Pharmacologyonline 1: 544-551 (2011) Tripathi et al. 544 A 14-DAY SUBCHRONIC GENOTOXICITY STUDY OF NIMESULIDE IN MOUSE BONE MARROW CELLS IN VIVO Rina Tripathi 1 , Dr.S.S.Pancholi 2 , Pankaj Tripathi 3* 1 Department of Pharmacology, Sarvajanik Pharmacy College, Mehsana-384001, Gujarat, India. 2 Department of Quality Assurance, Sree Babaria Institute of Pharmacy, Vadodara-391240, Gujarat, India. 3 Department of Pharmacology, S.K. Patel College of Pharmaceutical Education and Research, Kherva, Mehsana-390001, Gujarat, India. Summary A 14-day subchronic genotoxicity of Nimesulide was evaluated by employing mouse bone marrow chromosomal aberration test. The Nimesulide administered orally for 2 weeks at the rate of 1.5, 2.5, 5 mg/kg body weight in swiss albino mice. The results show decreased mitotic activity in all groups of Nimesulide treatments. Similar results concerning the chromosomal aberrations revealed in all treated animals. However statistically significant genotoxicity was seen only with the higher dose of Nimesulide. The obtained results indicate that 2 weeks continuous treatment of Nimesulide is moderately genotoxic in the bone marrow cells of swiss albino mice. Keywords: Nimesulide, Genotoxicity, Chromosomal aberration, Mitotic index. *Corresponding author: Pankaj Tripathi Department of pharmacology S.K. Patel College of Pharmaceutical Education and Research, Ganpat University, Kherva, Mehsana-390001, Gujarat, India. Tel +91 02762 286082 Fax +91 02762 286082. (M) 919978587678 E-mail: pankaj_pcol@yahoo.co.in