The efficiency of zinc sulfate immersion bath on improved wound healing via promoting antioxidant activity, gene expression biomarkers, and skin re-epithelization in a common carp-induced wound model

Abstract The experiment was designed to examine the influence of employing three doses of ZnSO 4 on the wound healing process in partially scaled common carp. A total of 240 healthy common carp fish (52.3 ± 0.9 g) were randomly allocated into four equal groups in triplicate (20 each). The first group left without any zinc sulfate treatment and served as a control group, while the second group through the fourth group were immersed in a zinc sulfate bath at a dose of 2.09, 1.05, and 0.53 mg/L corresponding to 1/5, 1/10, and 1/20 of 96 h LC 50 of Zn, (Zn/5, Zn/10, and Zn/20, respectively). After wound induction, tissue specimens were collected within three different intervals (6 h, 24 h, 72 h, and 14 days). The results indicated that the Zn/5 fish group induced doubled folding increments in the expression of transforming growth factor (TGF)‐β1 after 6 h compared to other groups, whereas collagen type I alpha 1 (COL1α1) and metallothionein (Met) genes exhibited a triple folding increment compared to Zn/10 and a fivefold increase compared to control after two days of wound induction. Moreover, vascular endothelial growth factor (VEGF)‐A and fibroblast growth factor (FGF)‐7 genes showed a dose-dependent manner of expression at all examined points after wound induction. Also, all estimated antioxidant biomarker (superoxide-dismutase, SOD; catalase, CAT; glutathione, GSH; and malonaldehyde, MDA) activities were boosted in the Zn/5 group till three days of wound induction compared to all groups. In addition, the reepithelization score and histological alteration results revealed clear improvement in the Zn/5 group, as most muscle fibers appeared regular, straight, and parallel arranged. In contrast, other groups exhibited a detectable limited area of disrupted muscle fibers. Finally, it could be concluded that the ZnSO 4 immersion bath at 1/5 of the calculated LC 50 effectively enhanced the healing process and skin reepithelization.