[ hepatotoxicity of aqueous methanol extract and fractionated-methanol extract of Phytolacca americana in male rat using perfusion method]

Phytolacca americana is a native plant in several states of USA and mostly its boiled leaves are used as a popular salad [called grandmother salad] in American diet. It grows widely in the coastal areas and forests in northern parts of Iran but is rarely used. In spite of having several medicinal properties, its side effect is digestive toxicity [especially hepatotoxicity]. To date, the hepathotoxicity of this plant from northern of Iran has not been studied. Therefore, this study was aimed to investigate the hepatotoxicity of P. americana using Isolated Rat Liver Perfusion [IRLP] system. The albino rats weighted 180-220 g were desighdted into 6 groups. Subsequently, the male rat's anesthetized using ether, were used for experiments. The inferior vena cava was cannnulated with PE-10 tubing. The portal vein was immediately cannulated with a 23 g catheter. Then the liver was perfused in site by Krebs-Henseleit buffer at 37°C with a rate of 20ml/min for 3hr. After 30-45 min of perfusion, various doses [10, 20, 40, 50, 100 mg/kg] of aqueous and methanol extracts and CHCl3, ETOAC and MEOH fraction [10, 20, 40mg/kg] were added to the buffer and perfused for 2 hr. Samples of perfused fluid were collected every 30min and analyzed for any liver injury by measuring the serum enzymes [ALT, AST]. Sections of liver tissue were also examined for pathological changes. The results showed that the activity of aminotransferase enzymes increased significantly and dose-dependently [p<0.01]. Also, methanol extract fractionates were increased compared with the control group [p<0.05]. The histopathological changes in the liver tissue were dose-dependent and confirmed the previous data. The enzymatic differences between the test groups and the control group showed the most difference at 60 min. The finding showed that the hepatotoxic effect of P. americana is dose dependent. Therefore, decreasing the administrated dose may be effective in prevention of its hepatic side effects