Phytochemical and antibacterial property of finger millet (Eleusine coracana) on some selected clinical bacteria

Abstract

Finger millet in northern Nigeria was subjected to phytochemical screening using standard procedures. The agar well method was used to test the antibacterial activities of methanolic and aqeous (combined) extracts of the grain on Salmonella typhi, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. The result of the antimicrobial activity as indicated by zone of inhibition ranged from 1 to 8 mm for different extract concentrations. The finger millet extract showed zones of inhibition of 8 mm against Pseudomonas aeruginosa at a concentration of 100 mg ml−1, 3 mm at 50 mg ml−1 and 2 mm at 25 mg ml−1 concentrations. The inhibition zones of Escherichia coli at extract concentrations of 100 mg ml−1, 50 mg ml−1, 25 mg ml−1, 12.25 mg ml−1 and 6.125 mg ml−1 were 4 mm, 3 mm, 3 mm, 6 mm and 1 mm respectively, and for Staphylococcus aureus were 5 mm,2mm, 1 mm at 100 mg ml−1, 50 mg ml−1 and 12.25 mg ml−1 respectively. The zones of inhibition against all the tested isolates at 100 mg ml−1 was not significantly different from those of 50 mg ml−1 (P=0.160), 25 mg ml−1 (P=0.067) and 12.5 mg ml−1 (P=0.160), but significantly higher than 6.125 mg ml−1 (P=0.05). Although S. aureus and S. typhi also did not differ significantly in their susceptibility to the varying concentrations of the extract (P=0.157), but susceptibility by S. typhi was significantly lower than those of E. coli (P=0.007) and P. aeruginosa (P=0.015). The qualitative phytochemical analysis indicated the presence tannin/phenol, flavonoids, alkaloid, saponin, glycosides, terpenoid and steroids in finger millet. The quantitative phytochemical revealed total phenolic content (6.57 mg/100 g) and total flavonoid content (0.224 mg/100 g). The overall results indicate that finger millet are potent antimicrobial preparations at least in vitro and also have high nutritional value.