Oxidative stress is injurious to cells causing damage to DNA, proteins and lipids. It is caused by increased levels of reactive oxygen species (ROS) or/and decreased levels of antioxidants including reduced glutathione (GSH). Oxidative stress has been implicated to play a role in ageing and many pathological diseases, including cancer, diabetes, cardiovascular disorders, atherosclerosis, Parkinson’s and Alzheimer’s Diseases.
Available testing markers
1- Glutathione S-transferases (GSTs)
Glutathione S-transferases (GSTs), previously known as ligandins, are a family of eukaryotic and prokaryotic phase II metabolic isozymes best known for their ability to catalyze the conjugation of the reduced form of glutathione (GSH) to xenobiotic substrates for the purpose of detoxification
2- Total Anti-oxidant capacity
Measurement of the combined non-enzymatic antioxidant capacity of biological fluids and other samples provides an indication of the overall capability to counteract reactive oxygen species (ROS), resist oxidative damage and combat oxidative stress-related diseases.
3- Reduced Glutathione
Glutathione is a small peptide composed of three amino acids: cysteine, glutamic acid, and glycine and is present in tissues in concentrations. Glutathione (GSH), the most abundant low molecular weight thiol containing peptide. GSH plays critical roles in protecting cells from oxidative damage and the toxicity of xenobiotic electrophiles, and maintaining redox homeostasis. Glutathione is involved in detoxification; it binds to toxins, such as heavy metals, solvents, and pesticides, and transforms them into a form that can be excreted in urine or bile. It is also helping to maintain the -SH groups of proteins in their reduced form. Chronic functional glutathione deficiency is associated with glucose 6-phosphate dehydrogenase deficiency, immune disorders, and an increased incidence of malignancies.
4- Superoxide Dismutase (SOD)
Superoxide dismutase (SOD) is one of the most important anti-oxidative enzymes. It catalyzes the dismutation of the superoxide anion into hydrogen peroxide and molecular oxygen.
Superoxide dismutases (SODs) are a group of metalloenzymes that are found in all kingdoms of life. SODs form the front line of defense against reactive oxygen species (ROS)-mediated injury. These proteins catalyze the dismutation of superoxide anion free radical (O2-) into molecular oxygen and hydrogen peroxide (H2O2) and decrease O2- level which damages the cells at excessive concentration. This reaction is accompanied by alternate oxidation-reduction of metal ions present in the active site of SODs.
5- Malondialdehyde (MDA)
Lipid peroxidation or reaction of oxygen with unsaturated lipids produces a wide variety of oxidation products. The main primary products of lipid peroxidation are lipid hydroperoxides (LOOH). Among the many different aldehydes which can be formed as secondary products during lipid peroxidation, malondialdehyde (MDA), propanal, hexanal, and 4-hydroxynonenal (4-HNE). MDA appears to be the most mutagenic product of lipid peroxidation, and commonly used market of oxidative stress and antioxidant status in the cell.
6- Catalase (CAT)
Catalase is a ubiquitous enzyme, present in almost all cells that carry on an aerobic metabolism. It catalyzes the decomposition of hydrogen peroxide to water and oxygen. Thus protecting the cell organelle’s and cells from oxidative damage by reactive oxygen species (ROS).
Catalase has various industrial applications. In the food industry, it is used in combination with other enzymes in the preservation of foodstuffs and in the manufacture of beverages and certain food items. Commercial catalases also are used to break down hydrogen peroxide in waste water.
7- Nitric Oxide (NO)
Nitric oxide (NO) is a key vertebrate biological messenger, playing an important role in neurotransmission, vascular regulation, immune responses and apoptosis. NO, also known as “endothelium-derived relaxing factor” or “EDRF”, is synthesized from L-arginine, oxygen and NADPH by various NO synthases. Most of the NO in the cell is oxidized to nitrite (NO2-) and nitrate (NO3-), and therefore the concentrations of these anions are generally as a quantitative measure of NO production.