Effects of Tomato Juice Intake on Salivary 8-Oxo-dG Levels as Oxidative Stress Biomarker after Extensive Physical Exercise

Abstract

Reactive oxygen species (ROS) at a normal level are important molecules involved in several cellular processes including immune response and cell signalling. Overproduction of ROS may lead to elevated oxidative stress and consequently to age-related diseases. Most of the studies related to oxidative stress in humans have been done on blood samples. However, blood sampling might be painful, requires special qualified personnel, and has to be performed at medical centers. An alternative to blood is saliva. Saliva sampling is noninvasive and can be performed by the donor. Biomarker determination in saliva is becoming an important part of laboratory diagnosis, but method development is needed before it can be used in the clinics. In the present investigation, 16 donors performed extensive physical exercise by cycling and keeping their heart rate at 80% of maximum for 20 minutes. The physical activity was repeated 3 times: before tomato juice intake, after daily intake of 100 ml tomato juice during 3 weeks, and finally 3 weeks after finishing tomato juice intake (washout period). The level of the stress biomarker, salivary 8-oxo-dG, was determined before and after the physical activity. The results indicate that (a) 20 min extensive physical activity increases the level of 8-oxo-dG in saliva significantly (p=0.0078) and (b) daily intake of 100 ml tomato juice may inhibit (p=0.052) overproduction of salivary 8-oxo-dG by 20 min physical activity. We conclude that the 20 min extensive physical activity increases the level of salivary 8-oxo-dG in healthy donors and 100 ml daily intake of tomato juice may inhibit the increase of 8-oxo-dG in saliva.

Tomatoes: An Extensive Review of the Associated Health Impacts of Tomatoes and Factors That Can Affect Their Cultivation

“…Exercise and increased muscle activity result in higher amounts of ROS due to increased ATP production and oxygen utilisation [ 312 ]. ROS are highly reactive and can damage macromolecules such as proteins, DNA, and lipids.…”

“…ROS such as peroxides and superoxides can be damaging to cells if concentrations are excessive [ 313 , 314 ]. Regular exercise builds resistance of the body against oxidative stress by upregulating the expression of genes that synthesise antioxidant enzymes such as superoxide dismutase [ 312 ].…”

Oxidative stress induction in woodworkers occupationally exposed to wood dust and formaldehyde

“…It is ubiquitous in the body, chemically stable in biological fluids and widely considered a reliable, sensitive and specific non-invasive biomarker of in vivo systemic OS [ 17 , 18 ]. Recently it has been speculated that 15-F 2t -IsoP excretion is associated with 7,8-dihydro-8-oxo-2′-deoxyguanosine (8-oxo-dGuo or 8-oxo-dG) [ 19 , 20 ], a guanine modification induced by free radicals and adopted as a non-invasive biomarker of OS [ 21 ]. The accumulation of such damages can lead to genetic information changes, and, consequently, to mutagenesis and cells apoptosis [ 22 ].…”