Seité S, Bredoux C, Compan D, Zucchi H, Lombard D, Medaisko C, Fourtanier A
L'Oréal Recherche, 90, rue du Général Roguet, FR-92583 Clichy Cedex, France.
Skin Pharmacol Physiol. 2005 Mar-Apr;18(2):81-7. doi: 10.1159/000083708.
Two double-blind studies versus vehicle were carried out to investigate the effects of a topically applied retinol plus vitamin C combination on epidermal and dermal compartments of aged or photoaged human skin. The two studies were performed on postmenopausal women who were selected for treatment based on the mild level of elastosis of their facial skin. At completion of treatment, skin biopsies were collected and processed for classical histology and immunohistochemistry. In the first study (aged skin), 8 volunteers applied the retinol- and vitamin C-containing preparation on the ventral side of one elbow and the vehicle on the other elbow twice daily for 3 months. After the 3-month treatment we observed histological changes mainly within the epidermis. The stratum corneum was thinner with a compact pattern, whereas the epidermal proliferation increased, resulting in a thickening of the viable epidermis. Moreover, the interdigitation index was increased. In the second study (photoaged skin), 11 volunteers were divided in two groups; one applied the retinol- and vitamin C-containing preparation and the other one the vehicle on their face twice daily for 6 months. Facial skin samples presented histologic hallmarks of photoaging, i.e. accumulation of elastotic material in the papillary dermis. After the 6-month topical treatment, the observed histological changes were mainly concentrated at the dermal level. Both treated and control groups showed the same distribution pattern of type I procollagen, however, the high level of type III procollagen originally observed in photoaged skin was reduced in the retinol- and vitamin C-treated group, resulting in a lower type III-to-type I procollagen ratio. Furthermore, a wide band of eosinophilic material just beneath the epidermis, devoid of oxytalan fibers and forming the 'grenz zone', appeared more frequently and was larger in the retinol- and vitamin C-treated group. In conclusion, our results show that repeated topical application of a preparation containing both retinol and vitamin C is able to reverse, at least in part, skin changes induced by both chronologic aging and photoaging.
开展了两项与赋形剂对照的双盲研究，以调查局部应用视黄醇加维生素C组合对老年或光老化人体皮肤的表皮和真皮层的影响。这两项研究针对的是绝经后女性，她们因面部皮肤弹性组织变性程度较轻而被选入接受治疗。治疗结束时，收集皮肤活检样本并进行处理，用于经典组织学和免疫组织化学分析。在第一项研究（老年皮肤）中，8名志愿者每天两次在一侧肘部腹侧涂抹含视黄醇和维生素C的制剂，另一侧肘部涂抹赋形剂，持续3个月。3个月的治疗后，我们观察到主要在表皮内出现了组织学变化。角质层变薄且呈致密模式，而表皮增殖增加，导致有活力的表皮增厚。此外，指状交叉指数增加。在第二项研究（光老化皮肤）中，11名志愿者被分为两组；一组每天两次在面部涂抹含视黄醇和维生素C的制剂，另一组涂抹赋形剂，持续6个月。面部皮肤样本呈现出光老化的组织学特征，即乳头真皮中弹性组织物质的积累。6个月的局部治疗后，观察到的组织学变化主要集中在真皮层。治疗组和对照组显示出相同的I型前胶原分布模式，然而，在视黄醇和维生素C治疗组中，光老化皮肤中最初观察到的高水平III型前胶原有所降低，导致III型与I型前胶原的比例降低。此外，在视黄醇和维生素C治疗组中，表皮下方一条不含氧化弹力纤维且形成“无细胞区”的嗜酸性物质宽带更频繁出现且更宽。总之，我们的结果表明，重复局部应用含有视黄醇和维生素C的制剂能够至少部分逆转由自然老化和光老化引起的皮肤变化。
