2 studies, simalr effect. In any event DHEA looks like it can build a bigger butt, and....,the way it looks, mr. happy can benefit from a topical DHEA solution, oops!
Topical application of 17beta-estradiol increases extracellular matrix protein synthesis by stimulating tgf-Beta signaling in aged human skin in vivo.
Son ED1, Lee JY, Lee S, Kim MS, Lee BG, Chang IS, Chung JH.
Author information
* 1Amorepacific Corp/R&D Center, Gyeonggi-do, Korea.
Abstract
To investigate the effects of topically applied 17beta-estradiol on the expression of extracellular matrix proteins in aged human skin, 17beta-estradiol (0.01%) and its vehicle (70% propylene glycol, 30% ethanol) were applied to aged (68-82 y, eight females and five males) human buttock skin under occlusion for 2 wk (three times per week). Topical 17beta-estradiol was found to increase the expression of type 1 procollagen mRNA and protein significantly in human aged skin in vivo. In addition, metalloproteinase (MMP-1 protein levels were reduced by topical 17beta-estradiol. The expressions of TGF-beta1, TGF-beta type II receptor, and Sma and Mad related (Smad)3 were increased by topical 17 beta-estradiol in aged human skin, and TGF-beta1 neutralizing antibody inhibited 17beta-estradiol-induced procollagen synthesis in cultured fibroblasts. We also found that the expressions of tropoelastin and fibrillin-1 mRNA and protein, and elastic fibers in aged skin were also increased by topical 17beta-estradiol. Topical 17beta-estradiol also increased keratinocyte proliferation and the epidermal thickness in aged human skin. We also observed the same effects of topical 17beta-estradiol in young skin.
In conclusion, our results suggest that topical 17beta-estradiol treatment may improve the cutaneous function of aged human skin by improving the connective tissue and increasing epidermal thickness.
PMID: 15955089 [PubMed - indexed for MEDLINE]
Modulation of collagen metabolism by the topical application of dehydroepiandrosterone to human skin.
Shin MH1, Rhie GE, Park CH, Kim KH, Cho KH, Eun HC, Chung JH.
Author information
* 1Department of Dermatology, Seoul National University College of Medicine and Laboratory of Cutaneous Aging Research, Clinical Research Institute, Seoul National University Hospital, 28 Yungon-dong, Chongno-Gu, Seoul 110-744, Korea.
Abstract
Dehydroepiandrosterone (DHEA) and its sulfate conjugate (DHEA-S) are the most abundantly produced human adrenal steroids to be reduced with age. DHEA may be related to the process of skin aging through the regulation and degradation of extracelluar matrix protein. In this study, we demonstrate that DHEA can increase procollagen synthesis and inhibit collagen degradation by decreasing matrix metalloproteinases (MMP)-1 synthesis and increasing tisuue inhibitor of matrix metalloprotease (TIMP-1) production in cultured dermal fibroblasts. DHEA was found to inhibit ultraviolet (UV)-induced MMP-1 production and the UV-induced decrease of procollagen synthesis, probably due to the inhibition of UV-induced AP-1 activity.
DHEA (5%) in ethanol:olive oil (1:2) was topically applied to buttock skin of volunteers 12 times over 4 weeks, and was found to significantly increase the expression of procollagen alpha1(I) mRNA and protein in both aged and young skin. On the other hand, topical DHEA significantly decreased the basal expression of MMP-1 mRNA and protein, but increased the expression of TIMP-1 protein in aged skin. We also found that DHEA induced the expressions of transforming growth factor-beta1 and connective tissue growth factor mRNA in cultured fibroblasts and aged skin, which may play a role in the DHEA-induced changes of procollagen and MMP-1 expression. Our results suggest the possibility of using DHEA as an anti-skin aging agent.
(Source-cantstopeating, ray peat forum)