DNA-REPAIR ENHANCEMENT BY A COMBINED SUPPLEMENT OF CAROTENOIDS, NICOTINAMIDE, AND ZINC

Four volunteers were involved for 5 weeks of a baseline period, follow ed by 7 weeks of a combined supplementation of nicotinamide, zinc, and carotenoids (Nicoplex). Blood sampling and bioassays were carried out every week during the evaluation period. The supplementation of Nicop lex resulted in statistically significant increased resistance to DNA single-strand breaks induced by H2O2 (DNA retained on filter % from 46 .7 +/- 1.9 to 59.4 +/- 4.3; p < 0.01), increased DNA repair 60 min aft er induction of damage (DNA retained on filter % from 74.6 +/- 4.8 to 88.3 +/- 4.2; p < 0.01), elevated poly (ADP-ribose) polymerase (PARP) activity (p < 0.05), and an increased proliferative response to phytoh emagglutinin (PHA) (p < 0.05) when compared with the levels before sup plementation. However, when the same subjects were supplemented with n icotinamide, zinc, and carotenoids together with another 17 nutrients or minerals, there were no changes in DNA damage, DNA repair, or proli ferative response to PHA, Through the use bf a rat model, DNA repair o f splenocytes 3 h after 12 Gy whole-body irradiation was significantly enhanced in rats supplemented with Nicoplex for 6 weeks (p < 0.05) an d 8 weeks (p < 0.01). Comparison of Nicoplex and its components admini stered separately revealed that there was an additive effect on DNA re pair for both single- and double-strand breaks (both p < 0.05). On the basis of the results, it is hypothesized that the enhanced effect of combined supplement of nicotinamide, zinc, and carotenoids on DNA repa ir depends on their diversified mechanisms of action while multinutrie nt supplementation may compromise the effects by inhibitory interactio ns including uptake and absorption.