Evaluation of the Antioxidant Activity of Extracts and Active Principles of Commonly Consumed Indian Spices.
J Environ Pathol Toxicol Oncol. 2016 ;35(4):299-315. PMID: 27992311
Accumulating evidence suggests that free radical reactions play a key part in the development of degenerative diseases and that an antioxidant-rich diet is a major defense against these free radical reactions. In this study, we explore comparative antioxidant capacities of extracts of some commonly used in Indian spices (anise, cardamom, Ceylon cinnamon, and clove) along with their purified components (anethole, eucalyptol, cinnamaldehyde, and eugenol, respectively). Eugenol shows the highest 1,1-diphenyl-2-picrylhydrazyl, hydroxyl, and superoxide scavenging and reducing power activity in terms of weight; however, this was not found when compared in terms of equivalence. Extracts of the other three spices were found to be more potent antioxidants than their corresponding active components. Interestingly, clove extract, despite possessing the highest phenol and flavonoid content, is not the most potent radical scavenger. At low concentrations, both the crude extracts and their purified components (except for anethole and eugenol) have low hemolytic activity, but at higher concentrations purified components are more toxic than their respective crude extract. This study suggests that spices as a whole are more potent antioxidants than their purified active components, perhaps reflecting the synergism among different phytochemicals present in spice extracts.