Abstract

The objective of this investigation was to evaluate the antioxidant potential of ethanolic extract of the aerial parts of Coleus spicatus. Antioxidant activity of ethanolic extract of C. spicatus was assessed by three different in-vitro model of measuring antioxidant profile; total antioxidant activity, ferric reducing ability of plasma (FRAP) assay and estimation of total flavonoid. Significant total antioxidant activity was found in ethanolic extract of C. spicatus. The IC₅₀ values of the ethanolic extract of C. spicatus and ascorbate were found to be 380 µg/ml and 410 µg/ml, respectively. The ethanolic extract of C. spicatus also showed significant result in FRAP assay method. High flavonoid content was found in ethanolic extract of C. spicatus. The high antioxidant capacity observed for ethanolic extract of C. spicatus suggests that this plant could be used as an additive in the food industry providing good protection against oxidative damage.

Key words: Coleus spicatus, total antioxidant activity, ferric reducing ability of plasma (FRAP) assay, total flavonoids.

Abbreviation

FRAP, Ferric reducing ability of plasma; ROS, reactive oxygen species; TPTZ, 2, 4, 6-tripyridyl-S-triazine; FeCl₃.6H₂0, iron(III) chloride hexahydride; HCl, hydrochloric acid.