Oxidative stress

  The imbalance between free radicals and antioxidants in the human body results in oxidative stress.

  Oxidative stress and benifits :

* During exercise free radicals formed in high amount  which resulted in temporary oxidative stress  in the muscle . These free radicals regulate tissue growth and also stimulate antioxidant production. 

* Mild oxidative stress protect us from many infections & diseases.

   Oxidative stress and harmful activities:

*Inflamations: When there is any bacterial infection macrophages involved in the  fight with the microbes   release free radicales which damage healthy cells to cause inflammation. If there is any kind of oxidative stress during inflammation it causes more release of free radicals to make further oxidative stress & if it is in chronic state then results in diabetes, cardiovascular disorders, arthritis ,etc.

*Neurodegeneration & oxidative stress:

   Generally oxygen is consumed in the brain to perform intense metabolism and release free radicals to support brain cells growth , neuroplasty, cognitive function, etc. If it results in oxidative stress due to excess free radicals :

(a) then Parkinson's disease results due to  brain cells , even death also.

(b) then amyloid plaques accumulated in brain due to alteration of amyloid beta peptides , even resulted into Alzheimer's disease .

Role of Superoxide dismutase , catalase & glutathione  in oxidative stress physiology

           Superoxide dismutase:

 (1) It is commonly called SODs are of 4 types: Cu, Zn- SOD 

                  Fe-SOD

                  Mn-SOD

                  Ni-SOD. .

 It is a kind of mettalo-enzyme .

 (2) It prevents human body from oxidative stress and acts as first line defence mechanism against ROS (Reactive Oxygen Species) mediated cell injury .

 The reaction is like that:

Superoxide anion free radical (O2)------------> molecular Oxygen + Hydrogen peroxide .

    It turns Superoxide into O² and H²O² by the process of dismutation thus, revents oxidative lethality .

(3) SODs are anti-aging ingradients and prevents wrinkles, fine lines, age spots. It also heal wounds .

                       Catalase

         Hydrogen peroxide is very toxic to living cells .Catalase converts hydrogen peroxide into water and oxygen Thus , it plays a vital role to prevent the tissue from oxidative stress .

               Catalase

H²O²---------------------------> H²O +O² 

 Catalase deficiency causes hyperyrnsion. diabetes mellitus,anaemia , Alzheimer's disease , Parkinson's Disease , bipolar disorder , etc .

         Glutathione

(1) It is the combination of three amino acids Cysteine , Glutamic acid and Glycine 

 (2) It acts as antioxidant and converts heavy metalic toxins and fat soluble toxins into water soluble form so that may be eliminated in the form of urine and stool.

e.g. it reduces Hg-toxicity :

           Glutathione acts on Methyl-mercury and prevents further binding of this toxic substance to other cellular proteins .

           Deficiency of Glutathione results in oxidative damage .