Plant derived antioxidants - Geraniol and camphene protect rat alveolar macrophages against t-BHP induced oxidative stress

Exploration of antioxidants of plant origin and scientific validation of their efficacies has unraveled bioactives from natural sources. In this study, two terpenoids camphene and geraniol were assessed for their cytoprotective and antioxidant potential using t-BHP stressed rat alveolar macrophages. Effect of these test substances along with a known plant derived antioxidant quercetin was seen on cell viability, some oxidative stress markers as well as on mitochondrial membrane potential. Both the test substances geraniol and camphene increased the cell viability significantly as indicated by MTT assay and LDH release assay, during pre-treatment of test compound. Camphene and geraniol showed 29% (P < 0.05) and 45% (P < 0.05) increase in SOD activity, 28% and 120% (P < 0.001) increase in GSH content and restored the mitochondrial membrane potential during pre-treatment as compared to stressed cells. Camphene and geraniol were found to significantly decrease lipid peroxidation, inhibit NO release (83.84% and 64.61%) and ROS generation in the pre-treated cells as compared to stressed cells. The test compounds also showed significant protection against ROS during post-treatment of the test compounds. Results indicate the pharmacological potential of these phytochemicals in lung inflammatory diseases where oxidative stress is a critical control point. (C) 2008 Elsevier Ltd. All rights reserved.