Abstract: BACKGROUND AND AIM: To study the protective effects of ursolic acid extract from Ledum Pulastre L. against genetic damage. MATERIALS AND METHODS: We used mice with genetic damage caused by cyclophosphamide,(CP), as a model of injury. Through mouse cells of bone marrow PCE micronuclear test, the protective effects of ursolic acid extract on genetic damage was measured. RESULTS: The bone marrow cells-nuclear PCE rates of ursolic acid extract at 1.16,2.30,4.60 g/kg dose were 2.20‰ ±0.37‰,2.00‰ ±0.45‰,1.80‰±0.37‰, respectively. There was no significant difference with the normal group (2.00‰±0.45‰) (P>0.05), but showed a significant difference with positive group (24.00‰±0.71‰)(P<0.01). The bone marrow cells-nuclear PCE rates of ursolic acid at 1.16,2.30,4.60 g/kg dose with added CP were 17.20‰±1.24‰,16.40‰±1.53‰,16.00‰±0.51‰,respectively,significantly different from the positive group(24.00‰±0.71‰)(P<0.05). CONCLUSION: Ursolic acid extract from Ledum Pulastre L. demonstrated protective effects against genetic damage.

Key words: Ledum pulastre L., ursolic acid, genetic damage, cell micronucleus