Evaluation of Antioxidant Activities of Alpinia galanga (L.) Willd

Abstract

Present research was designed to evaluate the free radical scavenging capacities and antioxidant activities of rhizome extracts of Alpinia galanga prepared in different solvent systems (60% aqueous methanol, 60% aqueous ethanol and distilled water) using different in vitro chemical assays. Antioxidant components such as total phenolic content (TPC), total flavonoid content (TFC) and ascorbic acid contents of the ginger species were screened. Antioxidant assays employed included sulphur free radical reactivity assay, ferric ion reducing power assay, DPPH free radical scavenging capacity assay, hydroxyl radical scavenging assay, nitric oxide scavenging activity assay and hydrogen peroxide scavenging assay. The obtained data reveal that the plant extracts contained significant amount of the observed antioxidant components and also exhibited significant free radical scavenging capacities. Methanol (60%) extract exhibited highest antioxidant activity than other solvents. The polyphenolic constituents of the plant extracts appear to be largely responsible for the radical scavenging capacity. The plant extracts act as promising source of antioxidants, and may be useful for development of nutraceuticals and pharmaceutical drugs.