Atividade antibacteriana in vitro e potencial cicatrizante in vivo de extratos de casca de jabuticaba

Abstract

One of the main problems faced in Public Health is the antimicrobial resistance aggravation. The jabuticaba skin is known by containing phenolic compounds (PC), which are substances that display antimicrobial activity (AA). In this study it was evaluated t he AA from phenolic compounds, obtained different methods from the jabuticaba skin meal (JSM). The phenolic compounds were quantified by high performance liquid chromatography, and it was studied their action on upon mice wound healing process. The PC were extracted from JSM using four different extraction methods, resulting in four extracts: aqueous, methanolic, ethanolic and acetonic. For antimicrobial activity in vitro, it was chosen four pathogenic bacterial strains (Staphylococcus aureus GL 5674, Staphylococcus aureus GL 8702, Pseudomonas aeruginosa ATCC 27853 and Listeria monocytogenes ATCC 19117), employing the minimum bactericidal concentration (MBC) by broth microdilution. Further, it was analyzed the growth of bacterial colonies in different extract concentration (%): 5.00; 2.50; 1.25; 0.63, 0.32, 0.16, 0.08, determining its MBC. For the in vivo test, it was used 24 male Wistar rats, with 60 days of age, weighing an average of 140 g. Wounds were made on the dorsocervical area of each animal. After this procedure, the rats were randomically arranged into four groups, with six rats each: group I - positive control group, treated with Bactrovet®, containing 0.580 mg of silver sulfadiazine mL -1 ; group II - treated with aqueous solution of the lyophilized JSM ethanolic extract at 10% containing 0.300 mg of PC mL -1 ; group III -treated with aqueous solution of EE at 5% containing 0.150 mg of PC mL -1 and the group IV -treated with aqueous solution of EE at 2.5% containing 0.075 mg of PC mL -1 . The wound site were daily instilled at the same hour with 50 µL of Bactrovet® or 50 µL of EE in different concentrations. Regarding the AA, the aqueous extract were not able to inhibit none of the bacterial strains. However, the ethanolic, acetonic and methanolic extracts inhibited the bacterial growth of all tested strains at the concentration of 1.25%, 2.50% and 5.00%, respectively. The ethanolic extract had the best antimicrobial activity against Gram-positive and negative strains. This potential was attributed to the phytochemicals present in the extract, such as PC, in special catechin, epicatechin and epicatechin gallate, which were the main phenolic compounds found in ethanolic extract, justifying its antimicrobial action. It was observed a progressive reduction on the wound size, the data obtained showed that the group control had a slower recovery in comparison the group treated with the extracts. The extract effectiveness were in the following order, 2.5% > 5% > 10%. Regarding the morphological and microscopic aspect of the wound, it was concluded that the use of the EE, especially at 5% and 2.5%, had a positive relation with rats cutaneous wound healing, by promoting a less intense inflammatory reaction and a quicker wound closure, a potential that could be explored by pharmaceutical industries.