【摘要】 目的　探讨紫外线 A(U VA)对原代培养人皮肤角朊细胞的氧化损伤及防晒化妆品的防护效果。方法　利用原代培养人皮肤角朊细胞 ,采用不同剂量的 UVA照射 ,测定细胞上清液丙二醛 ,细胞内过氧化氢酶和超氧化物歧化酶 ,并对防晒化妆品的防护作用进行评价。结果　 UVA照射剂量从 2 .88J/ cm2到 11.5 2 J/ cm2 ,MDA含量由 2 .5 4μmol/ L增加到 6 .75μmol/ L ,CAT含量由 15 .76 U/ mg(prot)减少至 6 .33U/ mg(prot) ,SOD含量由 2 5 .5 5 NU/ mg(prot)降至2 3.81NU/ mg(prot)。涂抹广谱防晒化妆品后照射同样剂量的 UVA,MDA由 2 .18μmol/ L增至 4.82μmol/ L ,CAT由17.19U/ mg(prot)减少至 10 .35 U/ mg(prot) ,SOD由 2 6 .5 2 NU/ m g(prot)降至 2 4.5 1NU/ mg(prot)。结论　 UVA对人皮肤角朊细胞具有明显的氧化损伤作用 ,本实验条件下的广谱防晒化妆品对细胞具有一定的防护功能。更多还原

【Abstract】 Objective To investigate the oxidative damage of ultraviolet A (UVA) radiation to primary cultured human keratinocytes and the protective effects of sunscreens from UVA Methods The levels of malondialdehyde (MDA) in supernatant and the activities of catalase (CAT) and superoxide dismutase (SOD) in intra keratinocytes were determined among primary cultured human keratinocytes irradiated by UVA radiation at different dosages The protective effects of sunscreens from UVA radiation were evaluated also Results With the dosages of UVA radiation increasing from 2 88 J/cm 2 up to 11 52 J/cm 2,the levels of MDA increased from 2 54 μmol/L to 6 75 μmol/L,the activities of CAT decreased from 15 76 U/mg(prot) down to 6 33 U/mg,the activities of SOD decreased from 25 55 NU/mg(prot) to 23 81 NU/mg(prot) After the primary cultured human keratinocytes were irridiated by UVA radiation with the same dosages as mentioned above through a piece of quartz glass surface of which was smeared by the broad spectrum sunscreens,the levels of MDA increased from 2 18 μmol/L to 4 82 μmol/L,the activities of CAT decreased from 17 19 U/mg(prot) to 10 35 U/mg(prot),the activities of SOD decreased from 26 52 NU/mg(prot) to 24 51 NU/mg(prot) Conclusion UVA radiation could cause significant oxidative damage to human keratinocytes Under the conditions of this study,the broad spectrum sunscreens had certain protective effects on keratinocytes from UVA radiation更多还原