Sun-drying diminishes the antioxidative potentials of leaves of Eugenia uniflora against formation of thiobarbituric acid reactive substances induced in homogenates of rat brain and liver

Extracts from leaves of Pitanga cherry (Eugenia uniflora) are considered to be effective against many diseases, and are therefore used in popular traditional medicines. In the present study, the antioxidative effect of sun-dried (PCS) and air-dried (PCA) ethanolic extracts of Pitanga cherry leaves were investigated. The antioxidant effects were tested by measuring the ability of both PCS and PCA to inhibit the formation of thiobarbituric acid reactive species (TBARS) induced by prooxidant agents such as iron (11) and sodium nitroprusside (SNP) in rat brain and liver tissues. The results showed that while PCA significantly (P<0.0001) inhibited the formation of TBARS in both liver and brain tissues homogenates, PCS did not. Further investigation reveals that the phenolic content of the PCS was significantly (P<0.0001) lower compared to PCA. Since phenolics in plants largely contributed to the antioxidative potency of plants, we conclude that air-drying should be employed in the preparation of extracts of Pitanga cherry leaves before it is administered empirically as a traditional medicament, and hence this study serves a public awareness to traditional medical practitioners. (C) 2008 Elsevier GmbH. All rights reserved.