Chemical composition, antioxidant and antimicrobial activities of the essential oil of Vetiveria nigritana (Benth.) Stapf roots from Burkina Faso

Abstract

The main objective of this study was to determine the chemical composition, antioxidant and antimicrobial properties of the essential oil of Vetiveria nigritana (Benth.) Stapf roots growing in Burkina Faso. The composition of the essential oil was analyzed by GC and GC / MS. DPPH radical scavenging method and FRAP test were used to demonstrate the antioxidant activity of the essential oil. Antimicrobial activity of the essential oil was determined using disk diffusion method and broth microdilution method. The major components of the essential oil of V. nigritana were dehydronigritene, zizanoic acid, preziza-7-(15)-en-3-ol, khusian-2-ol, ziza-6(13)-en-3-beta-ol, prezizaan-15-al and khusimone. The essential oil demonstrated weak radical scavenging power with an IC50 of 28.35±0.58µl and a low reduction capacity. The essential oil showed a relative good inhibitory action against strains of Bacillus, Escherichia coli, Staphylococcus, Clostridium perfringens, Listeria monocytogenes, Micrococcus luteus, Enterococcus faecalis, Candida kefir and Saccharomyces cerevisiae with inhibition diameter ranging from 11.5±0.71 mm to 23.5±0.71 mm. Minimum inhibitory concentrations of the essential oil of V. nigritana ranged from 1% to 8%, minimum bactericidal concentrations from 2% to 4% with minimum fungicidal concentration of 4%. These results suggest that essential oil of V. nigritana roots could be subjected for pharmaceutical drug formulations. Keywords: Vetiveria nigritana, essential oil, antioxidant, antimicrobial