ABSTRACT
INTRODUCTION: Cassia sieberiana DC (CAESALPINIACEAE) is a plant which grows in Southern Senegal. Its roots are used by traditional medicinal practitioners for its s pasmolytic and antiparasitic properties. The objective of our study was to investigate the myorelaxant and antispasmodic activity of the roots of C. sieberiana on the isolated Wistar rat ileum. MATERIAL AND METHODS: The powder of the roots of C. sieberiana was treated in a soxhlet with ethanol at 90 degrees. After dry evaporation, the extract was dissolved into water before successive treatments with ethyl acetate and butanol. Ethyl acetate, butanolic and aqueous residual fractions as well as the ethanolic total extract were tested on isolated rat ileum. RESULTS: The mean of inhibition Percentage (MIP) of the basal tonus of rat ileum after the total ethanolic extract (75 microg/ml) treatment was 50.51 +/- 10.18% (p < 0.05, n=5). Ethyl acetate and butanolic fractions were significantly more active on the ileal basal tonus to the one of total ethanolic extract. At 37.5 microg/ml, it decreased the ileal basal tonus with MIP respectively to 70.46 +/- 5.18% and 60.61 +/- 1.5% (p < 0.05, n=5). In contrast, the residual aqueous fraction was not active at all. After intestine precontracted with acetylcholine, the total ethanolic extract (MIP=52 +/- 20.49%) as well as the butanolic (MIP = 73 +/- 6.09%) and the ethyl acetate (MIP = 71 +/- 4.07 %) (p < 0.05, n=5) fractions induced a significant decrease of spasms (p < 0.05) (n=5). CONCLUSION: the butanolic and ethyl acetate fractions of the roots of C. sieberiana were more potent than the total ethanolic extract to induce myorelaxant a nd antispasmodic activity on isolated rat ileum. This study provides a pharmacological basis for a rational use of the roots of C. sieberiana in traditional medicine to treat gastro-intestinal disorders.