Laxative activities of Cassia sieberiana and Senna obtusifolia.

Background: The root and stem bark of Cassia sieberiana DC. (Caesalpiniaceae) and the root of Senna obtusifolia (Linn) Irwin and Barneby (Caesalpiniaceae), used for constipation in Nigeria, were assayed for laxative properties in male albino rats using the official senna leaf (Senna alexandrina Mill. family Caesalpiniaceae) as the reference standard.