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

Objective: The objective was to determine the effects of lycopene supplementation on endothelial function assessed by reactive hyperemia peripheral arterial tonometry (RH-PAT) and oxidative stress. Methods: Healthy men (n= 126) were randomized to receive placebo (n= 38), 6. mg (n= 41), or 15. mg (n= 37) lycopene daily for 8-week. Results: Serum lycopene increased in a dose-dependent manner after 8-week supplementation (P< 0.001). The 15. mg/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 15. mg/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 15. mg/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 15. mg 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). Conclusion: An increase in serum lycopene after supplementation can reduce oxidative stress which may play a role in endothelial function.