THE EFFECT OF PLANT PURINE ALKALOIDS ON HUMAN SERUM ADA ACTIVITIES

چکیده مقاله

Theobromine (3,7-dimethylxanthine) a nd theophylline (1,3-dimethylxanthine) are purine alkaloids and founded in plant sources such as cocoa. Adenosine deaminase (ADA) is the major enzyme of purine metabolism in human and can be found in all human tissues; itis also importa nt in various diseases. The important role of ADA with irreversible hydrolytic catalyzes of ade nosine or deoxyadenos ine to inosine or deoxyinosine, respectively [1-4].In this res earch, the effect of extracted and purified theobromine from cocoa powder and purchased theophylline were investigated on kinetic behavior of adenosine deaminase (ADA) by a UV– Vis spectrophotometer. The effect on therapeutic concentration (100 μM ) of theobromine and theophylline (as drug) were assayed on adenosine deaminase activity in Tris-HCl buffe r (pH 7.15) by UV-VIS spectroscopy and the results were repeated by using the enzymatic method.The results of enzymatic analysis showed that ADA satu ration curve is biphasic and doesn't obey Michaelis-Menten kinetics. Both the obromine and theophylline decreased ADA activity. Furthermore they irreversibly inhi bit the enzymatic activity. More analysis showed they effect on active si te function either directly or by affecting on homotropic effect quality. The results can be consider ed in treatment for ADA-related diseases.