Morphometric evaluation of wound healing in burns treated with Ulmo (Eucryphia cordifolia) honey alone and supplemented with ascorbic acid in guinea pig (Cavia porcellus)
A wound is defined as an interruption in the continuity of tissue, causing cell destruction, alteration of blood vessels, loss of blood components, and hypoxia. Wound healing (scar tissue formation) is a process involving three phases: inflammation, proliferation, and remodeling. It results from a series of interactions between cytokines, growth factors, blood components, and cell elements, which promote the production of components of the basal membrane, prevent dehydration, and increase inflammation and the formation of granulation tissue [1].
Burns are oxidative injuries, which increase the activity of free radicals in the damaged area, resulting in an increase in lipid peroxidation. According to clinical studies, early application of honey to burns has proven effective since it acts on free radicals, which validates its use on lesions of this kind [2, 3]. Furthermore, treatment with honey has presented significantly faster healing of burns than treatment with silver sulfadiazine, polyurethane film, and amniotic membrane [4, 5]. The anti-microbial, anti-inflammatory, and autolytic debridement activity of honey has also been validated [6–8].
Honey consists of water, sugars (especially glucose and fructose), antioxidants, amino acids, vitamins, minerals, glucose oxidase, and gluconic acid, which gives rise to honey’s acidity (pH 3.2 to 4.5). The medical properties of honey depend on its chemical composition, which varies principally as a function of the plant from which it is derived. This has led to the development of various products based on monofloral honeys, for example, the therapeutic Medihoney™ and Active Manuka Honey®, both made from the pollen of the Manuka tree (Europe). The establishment of a controlled designation of origin gives value-added honey. In Chile, Ulmo (Eucryphia cordifolia) honey has been shown to possess excellent bactericidal [9] and healing properties [10].
The stimulant effect of honey is due not only to its sugar content but to other constituents that act in synergy. Thus, the reduction in healing time may be the result of a double effect. On the one hand, prolonged inflammatory response is reduced by suppression of the production and propagation of inflammatory cells at the wound site; on the other, the production of pro-inflammatory cytokines is stimulated, resulting in a proliferation of fibroblasts and epithelial cells [11, 12].
The stress associated with a burn lesion increases the need for ascorbic acid, which is required for collagen synthesis, angiogenesis, and as an antioxidant [13, 14], as has been extensively studied in guinea pigs [15–17]. Horton [18] examined the effects of the treatment based on the administration of vitamins after burn trauma, showing the effects on the synthesis of cardiomyocytes and the secretion of pro-inflammatory cytokines. He also indicated that the combination of antioxidants (vitamins C, E, and A) could provide useful support to the healing effect.
Given the complexity of treating burns and the need for experimental studies offering similar or better alternatives to conventional treatments, the aim of this work was to carry out a histological and morphometric study of the effect of Ulmo honey supplemented with ascorbic acid on the healing and contraction of burn wounds and compare this effect with that of unsupplemented Ulmo honey.