Antibacterial activity and phytochemical profile of Senna occidentalis (L.) leaf extracts

Abstract

Senna occidentalis is a medicinal plant traditionally used for the treatment of various ailments. This study evaluated the phytochemical constituents and in vitro antibacterial activity of methanol and ethanol leaf extracts of S. occidentalis against clinical isolates of Staphylococcus aureus and Escherichia coli. The leaves were collected, authenticated, air-dried, pulverized, and extracted using methanol and ethanol. Phytochemical screening was conducted using standard qualitative methods, while antibacterial activity was evaluated using the agar well diffusion method, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). The extracts contained alkaloids, flavonoids, steroids, glycosides, tannins, and anthraquinones in varying intensities. Both extracts demonstrated antibacterial activity against the test organisms. The methanol and ethanol extracts produced inhibition zones ranging from 7–17 mm and 4–19 mm, respectively. The MIC was 12.5 mg/mL for both extracts against both organisms. The MBCs of the methanol extract were 50 mg/mL for E. coli and 100 mg/mL for S. aureus, while those of the ethanol extract were 25 mg/mL and 50 mg/mL, respectively. The findings demonstrate the antibacterial potential of S. occidentalis leaf extracts, support their traditional medicinal use and suggests its potential as a source for developing plant-based antimicrobial agents to combat drug-resistant infections.