Table 1.
The characteristics of the free radicals
| Reactive species | Chemical structure | Synthesis / pathways |
|---|---|---|
| Hydroxyl Radical | HO | Fentan reaction The transformation of hydrogen peroxide by the action of iron ions Mitochondrial damage – leakage of electrons |
| Superoxide Anion | O2− | Xanthine activity Mitochondrial dysfunction Endoplasmic reticulum dysfunction Activation of lipoxygenase Activation of cyclooxygenase |
| Oxide Anion | O2− | Mitochondrial dysfunction Respiratory chain Denaturation of myoglobin, haemoglobin and cytochrome |
| Hydrogen Peroxide | H2O2 | Biochemical reactions catalyzed by superoxide dismutase |
| Nitric Oxide | NO | Biological and biochemical activity of endothelial cells Inhibition of cell surface receptors |
| Peroxynitrite | ONOO | The reaction between nitric oxide and superoxide anion |
| Lipid Peroxyl | LOO | The action of iron ions on lipid hydroperoxide The action of superoxide anion on cell membranes |
| Lipid Alkoxyl | LO | The action of iron ion on lipid peroxyl |