Phytochemical Screening and Antibacterial Activity of Citrus Sinensis Peel Extracts on Clinical Isolates of Staphylococcus Aureus and Salmonella Typhi

Abstract

The study was conducted to determine the phytochemical composition, antibacterial activity and activity index orange (Citrus sinensis (L) Osbeck) peel extracts against clinical isolates of Staphylococcus aureus and Salmonella typhi. The result of phytochemical screening of the peel extracts showed the presence of alkaloid, glycoside, saponin, tannin, flavonoid, terpenoid and phenol. The result of the antibacterial efficacy of the extracts against the isolates indicated the extracts were active against the isolates with higher activity in ethanol extract (with average zone of inhibition of 15 mm) when compared to aqueous extract (12.25 mm). The result of susceptibility of the isolates to the extracts showed Staphylococcus aureus was more sensitive to the extract with average zone of inhibition of 15.25 mm when compared to Salmonella typhi with average zone of inhibition of 12.00 mm. The minimum inhibitory concentration (MIC) of the extracts showed that dilutions of various concentrations of aqueous and ethanol of peel extracts can inhibit the growth or kill the isolates at a concentration of between 2.125 – 20 mg/ ml. the average activity index of the extracts on the test isolates was found to be 0.64 which indicated that the plant extract can compete with the standard antibiotic used. Statistical analysis of the results indicated that there is no significant different in the activity of the extracts against the isolates used at p<0.05. Findings from this study support the use of orange peel extracts for medicinal purposes.