324ANTIPROLIFERATIVE EFFECT OF ZOLEDRONIC ACID IN VARIOUS HUMAN CANCER CELL LINESBisphosphonates are most competent agents which inhibit osteoclast-mediated bone resorption and tumor induced osteolysis and has become an integral part in the treatment of benign and malignant bone diseases. Bisphosphonates has been discovered 3 decades ago, newer drugs like Zoledronic are nitrogen containing bisphosphonates third generation bisphosphonates have either an aliphatic or a heterocyclic side chain containing one or two nitrogen atoms. Zoledronic acid has got additional properties like antiproliferative and apoptotic effects on human breast cancer cell lines (MCF7) in a dose dependent manner. MTT cell viability Assay is effective in analyzing the antiproliferative effect of bisphosphonates in various human cancer cell lines at various concentrations. Human colon cancer cell lines (COLO 205, HCT 116) have shown better inhibition in MTT Cell proliferation assay by Zoledronic acid, a third generation Nitrogen-containing bisphosphonates (N-BPs). so further in vivo studies are required to exploit fully the antitumor potential capabilities of Nitrogen-containing bisphosphonates (N-BPs).dr.seeni23@gmail.comResearch4122013Zoledronic acid,MTT assays,Antiproliferative,Human cancer cell lines, Immunomodulatory effectsSrinivasan V,Seetha Lakshmi S,Durairajan PDepartment of Pharmacology, Sri Ramachandra Medical College & Research Institute, Sri Ramachandra University, Porur, Chennai-600116, Tamil Nadu, India.,Department of Pharmacology, Sri Ramachandra Medical College & Research Institute, Sri Ramachandra University, Porur, Chennai-600116, Tamil Nadu, India.,Department of Pharmacology, Sri Ramachandra Medical College & Research Institute, Sri Ramachandra University, Porur, Chennai-600116, Tamil Nadu, India.