Abstract

In order to find new resources of natural antioxidants, antioxidant activities of 40 medicinal plants associated with prevention and treatment of cardiovascular and cerebrovascular diseases were evaluated using ferric reducing antioxidant power (FRAP) and Trolox equivalent antioxidant capacity (TEAC) assays, respectively, and their total phenolic contents were measured by the Folin-Ciocalteu method. Most of these plants were analyzed for the first time for their antioxidant activities. Generally, these plants had high antioxidant capacities and total phenolic contents. A significant correlation between the FRAP value and the TEAC value suggested that antioxidant components in these plants were capable of reducing oxidants and scavenging free radicals. A high correlation between antioxidant capacity and total phenolic content indicated that phenolic compounds could be the main contributor of the antioxidant activity of these plants. Several plants, such as Sanguisorba offivinalis, Rosa chinensis,Millettia dielsiana, Polygonum cuspidatum, Caesalpinia sappan and Sophora japonica,showed the highest antioxidant activities and total phenolic contents. These plants could be potential rich resources of natural antioxidants and could be developed into functional food or drug for prevention and treatment of diseases caused by oxidative stress.

Key words: Plant, antioxidant activity, phenolic content.