Antioxidants are the defense system and redox detoxification is an essential attribute for all aerobic organisms for their survival in highly oxidizing environment. In order to maintain an adequate cellular concentration of ROS and RNS, and also mechanisms to repair oxidative and nitrosative damage the organisms have developed many enzymatic and non-enzymatic antioxidative defense systems. Natural antioxidants are primarily phenolics and flavonoid that may occur in all parts of plants, such as flowers, fruits, vegetables, nuts, seeds, leaves, roots, and barks. The present study was aimed to compare and analyze total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activity of different extracts prepared from leaves and flowers of Moringa oleifera. Extracts were prepared by soxhlet sequential extraction using solvents such as n-hexane, ethyl acetate, dichloromethane, methanol, and water. Antioxidant potential of all the extracts was determined by the DPPH and FRAP assay. The dichloromethane extract of leaves and methanol extract of flowers contains higher levels of total phenolic, total flavonoids, and antioxidant activity compared to other extracts. The observed result suggest that all the extracts might serve as radical scavengers to certain level possibly due to presence of polyphenolic compounds that may have a role in antioxidant activity. Further study is required for isolation, identification and characterization of various antioxidants present in the samples, which may serve as a potential source of natural antioxidants.

Key Words: Antioxidant activity, Moringa oleifera, Total flavonoid content, Total phenolic content