One of the most well-known side effects of anticancer drugs is the disruption of spermatogenesis. One of the most important causes of infertility in men is impaired spermatogenesis. Busulfan is a cytotoxic alkylating agent and belongs to the alkyl sulfonate group. This agent causes DNA damage by cross-linking with DNA. It kills spermatogonial stem cells. The use of healthy antioxidants can reduce the side effects of alkylating agents. In this study, we measured the protective effect of curcumin on testicular tissue of mice treated with busulfan by measuring BAX expression as an apoptotic inducer and Bcl2 as an apoptotic inhibitor. The expression levels of the two apoptotic regulatory genes Bax and Bcl-2 were evaluated by realtime PCR in four groups of mice (control, treatment with busulfan, treatment with curcumin, and treatment with busulfan + curcumin). It was observed in the busulfan group that bcl2 expression decreased, and Bax increased significantly, and the busulfan + curcumin group showed the opposite effect. Curcumin can be beneficial as a dietary supplement in cancer patients treated with drugs such as busulfan.