Epidermal Growth Factor and Tocotrienol-Rich Fraction Cream Formulation Accelerates Burn Healing Process Based on Its Gene Expression Pattern in Deep Partial-Thickness Burn Wound Model

Our previous study has demonstrated that epidermal growth factor (EGF) with tocotrienol-rich fraction (TRF) cream formulation accelerating postburn wound healing with deep partial-thickness burn in rats. Current study was conducted to determine the gene expression levels related to burn wound healing process. A total of 180 Sprague-Dawley rats were randomly divided into 6 groups: untreated control, treated with Silverdin cream, base cream, base cream with 0.00075% EGF, base cream with 3% TRF or base cream with 0.00075% EGF, and 3% TRF, respectively. Burn wounds were created and the above-mentioned creams were applied once daily. Six animals from each group were sacrificed on days 3, 7, 11, 14, and 21 postburn. RNA was extracted from wound tissues and quantitative real-time polymerase chain reaction was performed to analyze the 9 wound healing-related genes against time postburn. Results demonstrated that topically applied EGF + TRF formulation downregulated the expression levels of IL-6 (interluekin-6), TNF-α (tumor necrosis factor-α) and iNOS (inducible nitric oxide synthase) throughout the whole healing process. TGF-β1 (transforming growth factor-β) and VEGF-A (vascular endothelial growth factor-A) were reduced on day 14 postburn. On the contrary, increased expression of Collagen-1 in the early stage of wound healing was observed with no effects on epidemal growth factor receptor (EGFR). The results showed beneficial application of EGF + TRF cream in the treatment of burn wound since it accelerated wound healing by relieving oxidative stress, decreasing inflammation, and promoting proper tissue modelling in the burn wound.