PHYTOCHEMICAL SCREENING AND ANTIMICROBIAL ACTIVITY OF METHANOL LEAVES EXTRACT OF SENNA SIAMEA

Medicinal plants remain an important source of bioactive compounds with therapeutic potential, especially in the search for new antimicrobial agents due to rising antibiotic resistance. This study investigated the phytochemical constituents and antimicrobial activity of the methanol leaf extract of Senna siamea. The leaves were collected, dried, pulverized, and extracted using the maceration method with 90% methanol. Phytochemical screening of the crude extract revealed the presence of alkaloids, flavonoids, terpenoids, tannins, carbohydrates, cardiac glycosides, and cardenolides, while saponins and anthraquinones were absent. Antimicrobial activity was evaluated using disc diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) assays against Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, Salmonella typhi, and Candida albicans. The extract exhibited dose-dependent antimicrobial activity, with the highest inhibition zones observed at 800 mg/ml, particularly against Staphylococcus aureus (18.00 mm). The MIC and MBC values for S. aureus were both 50 mg/ml, indicating significant sensitivity. Although the extract was less effective compared to the standard antibiotic ciprofloxacin, the findings confirm that Senna siamea contains bioactive compounds with notable antimicrobial potential. The study supports the traditional use of the plant in treating infectious conditions and provides a basis for further research into its pharmacological applications.