RESUMO
To asses the hepatoprotective potential of leaves of Calendula officinalis against experimentally produced liver damage in animals using acetaminophen as model hepatotoxin. This study was conducted at Department of Pharmacy, University of Peshawar. Preliminary experiments were performed in mice to estimate the protective effect of plant material against lethal dose of acetaminophen [1gm/kg]. Acute toxicity of plant material up to a dose of 3 gm was assessed in mice to note any behavioural changes and mortality. Hepatic damage in rats was induced by oral acetaminophen [640 mg/kg]. The effect of methanolic extract of leaves of Calendula officinalis was investigated against acetaminophen-induced hepatic damage in 30 male, albino rats. Acetaminophen produced 100% mortality at a dose of 1 gm/kg in mice, while pretreatment of mice with Calendula officinalis [l.0 gm/kg] reduced the death to 30%. Pretreatment of rats with leaves extract [500 mg/kg orally, four doses at 12 hours interval] prevented [p<0.05] the acetaminophen [640 mg/kg] induced rise in serum transaminase [GOT GPT], serum bilirubin and serum alkaline phosphatase. Post treatment with three successive doses of leaves extract [500 mg/kg, 6 hourly] restricted the hepatic damage induced by acetaminophen [P<0.05]. These results indicate that the crude extract of Calendula officinalis leaves exhibits hepatoprotective action