THE bold claims made for at least one anti-ageing cream might be true after
all. Dermatologists at the University of Michigan at Ann Arbor tested the
product Renova, which is commonly prescribed by doctors to protect and repair
sun-damaged skin, and found it boosted production of a vital skin component. The
critical ingredient in the cream is all-trans retinoic acid, also made
naturally in the body from vitamin A.
Ultraviolet rays in sunlight are known to damage skin by blocking the
synthesis of collagen鈥攖he key structural protein that gives skin its
strength and resilience. Collagen breakdown is associated with wrinkle
formation. Gary Fisher and his colleagues suspected that all-trans
retinoic acid boosted collagen production. The question was, how?
Tests on 45 white volunteers revealed the potion鈥檚 secrets. Fisher found that
production of procollagen鈥攖he forerunner of collagen鈥攈alted a day
after exposure to UV began, and took a day to return to normal when exposure
ceased (The Journal of Clinical Investigation, vol 106, p 663).
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Further tests on the patients鈥� UV-drenched skin revealed abnormally high
levels of the protein c-Jun, a genetic switch which shuts down the production of
procollagen. Additional tests revealed that UV triggers this build-up.
c-Jun failed to show up in the skin of controls who applied the cream between
12 and 16 hours before exposure. Production of procollagen also remained
normal.
In addition, Fisher鈥檚 earlier research showed that retinoic acid blocks the
build-up of metalloproteinases鈥攅nzymes that break down collagen in
UV-exposed skin.
However, Fisher doubts whether the milder substitute, pure vitamin A, used in
over-the-counter creams is powerful enough to match the benefits of the
prescription drug.
