Busulfan is used as a chemotherapeutic drug to treat childhood and adult chronic myelogenous leukemia, and as an immunosuppressive agent before bone marrow transplantation. A key side effect of busulfan is the alteration of male reproductive function. Infertility caused by anti-cancer treatments has become a significant concern, but there are currently limited treatments for this condition. Recently, we demonstrated that Gosha-jinki-gan, a traditional Japanese medicine, completely reversed the spermatogenesis defects caused by cancer treatment in mice. Hochu-ekki-to and Hachimi-jio-gan are commonly used to treat male infertility, and Hachimi-jio-gan shares herbal ingredients with Gosha-jinki-gan. Therefore, in the present study, we administered Hachimi-jio-gan and Hochu-ekki-to alone or in combination to mice with severe aspermatogenesis caused by busulfan treatment. We performed testis weight measurements, quantitative histological assessments of the testes and the epididymis, and evaluated sperm counts and morphology. We also assessed the expression of immune mediators and macrophage markers. Treatment with a combination of both the medicines significantly reduced busulfan-induced testicular toxicity when compared to the lone treatment with either medicine. We demonstrated that treatment efficacy was related to a differential impact on testicular inflammation, and that the synergistic effect of co-administration completely reversed the busulfan-induced damage to the reproductive functions.
Keywords: anti-cancer treatment; aspermatogenesis; co-administration; oriental medicine; testicular immunology.