Effects of lycopene supplementation on oxidative stress and markers of endothelial function in healthy men

Abstract

ObjectiveThe objective was to determine the effects of lycopene supplementation on endothelial function assessed by reactive hyperemia peripheral arterial tonometry (RH-PAT) and oxidative stress. MethodsHealthy men (n=126) were randomized to receive placebo (n=38), 6mg (n=41), or 15mg (n=37) lycopene daily for 8-week. ResultsSerum lycopene increased in a dose-dependent manner after 8-week supplementation (P<0.001). The 15mg/day group had greater increase in plasma SOD activity (P=0.014) and reduction in lymphocyte DNA comet tail length (P=0.042) than the placebo group. Intragroup comparison revealed a 23% increase in RH-PAT index from baseline (1.45±0.09 vs. 1.79±0.12; P=0.032) in the 15mg/day group after 8-week. hs-CRP, systolic blood pressure, sICAM-1 and sVCAM-1 significantly decreased, and β-carotene and LDL-particle size significantly increased only in the 15mg/day group. Interestingly, the beneficial effect of lycopene supplementation on endothelial function (i.e., RH-PAT and sVCAM-1) were remarkable in subjects with relatively impaired endothelial cell function at initial level. Changes in RH-PAT index correlated with SOD activity (r=0.234, P=0.017) especially in the 15mg lycopene/day group (r=0.485, P=0.003), lymphocyte DNA comet tail moment (r=−0.318, P=0.001), and hs-CRP (r=−0.238, P=0.011). In addition, changes in lycopene correlated with hs-CRP (r=−0.230, P=0.016) and SOD activity (r=0.205, P=0.037). ConclusionAn increase in serum lycopene after supplementation can reduce oxidative stress which may play a role in endothelial function.