Determination of Phenolic Content and Antioxidant Potential of Ethanol Extract of Three Species of Alpinia

The present study aims to investigate hither to unknown antioxidant activity of ethanol extracts of three species of Alpinia. Alpinia galanga (L.) Willd. commonly called as Rasna, Greater galangal or Kulinjan is a medicinally important rhizome used in Indian traditional system of medicine to cure a number of ailments. Due to the high demand for the rhizome of A. galanga traders are now substituting it with rhizomes of A. calcarata and A. officinarum. Antioxidant activity of ethanol extracts was studied by means of various assays including 1,1-diphenyl 2-picryl hydrazyl, -Carotene/linoleic acid bleaching and trolox equivalent antioxidant capacity (TEAC). Total phenolic content in each extract was determined with folin-ciocalteu reagent. The trend of phenol content was as: A. galanga (202.56± 0.36 mg/g) > A. officinarum (185.77 ± 0.71 mg/g) > A. calcarata (167.31 ± 0.44 mg/g). Ethanol extracts of A. galanga, having high percentage of phenol content showed potent in vitro antioxidant activity followed by moderate activity of ethanol extracts of A. officinarum and A. calcarata.