Radical scavenging activity (RSA), antioxidant activity (AA), reducing power, total polyphenol (TP) and flavonoid contents (TFC) of oregano (Oreganum vulgare spp.), ajowan (Trachyspermum ammi) and Indian borage (Plectranthus amboinicus) extracts were evaluated. Oregano exhibited maximum radical scavenging activity (88.2%, 82.3%) for aqueous and ethanolic extracts at 50 ppm concentration respectively, followed by ajowan (86.9%, 68.4%) and Indian borage (30.5%, 30.4%). Extracts of oregano and

more »

... an showed better antioxidant activity and reducing power than that of Indian borage. Aqueous extracts of oregano had highest TP (Gallic acid equivalents) and TFC (Catechin equivalents) of 27.7% and 50.6% respectively compared to ajowan (6.7%, 24.4%) and Indian borage (4.2%, 5.5%). Synergistic studies showed that the addition of oregano extract appreciably enhanced the RSA of ajowan and Indian borage extracts even at 50 ppm concentration.