Subacute toxicity study of the ethanolic extract of (L.) flowers in rats.

Linn. is used traditionally in India and South East Asian countries as an antiseptic, antidote and a brain tonic. Recent pharmacological studies on the plant have highlighted to be a rich source of secondary metabolites, with proven therapeutic applications. Since the toxicity of a plant following repeated exposure is of higher clinical significance, the present investigation was conducted to establish the subacute toxicity profile of the ethanolic extract of flowers (MFE). The study was conducted in accordance with the OECD Guideline 407, wherein MFE was administered orally to groups of male and female rats ( 5/group/sex) at the doses of 100, 500 and 1000 mg/kg, over a period of 28 days. Repeated administration of MFE had no adverse effect on the growth rate and hematological parameters of the animals. There were no changes in the biochemical parameters, except for a slight decrease in the CHOL (total cholesterol) levels, and an increase in the levels of AST (aspartate aminotransferase) and ALT (alanine aminotransferase), at the highest dose. The latter corroborated with the histopathological findings exhibiting mild lymphocytic infiltration and hepatocyte degeneration observed in the liver tissues of both sexes. According to the study, the no-observed-adverse-effect level (NOAEL) of in the 28-day repeated dose toxicity study in rats was 500 mg/kg. Though the overall effects of the extract at the highest dose did not translate into any serious complications, its effect on hepatic function needs to be established over a longer period of study.