Arid zone plants as natural antioxidant agents

Medicinal Plants and Biotechnology Laboratory, Department of Botany, University of Rajasthan, Jaipur-302 004,

Rajasthan, India

E-mail: jainnatpro3@rediffmail.com

Department of Chemistry, University of Rajasthan, Jaipur-302 004, Rajasthan, India

Manuscript received 12 May 2008, accepted 16 September 2008

Methanol and dichloromethane extracts of flowers for total phenolic content along with antioxidant potential were examined using 2,2'-diphenyl-1-picrylhydrazyl radical (DPPH) solution-based chemical assay of 15 medicinally important arid zone plants. The results showed that of all these extracts, highest total phenolic content was observed In Acacia nilotica (58.60 \(\pm\) 0.40 GAE/100 g FW) followed by Tephrosia hamiltonii (52.00 \(\pm\) 0.41 GAE/100 g FW). Likewise, each studied extract demonstrated potential antioxidant activity but the highest activity was recorded In dichloromethane extract of T. hamiltonii (RC₅₀ = 5.5 µg/ml) and in methanol extract of Calotropis procera (RC₅₀ = 4.5 µg/ml). All the arid zone plants selected in this study exhibited stronger antioxidant activity and significantly higher levels of total phenolics, which may prove to be potential natural sources of potent antioxidant and beneficial chemopreventive agents.