Synergistic Antioxidant Action of Oregano, Ajowan and Borage Extracts

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 (88.20/0, 82.3"/0) for
aqueous and elhanolic extracts at 50 ppm concentralion respectively,followed by ajowan (86.9%, 68.4%) and Indian
borage (30.5%, 30.4%). Extracts of oregano and ajowan 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)
of27.7% 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.