Essential oil of the leaves of Ricinus communis L.: In vitro cytotoxicity and antimicrobial properties

Abstract

Background: The aim of the present study was to appraise the antimicrobial activity of Ricinus communis L. essential oil against different pathogenic microorganisms and the cytotoxic activity against HeLa cell lines. Methods. The agar disk diffusion method was used to study the antibacterial activity of Ricinus communis L. essential oil against 12 bacterial and 4 fungi strains. The disc diameters of zone of inhibition (DD), the minimum inhibitory concentrations (MIC) and the concentration inhibiting 50% (IC50) were investigated to characterize the antimicrobial activities of this essential oil. The in vitro cytotoxicity of Ricinus communis L. essential oil was examined using a modified MTT assay; the viability and the IC50 were used to evaluate this test. Results: The essential oil from the leaves of Ricinus communis L. was analyzed by GC-MS and bioassays were carried out. Five constituents of the oil were identified by GC-MS. The antimicrobial activity of the oil was investigated in order to evaluate its efficacy against twelve bacteria and four fungi species, using disc diffusion and minimum inhibitory concentration methods. The essential oil showed strong antimicrobial activity against all microorganisms tested with higher sensitivity for Bacillus subtilis, Staphylococcus aureus and Enterobacter cloacae. The cytotoxic and apoptotic effects of the essential oil on HeLa cell lines were examined by MTT assay. The cytotoxicity of the oil was quite strong with IC50 values less than 2.63 mg/ml for both cell lines. Conclusion: The present study showed the potential antimicrobial and anticarcinogenic properties of the essential oil of Ricinus communis L., indicating the possibilities of its potential use in the formula of natural remedies for the topical treatment of infections. © 2012 Zarai et al.; licensee BioMed Central Ltd.