Superoxide dismutase (SOD) and glutathione peroxidase (GPx)
are antioxidants that help protect cells against ROS such as free radicals
and peroxides. Their levels were measured in red blood cells
(RBCs) because these cells are known to be subjected to increased
levels of free radical damage. Moreover, RBCs have a finite life span
in circulation and their sequestration and disposal by macrophages
may be related to the extent of peroxidative damage to their membrane
lipids, cytoskeletal proteins and enzymes (Mohammad et al.,
2009). Whole blood samples containing heparin as an anticoagulant
were centrifuged at 1500g for 10 min at 4 C to obtain packed erythrocytes.
The erythrocytes were carefully removed from the bottom
of the tubes to minimise contamination with leukocytes.