Antioxidant Activity and Phenolic content of Coleus blumei Benth. (LAMIACEAE)

Abstract

This purpose of this study was to select which among the factors temperature, boiling repetition, and concentration of sample are relevant in the boiling extraction to preserve antioxidants and phenol content in Coleus blumei Benth. (LAMIACEAE) (Malay: ati-ati). Fresh plants were boiled at 45oC for one hour. Then, the decoction was filtered and water was added again for subsequent boiling at the same temperature and time duration, and this process was repeated six times with the same sample. The antioxidants content of the extracted samples were measured on the basis of scavenging activity of the stable 1,1- diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay. Absorbance at 517 nm was determined after 30 min, and the percent inhibition activity was then calculated. Total phenols (TP) concentrations were measured using the Folin-Ciocalteu assay. The absorbance was measured at 760 nm using a UV spectrophotometer after 30 minutes of mixture. Results were expressed as gallic acid equivalents (GAE)/100 g dry weight. Results showed that the antioxidant activities and total phenols content of Coleus blumei from first boiling were significantly higher (p < 0.05) than those in the second to sixth boiling. The temperature observed (45oC) was found to be practicable to preserve the integrity of possible activity of extracted compounds.