HERBAL REMEDIES AS ANTIOXIDANTS: AN OVERVIEW

The primary cause of degenerative disease is not due to damaging free radicals, but rather it is due to the requirement of highly ordered cell biochemistry becoming disordered due to insufficient cellular energy to maintain the normal state of order. There is a complex defense system in the body, in which vitamins, minerals, amino acids and certain enzymes play a central role called the antioxidant system. Antioxidants are weapons for combating free radicals and mop up damaging chemicals in the body and guard against many chronic diseases. Heart disease, arthritis, cancer and many other common chronic diseases derive from the same source: fortuitous mutations caused largely by free radicals. Under optimum conditions, cells are protected against free radicals and lipid per oxidation. Antioxidants are substances, which react chemically with free radicals and render them harmless and at the same time break the vicious circle, which involves the decomposition of fatty acids & proteins, the creation of new free radicals and eventual cell death. Because free radical damage accumulates with age, people should start supplementing with antioxidants early to achieve long-term benefits. The scientific community has begun to unveil some of the mysteries surrounding this topic, and the media has begun whetting our thirst for knowledge.


Introduction
Athletes have a keen interest because of health concerns and the prospect of enhanced performance and/or recovery from injury due to exercise. The purpose of this article is to serve as a beginner's guide to what antioxidants are and to briefly review their role in exercise and general health. Traditional knowledge of medicinal plants has always guided the search for cures. In traditional drugs due to presence of antioxidants, property them contributing in cures of many diseases. The human body posses innate defense mechanisms to counter free radicals in the form of enzymes such as superoxide dismutase, catalase, and glutathione peroxide. VitaminC, vitaminE, selenium, βcarotine, lycopene, lutin and other carotinoids have been used as supplemantry antioxidantsplants secondary metabolites such as flavonoids and terpenoids play an important role in the defence against free radicals. list of Plants produces large amount of antioxidants to prevent the oxidative stress, they represent a potential source of new compounds with antioxidant .

Antioxidant 2
Role of Antioxidants: An antioxidant is a chemical that prevents the oxidation of other chemicals. They protect key cell components by neutralizing the damaging effects of free radicals, Major source of antioxidants is traditional herbs which are taken by human in life. In a normal cell, there are appropriate oxidant : antioxidant balance can be sifted, when production of oxygen species is increased or when levels of antioxidants are diminished This state is called oxidative stress.
To counter the harmful effects of free radicals like Reactive oxygen species (ROS) and Reactive nitrogen species (RNS), antioxidant defense mechanism operates to detoxify or scavenge these ROS and RNS. Antioxidants, together with the substances that are capable of either reducing Reactive Oxygen Molecules (ROMs) or preventing their formation, from a powerful reducing buffer and affects the ability of the oxygen metabolites. All reducing agents, thereby form protective mechanisms, which maintain the lowest possible level of ROMs in the cell.
Antioxidant defense system against oxidative stress is composed of several lines, and the antioxidants are classified into four categories based on function as follows: 5 • First line of defense is the preventive antioxidants, which suppress formation of free radical (enzymes such as glutathione peroxidase, catalase, superoxide dismutase: carotenoids, selenoprotein, lactoferrin, etc.) • Second line of defense is the radical scavenging antioxidants suppressing chain initiation and/of breaking chain propagation reactions, i.e., radical scavenging antioxidants.
• Third category antioxidants are repair and denovo antioxidants (some production enzymes, repair enzymes of DNA, etc.) • Fourth line is an adaptation where the signal for production and reactions of free radicals induces formation and transport of the appropriate antioxidant to the right site. Antioxidants act as radical scavenger, hydrogen donors, electron donor, peroxide decomposer, singlet oxygen quencher, enzyme inhibitor, synergist and metalchelating agents. It is considered to be stress protein, which is synthesized in response to oxidative stress. SOD is the most important enzyme as it is found in all aerobic organisms and is also present in mitochondria & cytosol. There are four families of SODs: Cu-SOD, Cu-Zn-SOD, Mn-SOD and Fe-SOD enzyme and has been detected in a large number of tissues and organism, and is thought that it is present to protect the cell from damage caused by O 2 . Increased plasma level of SOD has been reported in various diseases. Breast cancer patients have been reported to possess increased levels of plasma copper and zine. Thus, increased production of SOD in various genetic diseases may be in response of higher production of free radicals in those diseases.
• Glutathione peroxidase (GPx): Glutathione peroxidase (GPx) is a selenium containing enzyme, which catalyses the reduction of H 2 O 2 and lipid hydroperoxide (LO2H), generated during lipid peroxdation, to water using reduced glutathione as substrate. It is found in both cytosol and mitochondria and is a well-known first line of defense against oxidative stress, which in turn requires glutathione as a cofactor. It is involved in the generation of nucleotide precursors of DNA via the reduction of ribonucleotides to deoxyribonucleotides. GPx catalyses the oxidation of Reduced Glutathione (GSH) to Oxidized Glutathione (GSSG) at the expense of H 2 O 2 , by its selenium dependency. Since, selenium is an integral component of GOx, the measurement of this enzyme has been used as a functional index of selenium level. Low levels of selenium have been associated with a high risk of cardiovascular diseases and cancer in humans. Plasma GPx activity was found to be significantly elevated with respect to the controls in breast cancer patients. The reason of higher GPx activity in breast cancer patients may be in response to higher production of ROMs. • Catalase (CAT): Catalase (CAT) is present in most cells and catalyses the decomposition of hydrogen peroxide to water and oxygen. The mechanism of action is as follows: 2H 2 O 2 → 2H 2 O+O 2 CAT is found to act 104 times faster than peroxidase and is mainly localized in mitochondria and in subcellular respiratory organelles. CAT is found to be important in the inactivation of many environmental mutagens. Plasmid DNA strand scission causes by xanthine/xanthine oxidase (XO) has been reported to be prevented by both SOD and CAT enzymes. It also has a role in preventing chromosomal accompanied by significant increase in IL-2, which correlated with increased lymphocyte production 35 . By using parenteral nutrition with w-3 fatty acids, following haemorrhagic shock, it was possible to prevent an increase in the release of PGE 2 , and maintain normal defensive functions of splenocytes and macrophages . A rise in IL-2, as well as maintenance of postoperative interferon-production could be shown for surgical patients on parenteral w-3 fatty acids nutrition. These results indicated the positive influence of parenterally administering w-3 fatty acids to weakened post-operative and post-traumatic defensive functions. An animal experiment on rabbits even showed that intravenous administration of 1.5gm fish oil per kg body weight per day increased the elimination of bacteria from blood, in comparison with soyabean oil. Some internally generated sources of free radicals are a) Mitochondria b)phagocytosis c)Xanthenes oxidase d) Inflammation e) Arachidonate pathways g) Exercise h) Ischemia/Reperfution injury Some externally generated sources of free radicals are:

a) Cigarette smoke b) Radiation c) Industrial solvent d) Environmental pollutants e) Certain drugs and pesticides f) Ozone
The free radical diseases: Oxidative Or free radical injury is a fundamental mechanism of human diseases. Increasing evidence suggests that such injury is important in the pathogenesis of a diverse group of neurological disorders (Ebadi,2001) Various diseases/disorders linked to free radical and reactive oxygen species were listed in table1  Counteracting free radical damage: The human body has mechanisms to counteract damage by free radicals and other oxygen species. These act on different oxidants as well as in different cellular components. Various antioxidant defenses were listed in table Food rich in antioxidants: Antioxidants are abundant in fruits and vegetables as wells as in nuts, grains and some meats, poultry and fish. The list below describes food sources of common antioxidants • Beta-carotenes is found in many foods that are orange in color, including sweet potatoes, carrots, cantaloupe, squash, apricots, pumpkin, and mangoes. Some green leafy vegetables including collard greens, spinach, and kale are also rich in beta-carotene. • Lutein, better known for its association with healthy eyes, is abundant in green, leafy vegetables such as collard green, spinach, and kale. Lycopene is a potent antioxidant found in tomatoes, watermelon, guava, papaya, apricots, pink grapefruits, etc. Estimates suggest that 85% of American dietary intake of lycopene comes from tomatoes and tomatoes products. Selenium is a mineral but not an antioxidant nutrient. However, it is a component of antioxidant enzymes. Plants like rice and wheat are the major dietary sourcwe of selenium in most countries. The amount of selenium in soils, which varies by region, determines the amounts of selenium in the food grown in the soil. Animals the eat grains or plants grown in selenium-rich soil have higher levels of selenium in their muscle. In the united states, meat and bread are common sources of united states, meat and bread are common sources of dietary selenium while brazil nuts also contain large quantities of selenium's. Vitamins A is found in thre main forms: retinol (vitamin A), 3,4-didehydroretinol (vitamins A2), and 3-hydroxyretinol (vitamins A3). Food rich in vitamin A include liver, sweet potatoes, carrots, like, egg yolk and mozzarella cheese.
Vitamin C or ascorbic acid can be found in high abundance in many fruits and vegitables and is also found in cereals, beaf, poultry and fish. Vitamin E or tocopherol is found in almonds, oils including wheat germs, sunflower, corn and soybean (oils) , mangoes, nuts, broccoli and other foods.

Conclusions
Currently there has been an increased interest globally to identify antioxidant compounds from plant sources which are pharmacologically potent and have low or no side effects for use in protective medicine and the food industry. Modern civilization, use of different chemicals, pesticides, pollutant, smoking and alcohol intake and even some of synthetic medicine increases the chance of disease due to free radicals. Plants produces large amount of antioxidants to prevent the oxidative stress, they represent a potential source of new compounds with antioxidant activity. More or less the free radicals plays a role in health of modern era and the diseases caused from free radical are becoming a part of normal life. Increasing knowledge in antioxidant phytoconstituents and include them in daily uses and diet can give sufficient support to human body to fight those diseases. Phytoconstituents and herbal medicine are also important to manage pathological conditions of those diseases caused by free radicals. Explore the antioxidant principles from natural resources; identification and isolation of those phytoconstituents are simultaneously presenting enormous scope for their better therapeutic application for treatment of human disease. Therefore it is time for us, to explore and identify our traditional therapeutic knowledge and plant sources and interpret it according to the recent advancements to fight against oxidative stress, in order to give it a deserving place. Science herbs are considered to have less or no toxic effects would be the best alternative methods when the normal level of antioxidant defense mechanism fails. Many herbal antioxidants are used in the form of neutraceuticals products.