Evaluation of the Antioxidant Potential of Various Plant Essential Oils

摘要

The antioxidant activities of extracts from medicinal plant essential oils were evaluated using an aldehyde/carboxylic acid assay. The extracts from basil and thyme inhibited the oxidation of hexanal by 100% at a level of 500 μg/mL over 40 days. Rosemary (58%) and chamomile (44%) extracts exhibited moderate antioxidant activities, whereas cinnamon and lavender extracts did not show any appreciable activity. Clove bud extract inhibited hexanal oxidation by 100% at the levels of 200 and 500 μg/mL. Among three different species, E. polyanthemon showed the strongest antioxidant activity of 100% at the level of 500 μg/mL. Among the essential oils tested, rose essential oil exhibited the highest activity (90%) at the level of 500 μg/mL, followed by ylang (87%), and jasmine (86%). Eugenol, which is one of the major constituents of eucalyptus oil, exhibited potent antioxidative activity. Antioxidants such as eugenol and thymol may play an important role in the pharmaceutical activities of natural plant extracts used for aromatherapy.