This study aimed to examine two concentrations of Rosa damascene extract on toxic effect of Zn on the liver of common carp. For this purpose, four treatments with three replicates were designed as following: treatment one as control, treatment 2 exposed to 3 mg/l ZnSO4, and treatments 3 and 4 supplemented with 2.5 and 5 g of R. damascene extract along with exposure to 3 mg/L ZnSO4. After 45 days, the bioaccumulation of Zn and histopathological alternation in the liver, as well as aspartate aminotransferase (AST), alanine transaminase (ALT), triglyceride, cholesterol and albumin were measured. The results showed the highest concentration of Zn in treatment, and its decreasing trend in treatments 3 and 4. The histopathological examinations showed the most alternations in treatment 2, but lower changes in treatment 3 and 4 due to application of R. damascene extract. In addition, those measured biochemical parameters had increased in treatment 2 following exposure to ZnSO4, whereas they had decrease in treatments 3 and 4. These results revealed positive effect of R. damascene extract to decrease toxicity of Zn on the liver of common carp.
