Division of Pharmaceutical Technology, Defence Research Laboratory, Tezpur 784001, Assam, India; Department of Pharmaceutical Sciences, Dibrugarh University, Dibrugarh 784001, Assam, India.
Department of Pharmaceutical Sciences, Dibrugarh University, Dibrugarh 784001, Assam, India.
Eur J Pharm Sci. 2019 Jan 15;127:261-275. doi: 10.1016/j.ejps.2018.11.004. Epub 2018 Nov 9.
The presence of 40-50% more UV radiation in high altitude areas renders the plethora of sunscreen products available in the market virtually ineffective. In this light of event, four US FDA approved UV filters were combined with melatonin and pumpkin seed oil to produce a broad spectrum sunscreen cream, which is envisaged to provide optimum sunprotection along with enhanced antioxidant activity. The objective of this study is to evaluate the protective effect of the sunscreen cream against UV radiation-induced skin photoaging in adult Wistar albino rats and identify its possible underlying mechanism. Wistar rats were exposed to broad spectrum UV radiation for 28 days. The test group received the sunscreen formulation dermally every day prior to UV radiation. The effects of the formulation against UV induced symptoms; viz. skin thickness and edema, in vivo antioxidant activities, inflammatory cytokines, collagen content, histopathological examination and expression of specific genes established the protective activity of the formulation. The test formulation was able to mitigate the harmful effects of UV radiation by increasing in vivo SOD, GSH-Px, CAT and collagen levels; decreasing skin edema, skin thickness and cytokines like IL-6, IL-1β, TNF-α and TGF-β1. UV radiation induced changes in histological architecture and arrangement of collagen and elastin fibers were also prevented by the test formulation. Finally, the formulation was able to regulate the expression of COL3A1, COX-2, bFGF, VEGF-C, Smad2, Smad4, Smad7 genes which induced significant photoprotective activity. The sunscreen formulation ameliorated UV induced photoaging by preventing oxidative collagen degradation and augmentation of TGF-β-Smad-mediated collagen production.
高海拔地区的紫外线辐射比一般地区多 40-50%，这使得市场上现有的大量防晒霜几乎失去了效果。有鉴于此，我们将四种获得美国食品和药物管理局批准的紫外线滤光剂与褪黑素和南瓜籽油结合起来，制成了一种广谱防晒霜，旨在提供最佳的防晒效果，并增强抗氧化活性。本研究的目的是评估防晒霜对成年 Wistar 白化大鼠紫外线辐射引起的皮肤光老化的保护作用，并确定其可能的作用机制。Wistar 大鼠接受广谱紫外线辐射 28 天。实验组在每天接受紫外线辐射前将防晒霜配方涂于皮肤。配方对紫外线引起的症状（即皮肤厚度和水肿）的影响、体内抗氧化活性、炎性细胞因子、胶原蛋白含量、组织病理学检查和特定基因的表达，确定了配方的保护活性。该测试配方通过增加体内 SOD、GSH-Px、CAT 和胶原蛋白水平，减少皮肤水肿、皮肤厚度和细胞因子（如 IL-6、IL-1β、TNF-α 和 TGF-β1），减轻了紫外线辐射的有害影响。测试配方还防止了紫外线诱导的组织学结构和胶原蛋白及弹性纤维排列的变化。最后，该配方能够调节 COL3A1、COX-2、bFGF、VEGF-C、Smad2、Smad4、Smad7 等基因的表达，这些基因诱导了显著的光保护活性。防晒霜配方通过防止氧化胶原蛋白降解和增强 TGF-β-Smad 介导的胶原蛋白产生，改善了由紫外线引起的光老化。
