The Antioxidant Power of Bergamot Polyphenolic Fraction Gold Potentiates the Effects of L-Citrulline in Athlete Performance and Vasodilation in a Pilot Study

Abstract

Background: The dietary supplement citrulline might increase nitric oxide levels, leading to vasodilation and improved blood flow, potentially benefiting athletes' aerobic exercise performance. However, rapid oxidative impairment of the L-arginine/nitric oxide (NO) pathway limits these effects. This is countered by Bergamot Polyphenolic Fraction Gold^® (BPFG), a strong natural antioxidant. To investigate L-citrulline + BPFG supplementation's effects, we performed a randomized, double-blind, placebo-controlled pilot trial on athletic performance and blood flow in trained athletes (cyclists). Methods: Random assignment of 90 male athletes resulted in nine different groups: placebo for Group 1, BPFG at 500 and 1000 mg daily for Groups 2 and 3, L-citrulline at 1000 and 2000 mg/daily for Groups 4 and 5, and the combination product of BPFG plus citrulline (N.O. Max) for Groups 6-9. Baseline and 3-month pre- and post-exercise biochemical, reactive vasodilation (RHI), and maximal oxygen consumption measurements were taken for all subjects. Results: Three months of the combination of BPFG and L-citrulline (N.O. Max) produced a significant synergistic effect, markedly increasing NO (p < 0.001 vs. placebo) release and RHI (p < 0.001 vs. placebo). Cardiorespiratory fitness improved significantly with the BPFG and L-citrulline combination, resulting in substantially higher VO₂ max, VT1, VT2, and peak power and a significantly lower heart rate (p < 0.01 vs. placebo). No harmful adverse effects were observed. Conclusions: N.O. Max supplementation, providing beneficial effects on the antioxidant state and preserving the vascular endothelium might be a supplementation strategy to improve athletic performance and potentiate results. Given the small sample size, this study serves as a pilot, and further research is needed to validate these findings on a larger scale.

Keywords: Bergamot Polyphenolic Fraction Gold (BPFG); l-citrulline; maximal oxygen consumption; nitric oxide; oxidative stress; running performance; sport nutrition; supplements.

Figure 1

Study design.

Figure 2

The effects of BPFG, citrulline, and BPFV + citrulline (N.O. MAX) in nitric oxide release at rest and after exercise. * p < 0.05 group 2 vs. group 1 (placebo rest); ** p < 0.01 group 2, 3, 4 and 5 vs. group 1 (placebo rest), respectively; *** p < 0.001 group 6, 7, 8 and 9 vs. group 1 (placebo rest), respectively; § p < 0.05 group 2 vs. placebo group 1 (exercise). §§ p < 0.01 group 3, 4, 5 vs. placebo group 1 (exercise), respectively. §§§ p < 0.001 group 6, 7, 8 and 9 vs. vs. placebo group 1 (exercise).

Figure 3

The effect of BPFG, L-citrulline, and BPFG + L-citrulline (N.O. Max) on RHI at rest and after exercise. * p < 0.05 group 2, 3, 4 vs. group 1 (placebo rest) respectively; ** p < 0.01 group 5 vs. group 1 (placebo rest); *** p < 0.001 group 6, 7, 8 and 9 vs. group 1 (placebo rest), respectively; § p < 0.05 group 2, 3 vs. placebo group 1 (exercise), respectively; §§ p < 0.01 group 4, 5 vs. placebo group 1 (exercise), respectively. §§§ p < 0.001 group 6, 7, 8 and 9 vs. vs. placebo group 1 (exercise).

Figure 4

The effect of BPFG, L-citrulline, and BPFG + L-citrulline (N.O. Max) on MDA serum levels at rest and after exercise. §: p < 0.05 vs. group 1 (placebo exercise), respectively; §§: p < 0.01 vs. group 1 (placebo exercise); §§§ p < 0.001 vs. group 1 (placebo exercise).