Objective To investigate the effects and mechanisms of melatonin(MT)on improving oocyte quality in mice exposed to benzophenone-3(BP-3).Methods In this study,6～12-week-old female ICR mice were cultured in vitro in M16 culture,0.8 μmol/L BP-3 medium and 1 × 10-7 mol/L MT+0.8 μmol/L BP-3 mixed culture.Female ICR mice were randomly segregated into three groups:control,BP-3,and BMT.The control group received 0.5 mL of purified water,the BP-3 group was administered 0.5 mL of a 0.8 μmol/L BP-3 solution,and the BMT group received 0.5 ml of a combination of 0.8 μmol/L BP-3 and 15 mg/kg MT solution via gavage once daily for four weeks,to facilitate in vivo experimentation.Subsequently,the oocyte maturity rate,transcription levels and protein expression levels of mitochondrial dynamics-related genes Mfn1,Opa1,Fis1 and Drp1,mitochondrial membrane potential and spindle morphology were detected in the three groups to explore the rescue effect of MT on the mitochondria of BP-3-exposed mice.Results Compared to the control group,MT treatment markedly enhanced the transcription and protein levels of the mitochondrial fusion genes Mfn1 and Opa1 in oocytes,while concurrently down-regulating the mRNA and protein levels of the mitochondrial fission genes Fis1 and Drp1.Additionally,the BMT group exhibited significantly lower levels of ROS and abnormal spindle morphology in their oocytes compared to the BP-3 group,yet their mitochondrial membrane potential was notably elevated.Conclusion Physiological concentration of BP-3 exposure was toxic for reproduction,but the addition of appropriate concentrations of MT could significantly improve the mitochondrial dynamics and developmental potential of oocytes in BP-3-exposed mice.

Objective To investigate the protective effects of melatonin(MT)on early embryo in vitro development of mice after exposure to benzophenone-3(BP-3).Methods Fertilized mouse oocytes at the synge-neic stage were cultured in KSOM culture medium,0.8 μmol/L BP-3 culture medium,and 1×10-7 mol/L MT + 0.8 μmol/L BP-3 mixed culture medium,respectively.The rescue effect of MT on the early embryos developmental potential of BP-3-exposed mice in vitro was explored by detecting the blastocyst rate,gene transcription level,protein expression level,and the degree of DNA damage in the three groups of embryos.Results MT improved the developmental potential of mouse embryos exposed to BP-3 in vitro.Compared with the control group,MT treatment significantly increased the protein expression of ATP5A and ATP5B and decreased the DNA damage(P<0.05).Furthermore,the transcription levels of antioxidant gene Gpx1 and pluripotency related genes Pou5f1 and Cdx2 were significantly up-regulated in MT-treated blastocysts,and the expression of pro-apoptotic gene Bax was decreased.Compared with the control group,BP-3 treatment enhanced the signal intensity of γ-H2AX in blastocysts(P<0.05),while adding MT could effectively alleviate DSBs(P<0.05).Conclusion The physiological concentration of BP-3 exposure has reproductive toxicity,but the addition of appropriate con-centration of MT could significantly improve the in vitro developmental potential and quality of BP-3-exposed early embryos.

Objective To investigate the effects and mechanisms of melatonin(MT)on improving oocyte quality in mice exposed to benzophenone-3(BP-3).Methods In this study,6～12-week-old female ICR mice were cultured in vitro in M16 culture,0.8 μmol/L BP-3 medium and 1 × 10-7 mol/L MT+0.8 μmol/L BP-3 mixed culture.Female ICR mice were randomly segregated into three groups:control,BP-3,and BMT.The control group received 0.5 mL of purified water,the BP-3 group was administered 0.5 mL of a 0.8 μmol/L BP-3 solution,and the BMT group received 0.5 ml of a combination of 0.8 μmol/L BP-3 and 15 mg/kg MT solution via gavage once daily for four weeks,to facilitate in vivo experimentation.Subsequently,the oocyte maturity rate,transcription levels and protein expression levels of mitochondrial dynamics-related genes Mfn1,Opa1,Fis1 and Drp1,mitochondrial membrane potential and spindle morphology were detected in the three groups to explore the rescue effect of MT on the mitochondria of BP-3-exposed mice.Results Compared to the control group,MT treatment markedly enhanced the transcription and protein levels of the mitochondrial fusion genes Mfn1 and Opa1 in oocytes,while concurrently down-regulating the mRNA and protein levels of the mitochondrial fission genes Fis1 and Drp1.Additionally,the BMT group exhibited significantly lower levels of ROS and abnormal spindle morphology in their oocytes compared to the BP-3 group,yet their mitochondrial membrane potential was notably elevated.Conclusion Physiological concentration of BP-3 exposure was toxic for reproduction,but the addition of appropriate concentrations of MT could significantly improve the mitochondrial dynamics and developmental potential of oocytes in BP-3-exposed mice.