Antioxidants

by H.N.Shivaprasad & S.Mohan

Antioxidants are gaining a lot of importance as a panacea for a large number of life-style diseases like aging, cancer, diabetes, cardiovascular and other degenerative diseases etc. owing to our sedentary way of life and stressful existence. Added to these are the deleterious effects of pollution and exposure to harmful chemicals. All the above can cause accumulation of harmful free radicals.

Free radicals are types of Reactive oxygen species (ROS), which include all highly reactive, oxygen-containing molecules. Types of ROS include the hydroxyl radical, the super oxide anion radical, hydrogen peroxide, singlet oxygen, nitric oxide radical, hypochlorite radical, and various lipid peroxides. All these are capable of reacting with membrane lipids, nucleic acids, proteins and enzymes and other small molecules, resulting in cellular damage. In living organisms various ROSs can be formed in different ways, including normal aerobic respiration, stimulated polymorphonuclear leukocytes and macrophages and peroxisomes. These appear to be the main endogenous sources of most of the oxidants produced by cells. Exogenous sources of free radicals include tobacco smoke, ionizing radiation, certain pollutants, organic solvents and pesticides.

Free radicals may be defined as chemical species associated with an odd or unpaired electron. They are neutral, short lived, unstable and highly reactive to pair up the odd electron and finally achieve stable configuration. They are capable of attacking the healthy cells of the body, causing them to lose their structure and function. Cell damage caused by free radicals appears to be a major contributor to aging and degenerative diseases of aging such as cancer, cardiovascular disease, cataracts, immune system decline, liver diseases, diabetes mellitus, inflammation, renal failure, brain dysfunction and stress among others.

To protect the cells and organ systems of the body against reactive oxygen species, humans have evolved a highly sophisticated and complex antioxidant protection system, that functions interactively and synergistically to neutralize free radicals. Thus, antioxidants are capable of stabilizing or deactivating, free radicals before they attack cells. Antioxidants are absolutely critical for maintaining optimal cellular and systemic health and well-being.

Naturally there is a dynamic balance between the amount of free radicals produced in the body and antioxidants to scavenge or quench them to protect the body against deleterious effects. The amount of antioxidant principles present under normal physiological conditions may be insufficient to neutralize free radicals generated. Therefore, it is obvious to enrich our diet with antioxidants to protect against harmful diseases. Hence there has been an increased interest in the food industry and in preventive medicine in the development of "Natural antioxidants" from plant materials. That is why plants with antioxidant properties are becoming more and more popular all over the world.

Considering the importance of this area, we have listed some of the important medicinal plants having potent antioxidant property, which are traditionally used in the Indian subcontinent for various disorders where free radicals are thought to be involved. These medicinal plants include:
Terminalia chebula (Harada), Terminalia belerica (Bihara), Emblica officinalis (Amla), Camelia sinensis (Green tea), Theobroma cocoa (Cocoa), Vitex vinifera (Grapes), Panax ginseng (Ginseng), Withania somnifera (Ashwagandha), Ocimum sanctum (Tulsi), Asparagus racemosus (Satavari), Centella asiatica (Brahmi), Terminalia arjuna (Arjuna), Glycyrrhiza glabra (Liquorice), Curcuma longa (Turmeric) and Piper longum (Pipal) etc.

Incorporation of these plant antioxidants into one's diet results in providing a measure of protection against oxidative damage from free radicals. When added to a regimen of exercise, balanced diet and a clean environment, these agents could go a long way in providing protection against aging, cancer, liver diseases and other degenerative diseases.

All the above-mentioned plants are widely being used in various formulations as antioxidant supplements. There is much more to be learnt regarding antioxidants and their applications in improving the health and well being of humankind and needless to say there is a tremendous need to spread awareness about them.

About the Authors:

H.N.Shivaprasad is a lecturer in Pharmacognosy & Phytochemistry at PES College of Pharmacy, Bangalore. He has completed his graduation and post-graduation from Rajiv Gandhi University of Health Sciences, India. He is the university rank holder at graduate and postgraduate levels. He has worked as Executive, R & D in Himalaya Drugs, Bangalore. He is doing his Doctoral [Ph.D.] research at Dr. Hari Singh Gour Vishwavidyalaya, Sagar [M.P]. He has several National and International publications to his credit. He has written many health articles in Health and Fitness section of reputed daily Vijay Times. He has been awarded as Best presenter in 55th Indian Pharmaceutical Congress, Chennai. His research interest extends from screening of herbal drugs for various pharmacological activities, Standardization of crude drugs, Phytochemistry to Tissue culture.

Dr. S.Mohan is a Principal and Professor in Pharmaceutical chemistry at PES College of Pharmacy, Bangalore. He has a vast teaching experience of 30 years. He has several National and International publications to his credit. He has guided several M.Pharm and Ph.D. students till date.
He had the privilege to present scientific papers in International Conferences. He has delivered invited lectures and chaired many scientific sessions in India and abroad.
- He has received travel grant (partial) from AICTE to visit Vienna in August 1999. - He received travel grants (partial) from CSIR to visit Alexandria, Egypt, and delivered an invited lecture in March 2000.
- He was selected for Green Chemistry Workshop sponsored by American Chemical Society and Chemical Society of Thailand organized by Chulalongkorn University (May27-28, 2002).
- He received Astra Zeneca research foundation, India, sponsorship to deliver a lecture on "Drug design-an overview encompassing past and present" at Sheffield University, U.K (26.02.03) and to attend an International conference on Predictive toxicology on 27.02.2003).
- He has also presented a paper in Durban, South Africa. (July 1998)
- He has applied for a patent for "A NEW MOLECULAR SCAFFOLD FOR ANALGESIC AND ANTI-INFLAMMATORY ACTIVITIES"- Patent pending.
- Attended a "Molecular modeling" workshop in North Carolina, USA. (October 2000)
He was the President of the Association of Pharmaceutical teachers of India, Karnataka State branch and is a life member of several reputed professional and academic organizations.