Potencial cicatrizante de extratos hidroalcoólicos da casca verde da banana (Musa sp.): estudo in vivo e in vitro

Abstract

The scientific literature covers an extensive volume of works focused on the healing of cutaneous wounds as this is a problem that affects a large part of the population. In the search for alternative treatments for this disease, the use of natural products has been gaining prominence since Brazil possesses a great biodiversity of plants. The banana peel is popularly known as a natural cicatrizant because of its phenolic compounds, and is much used in the healing of nipple fissures during breastfeeding. This work, therefore, sought to assess the healing potential of the extracts obtained from the green banana peel in an in vivo and in vitro study. Hydroalcoholic extracts were obtained from dried green peel (dry BPE) and fresh green peel (fresh BPE) by the method of maceration in ethanol and water (9:1). For the in vitro study, human fibroblasts cultured in DMEM (Dulbecco's Modified Eagle Medium, Sigma-Aldrich), and with both extracts at the concentrations of 1%, 2%, 4%, 10%, and 15%, were incubated for 24h and 48h. Cell viability was tested using MTT. The topical product used was obtained by incorporating the extract into Natrosol gel at concentrations of 2%, 4%, and 10% of dry BPE and 4% and 10% of fresh BPE. A gel was also obtained from the natural green peel (natural BP) at 4% concentration. For the study, male Wistar rats (N = 56) divided into 7 groups (n = 8) were used: Group I - Control without treatment, with application of the gel without active components; Group II - natural BP; Group III - dry BPE 2%; Group IV - dry BPE 4%; Group V - dry BPE 10%; Group VI - fresh BPE 4%; and Group VII - fresh BPE 10%. The animals were anesthetized and a cutaneous surgical wound was made in the dorsal region with a dimension of 3cm x 2cm. The treatment was topical and daily for a period of 9 days. On the 10th day the animals were euthanized and the skin samples were sent for routine histological processing for descriptive histopathological analysis of the healing area and semi-automated count of the inflammatory infiltrate. The ratio between the initial and final areas was also calculated for the percentage of wound contraction. The dry BPE at concentrations of 1% and 2% induced fibroblast proliferation while the other concentrations, as well as fresh BPE, reduced the population of these cells. Groups II, III, IV, and V showed greater contraction of the wound compared to the control. According to descriptive analysis, GI presented adhered crust, discrete reepithelization and neutrophilic infiltrate; in GII there was thick adhered crust, extensive but thin reepithelization, dermis remodeling and eosinophilic infiltrate; GII keratin remodeling epidermis and detachment of the crust, remodeling dermis and mixed inflammatory infiltrate; GIV showed discreet and adherent thin crust, extensive and discreet reepithelialization, dermis remodeling and mixed infiltrate; SG presented thick crust, discreet reepithelialization, young granulation tissue and mixed infiltrate; GVI showed thick crust, discreet reepithelialization, remodeling and giant cell infiltration; In GVII there was thick crust, discreet reepithelialization and infiltration with giant cells. Therefore, dry BPE at 2% concentration has shown to be a potential treatment for wound healing due to fibroblast proliferation and epidermis and dermis remodeling.