In vitro antioxidant activity of a number of plant essential oils and phytoconstituents

The antioxidant capacity of the synthetic antioxidants BHA, BHT, pyrogallol and alpha-tocopherol, the essential oils from black pepper, clove, geraniu m, melissa, nutmeg, oregano and thyme and 33 phytoconstituents were assesse d in vitro, using an antioxidant assay. All the compounds demonstrated anti oxidant capacity superior to the water soluble alpha-tocopherol analogue Tr olox with the exception of the essential oil melissa and the phytoconstitue nts aromadendrene, myrcene and nerol. Clove, oregano and thyme were excepti onally potent in this assay, comparable with the activities of both BHA and pyrogallol. Eugenol, carvacrol, and thymol similarly demonstrated an equiv alent degree of activity. These phytoconstituents are the major components present in clove, oregano and thyme essential oils, respectively.