These processes are performed almost exclusively through the mediation of highly reactive molecules, so called "free radicals" which, during their biological life, are predominatly represented by Reactive Oxygen Metabolites (ROM's).
These are almost irreplaceable "journey companions" to living cells which supervise all oxide-reduction reactions vital to it's survival. It is, therefore, inevitable that cell structures are damaged given the presence of ROM's, with the lose of it's functional abilities and hence it's biological life. It is hence also logical that the greater the cell is protected the longer it lives.
It may be protected in two ways: through the maintenance of it's antioxidant patrimony or limiting the production of free radicals.
Therefore, the evaluation of a cell's antioxidant patrimony and oxidative state is the best indicator of a cell's condition.
However, whilst it is now possible to dose antioxidants via methods used in any main laboratory, the same cannot be said for free radicals as their hemilife is short and only detectable using extremely sophisticated instruments such as ESR which is not advised for routine research.
A test which is used for the evaluation of oxidative stress is the dosage of the reactive substances with theobarbiturate (aldehydes) or via more selective dosage using HPLC of MDA (malonialdehydes).
These, however, are late indicators of oxidative stress because in order to find the alteration of the above mentioned elements in circulating plasma, the endogenous antioxidant system, in the medium where the oxidant attack has taken place, should be exhausted. This permits radical fall, carried by arachidonic acid, to arrive up to the formation of MDA through further oxidation of cyclical endoperoxide (see enclosed diagram).
From the above we may conclude that although the determination of MDA is an important test for the evaluation of oxidative stress, it is not always able to detect an alterated oxidative state.
Elements which are the first indicators of oxidazation are hydroperoxides which are formed by dehydrogenate action and then peroxidation by hydroxil OH• radical on a vast range of compounds as, for example, proteins, lipides peptides, alpha-aminoacides, beta-aminoacides etc..
Iram suceeded in carrying out the only test at the moment able to dose all the hydroperoxides present in blood in a simple, fast, reliable and reproducible way, using that discovered by FENTON in 1894 and completed by HABER and WEISS in 1932: this stated that peroxide in the presence of a transition metal, which acts as a catalyst, generates free radicals through the following reactions:
| Me' + ROOH |  |
Me" + RO• + OH- |
| Me" + ROOH | |
Me' + ROO• + H• |
where Me' is a transition metal in a determinated valency stage and Me' is the same metal in a superior valency stage.
The test may be made on whole blood or capillary blood, using kynetics methods.
Because of the heterogeneity of peroxidized products, we have chosen to express results in conventional arbitrary units U.CARR. so that clinical interpretation is made easier.
The FRAS system has been validated by the National Research Committee (CNR) - Institute of formulation of Carbon containing Heteroatoms and their Application (I.Co.C.E.A.).
A reference interval < 250 U.CARR. was obtained from about 5000 tests on healthy persons and values ranging from 250-300 U.CARR. where interpreted as border-line.
Finally, 2.000 patients with diverse pathologies where tested and the following classification was concluded:
| Below 300 U.Carr. | normal |
| 300 - 320 U.Carr. | border line range |
| 320 - 360 U.Carr. | slight oxidative stress |
| 360 - 400 U.Carr. | oxidative stress |
| 400 - 450 U.Carr. | high oxidative stress |
| Above 500 U.Carr. | very high oxidative stress |