Tissues GST enzyme activity: it measures the conjugation of 1-chloro-2,4-dinitro benzene (CDNB) with reduced glutathione that produces a dinitrophenyl thioether which can be detected by spectrophotometer at 340 nm. One unit of GST activity is defined as the amount of enzyme producing 1 mmol of CDNB-GSH conjugate/min under the conditions of the assay according to the method described by Habig et al. [26 (link)].
Tissues GPx enzyme activity: it was measured as IU/gm wet tissue by the reaction between glutathione remaining after the action of GPx and 5, 5-dithiobis-(2-nitrobenzoic acid) to form a complex that absorbs maximally at 412 nm. Glutathione peroxidase activity of 1 U/mg protein was defined as 1 μg of GSH consumed/min/mg protein [27 ].
Determination of tissues CAT enzyme activity: it assayed by the method of Sinha which based on formation of chromic acetate from dichromate and glacial acetic acid in presence hydrogen peroxide, chromic acetate that produced was measures colorimetrically at 570 nm, one enzyme unit was defined as the amount of enzyme which catalyzed the oxidation of 1 μmole H2O2 per minute under assay conditions [28 (link)].
Tissues PON1 enzyme activity: PON1 activity towards paraoxon (O,O-diethyl-O-p-nitrophenyl phosphate) was determined by measuring the initial rate of substrate hydrolysis to p- nitrophenol, whose absorbance was monitored at 405 nm in the assay mixture, A PON1 activity of 1 U/mg protein was defined as 1 μmol p-nitrophenol formed per minute per mg protein [29 (link)].
Tissues GPx enzyme activity: it was measured as IU/gm wet tissue by the reaction between glutathione remaining after the action of GPx and 5, 5-dithiobis-(2-nitrobenzoic acid) to form a complex that absorbs maximally at 412 nm. Glutathione peroxidase activity of 1 U/mg protein was defined as 1 μg of GSH consumed/min/mg protein [27 ].
Determination of tissues CAT enzyme activity: it assayed by the method of Sinha which based on formation of chromic acetate from dichromate and glacial acetic acid in presence hydrogen peroxide, chromic acetate that produced was measures colorimetrically at 570 nm, one enzyme unit was defined as the amount of enzyme which catalyzed the oxidation of 1 μmole H2O2 per minute under assay conditions [28 (link)].
Tissues PON1 enzyme activity: PON1 activity towards paraoxon (O,O-diethyl-O-p-nitrophenyl phosphate) was determined by measuring the initial rate of substrate hydrolysis to p- nitrophenol, whose absorbance was monitored at 405 nm in the assay mixture, A PON1 activity of 1 U/mg protein was defined as 1 μmol p-nitrophenol formed per minute per mg protein [29 (link)].
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