Antioxidant capacity of Melampyrum barbatum--weed and medicinal plant.

This study was designed to examine antioxidant and free radical scavenging activities of red and yellow forms of Melampyrum barbatum L. In this study, we report the results concerning flower and leaf antioxidant enzyme activities (superoxide dismutase, catalase, guaiacol peroxidase and glutathione peroxidase), reduced glutathione quantity, flavonoids, photosynthetic pigments and soluble protein contents and quantities of malonyldialdehyde, (*)OH and O(2) (*-) radicals; total antioxidant capacity was determined by FRAP (Ferric Reducing Antioxidant Power) method and scavenger activity by DPPH (1,1-diphenyl-2-pycril-hydrasil radical) method. Lipofuscin 'plant age pigments' were also determined. According to our results, flowers of the red form of M. barbatum exhibited the highest antioxidant capacity.