative metabolism and biogenesis. The results from the present sudy show that curcumin prevents fatty liver disease through multiple mechanisms, and suggest that curcumin may be used to prevent the development and progression of non-alcoholic fatty liver disease (NAFLD).

Curcumin ameliorates mitochondrial dysfunction associated with inhibition of gluconeogenesis in free fatty acid-mediated hepatic lipoapoptosis

Insulin resistance occurs in almost all patients with non-alcoholic fatty liver disease (NAFLD), and mitochondrial dysfunction likely plays a pivotal role in the progression of fatty liver into non-alcoholic steatohepatitis (NASH). Curcumin is a compound derived from the spice turmeric, a spice that is a potent antioxidant, anti-carcinogenic, and anti-hepatotoxic agent. The aim of this study was to analyze the ability of curcumin to protect against the mitochondrial impairment induced by high free fatty acids (HFFAs) and to determine the underlying mechanism for this cytoprotection. Curcumin treatment inhibited the lipoapoptosis, ROS production and ATP depletion elicited by HFFA in primary hepatocytes. We demonstrate that curcumin effectively suppressed HFFA-induced production of phosphoenol pyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) in hepatocytes. Not only did curcumin treatment increase mitochondrial DNA (mtDNA) copy number in hepatocytes, but it also increased levels of transcriptional factors that regulate mitochondrial biogenesis, including peroxisome proliferator-activated receptor-γ coactivator 1α (PGC1α), nuclear respiratory factor 1 (NRF1) and mitochondrial transcription factor A (Tfam). In addition, curcumin contributed to cell survival, as indicated by the restoration of the mitochondrial membrane potential (MMP) and the inhibition of the mitochondrial biogenesis induced by HFFA. Furthermore, this cytoprotection resulted from curcumin-mediated downregulation of the NF-κB p65 subunit, thereby inhibiting lipoapoptosis. Together, these data suggest that curcumin protects hepatocytes from HFFA-induced lipoapoptosis and mitochondrial dysfunction, which partially occurs through the regulation of mitochondrial biogenesis.

Anti-oxidants do not prevent bile acid-induced cell death in rat hepatocytes

BACKGROUND

Bile acids, reactive oxygen species (ROS) and inflammatory cytokines are crucial regulators of cell death in acute and chronic liver diseases. The contribution of each factor to hepatocyte death, either apoptosis or necrosis, has not been clarified as yet. It has been suggested that the generation of oxidative stress by bile acids contributes to hepatocyte death during cholestasis and bile acid toxicity, although the beneficial role of ROS prevention in bile acid-mediated cell death is not fully understood.

AIM

Study the effects of anti-oxidants in bile acid-induced cell death in vitro.

METHODS

Primary rat hepatocytes were exposed to the bile acids glycochenodeoxycholic acid (GCDCA) or taurolithocholic acid-3 sulphate in the absence or presence of ROS scavengers or anti-oxidants. Haeme oxygenase (HO)-1 mRNA levels were analysed by quantitative polymerase chain reaction. Apoptosis was quantified by acridine orange staining and caspase-3 activity assay. Necrosis was detected by Sytox green staining.

RESULTS

Anti-oxidants do not attenuate bile acid-induced cell death. Furthermore, bile acid exposure does not enhance the mRNA expression of the oxidative stress-responsive gene HO-1. The Src-kinase inhibitor, SU6656, does reduce GCDCA-induced apoptosis and necrosis.

CONCLUSIONS

In hepatocytes, bile acid-induced toxicity is not prevented by scavengers of oxidative stress. The beneficial effects observed in patients might be because of the contribution of ROS and cytokines rather than bile acid-mediated oxidative stress. However, the use of specific Src kinase inhibitors might be a useful tool to prevent bile acid-induced injury in liver diseases.

Modulation of the cannabinoid receptors by andrographolide attenuates hepatic apoptosis following bile duct ligation in rats with fibrosis

Bile acid-induced apoptosis plays an important role in the pathogenesis of cholestatic liver disease, and its prevention is of therapeutic interest. The aim of this study was to test whether the andrographolide limits the evolution of apoptosis in a murine model of bile duct ligation (BDL)-induced hepatic fibrosis. Male Sprague-Dawley rats were divided into four groups and hepatic apoptosis was induced by BDL for 2 weeks. The BDL animals were also treated with andrographolide (50, 100, and 200 mg/kg, i.p.) during the same time period. BDL-induced liver injury was associated with apoptosis and fibrosis, and the latter was significantly reduced in animals receiving andrographolide. The increase in serum alanine aminotransferase, asparate aminotransferase, tumor necrosis factor-alpha and IL-1beta levels caused by BDL were also significantly reduced by treatment with andrographolide. Andrographolide decreased the intrahepatic protein levels of cannabinoid receptor 1 (CB1), Bax, and cytochrome c, along with of alpha-smooth muscle actin (alpha-SMA) and transforming growth factor-beta (TGF-beta), two markers of fibrogenesis. This effect was mediated by the inactivation of the c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK1/2) phosphorylation cascade, but it did not affect the p38 mitogen-activated protein kinase pathway. Additionally, andrographolide reduced the generation of hepatic lipid peroxidation and enhance senescence marker protein-30 levels to resist the hepatic oxidative stress in the presence of BDL. In conclusion, this study has identified AP as a potent protector against cholestasis-induced apoptosis in vivo. Its anti-apoptotic action largely relies on the inhibition of the oxidative stress pathway.

Active ingredients of traditional Japanese (kampo) medicine, inchinkoto, in murine concanavalin A-induced hepatitis

AIM OF THE STUDY

The traditional Japanese (kampo) medicine inchinkoto (ICKT) is used in Eastern Asia as a choleretic and hepatoprotective agent. Previously, we reported that ICKT ameliorates murine concanavalin A (con A)-induced hepatitis via suppression of interferon (IFN)-gamma and interleukin (IL)-12 production. In the present study, we investigated the active ingredients of ICKT.

MATERIALS AND METHODS

ICKT and extracts of its component herbs were fractionated, and their effects on liver injury and cytokine production in vivo (biochemical markers of liver injury and cytokine levels in serum) and in vitro (cytokine and nitrite production in the cultures of splenocytes and peritoneal macrophages).

RESULTS

Decoctions of component herbs, Artemisiae Capillari Spica (Artemisia capillaris Thunberg: 'Inchinko' in Japanese), Gardeniae Fructus (Gardenia jasminoides Ellis: 'Sanshishi') and Rhei Rhizoma (Rheum palmatum Linné: 'Daio') were administered orally. Inchinko and Sanshishi decreased serum transaminases and IFN-gamma concentrations. Examination of fractions of component herbs suggested that capillarisin, a component of Inchinko, has potent hepatoprotective activity in vivo. In in vitro studies, capillarisin and genipin, an intestinal metabolite of geniposide that is contained in Sanshishi, were examined. IFN-gamma production was significantly suppressed by capillarisin and genipin in con A-stimulated splenocyte culture. Genipin also suppressed IL-1beta, IL-6, and IL-12p70 synthesis. Capillarisin and genipin decreased nitrite release from IFN-gamma-stimulated macrophages.

CONCLUSIONS

These results suggested that both Inchinko and Sanshishi may contribute to the protective effects of ICKT against con A hepatitis. Capillarisin was found to be potently hepatoprotective, and genipin may also contribute, especially via modulation of cytokine production.