Free Radicals & Antioxidants - Current status

• Introduction
• What are Free radicals & Antioxidants
• Invivo origin of free radicals
• Sources of oxidative stress in human pathophysiology
• Major targets of oxidative activity
• Antioxidants
• General principles of Antioxidant therapy
• indications for Antioxidant therapy 
• Current status of Antioxidants

Current status of Antioxidants

The concept of "blanket protection" by antioxidant therapy against chaotic and damaging free radical oxidation is simple and attractive which contrast markedly with Receptor – based pharmacological developments in the last three and half decades. But it reflects the non specificity of damaging agents. The use of natural antioxidants to augment physiological antioxidants mechanism is particularly attractive but potential difficulties exists viz.,

1. In most of the diseases where oxidative damage has been demonstrated, free radicals are not the cause of the diseases but a consequences of it.
2. There are difficulties in targeting the therapy properly to the site of the problem.
3. The possibility of antioxidant therapy may be harmful. This is clearly a potential possibility for any synthetic agent but it may also be true for natural agents taken in excess. Some antioxidants may become pro-oxidants in certain circumstances. 

Clinicians should be aware of exaggerated claims with drugs having antioxidants properties. Many compounds which have in vitro activity rarely shows activity in vivo because of the difficulty in achieving adequate concentration. Work is underway for developing agents that can be a supplement to the natural antioxidants system. Efforts should be directed at the development of synthetic compounds that possess the versatility of the natural counterparts of  Ascorbic acid not only a scavenging antioxidant like tocopherol but can itself be regenerated by intracellular reduction.

Potential role of antioxidant in preventing the two important causes of premature death, cardiovascular diseases and cancer is partly attractive.

For the present however the message of the last two articles are-

 SUPPLEMENTATION OF THE DIET WITH NATURAL ANTIOXIDANTS  IS  THE SAFEST APPROACH FOR NOW.

Dr. T.R.RAMANUJAM. M.D.,
Professor & Head, Dept of Pharmacology,
Sri Ramachandra Medical College & Research Institute,   
Porur ,   
Chennai - 600 116 
SOUTH INDIA.