PHYSICOCHEMICAL STANDARDIZATION, PHYTOCHEMICAL PROFILING, AND BROAD-SPECTRUM ANTIBACTERIAL ACTIVITY OF CASSIA ANGUSTIFOLIA

Cassia angustifolia (Fabaceae), commonly known as Senna is a medicinal plant extensively used in traditional systems of medicine for gastrointestinal and inflammatory disorders. The present study investigated the physicochemical characteristics, qualitative phytochemical composition, and antibacterial activity of the methanolic leaf extract of C. angustifolia against clinically important Gram-positive and Gram-negative bacteria. Physicochemical parameters including moisture content, total ash, acid-insoluble ash, water-soluble ash, alcohol-soluble extractive value, pH, swelling index, and bulk density were determined following standard pharmacognostic procedures. Preliminary phytochemical screening was carried out using established qualitative tests for major secondary metabolites. Antibacterial activity was evaluated using the Kirby-Bauer agar disc diffusion method against Escherichia coli, Staphylococcus aureus, and Streptococcus pyogenes. The physicochemical analysis showed acceptable quality parameters, including moisture content (9.22% w/w), total ash (7.81% w/w), alcohol-soluble extractive value (13.63% w/w), and pH (6.35). Phytochemical analysis confirmed the presence of alkaloids, flavonoids, tannins, phenolic compounds, saponins, cardiac glycosides, terpenoids, steroids, and carbohydrates. The methanolic extract exhibited concentration-dependent antibacterial activity, with inhibition zones of 20 mm against E. coli, 21 mm against S. aureus, and 16 mm against S. pyogenes at 1000 µg/disc. The findings suggest that C. angustifolia possesses significant phytochemical richness and broad-spectrum antibacterial potential. The integration of physicochemical and biological evaluations provides a scientific basis for the authentication, standardization, and therapeutic application of C. angustifolia as a promising source of natural antibacterial agents.