Sports nutrition is one of the most dynamic segments in both the nutraceutical and functional food markets. An increasing number of athletes choose to include healthy food supplements in their diet to improve their performance and overall well-being. Nexira meets their needs with ViNitrox™. This all-natural ingredient has been specifically developed to satisfy the demands of athletes in search of natural dietary supplements that are free of doping substances.
Composition and technical specifications
ViNitrox™ is a unique synergistic combination of apple and grape polyphenols (total polyphenols content >95%) obtained from a proprietary mix of apple and grape extracts and containing ≥200 ppm of e-viniferin.
ViNitrox™ has a powerful antioxidant effect (ORAC up to 11,000 μmol Te/g).
The technical specifications of ViNitrox™ are reported in Table 1.
Mechanism of action
Preliminary studies (ex vivo and in vitro) have highlighted Vinitrox ™’s specific vasodilating properties. The first study conducted by Nexira showed Vinitrox’s dilating effect on the endothelium in isolated rat aortas. In this ex vivo study, increasing concentrations of ViNitrox™ (from 1 mg/l to 30 mg/l) were added to the isolated cross-sections of rat aortas. Results obtained showed that ViNitrox™ exerted a dilating effect on the endothelium of isolated rat aorta when used at those concentrations. The maximum dilating effect (+50%) was obtained at the concentration of 30 mg/l of ViNitrox™.
These vasodilating properties have been confirmed and demonstrated by two other studies in human umbilical vein endothelial cells (HUVEC), which show that the addition of Vinitrox™ (10 μg/ml) significantly boosts nitric oxide (NO) production by 24% and induces 43% endothelial nitric oxide synthase (eNOs) activation. The phosphorylation of the amino acid ‘Serine 1177’ was used as a specific marker of the eNOs activation.
The reference compound leucocyanidol (10 μg/ml) induces a similar effect to that obtained with ViNitrox™ and thus validates the experimental model (Fig. 1).
Two groups of hamsters were maintained under oxidative stress conditions generated by sustained and repeated physical activity. Hamsters were divided into two groups and were nourished throughout all periods of activity with either a standard food (placebo diet) or a standard food enriched with 100 mg of ViNitrox ™ (test diet).
The physical activity was characterised by a session in the form of a fast walk carried out in an ergometer for rodents. After an adaptation period, a first training period of 3 weeks allowed to prepare the hamsters for periods of physical activity. At the end of the training period, each hamster was subjected to a progressive levels test to determine its maximum aerobic speed (MAS).
During the ten sessions of the first training period, each hamster had a physical activity at constant intensity (70% of the MAS) although the duration varied gradually from 15 to 35 min. The second training period (5 sessions) was a stabilisation period where each hamster had a physical activity intensity set at constant 70% of the MAS for 35 min.
Analyses were performed on blood samples collected 45 min after the final training session. ViNitrox™ significantly reduced the concentration of plasmatic nitrotyrosin (degradation products from oxidative stress) by 74% compared to the placebo (Fig. 2), suggesting that it could help recovery by reducing the harmful effects of free radicals produced during sustained and repeated aerobic activity.
Following these studies highlighting ViNitrox™’s vasodilating and antioxidant properties, Nexira conducted a randomised, crossover, double-blind, placebo-controlled clinical study designed to assess the effects of ViNitrox™ on human physical capacities and muscle performance. Indeed, NO plays a major role in the physiological adaptation of muscle to exercise. Its vasodilating action occurs both during the effort to increase performance and endurance, and after effort, contributing to rapid recovery by maintaining a substantial blood flow which facilitates rapid toxin evacuation.
The aim of the clinical study was to demonstrate that the intake of ViNitrox™ will improve athletic performance. The muscle performance in this test is defined by the intensity and the time of exercise.
This was a clinical study based on constant high-intensity aerobic exercise over a specified time. To reduce variability, a crossover study design was implemented so that each subject was its own control reference.
The trial was conducted on 50 athletes aged between 25 and 45 years, and was composed of three experimental sessions with at least seven-day intervals between each session. During the first experimental session, subjects performed a maximal test on an ergocycle to determine their maximal aerobic power.
During the two following testing sessions, subjects realised an endurance test at 70% of the maximal power determined during the first session. Subjects were requested to pedal until exhaustion, i.e., until they were unable to maintain the power. Two hours before each test, subjects took a standardised breakfast. Moreover, the preceding evening and one hour before the endurance test, each volunteer took either two capsules with 250 mg ViNitrox™ or two placebo capsules according to randomisation. Subjects that took Vinitrox™ during phase I took the placebo during phase II and vice versa.
The primary endpoint was the time limit defined by the maximum time that intense effort was maintained on the ergocycle at a power equal to 70% of maximal aerobic power. During this test, maximal and mean heart rate, maximal blood pressure, maximal and mean VO2 and maximal and mean ventilation were also measured.
Every 4 min during the all-out test, the Borg scale was used to determine subjects’ perceived exertion.
This clinical study demonstrates that under intensive effort, 500 mg/day of ViNitrox™ significantly improves physical capacity and muscle performance.
The results of the study show a significant increase in the maximum duration of intense effort in subjects who took ViNitrox™ (+10%; p<0.05) compared to those who took the placebo. The maximal perceived exertion and pain was delayed by 13% (p<0.03) with ViNitrox™.
These significant results are all consistent and reflect the increased resistance to effort due to an increase in the aerobic potential of athletes taking ViNitrox™.
No significant differences were recorded for the maximal and mean heart rate, maximal blood pressure, maximal and mean VO2, maximal and mean ventilation and oxygen saturation between the two groups.
We can assume that the vasodilating effect of ViNitrox™ leads to an increase in muscle perfusion, which results in an increase in oxygen available to muscle cells, which in turn allows greater and longer aerobic utilisation of glycogen.
A toxicity study conducted on rats according to the Directive OECD no. 423 (Organization for Economic Cooperation and Development, Acute Oral Toxicity – Acute Toxic Class Method, December 2001) indicates that ViNitrox™ was not toxic after a single oral administration at the limit dose of 2000 mg/kg in male and female Wistar rats. The maximal tolerated dose (MTD) of ViNitrox™ is higher than the limit tested dose of 2000 mg/kg. Until now, no side effects have been reported in healthy subjects when consuming ViNitrox™.
ViNitrox™ is safe for human usage.
Applications and dosage
The recommended dosage is 500 mg/day, which corresponds to the dosage used during the clinical study. Vinitrox™ can be incorporated into dietary supplements (tablets, capsules) or functional food (bars, gels) and beverages (due to its high solubility).
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