Beneficial effect of Calculus Bovis Sativus on 17α-ethynylestradiol-induced cholestasis in the rat

Calculus bovis in hepatocellular carcinoma: Tumor molecular basis, Wnt/β-catenin pathway role, and protective mechanism

In this editorial, we comment on the recent article by Huang et al. The editorial focuses specifically on the molecular mechanisms of hepatocellular carcinoma (HCC), mechanism of Wnt/β-catenin pathway in HCC, and protective mechanism of Calculus bovis (CB) in HCC. Liver cancer is the fourth most common cause of cancer-related deaths globally. The most prevalent kind of primary liver cancer, HCC, is typically brought on by long-term viral infections (hepatitis B and C), non-alcoholic steatohepatitis, excessive alcohol consumption, and other conditions that can cause the liver to become chronically inflamed and cirrhotic. CB is a well-known traditional remedy in China and Japan and has been used extensively to treat a variety of diseases, such as high fever, convulsions, and stroke. Disturbances in lipid metabolism, cholesterol metabolism, bile acid metabolism, alcohol metabolism, and xenobiotic detoxification lead to fatty liver disease and liver cirrhosis. Succinate, which is a tricarboxylic acid cycle intermediate, is vital to energy production and mitochondrial metabolism. It is also thought to be a signaling molecule in metabolism and in the development and spread of liver malignancies. The Wnt/β-catenin pathway is made up of a group of proteins that are essential for both adult tissue homeostasis and embryonic development. Cancer is frequently caused by the dysregulation of the Wnt/β-catenin signaling pathway. In HCC liver carcinogenesis, Wnt/β-catenin signaling is activated by the expression of downstream target genes. Communication between the liver and the gut exists via the portal vein, biliary tract, and systemic circulation. This "gut-liver axis" controls intestinal physiology. One of the main factors contributing to the development, progression, and treatment resistance of HCC is the abnormal activation of the Wnt/β-Catenin signaling pathway. Therefore, understanding this pathway is essential to treating HCC. Eleven ingredients of CB, particularly oleanolic acid, ergosterol, and ursolic acid, have anti-primary liver cancer properties. Additionally, CB is important in the treatment of primary liver cancer through pathways linked to immune system function and apoptosis. CB also inhibits the proliferation of cancer stem cells and tumor cells and controls the tumor microenvironment. In the future, clinicians may be able to recommend one of many potential new drugs from CB ingredients to treat HCC expression, development, and progress.

Regulation of ABC transporters by sex steroids may explain differences in drug resistance between sexes

Drug efficacy is dependent on the pharmacokinetics and pharmacodynamics of therapeutic agents. Tight junctions, detoxification enzymes, and drug transporters, due to their localization on epithelial barriers, modulate the absorption, distribution, and the elimination of a drug. The epithelial barriers which control the pharmacokinetic processes are sex steroid hormone targets, and in this way, sex hormones may also control the drug transport across these barriers. Thus, sex steroids contribute to sex differences in drug resistance and have a relevant impact on the sex-related efficacy of many therapeutic drugs. As a consequence, for the further development and optimization of therapeutic strategies, the sex of the individuals must be taken into consideration. Here, we gather and discuss the evidence about the regulation of ATP-binding cassette transporters by sex steroids, and we also describe the signaling pathways by which sex steroids modulate ATP-binding cassette transporters expression, with a focus in the most important ATP-binding cassette transporters involved in multidrug resistance.

Calculus Bovis Sativus alleviates estrogen cholestasis-induced gut and liver injury in rats by regulating inflammation, oxidative stress, apoptosis, and bile acid profiles

ETHNOPHARMACOLOGICAL RELEVANCE

Natural Calculus Bovis (NCB) is a traditional Chinese medicine used for anti-inflammation, treating fever, pain, sedation, and recovering hepatobiliary function. Calculus Bovis Sativus (CBS), produced from in vitro artificial cultivation by bioengineering techniques, acts as an ideal substitute for NCB when treating various diseases.

AIM OF THE STUDY

Gut-liver injury is an important pathological feature of several cholestatic liver diseases, including estrogen-induced cholestasis (EIC). The strong link between cholestatic liver injury and intestinal damage emphasizes the need of considering gut-liver integrity during treatment. The purpose of this study is to look into the pharmacological activities of CBS on EIC-induced gut and liver damage.

MATERIALS AND METHODS

EIC-induced cholestatic rats were given oral gavage daily for five days with or without CBS (150 mg/kg). The liver/body weight, serum biochemistry, and tissue histopathology were then evaluated. Quantitative real-time PCR, Western blot analyses, and immunofluorescence were used to determine the gene expression associated with pathological alterations of the liver and intestine in EIC-induced cholestatic rats. Bile acid profiles within enterohepatic circulation were detected by liquid chromatography-mass spectrometry.

RESULTS

CBS significantly reduced relative liver weight, restored serum biochemistry levels, and improved the hepatic and intestinal pathological damage in EIC model rats. CBS reduced EIC-induced hepatic inflammation by inactivation of the NF-κB signaling and inhibition of TNFα, IL-1β, and IL-6 expression. CBS alleviated EIC-induced hepatic and intestinal oxidative stress by regulating Nrf2-GCLM/GCLC and Nrf2-HO-1 pathways, respectively. CBS treatment upregulated Bcl-2 and downregulated Bax and cleaved caspase3 to improve EIC-induced hepatic and intestinal cell apoptosis. Additionally, CBS reversed the disorders of bile acid profiles in the enterohepatic circulation by reducing bile acid accumulation in the liver and plasma and increasing bile excretion and intestinal reabsorption of bile acids.

CONCLUSION

CBS alleviates EIC-induced hepatic and intestinal injury through regulating inflammation, oxidative stress, apoptosis, and bile acid profiles. These results suggest that CBS or drugs targeting the gut-liver axis may be effective therapeutic agents for cholestasis.

Calculus bovis: A review of the traditional usages, origin, chemistry, pharmacological activities and toxicology

ETHNOPHARMACOLOGICAL RELEVANCE

Calculus bovis (C. bovis), a widespread known traditional animal drug in China and Japan, has been widely used for a long time to treat various diseases, including high fever, convulsion and stroke. The aim of the present paper is to comprehensively review knowledge about C. bovis in terms of traditional usages, origin, chemical constituents, pharmacological activities and toxicology to seek an applicable substitute for NCB and provide potential new strategies utilizing C. bovis. Additionally, directions and perspectives for future investigations regarding C. bovis are also discussed.

MATERIALS AND METHODS

In this paper, the traditional usages, origin, chemical constituents, pharmacology, and toxicology of C. bovis are comprehensively and systematically summarized by searching scientific databases, including Web of Science, PubMed, ScienceDirect, Springer, CNKI, Baidu Scholar and others. Additionally, some classic books of Chinese herbal medicine, academic papers authored by individuals with MSc and PhD degrees, local government reports as well as the state of local drug standards are also retrieved.

RESULTS

Currently, C. bovis mainly derives from four sources: natural Calculus bovis (NCB), Calculus bovis sativus (CBS), Cultured calculus bovis (CCB) and Calculus bovis artifactus (CBA). Owing to their different formation processes, the chemical constituents of the four kinds of C. bovis show certain differences. Additionally, over 44 chemical constituents have been isolated and identified from C. bovis, mainly including bile pigments, bile acids, cholesterols and amino acids. Further investigations have revealed a wide range of pharmacological effects of C. bovis, with effects on the nervous system, cardiovascular system, respiratory system, digestive system, immune system and others. Furthermore, NCB and CBA show hypotoxicity, but high concentrations of bilirubin can cause neurotoxicity and hearing impairment. Additionally, pharmacokinetic data for C. bovis are still lacking.

CONCLUSION

CBS contains analogous types and amounts of constituents and exerts similar therapeutic effects to NCB. Thus, CBS might be used as a sustainable substitute for NCB. Furthermore, the configuration and concentration of bile acids and bilirubin in C. bovis are responsible for the difference in pharmacological effects in the four types C. bovis. Further studies should focus on the structure-function relationship of bile acids and bilirubin in C. bovis by employing pharmacokinetics.

Identification of Calculus Bovis and its mixed varieties by ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC-Q/TOF-MS) combined with the principal component analysis (PCA) method

The method of ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC-Q/TOF-MS) was established and combined with principal component analysis (PCA) to identify natural Calculus Bovis, in vitro cultured Calculus Bovis and artificial Calculus Bovis. PCA, which was particularly powerful in dealing with multicollinearity and variables that outnumber the samples, was used to analyze the UHPLC-MS data of the processed samples, and potential markers were analyzed and described based on orthogonal partial least-squares discriminant analysis. According to the results in this study, the approach of combining UHPLC-QTOF-MS with PCA was proven to be credible and could be used to identify Calculus Bovis from in vitro cultured Calculus Bovis and artificial Calculus Bovis and to determine if there is Calculus Bovis in patented Chinese medicines that should contained Calculus Bovis medicinal materials.

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.

Bioinformatics‑based identification of key pathways and candidate genes for estrogen‑induced intrahepatic cholestasis using DNA microarray analysis

Estrogen‑induced intrahepatic cholestasis (EIC) has increased incidence during pregnancy, and within women taking oral contraception and postmenopausal hormone replacement therapy. However, the pathology underlying EIC is not well understood. The aim of the present study was to identify key pathways and candidate genes in estrogen‑induced intrahepatic cholestasis (EIC) that may be potential targets for diagnosis and treatment. A whole‑genome microarray (4x44K) analysis of a 17α‑ethinylestradiol (EE)‑induced EIC rat liver model was performed. Bioinformatics‑based methods were used to identify key pathways and candidate genes associated with EIC. The candidate genes were validated using a reverse transcription quantitative polymerase chain reaction assay. A total of 455 genes were differentially expressed (P<0.05 and fold change >2.0) following EE treatment, including 225 downregulated genes and 230 upregulated genes. Sulfotransferase family 1E member 1, cytochrome P450 family 3 subfamily A member 2, carbonic anhydrase 3, leukotriene C4 synthase and ADAM metallopeptidase domain 8 were the 5 candidate genes identified to be differentially expressed and involved in the metabolism of estrogens and bile acids and the regulation of inflammation and oxidative stress. The Analyses of Gene Ontology enrichment, Kyoto Encyclopedia of Genes and Genomes pathways and protein‑protein interaction network associated‑modules identified several key pathways involved in the homeostasis of lipids and bile acids and in AMPK, p53 and Wnt signaling. These key pathways and candidate genes may have critical roles in the pathogenesis of EIC. In addition, reversing the abnormal expression of candidate genes or restoring the dysfunction of key pathways may provide therapeutic opportunities for patients with EIC.

Calculus Bovis Sativus Improves Bile Acid Homeostasis via Farnesoid X Receptor-Mediated Signaling in Rats With Estrogen-Induced Cholestasis

Cholestatic diseases are characterized by toxic bile acid (BA) accumulation, and abnormal BA composition, which subsequently lead to liver injury. Biochemical synthetic Calculus Bovis Sativus (CBS) is derived from natural Calculus Bovis, a traditional Chinese medicine, which has been used to treat hepatic diseases for thousands of years. Although it has been shown that CBS administration to 17α-ethinylestradiol (EE)-induced cholestatic rats improves bile flow and liver injury, the involved underlying mechanism is largely unknown. In this study, we showed that CBS administration to EE-induced cholestatic rats significantly decreased serum and hepatic BA levels and reversed hepatic BA composition. DNA microarray analysis suggested that the critical pathways enriched by CBS treatment were bile secretion and primary BA synthesis. These findings led us to focus on the effects of CBS on regulating BA homeostasis, including BA transport, synthesis and metabolism. CBS enhanced hepatic BA secretion by inducing efflux transporter expression and inhibiting uptake transporter expression. Moreover, CBS reduced BA synthesis by repressing the expression of BA synthetic enzymes, CYP7A1 and CYP8B1, and increased BA metabolism by inducing the expression of metabolic enzymes, CYP3A2, CYP2B10, and SULT2A1. Mechanistic studies indicated that CBS increased protein expression and nuclear translocation of hepatic and intestinal farnesoid X receptor (FXR) to regulate the expression of these transporters and enzymes. We further demonstrated that beneficial effects of CBS administration on EE-induced cholestatic rats were significantly blocked by guggulsterone, a FXR antagonist. Therefore, CBS improved BA homeostasis through FXR-mediated signaling in estrogen-induced cholestatic rats. Together, these findings suggested that CBS might be a novel and potentially effective drug for the treatment of cholestasis.

Pharmacokinetic Characteristics of Baicalin in Rats with 17α-ethynyl-estradiol-induced Intrahepatic Cholestasis

Baicalin is one of the main active ingredients of choleretic traditional Chinese medicine drug Radix Scutellariae. The aim of this study was to explore the pharmacokinetic characteristics of baicalin in rats with 17α-ethynylestradiol (EE)-induced intrahepatic cholestasis (IC) based on its choleretic effects. Firstly, rats were subcutaneously injected with EE solution (5 mg/kg, 0.25 mL/100 g) for 5 consecutive days to construct an IC model. Then the bile excretion rate, serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and total bile acid (TBA) and pathological changes of the liver were detected. Secondly, after successfully modeling, the rats were intragastrically given baicalin solution (200 mg/kg) (n=6). Blood samples were collected from the tail vein at different time points after intragastric administration. The protective effects of low- (50 mg/kg), medium- (100 mg/kg) and high-dose (200 mg/kg) baicalin on the liver in IC rats were evaluated. The content of baicalin in plasma was detected by liquid chromatography-mass spectrometry/mass spectrometry and pharmacokinetics parameters were calculated. Pharmacodynamic results showed that low-, medium- and high-dose baicalin all significantly increased the average excretion rate of bile (P<0.05), and significantly decreased serum levels of ALT, AST and ALP and TBA (P<0.05). Meanwhile, HE staining showed that baicalin significantly relieved EE-induced hepatocyte edema and necrosis. Pharmacokinetic results exhibited that the absorption of baicalin in both IC and normal control rats showed bimodal phenomenon. C_max, AU_(0-t) and AUC_(0-∞) of baicalin in IC rats were significantly higher than those of the normal control group (P<0.01). T_1/2 of plasma baicalin in the model group was significantly extended to (11.09±1.84) h, with clearance dropping to 61.78% of that of the normal control group (P<0.01). The above results suggested that baicalin had protective effects on the liver of IC rats, accompanied by significantly increased in vivo exposure, delayed in vivo clearance and markedly alterative pharmacokinetic characteristics. This study provides a theoretical basis for further development of baicalin as a feasible drug for treating IC.

Protective Effects of Ginsenosides on 17α-Ethynyelstradiol-Induced Intrahepatic Cholestasis via Anti-Oxidative and Anti-Inflammatory Mechanisms in Rats

The present study was designed to assess the effects and potential mechanisms of ginsenosides on 17[Formula: see text]-ethynyelstradiol (EE)-induced intrahepatic cholestasis (IC). Ginsenoside at doses of 30, 100, 300[Formula: see text]mg/kg body weight was intragastrically (i.g.) given to rats for 5 days to examine the effect on EE-induced IC. Serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and total bile acid (TBA) were measured. Hepatic malondialdehyde (MDA) content and superoxide dismutase (SOD) activity were determined. Protein expression of proinflammatory cytokines TNF-[Formula: see text], IL-6 and IL-1[Formula: see text] was analyzed by immunohistochemistry and Western blot. Results indicated that ginsenosides remarkably prevented EE-induced increase in the serum levels of AST, ALT, ALP and TBA. Moreover, the elevation of hepatic MDA content induced by EE was significantly reduced, while hepatic SOD activities were significantly increased when treated with ginsenosides. Histopathology of the liver tissue showed that pathological injuries were relieved after treatment with ginsenosides. In addition, treatment with ginsenosides could significantly downregulate the protein expression of TNF-[Formula: see text], IL-6 and IL-1[Formula: see text] compared with EE group. These findings indicate that ginsenosides exert the hepatoprotective effect on EE-induced intrahepatic cholestasis in rats, and this protection might be attributed to the attenuation of oxidative stress and inflammation.

Chicken bile powder protects against α-naphthylisothiocyanate-induced cholestatic liver injury in mice

This study explored the effects of chicken bile powder (CBP), a 2000-year-old Chinese medicine, on α-naphthyl isothiocyanate (ANIT)-induced intrahepatic cholestasis in mice. CBP treatment for 14 days significantly ameliorated ANIT-induced changes in serum alanine aminotransferase, aspartate aminotransferase, bile acids, bilirubin, γ-glutamyl transpeptidase, alkaline phosphatase, and liver tissue morphology. Serum metabolomics showed changes in 24 metabolites in ANIT-exposed mice; 16 of these metabolites were reversed by CBP treatment via two main pathways (bile acid biosynthesis and arachidonic acid metabolism). Additionally, CBP administration markedly increased fecal and biliary bile acid excretion, and reduced total and hydrophobic bile acid levels in the livers of cholestatic mice. Moreover, CBP increased liver expression of bile acid efflux transporters and metabolic enzymes. It also attenuated ANIT-induced increases in hepatic nuclear factor-κB-mediated inflammatory signaling, and increased liver expression of the nuclear farnesoid X receptor (FXR) in cholestatic mice. CBP also activated FXR in vitro in HEK293T cells expressing mouse Na⁺-taurocholate cotransporting polypeptide. It did not ameliorate the ANIT-induced liver injuries in FXR-knockout mice. These results suggested that CBP provided protection from cholestatic liver injury by restoring bile acid homeostasis and reducing inflammation in a FXR-dependent manner.

Upregulation of PDZK1 by Calculus Bovis Sativus May Play an Important Role in Restoring Biliary Transport Function in Intrahepatic Cholestasis

Intrahepatic cholestasis is a main cause of hepatic accumulation of bile acids leading to liver injury, fibrosis, and liver failure. Our previous studies proved that Calculus Bovis Sativus (CBS) can restore biliary transport function through upregulating the multidrug resistance-associated protein 2 (MRP2) and breast cancer resistance protein (BCRP) in 17α-ethynylestradiol- (EE-) induced intrahepatic cholestasis rats. The regulation mechanism of CBS on these transporters, however, remains unclear. This study was designed to evaluate the possible relationship between the effect of CBS on transport activities and the regulation of CBS on the expression of PDZK1, a mainly scaffold protein which can regulate MRP2 and BCRP. Intrahepatic cholestasis model was induced in rats with injection of EE for five consecutive days and then the biliary excretion rates and cumulative biliary excretions were measured. The mRNA and protein expression levels of PDZK1 were detected by reverse transcription-quantitative real-time polymerase chain reaction, western blot, and immunohistochemical analysis. When treated with CBS, cumulative biliary excretions and mRNA and protein expressions of PDZK1 were significantly increased in intrahepatic cholestasis rats. This study demonstrated that CBS exerted a beneficial effect on EE-induced intrahepatic cholestasis rats by restoring biliary transport function, which may result from the upregulation of PDZK1 expression.

Geniposidic acid protected against ANIT-induced hepatotoxity and acute intrahepatic cholestasis, due to Fxr-mediated regulation of Bsep and Mrp2

ETHNOPHARMACOLOGICAL RELEVANCE

Geniposidic acid (GPA) is the main constituent of Gardenia jasminoides Ellis (Rubiaceae), which has long been used to treat inflammation, jaundice and hepatic disorders. The cholagogic effect of Gardenia jasminoides Ellis (Rubiaceae) and GPA have been widely reported, but the underlying occurrence mechanism remains unclear.

AIM OF THE STUDY

This investigation was designed to evaluate the hepatoprotection effect and potential mechanisms of GPA derived from Gardenia jasminoides Ellis (Rubiaceae) on fighting against α-naphthylisothiocyanate (ANIT) caused liver injury with acute intrahepatic cholestasis.

MATERIALS AND METHODS

Sprague-Dawley (SD) rats were intragastrically (i.g.) administered with the GPA (100, 50 and 25mg/kg B.W. every 24h) for seven consecutive days, and then they were treated with ANIT (i.g. 65mg/kg once in the 5th day) which induced liver injury with acute intrahepatic cholestasis. Serum and bile biochemical analysis, bile flow rate and liver histopathology were measured to evaluate the protective effect of GPA fight against ANIT treatment. The protein and mRNA expression levels of farnesoid X receptor (Fxr), bile-salt export pump (Bsep), multidrug resistance associated protein2 (Mrp2), were evaluated to study the effect of liver protection about GPA against ANIT induced hepatotoxicity and underlying mechanisms.

RESULTS

Some abnormalities were observed on ANIT treated rats including weight loss, reduced food intake and hair turned yellow. Obtained results demonstrated that at dose 100 and 50mg/kg B.W. (P<0.01) and 25mg/kg B.W. (P<0.05) of GPA pretreated dramatically prevented ANIT induced decreased in bile flow rate. Compared with ANIT treated group, the results of bile biochemical parameters about total bile acid (TBA) was increased by GPA at groups with any dose (P<0.01), glutathione (GSH) was increased significantly at high dose (P<0.01) and medium dose (P<0.05), total bilirubin (TB) was increased at high and medium dose (P<0.05), direct bilirubin (DB) was only increased at high dose (P<0.01). Serum levels of glutamic-Oxalacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), γ-glutamyltranspeptidase (γ-GT), TB, DB and TBA in comparison with ANIT treated group (P<0.01) were reduced by GPA (between 100 and 50mg/kg B.W.) pretreatment. Histopathology of the liver tissue showed that pathological damages and hepatic portal area filled with bile were relieved after GPA pretreatment compared with ANIT treated group. The protein and mRNA expression of Fxr, Bsep and Mrp2 were decreased in ANIT treated group. On the contrary, the protein and mRNA of Fxr, Bsep and Mrp2 were up regulated significantly pretreatment by GPA at dose of high and medium groups. On protein level of Bsep and Mrp2 the result shown no statistical difference in GPA (25mg/kg B.W.), but it was not same shown in mRNA level.

CONCLUSION

The results of this investigation have demonstrated that the GPA exerts a dose dependent hepatoprotection effect on ANIT induced liver damage with acute intrahepatic cholestasis in rats, which may due to Fxr mediated regulation of bile transporters like Bsep and Mrp2.

Protective Effect of Calculus Bovis Sativus on Dextran Sulphate Sodium-Induced Ulcerative Colitis in Mice

Calculus Bovis Sativus (CBS) is a commonly used traditional Chinese medicine, which has been reported to exhibit antispasmodic, fever-reducing, anti-inflammatory, and gallbladder-repairing effects. The present study aims to investigate the protective effect of CBS on dextran sulphate sodium- (DSS-) induced ulcerative colitis (UC) in mice. C57BL/6 male mice were exposed to 5% DSS in drinking water. CBS was given orally at 50 and 150 mg/kg once per day for 7 days. Body weight, disease activity index (DAI), colon length, colonic myeloperoxidase (MPO) activity, superoxide dismutase (SOD) activity, and malondialdehyde (MDA) and nitric oxide (NO) levels were measured. Administration of CBS significantly reserved these changes, decreased the MPO activity and MDA and NO level, and increased the SOD activity in the colon tissue. Histological observation suggested that CBS alleviated edema, mucosal damage, and inflammatory cells infiltration induced by DSS in the colon. Moreover, CBS significantly downregulated the mRNA expression of tumor necrosis factor-α (TNF-α), interleukin- (IL-) 1β and IL-6 in the colon tissue. Our data suggested that CBS exerted protective effect on DSS-induced UC partially through the antioxidant and anti-inflammatory activities.

Investigations of the total flavonoids extracted from flowers of Abelmoschus manihot (L.) Medic against α-naphthylisothiocyanate-induced cholestatic liver injury in rats

ETHNOPHARMACOLOGY RELEVANCE

The decoction of the flowers of Abelmoschus manihot (L.) Medic was traditionally used for the treatment of jaundice and various types of chronic and acute hepatitis in Anhui and Jiangsu Provinces of China for hundreds of years. Phytochemical studies have indicated that total flavonoids extracted from flowers of A. manihot (L.) Medic (TFA) were the major constituents of the flowers. Our previous studies have investigated the hepatoprotective effects of the TFA against carbon tetrachloride (CCl4) induced hepatocyte damage in vitro and liver injury in vivo. This study aimed to investigate the protective effects and mechanisms of TFA on α-naphthylisothiocyanate (ANIT)-induced cholestatic liver injury in rats.

MATERIAL AND METHODS

The hepatoprotective activities of TFA (125, 250 and 500mg/kg) were investigated on ANIT-induced cholestatic liver injury in rats. The serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) were used as indices of hepatic cell damage and measured. Meanwhile, the serum levels of alkaline phosphatase (ALP), gamma-glutamyltransferase (GGT), total bilirubin (TBIL), direct bilirubin (DBIL), and total bile acid (TBA) were used as indices of biliary cell damage and cholestasis and evaluated. Hepatic malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), glutathione transferase (GST), tumor necrosis factor-α (TNF-α) and nitric oxide (NO) were measured in the liver homogenates. The bile flow in 4h was estimated and the histopathology of the liver tissue was evaluated. Furthermore, the expression of transporters, bile salt export pump (BSEP), multidrug resistance-associated protein 2 (MRP2), and Na(+)-taurocholate cotransporting polypeptide (NTCP) were studied by western blot and reverse transcription-quantitative real-time polymerase chain reaction (RT-PCR) to elucidate the protective mechanisms of TFA against ANIT-induced cholestasis.

RESULTS

The oral administration of TFA to ANIT-treated rats could reduce the increases in serum levels of ALT, AST, LDH, ALP, GGT, TBIL, DBIL and TBA. Decreased bile flow by ANIT was restored with TFA treatment. Concurrent administration of TFA reduced the severity of polymorphonuclear neutrophil infiltration and other histological damages, which were consistent with the serological tests. Hepatic MDA and GSH contents in liver tissue were reduced, while SOD and GST activities, which had been suppressed by ANIT, were elevated in the groups pretreated with TFA. With TFA intervention, levels of TNF-α and NO in liver were decreased. Additionally, TFA was found to increase the expression of liver BSEP, MRP2, and NTCP in both protein and mRNA levels in ANIT-induced liver injury with cholestasis.

CONCLUSION

TFA exerted protective effects against ANIT-induced liver injury. The possible mechanisms could be related to anti-oxidative damage, anti-inflammation and regulating the expression of hepatic transporters. It layed the foundation for the further research on the mechanisms of cholestasis as well as the therapeutic effects of A. manihot (L.) Medic for the treatment of jaundice.