Janbaz K H, Saeed S A, Gilani A H
Faculty of Pharmacy, Bahauddin Zakariya University, Multan, Pakistan.
Phytomedicine. 2004 Jul;11(5):424-30. doi: 10.1016/j.phymed.2003.05.002.
Caffeic acid and quercetin, the well-known phenolic compounds widely present in the plant kingdom, were investigated for their possible protective effects against paracetamol and CCl4-induced hepatic damage. Paracetamol at the oral dose of 1 g/kg produced 100% mortality in mice while pretreatment of separate groups of animals with caffeic acid (6 mg/kg) and quercetin (10 mg/kg) reduced the death rate to 20% and 30%, respectively. Oral administration of sub-lethal dose of paracetamol (640 mg/kg) produced liver damage in rats as manifested by the significant (P<0.01) rise in serum levels of aminotransferases (aspartate transaminase (AST) and alanine transaminase (ALT)) compared to respective control values. The serum enzyme values were significantly (P<0.01) lowered on pretreatment of rats with either caffeic acid (6 mg/kg) or quercetin (10 mg/kg). Similarly, the hepatotoxic dose of CCl4 (1.5 ml/kg; orally) also raised significantly (P<0.05) the serum AST and ALT levels as compared to control values. The same dose of the caffeic acid and quercetin was able to prevent CCl4-induced rise in serum enzymes. Caffeic acid and quercetin also prevented the CCl4-induced prolongation in pentobarbital sleeping time confirming their hepatoprotectivity. These results indicate that caffeic acid and quercetin exhibited hepatoprotective activity possibly through multiple mechanisms.
咖啡酸和槲皮素是植物界广泛存在的著名酚类化合物，研究了它们对扑热息痛和四氯化碳诱导的肝损伤可能的保护作用。口服剂量为1 g/kg的扑热息痛可导致小鼠100%死亡，而分别用咖啡酸（6 mg/kg）和槲皮素（10 mg/kg）预处理动物组可将死亡率分别降至20%和30%。口服亚致死剂量的扑热息痛（640 mg/kg）可导致大鼠肝损伤，表现为与各自对照值相比，血清转氨酶（天冬氨酸转氨酶（AST）和丙氨酸转氨酶（ALT））水平显著（P<0.01）升高。用咖啡酸（6 mg/kg）或槲皮素（10 mg/kg）预处理大鼠后，血清酶值显著（P<0.01）降低。同样，四氯化碳的肝毒性剂量（1.5 ml/kg；口服）与对照值相比，也显著（P<0.05）提高了血清AST和ALT水平。相同剂量的咖啡酸和槲皮素能够预防四氯化碳诱导的血清酶升高。咖啡酸和槲皮素还能预防四氯化碳诱导的戊巴比妥睡眠时间延长，证实了它们的肝脏保护作用。这些结果表明，咖啡酸和槲皮素可能通过多种机制表现出肝脏保护活性。
