Benefits of Stryphnodendron adstringens when associated with hydrogel on wound healing in diabetic rats

Abstract The plant Stryphnodendron adstringens is a species of legume in the genus Stryphnodendron that is found in Brazil. It is also known as “barbatimão-verdadeiro” and it is popularly used in folk medicine due to its healing properties. Purpose: The aim of this study was to evaluate the healing activity of hydrogel, together with an S. adstringens hydroalcoholic extract, in diabetic and non-diabetic rats. Methods: The phytochemical analysis of the S. adstringens hydroalcoholic extract was evaluated through HPLC and its antioxidant activity was measured by the DPPH assay. The cytotoxicity, the scratch assay, and the fibroblast cell proliferation were also evaluated. Forty (40) Wistar rats were submitted to an excision for a full-thickness wound of 1.5 cm × 1.5 cm in their dorsum. The animals were treated twice a day over 16 days, with a rich layer of the corresponding treatment: Hydrogel; Hydrogel associated with 5% S. adstringens hydroalcoholic extract (H + SAHE); S. adstringens hydroalcoholic extract (SAHE); Collagenase with Chloramphenicol; or Carbopol. Morphological and histological analyses of the injury were performed. Results: The phytochemical analysis of SAHE indicated the presence of phenolic compounds, tannins, and flavonoids. The hydroalcoholic extract showed strong antioxidant activities (IC50 = 25.56 ± 1.04 μg/mL). H + SAHE induced the fibroblast proliferation (148 ± 6.9%) and it was not cytotoxic. The association with H + SAHE showed a more pronounced healing activity than did the other treatments in the non-diabetic animals and in the diabetic animals, hence, promoting angiogenesis and reepithelialization. Conclusion: Under these scenarios, this study has demonstrated effectiveness in the recovering wounds of diabetic rats. Graphical abstract