[Chosen non-enzymatic substances that participate in a protection against overproduction of free radicals].

Free radicals are substantial elements that take part in proper function of metabolic pathways of human cells and tissues in hydrophobic as well as in hydrophilic environment. Nevertheless overproduction of above molecules causes oxidative stress, a process which is very harmful for lipids, proteins, and others molecules what reduces their normal function. To protect against adverse effects of free radicals and theirs derivatives to human body there is a group of antioxidants divided into enzymatic and non-enzymatic substances. Enzymatic antioxidants are represented mainly by enzymes such as: copper-zinc superoxide dismutase (CuZnSOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR). Glutathione (GSH), thioredoxin (Trx), vitamins, melatonin, polyphenols, trace elements, albumin, and others function as non-enzymatic free radicals scavengers. This work in a brief way describes properties of chosen representants of non-enzymatic antioxidant system.