Melatonin ameliorates paclitaxel‐induced mice spermatogenesis and fertility defects

Chemotherapeutic drug of paclitaxel (PTX) has been shown to cause reproductive toxicity thus affecting male fertility, but its underlying molecular basis is unclear. Melatonin (MLT) can mitigate the reproductive damage caused by certain chemotherapy drugs. In this study, we aimed to identify impact of PTX on the main biological processes and protective effect of MLT on reproductive damage caused by PTX. Mice exposed to PTX mainly impaired spermatogenesis, such as decreased sperm counts, reduced sperm motility and increased abnormal sperm. Decreased expressions of germ cell proliferation‐associated protein PCNA and meiosis‐related protein SYCP3 induced by PTX were determined by Western blot, while MLT ameliorated this effect and increased the expressions of PCNA, SYCP3, DMC1, STRA8 and fertility‐related protein of HSPA2, resulting in significantly improved spermatogenesis and sperm quality levels. In vitro fertilization experiment showed that PTX significantly decreased blastocyst formation rates, which can be improved by MLT administration, but not two‐cell development rates. Taken together, this work demonstrated PTX can adversely affect germ cell proliferation and meiosis, which ultimately influence sperm quality and male fertility, and highlighted the protective ability of MLT on ameliorating the side effects of PTX, especially on sperm quality. The results provide information to further the study on the molecular mechanism of PTX's effects on male reproduction and the protective mechanism of MLT.