Analgesic Effects of Aqueous Extracts of the Leaves ofBryophyllum pinnatum.

Bryophyllum pinnatum. Linn (Crassulaceae) is a shrub with simple or trifoliate petiolate leaves used mainly in folk medicine to alleviate pains of various intensities and etiologies. The analgesic potency of the aqueous extract of the leaves of B. pinnatum. was investigated using animal models. Results showed that the aqueous extract of B. pinnatum. was devoid of severe toxic effects (LD50 = 660.9±2.65 mg/kg body weight), increased the pain threshold in rats using the hot plate or thermal methods, inhibited or reduced phenylbenzoquinone-induced writhing or abdominal stretches in mice in a dose-dependent manner, and produced a weak or an inferior anti-inflammatory activity than aspirin. It is concluded that the aqueous extract of B. pinnatum. can demonstrate strong analgesic potency comparable in a times-and dose-dependent manner to a nonsteroidal anti-inflammatory drug.