Hepatoprotective effect of Polygonum hyrcanicum methanolic extract on the carbon tetrachloride induced hepatotoxicity in mice

Production of reactive oxygen species (ROS) and induction of oxidative stress are the main mechanisms of xenobiotics-induced liver injury. Carbon tetrachloride, an organic solvent, has been extensively used as an animal model of liver toxicity through production of free radicals. Polygonum hyrcanicum, Polygonaceae, is an endemic species which grows in north and northeast parts of Iran. Decoction of this plant has been traditionally used in northern parts of Iran, mainly Turkman Sahra, for alleviation of anemia, kidney stones and liver disorders. Considering the phytochemical properties of this plant and its traditional use, in this study the hepatoprotective effect of the aerial parts of P. hyrcanicum was evaluated in CCL4-induced hepatotoxicity in mice.

P. hyrcanicum was collected from Veresk region in Mazandaran province. Methanolic extract of the aerial parts was prepared using maceration at room temperature. Male albino mice weighing 23±5 g were treated with different doses of P. hyrcanicum (500, 750 and 1000 mg/kg), N-acetylcystein (200 mg/kg, as positive control) and water (10 ml/kg, as negative control) by gavage for seven days. Two hours after the last dose, 0.5 ml/kg CCL4 was injected to mice intraperitoneally (i.p.) to induce liver toxicity. Twenty-four hours later, the animals were sacrificed and liver enzymes in the serum and lipid peroxidation in the liver samples were determined.

CCL4 significantly increased the serum levels of ALT and AST and lipid peroxidation in liver samples. Treatment of mice with P. hyrcanicum for seven days decreased significantly the serum liver enzymes and liver lipid peroxidation.

We showed for the first time that methanolic extract of P. hyrcanicum, an Iranian endemic plant, has hepatoprotective properties in mice through inhibition of oxidative stress iduced by oxidants. It is suggested that further studies on the fractions of the crude extract take place to determine the effective ingredient (s) and therapeutic mechanisms.