Abstract

Background: Skin burn is common universal problem that may lead to ugly scarring, serious handicapping. Availability of natural biological treatment to improve its outcome becomes concern of many researchers.

Aim of study: To explore the effect of aloe vera on the angiogenesis process during healing of a fullthickness experimental skin burn.

Materials and methods: Seventy rats were divided into three groups; control group (A), group B and group C. Group B was exposed to full-thickness (FT) skin burn. Group C was exposed to FT skin burn with application of local aloe vera (AV) gel. Each of group B and C was divided into 3 subgroups from which skin specimens were taken at 4,8,12 days. Skin specimenswere prepared for histological and immunohistochemical study by hematoxlyin and eosin (H&E), Masson`s trichrome (MT) and alpha smooth muscle actin (α-SMA). All data were measured morphometrically and statistically analyzed.

Results: After 4 days from inducing FT burn, the initial necrosis and inflammation gradually replaced by increased granulation tissue (GT) on 8^th and 12^th day skin specimens. The collagen deposition of GT increased progressively to make a coarse dense bundles, meanwhile the newly formed capillaries (NFC) of GT were surrounded by pericytes that showed extensive expression of α-SMA early on 4^th and till 8^th day specimens and decreased on 12^th day specimens. AV-treated groups showed relative decrease of α-SMA detection especially in 8^th and 12^th day specimens together with a significant decrease in the inflammatory infiltrate in all phases as well as deposition of more mature and finer collagen fibers compared with burn per se specimens.

Conclusion: In full-thickness skin burn, aloe vera shows a beneficial effect by reducing the inflammation significantly and providing a more mature granulation tissue which could accelerate healing and might produce a sound well-remodeled scar.

Keywords: Full-thickness skin burn, aloe vera, pericytes, inflammation, healing