Antibacterial and Cytotoxic Effects of the Cultivated Ruta chalepensis

Abstract

Background: Ruta chalepensis is a shrub from the Mediterranean basin widely used in the traditional medicine. The plant presents an interesting composition containing alkaloids, coumarins and volatile oil. The present work aims to study the antibacterial and the cytotoxic effects of the ethanol extract, its fractions, and the alkaloid extract from the cultivated Ruta chalepensis. Methods: Extracts were tested against five bacterial strains using the agar well diffusion method and the broth micro-dilution technique for the determination of the Minimum Inhibitory Concentration (MIC). Brine shrimp assay was used to evaluate the cytotoxicity. Results: Chloroform fraction exhibited a strong antibacterial activity against S. aureus, and B. subtilis with inhibition diameters of 25.5±0.7 and 18.5±2.12mm at 50mg/ml and 100mg/ml, respectively. Butanol and aqueous fractions were found to be inactive against all the tested strains. Ethyl acetate was the only active fraction against E. coli. Alkaloids showed a strong growth inhibition of B. subtilis and S. aureus at low concentrations (22.5±0.71 and 18.00±0,00mm, respectively at 20mg/ml). The cytotoxicity evaluation using the brine shrimp larvae indicated a high effect of alkaloids with an LC50 of 27.51μg/ml supporting their antibacterial activity. Conclusion: These findings suggest a possible use of Ruta chalepensis as a source of antibacterial and anti-proliferative agents.