PHYTOCHEMICAL SCREENING AND ANTIBACTERIAL EVALUATION OF ISOLATED ALKALOID FORM PILIOSTIGMA THONINGII

ABSTRACTThis study was conducted to evaluate the phytochemical composition and antibacterial activity of isolated alkaloids from Piliostigma thonningii leaves. The objectives of the study were to screen the leaves for major phytochemicals, isolate alkaloid compounds, and test their antibacterial efficacy against selected microorganisms. Fresh leaves were collected from the savannah region of northern Nigeria, shade-dried, pulverized, and subjected to qualitative phytochemical screening. Alkaloids were extracted using acid-base extraction and tested for antibacterial activity against Escherichia coli and Staphylococcus aureus using the agar well diffusion method. The phytochemical screening revealed the presence of alkaloids, flavonoids, tannins, saponins, steroids, phenols, and glycosides. The antibacterial evaluation showed that the isolated alkaloid exhibited strong inhibitory effects, particularly at higher concentrations (500 mg), with zones of inhibition comparable to the standard antibiotic Amoxil. The Minimum Inhibitory Concentration (MIC) was observed at 62.5 mg for both test organisms, while the Minimum Bactericidal Concentration (MBC) was recorded at 250 mg. The study concludes that Piliostigma thonningii leaves contain bioactive alkaloids with potent antibacterial properties, supporting its traditional medicinal use. It is recommended that further purification, toxicity studies, and formulation trials be carried out to fully harness its therapeutic potential.