- Source: Well-Known Antioxidants and Newcomers in Sport Nutrition: Coenzyme Q10, Quercetin, Resveratrol, Pterostilbene, Pycnogenol and Astaxanthin
- Abstract: Physical exercise induces an increase in production of free radicals and other reactive oxygen species (ROS) (Davies et al. 1982, Borzone et al. 1994, Halliwell and Gutteridge 1999). Current evidence indicates that ROS are the primary reason of exercise-induced disturbances in muscle redox balance. Severe disturbances in redox balance have been shown to promote oxidative injury and muscle fatigue (Reid et al. 1992, O’Neill et al. 1996) and thus impair the exercise performance. There are several potential sources of ROS that can be activated by exercise such as mitochondrial electron transfer chain, in the purine degradation pathway the reaction catalysed by xanthine oxidase, macrophage infiltration and metabolic degradation of catecholamines (Urso and Clarkson 2003, Finaud et al. 2006). The high production of ROS during exercise is also responsible for muscular damage (Aguiló et al. 2007). On the basis of the above-mentioned information, sportsmen have to improve their antioxidant defence systems to overcome the exercise-induced oxidative damage. Over the past few decades, many attempts have been made to improve antioxidant potential and therefore increase physical performance by improving nutrition, training programmes and other related factors. An antioxidant is generally defined as any substance that significantly delays or prevents oxidative damage of a target molecule (Halliwell 2007). The antioxidant defence system of the body consists of antioxidant enzymes (superoxide dismutases, catalase and glutathione peroxidase, etc.) and non-enzymatic antioxidants (vitamins A, C and E, coenzyme Q10 (CoQ10) and glutathione, etc.) (Deaton and Marlin 2003). There is a cooperative interaction between endogenous antioxidants and dietary antioxidants; therefore, antioxidant supplementation may improve the muscle fibre’s ability to scavenge ROS and protect the exercising muscle against exercise-induced oxidative damage and fatigue. However, antioxidant nutrient deficiency could induce an increased susceptibility to exercise-induced damage and thus leads to impaired exercise performance (Stear et al. 2009). Recently, the problem of whether or not athletes should use antioxidant supplements is an important and highly debated topic. To prevent these hypothetically negative or side effects of physical exercise, supplementation with different types of antioxidants has been used in a great number of studies (Snider et al. 1992, Rokitzki et al. 1994, Reid et al. 1994, Margaritis et al. 1997, Aguiló et al. 2007, Bloomer et al. 2012). In the context of this chapter, information in brief about the well-known and recently used antioxidants such as CoQ10, quercetin, resveratrol, pterostilbene, pycnogenol and astaxanthine is given. The effects of these antioxidants on exercise performance and exercise-induced oxidative stress are also explained. Pterostilbene (trans-3,5-dimethoxy-4-hydroxystilbene) is a stilbenoid chemically similar to resveratrol and is found in grapes, wine and berries (Rimando et al. 2004). Pterostilbene is generated by plants in response to microbial infestation or exposure to ultraviolet light (Langcake 1981). Pterostilbene is closely related structurally to resveratrol (a naturally occurring dimethylether analogue of resveratrol) and shows many of the same characteristics, as well as its own unique therapeutic potential (Rimando et al. 2002). Pterostilbene might show higher biological activity compared with resveratrol, because substitution of a hydroxy with a methoxy group increases the transport into cells and increases the metabolic stability of the molecule. Therefore, pterostilbene is not as quickly glucuronidated and sulphated as resveratrol. Pterostilbene is known to have many pharmacological benefits for the prevention and treatment of a wide variety of diseases, including cancer (McCormack and McFadden 2012), dyslipidaemia (Rimando et al. 2005), diabetes (Amarnath Satheesh and Pari 2006), cardiovascular degeneration (Amarnath Satheesh and Pari 2008) and pain (Hougee et al. 2005). Antioxidant and antiinflamatory effects of pterostilbene are also demonstrated (Roupe et al. 2006, Perečko et al. 2010, Hsu et al. 2013). Pterostilbene possesses strong, dose-dependent antioxidant effects (Rimando et al. 2002, Amorati et al. 2004). The antioxidant activity of pterostilbene was first demonstrated in vitro by its inhibition of methyl linoleate oxidation (Roupe et al. 2006). It inhibits the production of hydroxyl radicals (Perečko et al. 2010). In terms of the antiinflamatory effect of pterostilbene, Hsu et al. (2013) demonstrated that pterostilbene downregulates inflammatory TNF-α, IL-6, cyclooxygenase-2, inducible nitric oxide synthase, IL-1β, monocyte chemotactic protein-1, C-reactive protein and plasminogen activator inhibitor-1 expression by inhibiting the activation of NF-κB. According to our knowledge, to date no study has investigated the effects of pterostilbene supplementation on exercise performance, exercise-induced oxidative stress and inflammatory response in both sedentary and trained individuals. On the basis of the current studies, pterostilbene may improve athletic performance by activating and supporting both antioxidant and antiinflamatory cascades in untrained and trained subjects. However, detailed animal and human studies are needed in this subject.
< Back to Pterostilbene