In vitro antibacterial effect of Vernonia amygdalina leaves extract on Escherichia coli and Staphylococcus aureus in Kebbi State, Northern Nigeria In vitro antibacterial effect of Vernonia amygdalina leaves extract on Escherichia coli and Staphylococcus aureus in Kebbi State, Northern Nigeria

Abstract

In the developing world, sufficient access to conventional medicines has been arguably of immense
challenge perhaps due to socioeconomic predicaments. This has consequently led to an increase in the
use of ethnomedicinal regimens such as Vernonia amygdalina, commonly called bitter leaf. This study
is aimed at investigating the in vitro antibacterial effect of V. amygdalina leaves extracts on Escherichia
coli and Staphylococcus aureus. Conventional microbiological techniques were used to screen aqueous
extracts of V. amygdalina for antibacterial sensitivity and phytochemical properties. Zones of inhibition
produced by ethanolic extract ranged from 11.30 ± 0.30 mm at 25 mg/ml to 17.40 ± 2.88 mm at 100 mg/ml
against E. coli; 12.63 ± 2.97 mm at 25 mg/ml to 14.5 ± 2.5 mm at 100 mg/ml against S. aureus; the most
sensitive organisms on the ethanolic extract was E. coli while S. aureus was the least sensitive. The leaves
extracts were positive for flavonoids, terpenoids, saponins, anthraquinones, alkaloids, and phenols. This
outcome suggests the possibility of obtaining a safe and efficacious chemotherapeutic derivative from
V. amygdalina as it already serves as an important food ingredient in Nigeria.