Rat model of burn wound healing: effect of Botox.

ABSTRACT

Animal models of burn play a crucial role in studying the mechanisms of burn wound progression and the factors that regulate various stages of healing. In this study, using a rat model, we assessed the effect of Botox in the healing process through parameters like transepidermal water loss (TEWL), histological alterations, transforming growth factor beta (TGF-beta1) and tumor necrosis factor alpha (TNF-alpha). Fifty Sprague-Dawley rats were inflicted with 5 cm2 second degree burn and divided into 2 groups; one group was injected intralesionally with Botox and the other with saline. Daily observation and transepidermal water loss measurement were performed. Biopsies were taken on days 0, 3, 8, 14, and 28 for histology and polymerase chain reaction, testing TGF-beta and TNF-alpha. The results showed no significant difference in TEWL except for slightly better preservation of moisture with Botox. Histology revealed relatively better and faster regeneration with Botox, delayed lower grade inflammation, and increase in fibroblasts. TNF-alpha had an acute increase of 21-fold then tapered down while TGF-beta levels increased on day 3 after TNF-alpha, peaked on day 8 and then started to decrease until complete healing. Botox improved the healing process and the cosmetic appearance of burn scar.