Exogenous Plant-Based Nutraceutical Supplementation and Peripheral Cell Mononuclear DNA Damage Following High Intensity Exercise

Abstract

Plant-based nutraceuticals are categorised as nutritional supplements which contain a high concentration of antioxidants with the intention of minimising the deleterious effect of an oxidative insult. The primary aim of this novel study was to determine the effect of exogenous barley-wheat grass juice (BWJ) on indices of exercise-induced oxidative stress. Ten (n = 10) apparently healthy, recreationally trained (V̇O2max 55.9 ± 6 mL·kg−1·min−1), males (age 22 ± 2 years, height 181 ± 6 cm, weight 87 ± 8 kg, body mass index (BMI) 27 ± 1) volunteered to participant in the study. In a randomised, double-blinded, placebo-controlled crossover design, participants consumed either a placebo, a low dose (70 mL per day) of BWJ, or a high dose (140 mL per day) of BWJ for 7-days. Experimental exercise consisted of a standard maximal oxygen uptake test until volitional fatigue. DNA damage, as assessed by the single cell gel electrophoresis comet assay, increased following high intensity exercise across all groups (time × group; p < 0.05, Effect Size (ES) = 0.7), although there was no selective difference for intervention (p > 0.05). There was a main effect for time in lipid hydroperoxide concentration (pooled-group data, pre- vs. post-exercise, p < 0.05, ES = 0.2) demonstrating that exercise increased lipid peroxidation. Superoxide dismutase activity (SOD) increased by 44.7% following BWJ supplementation (pooled group data, pre- vs. post). The ascorbyl free radical (p < 0.05, ES = 0.26), α-tocopherol (p = 0.007, ES = 0.2), and xanthophyll (p = 0.000, ES = 0.5), increased between the pre- and post-exercise time points indicating a main effect of time. This study illustrates that a 7-day supplementation period of a novel plant-derived nutraceutical product is insufficient at attenuating exercise-induced oxidative damage. It is possible that with a larger sample size, and longer supplementation period, this novel plant-based nutraceutical could potentially offer effective prophylaxis against exercise-induced oxidative stress; as such, this justifies the need for further research.

DNA Damage Following Acute Aerobic Exercise: A Systematic Review and Meta-analysis

“…Previous work from our laboratory has shown a 63% increase in DNA damage following exercise as well as a greater production of H 2 O 2 as a function of exercise, compared to rest, indicating a possible mechanism of exerciseinduced DNA damage through the increased production of H 2 O 2 [66]. Moreover, the activation of inflammatory cells such as neutrophils and lymphocytes during exercise, due to muscle tissue damage, can further enhance superoxide production, which can cause direct damage to DNA [75,80].…”

The mitochondria-targeted antioxidant MitoQ, attenuates exercise-induced mitochondrial DNA damage

“…For one, the majority of emerging evidence would suggest mitochondria generate the greatest amount of O 2 ·-/H 2 O 2 at rest [ 6 , 67 , 81 ], and as a result, it could be hypothesised that chronic MitoQ supplementation would have altered quiescent mitochondrial and/or nuclear DNA damage. It could potentially be the case that MitoQ does indeed alter State 4 mitochondrial O 2 ·-/H 2 O 2 dynamics which may not be detectable by measures of oxidative damage to DNA or lipids employed within the current study; especially considering the low levels of basal oxidative damage presented in healthy individuals [ 9 , 82 , 83 ]. This highlights the potential that MitoQ may be predominately applicable in conditions characterised by chronic oxidative stress and/or mitochondrial dysfunction such as chronic kidney disease, cardiovascular disease, chronic obstructive pulmonary disorder, acyl-CoA dehydrogenase deficiency, and neurodegenerative diseases [ [84] , [85] , [86] , [87] ].…”

Wound Healing: Contributions from Plant Secondary Metabolite Antioxidants

“…Additionally, there are numerous dietary antioxidants that can be consumed which contribute to an enhanced cellular protection. Ascorbic acid, for example, effectively scavenges ROS and resynthesizes α-tocopherol [48].…”