The leaves of Eupatorium adenophorum Spreng were powdered and extracted with methanol. An acute oral toxicity study was conducted in male Swiss albino mice and a LD50 of 3501 mg/kg was obtained during 14 days observation period. Twenty Swiss albino mice (male) randomly divided into four groups were administered orally with vehicle (5% tween 80), 1/20th (i.e. 175 mg/kg), 1/10th (i.e. 350 mg/kg) and 1/5th (i.e. 750 mg/kg) LD50 doses of methanolic leaf extract of E. adenophorum Spreng; respectively for a period of 30 days. The mice were sacrificed on day-31 and the liver dissected out freed from adherent tissue weighed to nearest milligram. The liver histology, estimations of biochemical contents and enzyme activities were carried out. Treatment of the mice with methanolic extract of E. adenophorum at the dose level of 750 mg/kg (i.e. 1/5th LD50) elicited hepatotoxicity and the animals had yellow discoloration of liver, subcutaneous tissue and musculature indicating jaundice. Study on liver enzymes revealed marked increase in the activities of alkaline phosphatase (ALP), alanine transaminase (ALT), aspartate transaminase (AST) and lactate dehydrogenase (LDH), while significant increase in serum bilirubin level. Histopathological examination of the livers of the group IV animals had focal areas of necrosis and bile duct proliferation. Elevation in plasma bilirubin concomitant with alterations in enzyme profile and histopathological lesions are consistent with liver injury and cholestasi
