方法：晶状体上皮细胞传代培养后，分别加入不同浓度褪黑素预处理12h后，加入100 μmol/L H₂O₂继续孵育24h，MTT比色法检测褪黑素对H₂O₂诱导的晶状体上皮细胞活力的影响，流式细胞仪检测细胞凋亡率，比色法检测凋亡相关因子Caspase-3及Caspase-9的活性。

结果：MTT结果显示褪黑素对晶状体上皮细胞活性无影响，该药物可以抑制过氧化氢诱导的细胞活性的下降，流式细胞计数结果显示褪黑素可以抑制过氧化氢诱导的细胞凋亡，此外，褪黑素还可以减少过氧化氢所致晶状体上皮细胞内Caspase-3及Caspase-9的活性，并且，伴随褪黑素作用时间的延长其活性呈下降趋势。

结论：褪黑素可以明显抑制过氧化氢诱导的晶状体上皮细胞的凋亡，从而为寻求有效的防治白内障药物提供可靠的实验依据。

METHODS: Sub-culture human lens epithelial cells preprocessed with different concentrations of melatonin for 12h and then 100 μmol/L H₂O₂ for 24h. The impact of melatonin on H₂O₂-induced lens epithelial cell viability was detected by MTT assay, rate of apoptosis was detected by flow cytometry instrument and activity of apoptosis-related factors, Caspase-3 and Caspase-9, were detected by colorimetric method.

RESULTS: MTT assay showed that melatonin had no effect on the activity of lens epithelial cells, and the drug can inhibit the decrease of H₂O₂-induced cell activity, as well as flow cytometry showed that melatonin can inhibit H₂O₂-induced apoptosis. In addition, melatonin can also reduce H₂O₂-induced Caspase-3 and Caspase-9 activity in lens epithelial cells, and their activity decreased with effect of melatonin along with extending time.

CONCLUSION: Melatonin can obviously inhibit H₂O₂-induced apoptosis of human lens epithelial cells, which provide reliable experimental basis for drug on treatment of cataract.