Protective effects of an aqueous extract of Protaetia brevitarsis seulensis larvae against radiation‐induced testicular injury in mice

The larvae of Protaetia brevitarsis seulensis have been used as a food ingredient and are known for their nutritional value and anti‐inflammatory properties. However, whether P. brevitarsis seulensis larvae demonstrate protective effects against radiation‐induced testicular injury has not been investigated. In this study, the protective effects of an aqueous extract of P. brevitarsis seulensis larvae (PBE) against radiation‐induced testicular injury were tested. Male C57BL/6 mice were administered PBE (5 or 10 mg/kg) orally for 14 days before exposure to focal pelvic irradiation. Histopathological examinations were conducted at 8 h and 30 d after radiation exposure. PBE pretreatment reduced the radiation‐induced apoptosis of germ cells at 8 h after irradiation and significantly increased testis and epididymis weights relative to those of the irradiated control mice at 30 days. PBE protected against histopathological damage and decreased the radiation‐induced effects on the epithelium height and seminiferous tubule diameter. Furthermore, the extract ameliorated the radiation‐induced morphological abnormalities of sperm cells and improved their motility. It also prevented a decrease in the epididymal sperm count caused by irradiation. Moreover, the extract alleviated the generation of reactive oxygen species, and its antioxidative activity increased in a dose‐dependent manner. Among the six major compounds isolated from PBE, benzoic acid and uridine showed the highest antioxidant activities. These results suggest that PBE protects against radiation‐induced testicular injury via its antioxidative properties. Thus, it has potential clinical applicability as a neoadjuvant therapy for the prevention of testicular damage caused by cancer radiotherapy.