Biochemical alterations in the blood plasma of rats associated with hepatotoxicity induced by Eupatorium adenophorum

Eupatorium adenophorum (Crofton weed), a native of Central America, has app eared as a major weed in several areas in different parts of the world. Hor ses that eat this plant are poisoned on prolonged exposure. Toxicity due to consumption of this plant by other grazing animals is not clear. Administr ation of freeze-dried leaf powder to mice results in hepatotoxicity. Earlie r attempts to produce toxicity in rats using the leaves of this plant were not successful. In the present study, administration of oven-dried E. adeno phorum leaves collected at the flowering stage elicited hepatotoxicity in r ats. The affected animals had a marked increase in the concentration of pla sma bilirubin and in the activities of 5'-nucleotidase, alkaline phosphatas e, aspartate aminotransferase, alanine aminotransferase and lactate dehydro genase. There were no significant differences in plasma creatinine, urea or total protein values in the affected animals compared to controls. The liv ers of the affected animals had focal areas of necrosis throughout the pare nchyma and hepatocytes showed megalocytosis. The bile ducts were dilated an d the epithelium showed degenerative to necrotic changes. The alterations i n bilirubin, enzymes and histopathological changes imply cholestasis and li ver injury.