Analysis of antibacterial activity of different concentrations of leaf extract of gynandropsis gynandra on escherichia coli bacteria.

Abstract

Medicinal plants have been sources of a number of important compounds which have been discovered during last century. Eighty percent of the world population still depends on herbal medicine as their main source of medicinal therapy. Until the 1950‘s the organism was more or less regarded as a normal non-pathogenic cohabitant of the enteric tract of warm-blooded animals and humans. However, during the last four-five decades, a tremendous amount of research has established E. coli among the important etiological agents of enteritis and several extra intestinal diseases such as urogenital infections, wound infections, mastitis, septicemia and meningitis. The main objective of this research therefore is; to elucidate scientifically the effect of the leaf extract of Gynandropsis gynandra on the E. coli. In vitro experiment was performed with the test organism E. coli where the organism was cultured on selective EMB Agar, refrigerated in the Agar slants of TSA and then inoculated on the Petri dishes containing TSA and then disc diffusion method was used to determine the level of antibacterial inhibition to the nearest mm. For the three samples of the plant from different gardens, the minimum average level of inhibition was 7.8mm for 50mg/ml, 12.4mm for 200mg/ml. A maximum average level of inhibition of 12.8mm for concentration 200mg/ml. The control experiment was constant at 16mm. The small difference in the level of antibacterial inhibition was ascribed to the tender leaves of the first sample research also showed that 200mg/ml is not the optimum concentration for inhibition of E. coli. In the research the controlled experiment exhibited the highest level of inhibition of e coli, this shows that the concentration of the extract was still less toxic to the bacteria and hence a basis that e coli can still be further studied in vivo experiments to discover the potentialities of the plant extract in antimicrobial activity.

Key terms; Antibacterial, Extracts, Gynantropsis gynandra, inhibition.