Chemical composition, antioxidant and antimicrobial activity of the essential oil and methanol extract of the Egyptian lemongrass Cymbopogon proximus Stapf.

摘要

The present study was conducted to evaluate the in vitro antimicrobial and antioxidant properties of the essential oil (Eo) and methanol extract from a unique, Egyptian endemic plant, Cymbopogon proximus STAPF. The chemical composition of a hydrodistilled Eo of C. proximus was analyzed by a GC and GC/MS system. A total of 19 constituents representing 95.47% of the oil were identified: piperitone (72.44%), elemol (9.43%), α - eudesmol (4.34%), limonene (2.45%) and β- eudesmol (1.26%) were the main components comprising 88.92% of the oil. The antimicrobial test results showed that the Eo of C. proximus strongly inhibited the growth of the test bacteria studied, except for yeast species while the methanol extract had moderate antibacterial, but no anti-cand/da activity. Bacillus cereus and Salmonella choleraesuis were proven to be the most susceptible against Eo. The exposure time of Eo for complete inhibition of cell viability of B. cereus and S. choleraesuis were found to be 5 % at 10 min and 1% at 10 min, respectively. The antioxidative potential of the samples was evaluated using methods of inhibition of the free radical 2,2-diphenyl-1- picrylhydrazyl (DPPH) system. The methanol extract was able to reduce the stable free radical DPPH with an IC_(60) of 48.66±3.1 μg/ml. The results presented here may suggest that the Eo and extracts of C. proximus possess antimicrobial and antioxidant properties, and therefore, can be used as natural preservative ingredients in food and/or pharmaceuticals.