Chemical Composition, Antioxidant and Antimicrobial Activities of Essential oil from Callistemon viminalis (Gaertn.) G. Don Leaves

The present study aims to analyze the chemical composition of essential oil from Callistemon viminalis (Gaertn.) G. Don leaves and to evaluate its antioxidant and antimicrobial potential. The chemical composition was analysed by GC-FID and GC-MS. Twenty three components were identified representing 98.2% of the total oil components. alpha-Pinene (31.4%) was found as a major component followed by 1,8-cineole (24.9%), p-cymene (15.9%), alpha-terpineol (11.2%), limonene (5.7%) and alpha-phellandrene (4.3%). Callistemon viminalis essential oil exhibited good antioxidant activity by inhibiting 90.4% of 2,2-diphenyl-1-picrylhydrazyl radical and ferric reducing power (1.89 +/- 0.04) at 100 mu g/ml. Essential oil of C. viminalis was found highly effective against tested food borne bacterial as well as fungal pathogens inducing 17.7-46.0 mm and 43.2-46.0 mm zones of inhibition respectively at concentration of 8-250 mu g/ml. Antibacterial and antifungal potentiality of C. viminalis (Gaertn.) G. Don essential oil was further evaluated by minimum bactericidal concentrations (MBC) and minimum fungicidal concentrations (MFC) respectively. Like minimum inhibitory concentration (MIC), MBC against tested bacterial strains and MFC against fungal strains were found to be 8 mu g/ml. Time kill assay showed significant microbiocidal effect of essential oil for four weeks.