Sevin A, Oztaş P, Senen D, Han U, Karaman C, Tarimci N, Kartal M, Erdoğan B
1st Plastic and Reconstructive Surgery Department, Ankara Numune Education and Research Hospital, Ankara, Turkey.
J Eur Acad Dermatol Venereol. 2007 May;21(5):650-6. doi: 10.1111/j.1468-3083.2006.02045.x.
Ultraviolet (UV) radiation causes many acute and chronic conditions such as oedema of the skin, sunburn, immunosuppression, photo-ageing and skin cancer. The use of antioxidants has become of paramount importance in prevention of the damage caused by ultraviolet radiation. Epigallocatechin-3-gallate (EGCG), one of the main components of green tea, has been reported to have anti-inflammatory, antioxidant and anticarcinogenic properties.
The aim of this experimental study was to investigate to what extent EGCG prevented acute skin damage caused by UVA.
The sample contained 2% EGCG, which was prepared in hydrophilic ointment (USP XXIV) as the vehicle. Twenty-four 12-week-old Wistar albino rats are included in the study and divided into four groups, each containing six rats. Group I was formed to be the control group, which was not applied any topical medication or exposed to UV radiation. Group II was formed to observe acute effects of UVA on the skin, Group III was formed to observe effectiveness of topical EGCG on the skin applied 30 min after exposure to UVA, and Group IV was formed to observe topical EGCG applied 30 min before exposure to UVA. All groups were examined for sunburn cells, leucocyte infiltration, dermo-epidermal activity, collagen changes and elastic fibre pathologies on 24 and 72 h. Statistical analysis was performed using spss 11.5, and chi-squared test was used for the evaluation of parameters.
Group IV showed a statistically significant decrease in sunburn cells and dermo-epidermal activation compared with Group II. Group II showed significant increase in all parameters compared with Group I, showing the effects of UV exposure alone, and no difference was detected in Group II and III.
These results show a protective effect of EGCG when applied topically before UVA exposure. No benefit was detected when EGCG was applied after UV exposure.
紫外线（UV）辐射会引发许多急性和慢性病症，如皮肤水肿、晒伤、免疫抑制、光老化和皮肤癌。抗氧化剂的使用在预防紫外线辐射造成的损害方面变得至关重要。表没食子儿茶素-3-没食子酸酯（EGCG）是绿茶的主要成分之一，据报道具有抗炎、抗氧化和抗癌特性。
本实验研究的目的是探究EGCG在多大程度上能预防UVA引起的急性皮肤损伤。
样品含2%的EGCG，以亲水软膏（USP XXIV）作为赋形剂制备。24只12周龄的Wistar白化大鼠纳入研究，分为四组，每组六只。第一组作为对照组，不涂抹任何局部用药，也不暴露于紫外线辐射。第二组用于观察UVA对皮肤的急性影响，第三组用于观察在暴露于UVA 30分钟后涂抹局部EGCG对皮肤的效果，第四组用于观察在暴露于UVA 30分钟前涂抹局部EGCG的效果。在24小时和72小时时，对所有组进行晒伤细胞、白细胞浸润、真皮-表皮活性、胶原蛋白变化和弹性纤维病变检查。使用SPSS 11.5进行统计分析，采用卡方检验评估参数。
与第二组相比，第四组的晒伤细胞和真皮-表皮活化在统计学上有显著降低。与第一组相比，第二组所有参数均显著增加，表明仅紫外线暴露的影响，且第二组和第三组未检测到差异。
这些结果表明，在UVA暴露前局部应用EGCG具有保护作用。在紫外线暴露后应用EGCG未发现益处。
