Hydroxyl Radical (ºOH) Scavenger Power of Tris (hydroxymethyl) Compared to Phosphate Buffer

Abstract

Tris and phosphate buffer are regularly used in experimental investigations. These buffers might have radical scavenger properties toward different kinds of Reactive Oxygen Species (ROS) produced in solutions during chemical reactions like Fenton reaction and gamma radiolysis. Hydroxyl radicals (ºOH) are the most reactive and oxidizing agents having a great potential in oxidization of macromolecules like DNA and proteins. This <em>in vitro</em> study was aimed to evaluate radio-protective effects of Tris and phosphate buffer toward hydroxyl radicals generated by Fenton reaction. Hence, ºOH radicals were produced using a mixture of Hydrogen Peroxideand Ferrous Sulfate, called Fenton system. Human serum albumin (500µM) was prepared in Tris (10mM) and phosphate buffer (10mM), separately. These two samples were incubated with Fenton reaction (Ferrous Sulfate + Hydrogen peroxide) (10 mM) for 30 minutes and carbonyl groups were quantified by spectrophotometric carbonylation assay. The results of this study revealed the values of 1.04 ± 0.02 and 1.73 ± 0.03 for Tris and phosphate buffer treated samples, respectively. In conclusion, these findings confirmed that Tris buffer is a stronger radical scavenger toward ºOH radicals<strong> </strong>than phosphate buffer.<strong> </strong>