Antioxidant potential and polyphenol content of ten medicinal plants from North Eastern region of India.

Ten ethno-medicinally important plants of North East India were selected to evaluate their in vitro antioxidant activity. In vitro antioxidant activity of the methanolic extract of the leaves of these medicinal plants was tested using two wellestablised methods, DPPH free radical scavenging activity and reducing power assay. Polyphenol content of these medicinal plants was determined by the Folin Ciocalteu method. The methanolic extract of all the plants showed a concentration dependent DPPH free radical scavenging activity. Out of ten medicinal plants, Nyctanthes arbor-tristis, Vinca rosea, Xanthium strumarium, Lawsonia inermis, Solanum indicum, Pongamia pinnata, Jatropha curcas showed higher reducing power. The leaves of all plants possessed good source of polyphenolic compounds which varied between 11 to 56 mg g−1. Present study revealed that these plants are of therapeutic potential due to their high free-radical scavenging activity and may be used in further drug development research.