Effect of GHK-D-Ala peptide on innate immunity mechanisms and lipid peroxidation processes in infected wounds

The objective is to study the effects of Gly-His-Lys-D-Ala (GHK-D-Ala) peptide on mechanisms of innate immunity and lipid peroxidation processes in infected wound. Materials and methods. The experiments were carried out on 80 Wistar male rats. The infected wound was modeled by applying a full-layer wound on the back and performing primary wound surgery with primary suturing 24 hours later. GHK-D-Ala peptide was injected at a dose of 0.5 µg/kg into the wound area every day for 30 days. The phagocytic activity of blood neutrophils was studied in spontaneous and stimulated nitroblue tetrazolium reduction test (NBT-test). The activity of lipid peroxidation (LPO) processes in rats’ blood serum was assessed by the content of malondialdehyde (MDA) and acylhydroperoxides (AHP). Results. GHK-D-Ala administration had a positive effect on both phagocytosis mechanisms and the level of LPO products in comparison with the control group. There was a significant increase in NST-positive neutrophils in the spontaneous test against peptide administration on days 3, 7, 10, and 30 (p˂0.001) and in the stimulated NST test on days 3, 7, and 10 (p < 0.001). The functional neutrophil reserve had been significantly increased by day 10 (p˂0.05) and had been significantly lower by day 30 (p < 0.05). Phagocytic index and phagocytic number were significantly higher on days 3 and 10 (p < 0.01). The phagocyte activity index significantly increased on days 3 and 10 (p < 0.05-0.001).A significant decrease in the MDA concentration was demonstrated on days 3, 7, 10, and 30 (p<0,001). There was a significant decrease in the content of AGP on days 3, 7, 10 and 30 (p < 0.001). Conclusion. The corrective effect of Gly-His-Lys-D-Ala peptide on the phagocytic activity of granulocytes and the processes of lipid peroxidation in infected skin wounds was established.