Antioxidant activity of the medicinal plant Coleus forskohlii Briq.
Antioxidant status of different parts of Coleus forskohlii including roots, stem, leaves and tubers was analyzed. For the enzymatic antioxidant properties, the activities of superoxide dismutase, peroxidase, polyphenol oxidase and catalase were significantly higher (P < 0.05) in tubers than in the leaves, roots and stem. Among the non-enzymatic antioxidants, except for the chlorophyll and lycopene content, the reducing power and chelating abilities on Fe2+, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity, total phenol, flavonoids and β-carotene were significantly higher (P < 0.05) in tubers than in the leaves, roots and stem, respectively. The tubers possessed significantly rich sources of both enzymatic and non-enzymatic antioxidants besides their medicinal properties.
Key words: Coleus forskohlii, roots, stem, leaves, tubers, enzymatic antioxidants, non enzymatic antioxidants.