FREE RADICALS AND ANTIOXIDANTS – CURRENT STATUS A REVIEW I
DR T R RAMANUJAM M.D., C.MI.Biol (Lond)
INTRODUCTION
WHAT ARE FREE RADICALS AND ANTIOXIDANTS
INVIVO ORIGIN OF FREE RADICALS
SOURCES OF OXIDATIVE STRESS IN HUMAN PATHOPHYSIOLOGY
MAJOR TARGETS OF OXIDATIVE ACTIVITY
SOURCES OF OXIDATIVE STRESS IN HUMAN PATHOPHYSIOLOGY
| Source | Mechanism |
| Mitochondrial electron transport | Leakage of superoxide due to inefficient reduction of O2 |
| Transition metal icons | Cu and Fe facilitate hydroxyl radical formation |
| Inflammation | Free radicals released by activated phagocytes |
| Enzymes eg. Xanthine Oxidase | Release superoxide during reperfusion of ishemic tiss |
| Drug metabolism. eg. Paracetamol | Free radical intermediates created during metabolism |
| Cigarette smoke | Gas phase rich in free radicals |
| Radiation | X-rays, UV light |
Diseases associated with increased oxidative activity implicated in the pathophysiology:
| Atherosclerosis | Ishemica reperfusion injury |
| Diabetes | Inflammation-Rh arthritis -Infl bowel dis -pancreatitis |
| Cancer Neurological dis: -stroke -parkinson’s dis -trauma |
Hypertension Hyponia Sepsis |
Idiopath Pul fibrosis
Neonatal resp distr syndr
Cystic fibrosis
Aids,
Hematological dis
Exercise.
Increased quantities of oxidized metabolites of theses molecules have been detected in patients with a variety of diseases and although a rich array of natural antioxidant mechanisms exit to prevent or retard oxidation, it is often found to be inadequate in many of these diseases.
