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Physical exercise is considered to be one of the beneficial factors of a proper lifestyle and is nowadays seen as an indispensable element for good health, able to lower the risk of disorders of the cardiovascular, endocrine and osteomuscular apparatus, immune system diseases and the onset of potential neoplasms. A moderate and programmed physical exercise has often been reported to be therapeutic both in the adulthood and in aging, since capable to promote fitness. Regular exercise alleviates the negative effects caused by free radicals and offers many health benefits, including reduced risk of all-cause mortality, sarcopenia in the skeletal muscle, chronic disease, and premature death in elderly people. However, physical performance is also known to induce oxidative stress, inflammation, and muscle fatigue. Many efforts have been carried out to identify micronutrients and natural compounds, also known as nutraceuticals, able to prevent or attenuate the exercise-induced oxidative stress and inflammation.The aim of this review is to discuss the benefits deriving from a constant physical activity and by the intake of antioxidant compounds to protect the body from oxidative stress. The attention will be focused mainly on three natural antioxidants, which are quercetin, resveratrol and curcumin. Their properties and activity will be described, as well as their benefits on physical activity and on aging, which is expected to increase through the years and can get favorable benefits from a constant exercise activity.

The flavonoid quercetin (3,3′,4′,5,7-pentahydroxyflavone) is widely distributed in plants, foods, and beverages. This polyphenol compound exhibits varied biological actions such as antioxidant, radical-scavenging, anti-inflammatory, antibacterial, antiviral, gastroprotective, immune-modulator, and finds also application in the treatment of obesity, cardiovascular diseases and diabetes. Besides, quercetin can prevent neurological disorders and exerts protection against mitochondrial damages. Various in vitro studies have assessed the anticancer effects of quercetin, although there are no conclusive data regarding its mode of action. However, low bioavailability, poor aqueous solubility as well as rapid body clearance, fast metabolism and enzymatic degradation hamper the use of quercetin as therapeutic agent, so intense research efforts have been focused on the modification of the quercetin scaffold to obtain analogs with potentially improved properties for clinical applications. This review gives an overview of the developments in the synthesis and anticancer-related activities of quercetin derivatives reported from 2012 to 2016.

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Corolla life span of undetached flowers of Nicotiana tabacum was divided into stages from the closed corolla (stage 1) through anthesis (stage 5) to death (stage 9). Senescence began around stage 6 in the proximal part, concomitantly with DNA laddering. Nuclear blebbing, DNA laddering, cell wall modification, decline in protein, water, pigment content and membrane integrity were observed during senescence and PCD. Transglutaminase activity was measured as mono-and bis-derivatives of putrescine (mono-PU; bis-PU) and bis-derivatives of spermidine (bis-SD). Bis-derivatives decreased with the progression of senescence, while mono-PU increased during early senescence; derivatives were present in different amounts in the proximal and distal parts of the corolla. In excised flowers, exogenous spermine delayed senescence and PCD, and caused an increase in free and acid-soluble conjugated PA levels. Bis-PU was the most abundant PA-derivative before DNA laddering stage; thereafter, bis-PU generally decreased and mono-PU became the most abundant derivative.