RESUMO
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.
Assuntos
Ácido Elágico/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Proteínas Substratos do Receptor de Insulina/metabolismo , Silibina/farmacologia , Pele/metabolismo , Pele/efeitos da radiação , Animais , Ácido Elágico/administração & dosagem , Ácido Elágico/química , Regulação da Expressão Gênica/efeitos da radiação , Proteínas Substratos do Receptor de Insulina/genética , Estrutura Molecular , Substâncias Protetoras/administração & dosagem , Substâncias Protetoras/farmacologia , Ratos , Silibina/administração & dosagem , Silibina/químicaRESUMO
Insulin Receptor Substrate (IRS) proteins are the main cytoplasmic adaptor molecules involved in transducing extracellular signals from receptors to downstream proteins. This protein family have pivotal roles on maintenance, distribution and regulation of signaling networks. Since IRS1/2 interact with and transmits signals from the receptors of insulin, Insulin Like Growth Factor 1 (IGF1), prolactin, growth hormone (GH), leptin, Vascular Endothelial Growth Factor (VEGF), TrkB, ALK and integrins this promoted scientist to think that IRS1 may have functions in cell proliferation, tumorigenesis and metastasis. Therefore, over the past decade, studies on IRS proteins and their functions in cancer has been increased and these studies provided valuable results claiming the involvement of IRS1/2 in cancer development. In this review, we discuss the function and contributions of IRS1 and IRS2 in development of breast cancer.