Antioxidant and antifungal activities of essential oil of Alpinia calcarata Roscoe rhizomes.

Antioxidant and antifungal activity were determined for the essential oil of Alpinia calcarata Roscoe (Zingiberaceae) rhizomes. Its antioxidant properties were investigated by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay and thiobarbituric acid reactive substances (TBARS) assay. Butylated hydroxy toluene (BHT) and vitamin E served as positive controls. Antifungal activities were investigated against crop pathogens Curvularia spp. and Colletorichum spp. using the agar plate method. Fifty percent effective concentration (EC(50)) and % antioxidant index of the essential oil were 45 ± 0.4 and 16.1 ± 0.2 for DPPH and TBARS assays, respectively. The degree of, the essential oil's inhibition of the growth of crop pathogens Curvularia spp. and Colletorichum spp. varied with time period its effects were higher than greater than for the positive control, daconil. In conclusion, the essential oil of A. calcarata rhizomes possess moderate antioxidant property and promising antifungal activity.