Property and manifestation of free radical are similar to those of Ama. Free radicals are atoms, ions or molecules that contain an unpaired electron. Thus, they become electrically charged because number of negatively charged electron does not match with positively charged protons. When a molecule looses or gains a single electron in its outer orbit, it becomes free radical. In fact a free radical is defined as “A molecule that can exist independently for a period of time with one or more unpaired electrons.” Free radicals are unstable chemicals formed in the body during normal metabolism or exposure to environmental toxins such as air, food and water pollution. Free radical helps our body to generate energy and fight infection but when we have too many free radicals they attack healthy cells causing them to age prematurely. Free radical also plays an important role in a number of biological processes such as intra cellular killing of bacteria by phagocytic cells like granulocyte and macrophage. Superoxide, nitric oxide and their reaction product regulate many processes such as control of vascular tone and then blood pressure. They also play key role in intermediary metabolism of various biological compounds. Such radical can even be messenger in a process dubbed redox reaction. Oxygen and hydrogen peroxide are oxidants that are effective bactericidal agent in the conjunction with neutrophils. Above description of free radical show that these species are not only harmful to the body but they are beneficiary too!
Now the similarities between the Ama and the free radical are as follows :-
Similarities in properties:
1. Free radical is an atom/molecule that contains one or more unpaired electron, which requires neutralisation by free radical scavengers. Thus it exists in an incomplete metabolic state which is also the state of Ama described as Avipakvam (incompletely digested/metabolised).
2. Free radicals cause damage to cell membrane and thus the cell is destroyed. This destruction may lead to purification and foul smell generation, which is similar to one of the property of Ama described as durgandham.
3. To seek stability in their structure they quickly attack the healthy molecules of the body and thus setting a chain reaction. The cells throughout body are continuously exposed to these damaging molecules. Same has been described for Ama as “sadanam sarvagatranam.”
Similarities in production:
The primary defence of the body includes the activity of certain enzymes like superoxide dismutase, catalase and glutathione peroxidase. The impairment of these enzymes can lead to production of free radicals. Similarily Ama is also being produced whenever there is malfunction of Agni in the body. Many modern Ayurvedic scientists consider the action of various enzymes as the action of Agni Therefore it may be concluded that impairment of Angi at cellular level causes the generation of free radicals.
2. Some exogenous causes are also responsible for free radical production like pollutants, dangerous chemicals, certain food products. All these may be termed under the heading of Mithyaharavihara.
3. Certain enzymes produce radicals as intermediary substances, which are supposed to go into further metabolism, but they somehow jump out of the normal metabolic cycle and work as harmful entities. In case of Ama, it is seen that Ama is also an intermediary metabolite in the process of digestion at different levels and if the process is not completed or Ama remains as it is, it becomes harmful to body.
4. Certain toxic substances like heavy metals also produce free radicals. Ama is also said to be produced from Visaja dravyas.
Similarities in production of disease:
According to Susruta, a disease is produced in six steps viz. Sancaya, Prakopa, Prasara, Sthanasamsrya Vyakti and Bhedadvstha. In case of diseases produced by Ama, Sancaya of Ama is first step. It happens due to impairment of Agni at that place. Similar is the case with free radicals. At certain site due to impairment in action of free radical scavengers, increased production of free radicals takes place. When this Sancaya or accumulation is in small amount it does not cause any harmful effects, but if treatment is not given, this Sancaya exceeds the threshold. Then it starts producing minimal symptoms, this is the state of Prakopa. After this state, Ama goes into circulation, same is the case with free radicals. Now this Ama requires a site for creating disease in form of Khavaigunya, which should be considered as weakness in any body tissue(weak cell membranes )where Ama may be Sthanasamsrya, or many adhere with this tissue or cells. In case of free radicals also, they look for a site, which is weak and can easily take part in electron exchange with them. Therefore depending upon this site of Khavaigunya different diseases are produced in different manner from same root cause, i. e. Ama or free radicals. This is the stage of Sthanasamsrya. Now symptoms of diseases become clear.
Similarities in Line of treatment:
For Ama basically three types of procedures are required. First is the use of Langhana (Starvation) which helps in load shedding on Agni and production of Ama is decreased. Second is the use of Dipana dravya, which helps in improving status of Angi and enhancing it action. Next is Pacana, done with Pacana dravyas. Pacana dravyas help in digestion of already produce Ama. In protecting body from free radical damages Antioxidant therapy is used which also acts in three ways, as already mentioned, these are : First is by inhibiting the generation of reactive oxygen species. This can be achieved by removing causative factors and can be taken as Langhan karma. Second is by increasing action of antioxidant enzymes like SOD or catalase. This is done by the use of certain drugs, which enhance the action of these coenzymes in other words this may be considered as Dipana karma. Third one is the use of certain substances, which help in neutralising free radicals by either donating or accepting electrons from free radicals. Many vitamins like vitamin C and vitamin E have such properties due to which they can take part in electron transfer reactions and can neutralize free radicals. This activity can be compared to Pacana. Therefore, similarity in line of treatment of both concepts is also seen.
Rohit Ranjan et al. Correlation of Concept of Ama and Free Radical Theory. Int. J. Ayur. Pharma Research, 2014; 2(2): 9-13