2.2 SOD, GSH and MDA measurement
Colon tissue was cleaned with PBS, homogenized with tissue homogenate and centrifuged. The activities of SOD, MDA and GSH were determined by using SOD, GSH and MDA assay kit (Nanjing Jiancheng Bioengineering Institute, Nanjing, China) according to the manufacturer’s instructions.
2.3 Myeloperoxidase (MPO) assay
The colon tissue was homogenized and the protein concentration was quantified with the BCA protein detection kit (Meilunbio, Liaoning, China). Plasma and colon tissues were measured according to the instructions for the myeloperoxidase (MPO) test kit (Nanjing Jiancheng Bioengineering Institute, Jiangsu, China). The changes of absorbance was measured at 460nm. In the reaction system at 37oC, H2O2 was decompose .into 1μmol as one unit of MPO activity.