當皮膚暴露於紫外線下，會誘導自由基的大量產生而使皮膚產生光老化之現象。本研究針對大葉欖仁甲醇萃取物 (TCM) 防護人類纖維母細胞經 UVB 及 H2O2 誘導之氧化壓力與老化相關機制的探討。研究結果顯示 TCM 可抑制因 UVB/H2O2 產生的 ROS 及回復細胞存活率。此外，也針對不同的體外抗氧化試驗進行活性評估，TCM 於 DPPH 自由基、超氧陰離子、螯合亞鐵離子、氫氧自由基及過氧化氫之清除能力試驗中， IC50 分別為 8.2 μg/mL、20.7 μg/mL、173.0 μg/mL、458.7 μg/mL 及 44.8 μg/mL，並可抑制 UVB/H2O2 所引起纖維母細胞之 ROS。
再者，TCM 可抑制因 UVB/H2O2 所誘導的 MAP kinase 之訊息傳遞，包括抑制 c-Jun、c-Fos、MMP-1、MMP-3、MMP-9 及 COX-2 的蛋白表現量。此外，於 UVB 照射纖維母細胞的試驗中，顯示 TCM 可促進第一型膠原蛋白增生及總膠原蛋白的分泌；H2O2 誘導纖維母細胞的試驗中，顯示 TCM 可促進 HO-1 的表現。由上述實驗結果顯示大葉欖仁甲醇萃取物具抗氧化、抗老化及抗光老化的能力，因此可用於開發成為抗老化化妝品之潛力。
UVB irradiation induced ROS production caused skin photoaging. The aim of this study was to investigate the protective role of Terminalia catappa L. methanolic extracts (TCM) in human fibroblasts (Hs68) against UVB/H2O2-induced oxidative damage and the possible mechanism. TCM suppressed UVB/H2O2-induced ROS generation and increased Hs68 cell viability. Various in vitro antioxidant assays were employed in this study. The IC50 of DPPH radical scavenging was 8.2 μg/mL, superoxide anion scavenging was 20.7 μg/mL, hydrogen peroxide scavenging was 173.0 μg/mL, feerous chelation was 458.7 μg/mL, and hydroxyl radical scavenging was 44.8 μg/mL.
Moreover, TCM could inhibit UVB/H2O2-induced MAP kinase signaling pathway, resulting in the inhibition of c-Jun, c-Fos, MMP-1, MMP-3, MMP-9 and COX-2 expression. In addition, TCM could restore typeⅠprocollagen expression and total collagen synthesis after UVB-irradiation in fibroblasts. According to our findings, TCM is a potent anti-oxidant, anti-aging and anti-photoaging agent, and it could be the potential anti-aging material of cosmetics.
