Catharanthus roseus is a medicinal plant at which its medicinal compounds and alkaloids have been under a great consideration. Environmental pollution affects the quality of pedosphere, hydrosphere, atmosphere, lithosphere and biosphere. Lead has damaging effects to plants, animals and ultimately to human health, which can result from oxidative stress. Thus activities of enzymatic antioxidant and content of some secondary metabolites of plant callus were investigated, under lead pollution. Catharanthus roseus seeds were planted in the vase containing Pearlite. To induce callus, parts of leaves were placed on the solid MS culture media. Calluses were subcultured every three weeks and the after two subculture were treated with different amounts (0, 10 and 50 �M) of lead nitrate for 5 days. Changes in protein profile, the content of total alkaloids, flavonoids, total phenol and enzymatic antioxidant activities were determined. Data were analyzed statistically by ANOVA procedure and p<0.05 was taken at the level of significant. The results showed that oxidative stress, resulted from lead nitrate increased contents of total alkaloids, flavonoids, phenol and enzymatic antioxidants, significantly (p<0.05) in comparison to control. Moreover a polypeptide bond of 99 KD showed increase in the intensity as well as bond with 28 molecular weight declines in the protein profile of the treated cell compared to control.
