Effect of small molecular weight soybean protein-derived peptide supplementation on attenuating burn injury-induced inflammation and accelerating wound healing in a rat model

The populations most afflicted by burn injuries have limited abilities to support the significant specialized requirements and costs for acute and long-term burn injury care. This article describes the results of optimizing the use of readily absorbed small molecular weight soybean protein enzymolysis-derived peptide to attenuate rat burn injury-induced inflammation and accelerate wound healing. A major full-thickness 30% total body surface area burn-injury rat model was utilized and the systemic white blood cell (WBC) counts, the relative level of stimulation index of respiratory burst, and the inflammatory markers procalcitonin (PCT), tumor necrosis factor-α (TNF-α), chemokine (C–C motif) ligand 3 (CCL-3), chemokine (C–C motif) ligand 11 (CCL-11) and interleukin-10 (IL-10) were assessed. The burn injury-induced neutrophil and macrophage immune cell infiltration of the cutaneous tissues was detected by immunohistochemical analysis of the protein markers myeloperoxidase (MPO) and cluster of differentiation 68 (CD-68). The local induction of the burn injury-induced toll-like receptor 4/nuclear factor kappa-light-chain-enhancer of activated B (TLR4/NF-κB) signaling pathway in the effected cutaneous tissues was determined by the quantification of the protein expression of TLR4 and phosphorylated NF-κB/p65 using Western blots. In addition, burn wound size and healing rate were assessed biweekly for 8 weeks by imaging and measuring the burn wound surface area, and the angiogenesis protein marker of cluster of differentiation 31 (CD-31) expression in cutaneous tissues was also detected by immunohistochemical analysis. The results showed that nutrient supplementation with optimized readily absorbed small molecular weight soybean protein-derived peptide resulted in a dramatic anti-inflammatory effect as evidenced by the significant increase in the burn injury-induced systemic white blood cell counts and their relative level of stimulation index of respiratory burst, reduction in the burn injury-induced activation of NF-κB transcriptional signaling pathways, significant reduction in the local burn injury-induced cutaneous infiltration of neutrophils and macrophages at all measured time points, reduction in wound size and improved rate of burn injury wound healing with increased CD-31 protein expression. These results indicated that dietary supplementation with small molecular weight soybean-derived peptides could be used as an adjunct therapy in burn injury management to reduce inflammation and improve overall patient outcomes.