ABSTRACT
Abstract Polyphenolics from Rhizophora mangle (R. mangle) have shown wound healing and anti- inflammatory effects that may be potentiated by being associated with ascorbic acid, an important substance for collagen and elastin synthesis that plays a role in tissue repair. In our study, we aimed to formulate an association of R. mangle and ascorbic acid in hydrogels and evaluate the association's cytotoxic and immunomodulatory effects. In a pre-formulation study, three gelling polymers (i.e.xanthan gum, poloxamer and hydroxyethyl cellulose) were tested. The selected polymer (i.e. xanthan gum) was used to evaluate cytotoxic and immunomodulatory effects using flow cytometry. Xanthan gum (1.5%) had a homogeneous appearance, an orange colour, a smooth surface, intense brightness and the typical odour, as well as non-Newtonian pseudoplastic behaviour. With a pH of 5.0-5.3 and a non-cytotoxic profile, xanthan gum induced the proliferation and activation of CD4 +, CD8+ and NK T lymphocytes and the production of IL- 2, IL-4, IL-10, IL-17 and TNF-α cytokines in stimulated splenocytes. The results suggest that the association of R. mangle and ascorbic acid in 1.5% xanthan gum hydrogel may be promising in preparations for wound-healing processes.
ABSTRACT
INTRODUCTION: Necrosis in ischemic cutaneous flaps (ISF) is a type of surgical failure more feared among surgical complications. Currently, synthetic drugs are applied during the treatment of necrosis in ISF and although several substances show improvement in viability, some require application at high systemic doses, which can produce important side effects. Therefore, the search for natural substances with fewer side effects is constant. The use of medicinal plants that stimulate angiogenesis is commonly mentioned in previous studies and in this case Rhizophora mangle L. (R. mangle) highlights that among its main compounds have tannins and flavonoids that are very chemically reactive in various biological activities. This study aimed to associate a natural hydrogel to the 5% extract of R. mangle and to evaluate its potential in the prevention of tissue necrosis in distal portions of ISF in rats, using the model proposed by Macfarlane, et al. (1965). METHODS: Ischemic skin flaps were made in the thin dorsal skin area of 28 Wistar rats and divided into 4 groups, group A: received only saline, group B where the aqueous extract of R. mangle was applied, group C received the 1.5% hydrogel of xanthan gum (XG) + placebo and group D was applied the hydrogel associated with 5% R. mangle extract. Morphometric analyses of the areas of tissue necrosis were performed from photographic records using the software Photoshop® and ImageJ®. In addition, 5 photomicrographs were taken from each histological sample of each animal for histomorphometric analysis that obtained the count of fibroblasts and blood vessels. RESULTS: The mean percentage of necrotic areas was: group (A) - 50,66%, group (B) - 40,49%, group (C) - 37,44% and group (D) - 34,25%. The statistical analysis, using the Kruskal-Wallis test, showed a significant difference (p < 0.001).
