Assessment of the in vitro antibacterial activity of a combination of Methanolic extracts of Magnifera indica leaves and Citrus Aurantium leaves against Escherichia coli.

Abstract

Introduction: Escherichia coli is a common causative pathogen in human bacterial infections like UTIs, neonatal meningitis, sepsis and diarrhea. The various strains exhibit multiple-antibiotic resistance thus a need to find alternative sources of new anti-infective agents. Mango and bitter orange plant leaves were assessed for potential activity to establish their potential use as new sources of anti-infective agents. Objectives: To evaluate the in vitro antibacterial activity of a combination of methanolic extracts of Magnifera indica and Citrus aurantium leaves against Escherichia coli. Methodology: Citrus aurantium and Magnifera indica, the plants of interest were freshly collected from mutundwe Kanaala zone, washed, dried, ground and extracted with 96% methanol. Dilutions of 20mg/ml, 10mg/ml, 5mg/ml and 2.5mg/ml for each of the extracts were tested for antibacterial activity against Escherichia coli, to determine individual MICs. In combination, the plant extract proportions were varied at percentage ratios of 75:25, 50:50, 25:75 of Citrus aurantium: Magnifera indica respectively, and the MIC of the most active combination Magnifera indica 75: 25 Citrus aurantium was determined. Gentamicin (40mg/ml) was the positive control and 10% DMSO the negative control. One-way ANOVA analysis was run using graph pad prism ver 7. 03. Results: Individual methanolic extracts of Citrus aurantium did not exhibit antibacterial activity, while the Magnifera indica extracts exhibited activity with an MIC of 0.678mg/ml against Escherichia coli. The combination was less active than the individual Magnifera indica extract. The combination exhibited additive effect with FICI = 0.55. Conclusion: The individual Magnifera indica extract exhibited greater activity than the combination, thus a need for further evaluation of the combinations to ascertain ideal concentrations for antibacterial activity