Phytochemical screening and antimicrobial studies on the methanolic bulb extract of Allium sativum L.

Abstract

Methanolic extract of the bulb of Allium sativum was screened for phytochemical and antimicrobial properties. The crude extract of A. sativum bulb showed positive results for carbohydrates, glycosides and proteins in high concentrations; alkaloids, saponins, reducing sugars, oils and steroids in medium concentrations, while flavonoids and acidic compounds were present in low amounts. Tannins, resins and terpenoids were however absent in the extract. All the six tested microorganisms exhibited varied susceptibility to the plant extract. The minimum inhibitory concentration (MIC) of the organisms were, 50 mg/ml for Salmonella paratyphi, 25 mg/ml for Bacillus subtilis, 100 mg/ml for Klebsiella pneumoniae, 12.5 mg/ml for Candida albicans, 3.12 mg/ml for Candida paralopsis and 6.25 mg/ml for Candida tropicalis. A. sativum showed both antifungal and antibacterial properties.

Keywords: Phytochemical screening, antimicrobial activity, Allium sativum, bulb extract

African Journal of Biotechnology Vol. 12(14), pp. 1665-1668