Evaluation of Phytochemical Constituents and Antibacterial Activity of Methanolic and Aqueous Leaf Extracts of Coffee Senna (Cassia occidentalis L.)

Abstract

Cassia occidentalis commonly known as Coffee senna is a herbaceous plant that belongs to the family fabaceae. The plant is called “Sanga-Sanga" in Hausa, “Ewe Oriesi” in Yoruba, and “Akidi Agbara” in Igbo. Coffee senna is a pan-tropical plant. This research was aimed at evaluating the phytochemicals and antibacterial activity of extracts of leaves of Coffee Senna. Plant leaf samples were collected behind Department of Biological Sciences Federal University Gusau. The samples were air dried and grounded into powder using mortar and pestle. The phytochemical analysis of both methalonic and aqueous leaf extracts revealed the presence of Cardiac glycosides, Steroids, Flavonoids, Alkaloids, Saponin glycosides, Saponins glycosides, Tannins and Anthraquines. Volatile oils, Balsams and glycosides were absent in the extracts. Methanolic and aqueous extracts of leaves of Cassia occidentalis were screened for their antimicrobial activity against two bacterial strains by disk diffusion assay. The pattern of inhibition varied with the solvent used for extraction and the microorganism tested. Among these extracts, methanol and aqueous extracts showed significant antimicrobial activity against the tested microbes. The most susceptible microorganism was Salmonella typhi  22 mm zone of inhibition in both the extract (Methanol and aqueous extract), then, followed by Streptococcus epidermidis with 20 mm zone of inhibition in both the extract (Methanol and Aqueous). The study concludes that Senna occidentalis leaf extracts studied showed high inhibition of bacterial growth, therefore the plant can be used in ethno-medicine and the pharmaceutical industries.