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Sat Mar 31, 2012 5:47 pm  |
| ShastaGirl wrote: |
| DarkMoon wrote: |
Always differing opinions?
Abstract
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.
Copyright © 2005 S. Karger AG, Basel
http://content.karger.com/ProdukteDB/produkte.asp?Doi=83708 |
Any idea what derivative of vitamin C was used in this study? L-AA, MAP, tetra? I couldn't find it without buying the study. Looks like it was sponsored by l'oreal. |
It was L-Ascorbic acid and Retinol (not retinoic acid). L'Oreal did the study for their Reti-C line of products under the Vichy name.
Seité and colleagues (2005) conducted two double-blind vehicle-controlled clinical studies in postmenopausal women to investigate the effects of a topically applied retinol plus vitamin C combination on epidermal and dermal compartments of aged or photoaged skin.
Study 1 involved a 3-month treatment with a combination of retinol (0.07%) and vitamin C (3.5%) applied twice daily in 8 volunteers. After the 3-month treatment, histological changes such as thinning of stratum corneum, thickening of the viable epidermis, and increase in interdigitation index were observed. In the second study, volunteers with photoaged skin were treated for 6-months with retinol (0.04%) and vitamin C (3%) combination twice daily. 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.
Finally, the authors concluded that repeated topical application of a preparation containing both retinol and vitamin C could reverse, at least in part, skin changes induced by both chronological and photoaging.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2699641/
L-ascorbic acid at 3% in combination with 0.04% retinol was formulated in a polyphasic emulsion (Reti-C, Vichy). Histological evaluation (in vivo) showed thickening of the epidermis and after six months a smaller Type III to Type I procollagen ratio—affecting both chronologic aging and photoaging.
http://www.nyscc.org/cosmetiscope/backissues/Cosmetiscope_01.2010_FINAL.pdf |
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Born 1953; Blonde-Blue; Normal skin |
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