EFFECT OF DEFICIENCY IN MAN 



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Biol. Med., 1941, 47, 26. 



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Hart, Proc. Soc. Exp. Biol. Med., 1943, 62, 7. 



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6. EFFECT OF p-AMINOBENZOIC ACID DEFICffiNCY IN 



MAN 



The possibility that, by analogy with its effects in experimental 

 animals, ;/)-aminobenzoic acid might have a favourable effect in nutri- 

 tional achromotrichia in man was first suggested by B. F. Sieve. ^ 

 Attempts to restore the colour of grey hair in elderly men and women 

 by means of ;/)-aminobenzoic acid were unsuccessful, however. In 

 one experiment, 2 only two out of nineteen subjects showed any im- 

 provement when given ^-aminobenzoic acid together with calcium 

 pantothenate and yeast. In another experiment,^ only three out of 

 eighty-eight cases of achromotrichia given 100 mg. of ;/)-aminobenzoic 

 acid three times daily for ten to twelve weeks showed any tendency 

 to re-pigmentation, and in one of these the pigmentation disappeared 

 again soon after treatment was stopped. Any claims, therefore, that 

 preparations containing ^-aminobenzoic acid are of value in restoring 

 the grey hair of elderly patients to its former colour are completely 

 unjustified, and there is no scientific evidence in support of them. 



It has been claimed * that ointments containing ;/)-aminobenzoic 

 acid protect the skin against sunburn, and that _/)-aminobenzoic acid 

 and local anaesthetics such as procaine derived from it protect the 

 injected area from the erythema action of ultra-violet light when 

 injected intracutaneously. Irradiated solutions of ^-aminobenzoic acid 

 were said to cause inflammation when injected intradermally in man. 



Several workers observed that ^-aminobenzoic acid had a leucopenic 



