紫外線A可能造成自由基增加，引起皮膚膠原蛋白受傷，被認為是引起皮膚光老化的原因。茄紅素(lycopene)為天然脂溶性紅色色素的類胡蘿蔔素；文獻指出茄紅素具有抗氧化作用，而且最近研究亦發現茄紅素可應用於皮膚保護的作用，包含對膠原蛋白含量的影響與抗紫外線傷害。但對Rhodobacter sphaeroide改良菌株生產之類茄紅素應用於皮膚保護功效瞭解甚少。目前茄紅素的來源除了透過蔬果可獲得外，也可透過光合成菌來生成茄紅素，但市售價格仍然偏高。本研究利用Rhodobacter sphaeroide改良菌株除了具有可大量生產類茄紅素的特性，亦可使類茄紅素取得容易且成本降低，同時也可應用於皮膚保護的相關研究，觀察評估Rhodobacter sphaeroide改良菌株生產之類茄紅素對皮膚膠原蛋白含量與抗紫外線傷害作用的影響。實驗以MTT方法測定人類纖維母細胞(Hs68 cells)細胞存活率；以西方墨點法及明膠蛋白酵素電泳法來探討類茄紅素與茄紅素對第I型膠原蛋白 (type I procollagen)、基質金屬蛋白酶-1 (matrix metalloproteinase-1, MMP-1)及基質金屬蛋白酶-2 (matrix metalloproteinase-2, MMP-2)蛋白表現的影響；另一方面，將Hs68細胞先經紫外線A照射，再加入類茄紅素與茄紅素進行培養，觀察其type I procollagen及MMP-1蛋白表現情形。結果發現類茄紅素對Hs68細胞的毒性明顯地較茄紅素小(843% vs. 682%; 1 μM lycopene-like vs. 1 μM lycopene)。第I型膠原蛋白表現量與類茄紅素劑量呈正相關。而類茄紅素對紫外線A誘導MMP-1及MMP-2蛋白表現亦具有顯著抑制作用(p<0.05)。根據我們實驗結果發現，類茄紅素可能經由抑制MMP-1蛋白表現而達到增加皮膚第I型膠原蛋白，並且可降低紫外線A對細胞的老化傷害。因此推測Rhodobacter sphaeroide改良菌株生產之類茄紅素，可能具有降低皮膚老化及紫外線傷害的作用，可應用於皮膚保護相關產品的開發。 Ultraviolet A (UVA) is a main cause to evoke photoaging by increasing free radical production and collagen damage. Lycopene, one member of carotenoids families, is a nature liposoluble red pigment. The related studies suggest that lycopene has effective on antioxidation, recent studies had found that the influences of lycopene on skin protection, such as the effect of lycopene on expressions of collagen and UVA-induced injury. However, there is less attention to investigate the influences of lycopene-like from transformant Rhodobacter sphaeroide on skin protection. The sources of lycopene can be obtained from fruits and vegetables. Additionally, many reports indicated that lycopene could be also produced from some photosynthetic bacteria, but the selling price of lycopene is still expensive. The present study utilizes the characteristic of transformed Rhodobacter sphaeroide that can be produced on large scale to obtain not only lycopene-like smoothly but also decrease the cost. We speculate that lycopene-like may be worth to researching the new efficiency in application of skin protective field, especially in the effect of lycopene on expressions of collagen and UVA-induced injury. The effects of lycopene-like on the cell viability of human fibroblast (Hs68 cells) were evaluated by method of MTT assay. We observe the influence of lycopene-like on type I procollagen and matrix metalloproteinase (MMP-1 and MMP-2) by western blot analysis and gelatin zymography. On the other hand, we also evaluated expression of type I procollagen and MMP-1 in Hs68 cells incubated with lycopene-like or lycopene after pretreatment with UVA radiation. It was found that lycopene-like had only weak effects on cell cytotoxicity at 20 M, and the effect was equivalent to the effect of 0.1 M lycopene (843% vs. 682%; 1 μM lycopene-like vs. 1 μM lycopene). Incubation with lycopene-like led to dose-dependent increased on the effects of type I procollagen. Effect on UVA-induced expression of MMP-1 and MMP-2 were significantly reduced on incubation with lycopene-like. Our findings obtain that the lycopene-like may ameliorate the UVA irradiation-induced type I procollagen decrease via mediated with the MMP-1 expression, and thereby lead to increase the collagen expression. Therefore, lycopene-like from transformant Rhodobacter sphaeroide may have great potential to further develop products and apply on skin anti-aging and anti-ultraviolet-induced injury efficacies.
