Antimicrobial Activities and Phytochemical Screening of Citrus Aurantifoila (Lime) Leaf Extracts and Fruit Juice on Some Microorganisms

Abstract

This work studies the antimicrobial activities and phytochemical constituents of Citrus aurantifoila (lime) leaf extracts and fruit juice on some microorganisms. The antimicrobial activities and minimum inhibitory/ minimum bacteriocidal/fungicidal concentrations (MIC/MBC/MFC) of ethanolic, methanolic and aqueous extracts of Citrus aurantifolia leaves and fruits juice were determined on some pathogenic microorganisms namely: Staphylococcus aureus, Escherichia coli, Psuedomonas aeruginosa, Pseudomonas aeruginosa (ATCC 27853) and Trichophyton rubrum using agar well diffusion method. The methanolic extract was found to show more activity than the ethanolic and aqueous extract on all the isolates except for E.coli that showed resistance to all the extracts. The inhibition zone diameters (IZD) of methanol, ethanol and aqueous extracts ranged between 5 and 23 mm, 4 and 14 mm and 4 and 11mm respectively. The MICs of ethanolic extracts were 0.76 mg/ml for Staphylococcus aureus, 200 mg/ml for Escherichia coli, 1.56 mg/ml for Pseudomonas aeruginosa, 0.76 mg/ml for Pseudomonas aeruginosa (ATCC 27853) and 50 mg/ml for Trichophyton rubrum. The MICs of methanolic extract were 0.76 mg/ml for Staphylococcus aureus, 200 mg/ml for Escherichia coli, 1.56 mg/ml for Pseudomonas aeruginosa, 0.76 mg/ml for Pseudomonas aeruginosa (ATCC 27853) and 25 mg/ml for Trichophyton rubrum. The MICs of aqueous extract were 0.76mg/ml for Staphylococcus aureus, 200 mg/ml for Escherichia coli, 1.56 mg/ml for Psuedomonas aeruginosa and Psuedomonas  aeruginosa (ATCC 27853) and 100mg/ml for Trichophyton rubrum. The MBC/MFC ranged from 3.125 mg/ml to 12.5 mg/ml for all organisms tested. The standard control antibiotic/antifungal (ciprofloxacin/fluconazole) showed comparable results with the plant extracts. The phytochemical analysis carried out on the plant extracts revealed the presence of saponins, flavonoids, steroids, alkaloids, tannins, glycosides and reducing sugars. Statistical analyses showed that there were significant differences in the antimicrobial activities of each extract on the test organisms. The presence of these phytochemicals supports the use of this plant as antimicrobial agent and thus can be used in the treatment of some infections caused by these tested pathogenic microorganisms.