Spermatogenesis process is sensitive to heat stress because the testicular temperature is 2 to 4 °C lower than the core body temperature. The current study aimed to investigate the effects of iron oxide nanoparticles containing curcumin on spermatogenesis in mice induced by long-term scrotal hyperthermia. In this experimental study, 18 mice were equally divided into the following three groups: control, scrotal hyperthermia, and scrotal hyperthermia + curcumin-loaded iron particles (NPs) (240 μL) (mice were treated for 20 days). Hyperthermia was induced by exposure to the temperature of 43 °C for 20 min every other day for 5 weeks. Afterward, the animals were euthanized; sperm samples were collected for sperm parameters analysis, and testis samples were taken for histopathology experiments, evaluation of serum testosterone level, and RNA extraction in order to examine the expression of c-kit, STRA8 and PCNA genes. Our study showed that curcumin-loaded iron particles could notably increase the volume of testis, length of seminiferous tubules, sperm parameters, and stereological parameters (i.e., spermatogonia, primary spermatocyte, round spermatid, and Leydig cells) thereby increasing serum testosterone level; in addition, TUNEL-positive cells showed a significant decrease in curcumin-loaded iron particle group. Thus, based on the obtained results, the expression of c-kit, STRA8, and PCNA genes was significantly increased in treatment groups by curcumin-loaded iron particles compared with scrotal hyperthermia-induced mice. In conclusion, curcumin-loaded iron particles can be considered an alternative treatment for improving the spermatogenesis process in scrotal hyperthermia-induced mice.
Keywords: Curcumin-loaded iron particles; Long-term scrotal hyperthermia; Spermatogenesis.