5alpha-reductase activity in human skin by zinc and Azelaic
British Journal of Dermatology, 1988 Nov, 119(5):627-32.
Stamatiadis, D; Bulteau-Portois, MC;
The effects of zinc sulfate and azelaic acid on 5 alpha-reductase
activity in human skin were studied using an in vitro assay with
1,2[3H]-testosterone as substrate. When added at concentrations
of 3 or 9 mmol/l, zinc was a potent inhibitor of
5-alpha-reductase activity. At high concentrations, zinc could
completely inhibit the enzyme activity. Azelaic acid was also a
potent inhibitor of 5 alpha-reductase; inhibition was detectable
at concentrations as low as 0.2 mmol/l and was complete at 3
mmol/l. An additive effect of the two inhibitors was observed.
Vitamin B6 potentiated the inhibitory effect of zinc, but not of
azelaic acid, suggesting that two different mechanisms are
involved. When the three substances were added together at very
low concentrations which had shown to be ineffective alone, 90%
inhibition of 5 alpha-reductase activity was obtained. If this
inhibition is confirmed in vivo, zinc sulfate combined with
azelaic acid could be an effective agent in the treatment of
androgen related pathology of human skin.