Comparative Study of the Phytochemical Constituents and Antibacterial Activity of Vernonia amygdalina and Moringa oleifera Crude Extracts

Vernonia amygdalina Amharic vernacular name “Grawa” and Moringa oleifera Amharic vernacular name “Shiferaw”, are the most common traditional medicinal plants used in Ethiopia. The parts of these plants such as stem bark, leaves and flowers showed varieties of medicinal properties and cure various human and animal diseases and ailments. The purpose of this study was to investigate the antibacterial activity and the phytochemical constituents of the crude extracts of Vernonia amygdalina and Moringa oleifera. Maceration technique was employed to obtain crude extracts from the various parts of the plants. The phytochemical composition of the stem bark, leaves and flower extracts was qualitatively assessed using standard procedures as indicated in the literature. The screening test revealed that different classes of phytochemical constituents including flavonoids, alkaloids, saponnins, tannins, phenols, steroids, terpenoids. Antimicrobial activities of the ethanol crude extracts of stem bark, leaves and flowers of Vernonia amygdalina and Moringa oleifera were screened against ten bacteria and a yeast using the disc diffusion method on Mueller Hinton agar (MHA). The antimicrobial activity was measured by the size of the inhibition zone. The ethanol extract derived from Vernonia amygdalina demonstrated superior antibacterial activity compared to the extracts of Moringa oleifera against nine bacterial strains (excluding Salmonella typhimurium) and one yeast species. Based on the results, the ethanol extracts of Vernonia amygdalina have shown good antimicrobial effects that make them promising for treating bacterial and fungal infections as compared to Moringa oleifera.