Gardenia latifolia was extracted with ethanol and aqueous using cold-extraction. To evaluate the antiradical and antioxidant abilities of the extracts, four in vitro test systems were employed, i.e., dpph (1,1,diphenyl-2-picryl hydrazyl), nitric oxide, hydrogen peroxide and reducing power assay. The extracts exhibited outstanding antioxidant activities that were superior to that of standard. The ethanol extract exhibited the most significant antioxidant activities, and cold-extraction under stirring seemed to be the more efficacious method for acquiring the predominant antioxidants. Furthermore, the antioxidant activities and total phenol & flavonoids content of the extracts followed the same order, i.e., there is a good correlation between antioxidant activities and phenolic compounds. The results showed that these extracts, especially the ethanol extract, could be considered as natural antioxidants and may be useful for curing diseases arising from oxidative deterioration.
