Depletion of reduced glutathione, ascorbic acid, vitamin E and antioxidant defence enzymes in a healing cutaneous wound

In the present investigation the involvement of free radicals in a self-healing cutaneous wound has been demonstrated. The levels of different enzymatic and non-enzymatic antioxidants have been studied in 2, 4, 7 and 14 days old wounds and compared with normal skin. Except for glutathione reductase (GR), all other enzymatic and non-enzymatic antioxidants were found to decrease following wounding. The decrease was 60-70% in superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) at 2, 4 and 7 days, while in the case of catalase (CAT) the decrease was 40-60% during this period. Although a complete recovery in the activity of CAT was observed, SOD and GPx did not recover completely and GST was found to be slightly elevated on 14th day post wounding. Non-enzymatic antioxidants viz. ascorbic acid, vitamin E and glutathione were also found to decrease to about 60-70% and except glutathione none of them was found to recover completely at 14th day post wounding. Interestingly thiobarbituric acid reactive substance (TEARS) expressed as malondialdehyde (MDA) equivalent, a marker of lipid peroxidation, decreased following wounding which could be because of meagre availability of lipid substrate and/or of ascorbic acid. The results indicate that wounding results in loss of different free radical scavengers both enzymatic and nonezymatic which either partially or completely recover following healing.