Antimicrobial effect of fresh lemon peel and garlic extracts mixture on Escherichia coli

Abstract

The study was conducted to compare the antibacterial activity of the single and mixture ethanolic extracts of garlic and lemon peels, traditional plants commonly used for food and medicinal purposes among local communities in different parts of the world. The microorganism tested was Escherichia coli (gram negative) which is a common etiological agent of diarrheal diseases. Crude extracts were used and the method used for extraction was solvent extraction technique using ethanol as the extracting solvent. Antibacterial activity of the extracts was tested using agar-well diffusion technique on Mueller Hinton (MH) media. Garlic showed inhibitory properties on Escherichia coli whereas the lemon peel extract turned out to have no inhibitory effect on the Escherichia coli. Combination of the two extracts in a ratio of 1:1 showed antagonistic effect. Data analysis was by paired T-test, garlic extracts had more antibacterial activity compared to combination of the two extracts on Escherichia coli with a P-value 0.0000006909 at 95% level of confidence. In conclusion, single garlic extract had significantly better antimicrobial activity than both the single lemon peel extracts and the combination of both extracts at inhibiting growth of Escherichia coli. Lemon peel extracts exhibited antagonistic effect on combination with garlic extract.