桑椹花青素粗萃物對人類皮膚纖維母細胞光老化之保護

Abstract

皮膚長時間曝曬於紫外線 (ultraviolet, UV) 中，可能會造成光老化，其主要症狀包括產生皺紋及黑色素沉澱等，其中皺紋的產生與膠原蛋白減少有關。UVA能穿透至皮膚真皮層，刺激真皮纖維細胞內的活性氧物質 (Reactive oxygen species, ROS) 增加，經一連串訊息傳遞路徑，最終抑制膠原蛋白生成並促進基質金屬蛋白酶 (Matrix Metalloproteinase-1, MMP-1) 表現，進而促進膠原蛋白之降解。抗氧化物質能藉由抑制細胞內ROS生成，達到減緩皮膚膠原蛋白流失之保護功效。桑椹 (Morus alba) 是台灣抗氧化活性最高的常見水果之一，富含花青素，有很強的抗氧化功效，能降低細胞內氧化壓力。本研究目的為探討桑椹花青素粗萃物對紫外線造成皮膚光老化之保護功效。桑椹經均質、離心、冷凍乾燥，製得桑椹汁粉末 (mulberry juice powder, MJP)，MJP再經固相萃取管柱分離，凍乾後得桑椹花青素粗萃物 (anthocyanin crude extract from mulberry juice, AEMJ)。將MJP和AEMJ回溶後，測定其花青素含量、酪胺酸酶活性之抑制、及DPPH、ORAC等抗氧化力。結果顯示，AEMJ中花青素含量約為桑椹汁之15倍，清除DPPH能力也由119 μmol TE/gDW增為2506 μmol TE/gDW，而500

Exposure to ultraviolet (UV) radiation may cause skin photoaging, including pigmentation and wrinkling. The latter is relevant to degradation of collagen. UV radiation promotes the generation of reactive oxygen species (ROS) in skin fibroblasts, and therefore induce signal pathways to accelerate the degradation of collagen. Antioxidants protect cells from UV-induced oxidative stress. Mulberry (Morus alba) fruit is rich in anthocyanin with great antioxidative properties. The present study aimed at investigating the protective effect of mulberry juice and anthocyanin crude extract from mulberry on UV-induced photoaging in human skin using fibroblasts as the model. Mulberry fruit were bought from Hualien, Taiwan, homogenized, centrifuged to recover the juice, and lyophilized to obtain mulberry juice powder (MJP). Anthocyanin crude extract from mulberry juice (AEMJ) was separated from MJP by solid phase extraction (SPE). MJP and AEMJ were re-dissolved to determine the anthocyanin content, anti-tyrosinase and antioxidant activities. The anthocyanin content of AEMJ is about 15-fold that of MJP. The DPPH scavenging activity of AEMJ is 2506 μmol TE/gDW, while that of MJP is 119 μmol TE/gDW only. The anti-tyrosinase activity of 500