Phytochemical and antimicrobial evaluation of <i>Moringa oleifera</i>

Abstract

The leaves of Moringa oleifera were subjected to ethanol extraction. The extract was fractioned and patitioned using different organic solvents in order of increasing polarity. Standard methods were used for both extraction and phytochemical screening. Modified agar well diffusion method was adopted for screening the antimicrobial activities of the leaf extracts. The test was carried out in triplicates. The extract was phytochemically screened and revealed the presence of Flavonoid, Alkaloid, Tannins, Steroid, Saponins, Cardic glycosides, Terpenoids, Anthraquinone. The chloroform extract at 100 mg / ml concentration showed highest antimicrobial activity of 18mm on both gram positive and gram negative organisms (S. aureus, P. mirabilis and P. vulgaris) and 17mm on P. auriginosa, E. coli and K. pneumoniae. However it had 16mm on S. epidermidis and 14mm on C.albicans. The aqueous extract had strong antimicrobial activity (17mm, 14mm, 14mm, 14mm, 13mm, 13mm, 13mm and 12mm, on S.aureus, P.auriginosa, E. coli, K. pneumoniae, P. mirabilis, P. vulgaris, S.epidermidis, and C.albicans respectively). Ethyl acetate extract showed moderate antimicrobial activity of 13mm, 12mm, 15mm, 13mm, 14mm, 13mm, 13mm and 12mm on S. aureus, S.epidermidis, P.auriginosa, E. coli, K. pneumoniae, P. mirabilis, P. vulgaris and C. albicans respectively. n-hexane extract had the least antimicrobial activity of 14mm, 12mm, 14mm, 14mm, 13mm, 12mm, 12mm and 12.5mm on S.aureus, S.epidermidis, P. auriginosa, E. coli, K.pneumoniae, P. mirabilis, P. vulgaris and C. albicans respectively. The 50mg/ml and 25mg/ml extract’s concentrations had lesser diameter zones of inhibitions in decreasing order of the decreasing concentrations.The extracts were subjected to MIC evaluation and the findings of the chloroform extract showed that S. aureus was the most sensitive; followed by E. coli, K. pneumoniae, followed by P. auriginosa, P. mirabilis, P. vulgaris, S. epidermidis and C. albicans. The MBC showed no value. This study proved that the leaves of M. oleifera contain some active principles with antimicrobial activity and could enhance its use in preventing and curing diseases, when purified to the appropriate pharmacological level.

Keywords:  M. oleifera, Phytochemical, Antimicrobial, Infectious isolates