表没食子儿茶素没食子酸酯对紫外线辐射后小鼠表皮细胞凋亡的影响

目的：观察表没食子儿茶素没食子酸酯（-）-epigallocatechin-3-gallate，EGCG]脂质体对急、慢性中波紫外线（UVB）辐射后BALB／c小鼠表皮细胞凋亡的影响。方法：EGCG脂质体局部外用于BALB／c小鼠背部皮肤，将小鼠分为5组，分别给予中波紫外线180mJ／cm^2照射1次为急性损伤组：30mJ／cm^2每天照射1次，持续30d，为慢性损伤组。采用末端转移酶介导的缺口末端标记法（TUNEL）检测小鼠表皮中的凋亡细胞。结果：急性损伤组中接受UVB照射的小鼠表皮中大部分细胞发生凋亡，EGCG脂质体未表现出对表皮细胞凋亡的影响；慢性损伤组中照光加药组的凋亡细胞多于其他组，EGCG脂质体表现为促凋亡作用（P〈0．05）。结论：EGCG脂质体不影响急性大剂量UVB辐射所致的表皮细胞凋亡；对慢性低剂量UVB辐射有促凋亡作用。

(-)-epigallocatechin-3-gallate interferes the apoptosis of epidermal cells after UVB irradiation in vivo

Objective: To investigate the influence of (-)-epigallocatechin-3-gallate (EGCG) liposome to the apoptosis of epidermal cells of BALB/c mice irradiated by UVB. Methods: BLAB/c mice were divided into acute and chronic injury groups and treated with EGCG liposome to the back skin of the mice and then irradiated with UVB in dosages of 180 mJ/cm2 for one day and 30 mJ/cm2 once a day for 30 days separately. The apoptotic cells were detected by TUNEL. Results: In the acute injury groups(180 mJ/cm2), most epidermal cells showed apoptosis, EGCG liposome showed no effect on the apoptotic cells. In the chronic injury groups(30 mJ/cm2), the number of apoptotic cells in the UVB plus EGCG liposome group were more than those in other groups. EGCG liposome promoted apoptosis(P<0.05). Conclusions: EGCG liposome showed no effect on apoptosis after acute UVB radiation in high dosage, and it can promote apoptosis after chronic UVB radiation in low dosage.