基金The financial assistance was provided by Department of Biotechnology,Government of India(sanction order no.BT/09/NE/TBP/2010).The authors are thankful to Prof.Anupam Chatterjee of the Department of Biotechnology&Bioinformatics,North-Eastern Hill University for supplying the plant material and to Dr.Nripendranath Mandal,Division of Molecular Medicine,Bose Institute for his kind help in preparation of the plant extract.