DELGADO, L. A.; DELGADO, Letícia Ataíde.
Résumé:
Antibacterial effect of crude ethanolic extract of Gossypium hirsutum L. Medicinal plants have demonstrated superior healing power and knowledge of their permanent therapeutic properties rooted in the culture tradition. The specie G. hirsutum L. belongs to the family Malvaceae, widely found in the Brazilian Northeast. Its extract presents substances like alkaloids, flavonoids, saponins and tanóides. The biological activity of alkaloids encompasses property, ancient, anticancer, antiparasitic, anti-inflammatory, antimicrobial, insecticide, among others. The objective of this paper is an in vitro evaluation of the antibacterial action of Gossypium hirsutum L. extract against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae in different concentrations. For the pharmacological tests, the substances were solubilized in DMSO and diluted in distilled water. For the evaluation of the antibacterial activity and determination of MIC, the 96-well plate microdilution technique is used. In a 96-well plate, Mueller Hinton broth and the crude ethanolic extract under study at different concentrations. The assay was performed in duplicate. The plates were incubated at 37 ° C for 24-48 hours. The MIC was determined as the lowest concentration of the extract that inhibited the visible growth of the microorganism. After reading the MIC, aliquots of 20 μL were withdrawn from each well that did not show bacterial growth, and transferred to wells of a new plaque, devoid of any antimicrobial. The inoculated plates were aseptically closed and incubated at 35 ° C, and the MBCs were recorded after 48 h. MBC was defined as the lowest extract concentration that results in visible inhibition of microorganism growth. It was observed that the extract presented MIC50 values between 256 μg / mL and greater than 1024 μg / mL and MBC50 values between 256 μg / mL and greater than 1024 μg / mL for the strains tested. In view of the obtained results it can be affirmed that the extract has a promising antibacterial effect against the strains of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa.
