Nicotinic acid supplementation: effects on niacin status, cytogenetic damage, and poly(ADP-ribosylation) in lymphocytes of smokers.

G.J. Hageman*, R.H. Stierum, M.H.M. van Herwijnen, M.S. van der Veer, J.C.S. Kleinjans

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Department of Health Risk Analysis and Toxicology, Universiteit Maastricht, The Netherlands.

As a substrate for poly(ADP-ribose) polymerase (PARP; EC, 2.4.2.30), an enzyme that is activated by DNA strand breaks and is thought to facilitate efficient DNA repair, NAD+ and its precursor nicotinic acid (niacin) are involved in the cellular defense against DNA damage by genotoxic compounds. In this study, the effect of nicotinic acid supplementation on cytogenetic damage and poly(ADP-ribosylation) was evaluated in a human population that is continuously exposed to genotoxic agents, e.g., smokers. By use of a placebo-controlled intervention design, 21 healthy smokers received supplementary nicotinic acid at 0-100 mg/day for 14 weeks. An increased niacin status, as assessed from blood nicotinamide concentrations and lymphocyte NAD+ concentrations, was observed in groups supplemented with 50 and 100 mg/day. This effect was most pronounced in subjects with lower initial NAD+ levels. An increased niacin status did not result in decreased hypoxanthine guanine phosphoribosyltransferase variant frequencies and micronuclei induction in peripheral blood lymphocytes (PBLs). Sister chromatid exchanges in PBLs, however, were increased after supplementation with nicotinic acid. This increase was positively associated with the daily dose of nicotinic acid. No effects of nicotinic acid supplementation were found for ex vivo (+/-)-7 beta, 8 alpha-dihydroxy-9 alpha, 10 alpha-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene-induced poly(ADP-ribosylation), although the small number of samples that could be analyzed (n = 12) does not allow firm conclusions. Because no evidence was found for a decrease in cigarette smoke-induced cytogenetic damage in PBLs of smokers after nicotinic acid supplementation of up to 100 mg/day, it is concluded that supplemental niacin does not contribute to a reduced genetic risk in healthy smokers.

Publication Types:
Clinical Trial
Randomized Controlled Trial
Original languageEnglish
Pages (from-to)113-120
Number of pages8
JournalNutrition and Cancer-An International Journal
Volume32
Issue number2
DOIs
Publication statusPublished - 1 Jan 1998

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