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

• Published in: Journal of ethnopharmacology 2015-08, Vol.172, p.202-213
• Main Authors: Yan, Jia-Yin, Ai, Guo, Zhang, Xiao-Jian, Xu, Hai-Jiang, Huang, Zheng-Ming
• Format: Article
• Language: English
• Subjects: 1-Naphthylisothiocyanate - toxicity; Abelmoschus - chemistry; Abelmoschus manihot (L.) Medic; Administration, Oral; Animals; Cholestasis - prevention & control; Cholestatic; Disease Models, Animal; Dose-Response Relationship, Drug; Drugs, Chinese Herbal - administration & dosage; Drugs, Chinese Herbal - isolation & purification; Drugs, Chinese Herbal - pharmacology; Flavonoids - administration & dosage; Flavonoids - isolation & purification; Flavonoids - pharmacology; Flowers; Hepatoprotective; Liver - drug effects; Liver - pathology; Male; Rats; Rats, Wistar; Total flavonoids; α-Naphthylisothiocyanate
• ISSN: 0378-8741; 1872-7573
• DOI: 10.1016/j.jep.2015.06.044

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. 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. 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 i