Comparative Antioxidant Properties of Water Extracts from Different Parts of Beefsteak Plant (Perilla frutescens)
HUNG-JU CHOU1, JONG-TAR KUO2 AND EN-SHYH LIN1*
1. Department of Beauty Science, National Taichung Nursing College, Taichung, Taiwan, R.O.C.
2. Department of Biological Science and Technology, China University of Science and Technology, Taipei, Taiwan, R.O.C.
(Received: May 8, 2009; Accepted: November 5, 2009)
ABSTRACT
Water extracts from beefsteak plant stems (BS), leaves (BL), and ripe seeds (BR) were examined for their antioxidant activities and phenolic compounds. Based on superoxide anion radicals scavenging activity, the BS extract (61.8%) is the most effective one followed by BL and BR extract (60.8% and 33.3%, respectively). The antioxidant activity determined by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method revealed that the BS extract had the highest activity on DPPH free radicals (54.8%). In addition, the extracts of BS, BL and BR were effective in reducing capacity and chelating effect on ferrous ions in comparison with the control. Total phenolic compound and flavonoid content of the BS extract was found to be superior to other beefsteak plant extracts. The results indicated that the BS extract of beefsteak plant has effective antioxidant functions, especially in superoxide anion radical and DPPH radical scavenging activities and reducing power. It was of our paramount interest to further identify the specific antioxidant components in BS which may be a new health-care food supplement or functional food for special use in the future.
Key words: beefsteak plant, antioxidant activity, water extract