| abstract |
The deleterious effects of the passage of time on human skin (i.e., chronological aging of human skin) can be prevented and treated with the topical application of a retinoid, preferably retinol. We have found that some of the same pathways (namely the stress-activated pathways, SAPs) activated in photoaging of human skin (i.e., sun-induced premature skin aging) are similarly elevated in the skin of elderly people. We have also found that other pathways (namely the mitogen-activated ERK pathway) is depressed in the same skin. Treatment of chronologically-aged skin with a non-retinoid MMP inhibitor and optionally a retinoid both inhibits degradation of dermal collagen and promotes procollagen synthesis. Biopsied sections from skin of elderly (80+ years old) show that a single treatment can increase epidermal thickness, improve the dermal collagen density, and promote the formation of rete pegs and dermal papillae (see FIG. 13 ), and can decrease the amount of c-Jun and increase the amounts of Types I and III procollagen (see FIG. 18 ). Such benefits are also helpful in preventing bruising, tearing, and ulceration of elderly skin. |