Measurement of total antioxidant capacity [TAC]
Measurement of total antioxidant capacity in tissue samples was performed spectrophotometrically with a commercial kit [Rel Assay Diagnostics]. According to the principle of this method, the antioxidant molecules in the studied sample cause the formation of a lighter colored compound by reducing the dark blue-green colored ABTS radical. The absorbance of the resulting color is read in the spectrophotometer at a wavelength of 660 nm (18). The level of antioxidant molecules in the sample is calibrated with the stable antioxidant compound Trolox Equivalent [a vitamin E analog] present in the kit.