ABSTRACT

Daily exposure to ultraviolet (UV) light induces inflammation and tumorigenesis in the skin. Silibinin and ellagic acid are natural products that exhibit anti-inflammatory and anti-tumorigenic properties. Insulin receptor substrate protein 1 (IRS1) is important for skin homeostasis and physiology, but its activity following UV radiation remains unclear. We investigated the effects of ellagic acid and silibinin on IRS1 expression in ultraviolet A (UVA) and ultraviolet B (UVB) irradiated rat skin. Forty-two female Wistar rats were divided randomly into six groups of seven animals. The dorsal skin of rats was exposed to UVA + UVB, then treated with ellagic acid and silibinin by gavage. IRS1 expression in skin tissues was determined by western blot analysis. IRS1 expression increased significantly following treatment with ellagic acid and silibinin in UVA + UVB irradiated skin compared to the UVA + UVB only group. After UVA + UVB treatment, ellagic acid effected greater induction of IRS1 expression than silibinin. Our findings suggest that the photoprotective roles of ellagic acid and silibinin may be due to induction of IRS1 expression in UVA + UVB treated rat skin.

摘要

每天暴露于紫外线（UV）会引起皮肤发炎和肿瘤发生。水飞蓟宾和鞣花酸是天然产品，具有抗炎和抗肿瘤的特性。胰岛素受体底物蛋白1（IRS1）对于皮肤稳态和生理很重要，但其在紫外线辐射后的活性仍不清楚。我们调查了鞣花酸和水飞蓟宾对紫外线A（UVA）和紫外线B（UVB）照射的大鼠皮肤中IRS1表达的影响。将四十二只雌性Wistar大鼠随机分为六组，每组七只动物。将大鼠的背部皮肤暴露于UVA + UVB，然后通过强饲法用鞣花酸和水飞蓟宾处理。通过蛋白质印迹分析确定IRS1在皮肤组织中的表达。与仅UVA + UVB组相比，鞣花酸和水飞蓟宾处理后，经UVA + UVB照射的皮肤中IRS1表达显着增加。在UVA + UVB处理后，鞣花酸比水飞蓟宾对IRS1表达的诱导作用更大。我们的发现表明，鞣花酸和水飞蓟宾的光保护作用可能是由于在UVA + UVB处理的大鼠皮肤中IRS1表达的诱导。