Marginal zinc deficiency increases oxidative DNA damage in the prostate after chronic exercise

Abstract

Approximately 12% of Americans do not consume the recommended level of zinc and could be at risk for marginal zinc deficiency. Zinc functions in antioxidant defense and DNA repair and could be important for prostate health. We hypothesized that marginal zinc deficiency sensitizes the prostate to oxidative stress and DNA damage. Rats were fed a zinc-adequate (ZA; 30 mg Zn/kg) or marginally zinc-deficient (MZD; 5–6 mg Zn/kg) diet for 6 weeks. MZD increased p53 and PARP expression but no change in 8-hydroxy-2′-deoxyguanosine levels was detected. To examine the susceptibility to exogenous oxidative stress, rats fed a ZA or MZD diet were assigned to exercising (EXE) or sedentary (SED) groups for 9 weeks. MZD or EXE alone did not affect oxidative DNA damage in the prostate; however, combined MZD + EXE increased DNA damage in the dorsolateral lobe. PARP and p53 expression was not further induced with MZD + EXE, suggesting that MZD interferes with DNA repair responses to stress. Finally, the addition of phytase to the MZD diet successfully restored zinc levels in the prostate and decreased DNA damage back to ZA levels. Overall, this study suggests that marginal zinc deficiency sensitizes the prostate to oxidative stress and demonstrates the importance of maintaining optimal zinc nutrition in physically active populations.

Zinc deficiency induces dysregulation of cytokine productions in an experimental colitis of rats

“…Epidemiological studies have revealed associations between low blood Zn concentrations and an increased risk of sepsis (2) and cancer (28). Consistent with literature reporting human IBD, experimental animals with marginal Zn deficiency after chronic exercise exhibit oxidative DNA damage in the prostate (25). It has also been shown that marginally Zn-deficient rats experience increased susceptibility to acute lipopolysaccharide (LPS)-induced liver injury (24).…”

Association of Prostate Specific Antigen Concentration with Lifestyle Characteristics in Korean Men

“…There have been some studies investigating the association of dietary supplement use with prostate cancer risk. Multivitamin use (Lawson et al, 2007) and calcium intake (Butler et al, 2010) are known to increase the risk of prostate cancer, while selenium (Lindshield et al, 2010) and zinc (Song et al, 2010) showed in-vitro inhibitory effects on the growth of prostate cancer cells and decreased oxidative DNA damage in the prostate, respectively. Considering that this study showed no association of vitamin intake with increased PSA, vitamin use might increase the risk of prostate cancer without elevation of serum PSA.…”

Effects of micronutrients on DNA repair

“…higher BER activity immediately after birth [52,53] subjected to a marginal zinc deficiency, and in combination with chronic exercise, there was an increase in DNA oxidation [44]. Activities of PARP as well as DNA polymerase b and DNA ligase, three enzymes induced in rat liver by aflatoxin B1-treament were higher in rats deficient in vitamin A [45] or copper [46] and were brought down by supplementation.…”