Melatonin Reverses 10-Hydroxycamptothecin-Induced Apoptosis and Autophagy in Mouse Oocyte

10-Hydroxycamptothecin (HCPT) is a widely used anticancer drug that induces cytotoxicity by triggering the cell apoptotic pathway. Studies have shown that HCPT has harmful effects on normal cells, but whether HCPT affects the development of mouse oocytes in vitro has not been reported. First, this study investigated the development of oocytes exposed to 60 μM HCPT in vitro. In the HCPT-treated group, the first polar body extrusion (PBE) rate of oocytes decreased, spindle morphology was abnormal, DNA double-strand break, oxidative stress level increased, and mitochondrial distribution was abnormal. The apoptosis and autophagy levels of oocytes in the HCPT-treated group were detected by qRT-PCR and western blot. Compared with the control group, the expressions of key regulators of oocyte apoptosis (bax, caspase-3) and autophagy (lc3, beclin, ATG12) pathway were increased in the HCPT-treated group. HCPT treatment induced apoptosis and autophagy in oocytes. Melatonin (MT) can protect cell structure, prevent DNA damage, and reduce the content of peroxides. So we wondered whether MT could ameliorate the harmful effects of mouse oocytes induced by HCPT. Interestingly, the addition of 1 mM MT can protect oocytes from HCPT toxicity to some extent. Compared with the HCPT group, the addition of 1 mM MT increased the PBE ratio of oocytes, decreased ROS levels, and decreased spindle abnormalities and DNA breakage ratio. In summary, these results revealed that HCPT exhibited adverse effects on mouse oocyte maturation and quality, and MT administration alleviated the negative influence of HCPT.