Abstract

Antimicrobial properties of leaf extracts of Senna obtusifolia (L) were investigated against both clinical and laboratory isolates of both bacteria and fungi using the disc diffusion method. Acetone extracts (12 mm zone diameter of inhibition, MIC 200 μg/mL and MBC 300 μg/mL) demonstrated the highest activity, followed by dichloromethane (8 mm zone diameter of inhibition, MIC 300 μg/mL and MBC 400 μg/mL), methane (7 mm zone diameter of inhibition, MIC 400 μg/mL and MBC 400 μg/mL) and hexane (6 mm zone diameter of inhibition, MIC 800 μg/mL and MBC 1000 μg/mL). Water extracts demonstrated the least activity against the test bacteria and fungi (4 mm zone diameter of inhibition, MIC 800 μg/mL and MBC 800 μg/mL). Phytotoconstituents present included Saponins, Tannins, Alkaloids and Flavonoids. S. obtusifolia (L) can be used to source antibiotic substances for possible treatment of bacterial and fungal infections including gonorrhea, pneumonia, urinary tract and some mycotic infections.

Key words: Senna obtusifolia (L), antimicrobial property, extract antibiotic.