Biocurativos inovadores para o tratamento de feridas contendo Jambu (Acmella oleracea): caracterização físico-química e avaliação de propriedades multifuncionais

Abstract

Aging and chronic diseases are associated with an increase in difficult-to-heal wounds. The global wound care costs was estimated at USD $3.5 billion in 2021. Polymeric wound dressings offer a new approach to repairing skin injuries. Therefore, the aim of the present work is to develop chitosan based wound dressings composed of the methanolic extract of Acmella oleracea leaves. The polymeric films were characterised in terms of their physico-chemical and biological properties. The leaves were crushed and subjected to maceration in metanol 99,8% (v/v). Phenolic compounds and alkamides, such as spilanthol, were identified in the methanolic extract (AOM) by UFLC-QTOF-MS. The extract did not induced cytotoxicity on L929 fibroblasts and murine macrophages. AOM reduced celular production of the inflammatory mediators IL-6, TNF-α, NO and lipid bodies in macrophages by 100%, 96.66%, 46.06% and 97.72%, respectively, at the highest concentration tested (300.00 µg/ml). Antioxidant effects were also observed for AOM. The extract obtained an IC50 of 44.50 ± 4.46 and 127.6 ± 14.42 µg/mL in the DPPH and NO radical scavenging assays, respectively. The reducing power of phosphomolybdenum was 63,56 ± 13,01 of AAR% for quercetin and 104.01 ± 21.29 of AAR% for rutin, and the percentage of lipid peroxidation inhibition was 63.69%. Furthermore, it was observed a reduction of 61,38% in celular production of reactive oxygen species by murine macrophages. The extract showed moderate to high antimicrobial activity against S. aureus, P. aeruginosa, S. epidermidis, E. coli and C. albicans strains (MIC values ≤ 1000 µg/mL). The films were prepared by the solvent casting method, with 2% (w/v) of chitosan, in the absence (QBR) and the presence of diferente concentrations of AOM (Q-AOM5%, Q-AOM2,5% and Q-AOM1%). The films showed uniformity concerning weight and thickness, and good swelling capacity. SEM photomicrographs showed particles of irregular size, most likely the result of crescent extract concentration. Furthermore, the release profile showed that the films were able to release the AOM phytoconstituents in a satisfactory and gradual manner after 8 h of experiment (Q-AOM5%: 67.15 ± 2.16; Q-AOM2.5%: 66.78 ± 2.47; Q-AOM1%: 39.38 ± 0.11). In addition, the films showed a good thermal resistance above the body temperature and a good mechanical resistance. FTIR analysis revealed the formation of intermolecular interactions between the polymer and the AOM phytoconstituents. As with AOM, the films did not show any cytotoxic effects. The films reduced cellular production of the inflammatory mediators IL-6, IL-12 and NO in macrophages by 95,41, 100 and 66,87%, respectively, at the highest concentration of AOM (Q-AOM5%). Antioxidant effects were also observed in the films. The reducing power of phosphomolybdenum was 28.29 ± 3.41 AAR% for quercetin and 46.29 ± 5.58 AAR% for rutin and the percentage of maximum DPPH radical scavenging was 90.41%. The biocuratives also exhibited antimicrobial activity by inhibiting microbial growth and biofilm adhesion of the aforementioned microorganisms. The current work demonstrated that chitosan and AOM biodressings represent an unprecedented formulation for wound care with promising physicochemical properties and bioactive potential. In vivo skin wound models, scratch assay, skin permeation tests and physicochemical stability tests can be performed as an extension of the reported work.