<i>In vitro<i> antimicrobial activity of <i>Citrus Sinensis<i> (orange), <i>Citrus Limetta</i> (sweet lime) and <i>Citrus Limon</i> (lemon) fruit peel oil extracts on selected causal organisms of urinary tract infection

Abstract

Oils from the fruit peels of Citrus sinensis (Orange), Citrus limetta (Lime) and Citrus limon (Lemon) were extracted and investigated for their antimicrobial activities against some selected microorganisms (Escherichia coli, Staphylococcus aureus, Klebsiella pneumonia, Pseudomonas aeruginosa and Candida albicans). Phytochemical analysis of the oil extracts shows the presence of tannins, saponins, flavonoids, terpenoids, cardiac glycosides, alkaloids, carbohydrates (reducing sugar) and phenol. Flavonoids occurred in the highest amount in C. sinensis. Infrared spectroscopy revealed the various functional groups present in the extracted oils.. antimicrobial studies showed that the extracted oils had antimicrobial effect on the test organisms, which is attributed to the phytochemicals and functional groups of the oil. The oils in combination showed synergistic antimicrobial effects on the organisms tested. With C. sinensis essential oil (1.5 ml), the zone of inhibition was highest on Staphylococcus aureus. With C. limetta (1.0 ml), the inhibition zone (27 mm) was also highest on S. aureus. Concentration of 2.0 ml gave the highest inhibition (15.5 mm) on S. aureus. The zones of inhibition with different quantities of orange peel oil, against the selected microbes were not significantly different (P-Value - 0.013). There was also no significant difference in the zone of inhibition of microbes at different concentrations of lime and lemon essential oils, with PValues of 0.0956 and 0.01225 respectively. It may be concluded that essential oils of C. sinensis, C. limetta and C. limon have antimicrobial properties and may be applied in the treatment of diseases induced by the pathogens. Further research is needed to achieve appropriate formulation into dosage forms, of the test oils. The superior antimicrobial properties demonstrated by the oil blends can be exploited further with a view to generating new effective antimicrobial compounds.

Keywords: Antimicrobial Activity, Urinary Tract Infections, Citrus limetta, Column Chromatography, Candida albicans.