Background: Doxorubicin is one of the most commonly used anticancer drugs. The purpose of this study was to investigate the protective effect of hydroalcoholic extract of Carob (Ceratonia Siliqua) on testicular tissue in adult rats treated with doxorubicin.

Materials and Methods: In this experimental study, 56 adult male Wistar rats were used in 8 groups of seven. The control group received only ordinary water and food. The sham group received distilled water at a dose of 3 mg / kg by intraperitoneal injection. The sham group 1 received dose of doxorubicin (3mg / kg) once weekly for 4 weeks intraperitoneally. The sham group 2 group received (600 mg / kg) maximum dose of hydroalcoholic extract of Carob (Ceratonia Siliqua)  for 48 days by  gavage method. Experimental groups 1, 2 and 3 received doxorubicin with  3 mg/kg once weekly for 4 weeks intraperitoneally and 150, 300 and 600 mg / kg  of hydroalcoholic extract of Carob (Ceratonia Siliqua) for 48 days with gavage  method. Hematoxylin-eosin staining method was used to test the testicular tissue.

Results: The mean body weight, number of spermatogonial cells, spermatocyte count, spermatocyte count and number of leydig cells in the experimental group receiving doxorubicin and 300 mg / kg dose of hydroalcoholic extract of Carob (Ceratonia Siliqua) increased significantly compared to the group receiving doxorubicin. In experimental groups receiving doxorubicin and 150 and 600 mg / kg doses of  hydroalcoholic extracts of Carob (Ceratonia Siliqua), the mean number of spermatogonia, spermatocyte, spermatid and leydig cells decreased significantly compared to control and sham groups (P <0.05). Histologic studies also showed that the amount of  shrinkage  in testicular tissue in the experimental group receiving doxorubicin and 300 mg / kg dose of hydroalcoholic extract of Carob (Ceratonia Siliqua) , as compared with the group receiving doxorubicin, was decreased, which indicates the effect of this dose on the recovery of testicular tissue.

Conclusion: Hydroalcoholic extract of 300 mg / kg dose of Carob (Ceratonia Siliqua) has a protective effect on spermatogenesis poisoning  induced by doxorubicin.