Effect of papain enzyme administration in pH alteration, VEGF phosphorylation, and its impact on collagen degradation using a rat model of abnormal scarring

Purpose: To analyze the effect of enzyme papain administration, after its injection into abnormal scars of Rattus norvegicus rats, on pH alteration (ΔpH) of scar tissue, vascular endothelial growth factor (VEGF) expression levels, and determine their impact on collagen degradation. Methods: This study used Rattus norvegicus as an experimental animal. The pH measurement of the scar tissue was carried out before papain injection at 12th weeks while abnormal scar was established after papain injection at 15th weeks. Expression of vascular endothelial growth factor (VEGF) was examined by Western blot technique, while hydroxyproline levels were measured using QuickZyme Total Collagen Assay. Results: Changes in ΔpH, VEGF expression, and hydroxyproline levels in the treatment group were significant (p < 0.05) compared to control. Path analysis showed a direct relationship between the parameters (p < 0.01), except for the correlation between VEGF and hydroxyproline value (p = 0.23). Conclusion: Papain enzyme administration increased ΔpH value of abnormal scar tissue. A high dose of papain also causes an increase of collagen degradation process, as a response to angiogenesis deflation.