Assessment of wound contraction, re-epithelialization and histological changes in full thickness excision wounds of rats treated with different concentrations of hydrogen peroxide

Abstract

Purpose: To investigate the impact of treatment with different strengths of hydrogen peroxide (H2O2) on healing of excision-type wounds in rats. Methods: Thirty-two (n = 8) adult wistar rats randomly assigned to four groups A - D were used for the study. Full-thickness excision-type wound was surgically made on each rat on day 0. While wounds in group A, the control, were treated with 0.9 % normal saline, wounds in groups B - D received 1, 3, and 5 % H2O2, respectively. Following the surgical wounding and treatment, the epithelialization time, wound contraction, and histological changes of the wounds were assessed. Results: On day 21, animals in group C recorded 100% wound contraction, whereas in groups A, B and D the contraction degrees of 68.75, 79.33 and 79.00 %, respectively, were reported on the same day. Group C animals treated with 3 % of H2O2 had significantly (p < 0.05) higher degree of wound contraction and epithelialization. Histologically, by day 14, wounds of animals in group C presented with a preponderance of fibrocytes over fibroblasts spread across organized connective tissue fibres. Group C treated animals also had significantly (p<0.05) faster epithelialization. No visible side effects were observed in this group following the treatments. However, the wounds of animals in groups A, B and D showed fibroblasts embedded in loose irregular connective tissue fibres with haemorrhagic lesions, alongside pronounced polymorphonuclear cell infiltration. Conclusion: When compared to other concentrations used in the study, the optimum strength of H2O2 for wound dressing is 3 % in terms of rate of wound contraction, epithelialization time, histological changes and physical tissue damage.