The radical scavenging activity of the extracts was investigated by means of the decolorizing of stable DPPH radical. The highest activity was obtained from acetone extract of 184.36 mg TEAC/g extract followed by the 95% ethanol and ethyl acetate extracts, respectively. The first and last extraction steps of hexane and water gave the lowest activity. Comparison of antioxidant capacity in the seed, flower and husk of areca nut showing the seed extract possessed the higher DPPH and hydroxyl radical scavenging activities and reducing power than other two extract [Zhang et al., 2009].
The reducing power of the extracts was determined by observing its ability to reduce Fe(III) to Fe(II) with the complex with TPTZ. The activity was similar to the DPPH, and the highest reducing capacity was also found in the acetone extract. The extracts were found to have significant difference with each others. Similarly, the lowest value of water and hexane extracts was not statistically different.