PHYTOCHEMICAL CONSTITUENTS AND ANTIBACTERIAL ACTIVITIES OF SCENT LEAF EXTRACTS
Daniel PS, Nuhu* AA
Department of Chemistry, Ahmadu Bello University, PMB 1069, Zaria, Nigeria
Afr. J Pharm Res Dev; Volume 8(2): 140-146; Nov/Dec 2016
Scent leaf (Ocimum gratissimum) is a plant that is widely distributed in the tropics of Africa and Asia. It is rich in a good number of ethnomedicinal applications including treatment of diarrhea, pneumonia and upper respiratory tract infection. In this study, we carried out phytochemical screening to detect the chemical components present in methanol and n-hexane extracts of Ocimum gratissimum and tested the anti-microbial activities of these extracts against four different species of bacteria: Staphylococcus aureus, Escherichia coli, Bacillus subtilis and Pseudomonas aeruginosa. The phytochemical screening revealed the presence of alkaloids, saponins, tannins, flavonoids, steroids and triterpenes in the methanol extract, but only steroids and triterpenes in the n-hexane portion. The methanol extract showed zone of inhibition that ranged from 12-29 mm, and minimal inhibitory concentration (MIC) of 6.25, 12.5 and 25 mg/ml were recorded against B. subtilis, P. aeruginosa and E.coli respectively. However, the n-hexane extract had zone of inhibition of 14-28 mm, and MIC of 6.25 mg/ml against B. subtilis and E. coli, and 12.5 mg/ml against P. aeruginosa. In all cases, twice the MICs were recorded as the respective minimal bactericidal concentration (MBC). These results indicate that consumption of scent leaves is a good source of nutrients and can sufficiently confer physiological protection against different disease-causing organisms.
KEYWORDS: Phytochemical screening, Ocimum gratissimum, ethnomedicinal activities, antibacterial activity, minimal inhibitory concentration
*Corresponding Author: email@example.com