Acute and 28-Day Repeated Dose Oral Toxicity of Bauhinia variegata (Caesalpiniaceae) Stem Bark Extract

Abstract

Toxicity of aqueous extract (AE) of stem bark of Bauhinia variegata was evaluated. In the acute toxicity study, Sprague-Dawley rats were treated orally with AE (2,000 or 5,000 mg.kg−1 b.w). The animal behavior and mortality were observed periodically for up to 14 d. In the repeated dose toxicity study, the AE was administered daily at doses of 1,000 or 2,000 mg.kg−1 b.w, for 28 d. Behavior and mortality of animals were observed during the test period and hematological, biochemical parameters and histopathological examinations were carried out. In acute toxicity study, AE did not produce any mortality, changes in behavior, or any other physiological activities in rats at all selected doses. In repeated dose toxicity study, the monocytes and lymphocytes decreased at high doses. AE did not affect the biochemical parameters (except glucose) and the organs’ weight. Histopathology studies revealed no changes in cellular structure of the organs studied. The AE of B. variegata had maximally tolerated dose (MTD) of 5,000 mg.kg−1 in acute toxicity study and lowest observed adverse effect level of 1,000 mg.kg−1 in repeated-dose toxicity study in rats.