Department of Dermatology, First Affiliated Hospital of Dalian Medical University, No. 222 Zhongshan Road, Dalian 116011, Liaoning, China.
Phytother Res. 2010 Mar;24(3):352-9. doi: 10.1002/ptr.2943.
The chemoprotective effect of hydroxytyrosol (HT) against UVB-induced DNA damage was investigated in a human skin keratinocyte cell line, HaCaT. The comet assay was used to monitor DNA strand breaks. Intracellular reactive oxygen species (ROS) formation was measured by flow cytometry using 2,7-dichlorofluorescein diacetate (DCFH-DA). The levels of oxidatively generated damage to DNA were estimated by immunocytochemistry analysis of 8-hydroxy-2'-deoxyguanosine (8-OHdG). The protein expression of p53 and NF-kappaB was estimated by western blotting. The results showed that HT significantly reduced the DNA strand breaks caused by UVB. It was also found that HT reduced intracellular ROS formation and 8-OHdG level caused by UVB. Furthermore, HT attenuated the expression of p53 and NF-kappaB in a concentration-dependent manner. These results strongly suggest that HT has a significant protective ability against UVB-induced DNA damage and that oxidative stress plays an important part in it.
羟基酪醇（HT）对 UVB 诱导的 DNA 损伤的化学保护作用在人皮肤角质形成细胞系 HaCaT 中进行了研究。彗星试验用于监测 DNA 链断裂。通过使用 2,7-二氯荧光素二乙酸酯（DCFH-DA）的流式细胞术测量细胞内活性氧（ROS）的形成。通过免疫细胞化学分析 8-羟基-2'-脱氧鸟苷（8-OHdG）来估计氧化产生的 DNA 损伤水平。通过蛋白质印迹法评估 p53 和 NF-κB 的蛋白表达。结果表明，HT 可显著减少 UVB 引起的 DNA 链断裂。还发现 HT 减少了由 UVB 引起的细胞内 ROS 形成和 8-OHdG 水平。此外，HT 以浓度依赖的方式减弱了 p53 和 NF-κB 的表达。这些结果强烈表明 HT 对 UVB 诱导的 DNA 损伤具有显著的保护能力，并且氧化应激在此过程中起重要作用。
