Mantena Sudheer K, Katiyar Santosh K
Department of Dermatology, University of Alabama at Birmingham, Volker Hall 557, 1670 University Boulevard, P.O. Box 202, Birmingham, AL 35294, USA.
Free Radic Biol Med. 2006 May 1;40(9):1603-14. doi: 10.1016/j.freeradbiomed.2005.12.032. Epub 2006 Jan 26.
Solar ultraviolet (UV) radiation-induced oxidative stress has been implicated in various skin diseases. Here, we report the photoprotective effect of grape seed proanthocyanidins (GSPs) on UV-induced oxidative stress and activation of mitogen-activated protein kinase (MAPK) and NF-kappaB signaling pathways using normal human epidermal keratinocytes (NHEK). Treatment of NHEK with GSPs inhibited UVB-induced hydrogen peroxide (H2O2), lipid peroxidation, protein oxidation, and DNA damage in NHEK and scavenged hydroxyl radicals and superoxide anions in a cell-free system. GSPs also inhibited UVB-induced depletion of antioxidant defense components, such as glutathione peroxidase, catalase, superoxide dismutase, and glutathione. As UV-induced oxidative stress mediates activation of MAPK and NF-kappaB signaling pathways, we determined the effects of GSPs on these pathways. Treatment of NHEK with GSPs inhibited UVB-induced phosphorylation of ERK1/2, JNK, and p38 proteins of the MAPK family at the various time points studied. As UV-induced H2O2 plays a major role in activation of MAPK proteins, NHEK were treated with H2O2 with or without GSPs and other known antioxidants, viz. (-)-epigallocatechin-3-gallate, silymarin, ascorbic acid, and N-acetylcysteine. It was observed that H2O2-induced phosphorylation of ERK1/2, JNK, and p38 was decreased by these antioxidants. Under identical conditions, GSPs also inhibited UVB-induced activation of NF-kappaB/p65, which was mediated through inhibition of degradation and activation of IkappaBalpha and IKKalpha, respectively. Together, these results suggest that GSPs could be useful in the attenuation of UV-radiation-induced oxidative stress-mediated skin diseases in human skin.
太阳紫外线（UV）辐射诱导的氧化应激与多种皮肤疾病有关。在此，我们报道了葡萄籽原花青素（GSPs）对紫外线诱导的氧化应激以及丝裂原活化蛋白激酶（MAPK）和核因子κB信号通路激活的光保护作用，实验使用了正常人表皮角质形成细胞（NHEK）。用GSPs处理NHEK可抑制紫外线B（UVB）诱导的NHEK中过氧化氢（H2O2）生成、脂质过氧化、蛋白质氧化和DNA损伤，并在无细胞体系中清除羟自由基和超氧阴离子。GSPs还抑制UVB诱导的抗氧化防御成分（如谷胱甘肽过氧化物酶、过氧化氢酶、超氧化物歧化酶和谷胱甘肽）的消耗。由于紫外线诱导的氧化应激介导MAPK和核因子κB信号通路的激活，我们测定了GSPs对这些通路的影响。在研究的各个时间点，用GSPs处理NHEK可抑制UVB诱导的MAPK家族ERK1/2、JNK和p38蛋白的磷酸化。由于紫外线诱导的H2O2在MAPK蛋白激活中起主要作用，用H2O2处理NHEK，同时加入或不加入GSPs以及其他已知抗氧化剂，即（-）-表没食子儿茶素-3-没食子酸酯、水飞蓟宾、抗坏血酸和N-乙酰半胱氨酸。结果发现，这些抗氧化剂可降低H2O2诱导的ERK1/2、JNK和p38的磷酸化。在相同条件下，GSPs还抑制UVB诱导的核因子κB/p65激活，这分别是通过抑制IκBα的降解和IKKα的激活介导的。总之，这些结果表明GSPs可能有助于减轻紫外线辐射诱导的氧化应激介导的人类皮肤疾病。
