Free Radical Effects -

Tretinion and Ageing Skin

The new knowledge concerns the way that ultraviolet radiation actually causes the damage. Paradoxically, in this case, the treatment came before the explanation. Back in 1986, a paper appeared in the Journal of American Academy of Dermatology entitled, “Tropical Tretinion for photo-aged skin’> this paper recounted how the proportion of sun-damaged to normal skin collagen could be markedly reduced by treatment with the drug Tretinion. This was followed by similar papers in other journals including one in the Journal of the American Medical Association entitled, ‘At last, a medical treatment for skin aging’. Some trails involved large numbers of patients treated with Tretinion over a period of several months. Tretinion is all-trans-retinoic acid and is the active forms of vitamin A in all the tissues of the body except the retina. It is a powerful antioxidant (see p. 24) and is sold in Britain in a 0.05% cream under the trade name of Retinova. Note that taking tretinion is not the same as taking vitamin A

We now know, of course, that ultraviolet light causes production of free radicals and that it is these that do the damage. By the time this became clear, dermatologists already knew that they could partially reverse the effects of solar radiation on the skin by using Tretinion. In a typical trial of this treatment, one side of the face of volunteers was treated with 0.05% tretinoin cream once a day and the other side treated with the cream base without the tretinoin. At the end of 12 weeks, skin thickness, as measured by ultrasound and other methods, had increased by 10% in the areas treated with tretinion.

Other trials of longer periods of treatment showed improvement in skin thickness, in the roughness of the skin and in fine wrinkling, but, as might be expected since much damage had already been done, did not affect sagging, age freckles ( lentigines) or broken veins. The thickening of the outer skin layer, the epidermis, was, in many cases, remarkable, and could be as great as two and three-qaurter times. Almost all the people in the trial suffered some degree of minor inflammation with itching and a feeling of tightness. This side effect settled on stopping the cream applications for a day or two and the treatment could then be safely resumed. These trials make it clear that people whose skin has already been severely damaged by the sun are likely to derive much less benefit from tretinoin treatment than people who have had less exposure to solar radiation. Tretinoin, under the trade name of Retin-A, is also widely used in the tretment of the adolescent skin disease acne, in which it is highly effective. It has been used by well over a million people.