Evaluación de la actividad antimicrobiana de semillas de Leucaena esculenta y Leucaena leucocephala recolectadas en Tlayacapan, Morelos, México

Abstract

and methanol from the same plant material and reduced by vacuum distillation using a rotary evaporator. The antimicrobial activity of the extracts was determined qualitatively and quantitatively in 20 bacterial strains, 3 yeast strains and 4 strains of filamentous fungi. In qualitative tests, antimicrobial activity was found in 6 bacterial strains (all of Staphylococcus aureus and Escherichia coli ), 1 strain of yeast fungi and 4 of mycelial fungi. Using the broth microdilution technique, Escherichia coli CUSI showed MIC values of 2000 and 3000 μg / mL for L. leucocephala and L. esculenta respectively and for Staphylococcus aureus CUSI, MIC = 4000 and 2000 μg / mL for methanolic extracts of L. leucocephala and L. esculenta respectively. The MBC values for the kinetics of death (6000 μg / mL for L. leucocephala and 4000 μg / mL for L. esculenta ) had a significant effect in the first 10 hours of treatment. Meanwhile, Candida glabrata was susceptible to methanolic extracts with MFC values of 4000 μg / mL ( L. leucocephala ) and 6000 μg / mL ( L. esculenta ). In radial growth inhibition technique, it was reported that the lowest values of CF 50 correspond to the acetonic extracts of seeds ( L. lecucocephala = 2.28 mg / mL and L. esculenta = 2.72 mg / mL) having a significant effect against strains Trichophyton mentagrophytes and Aspergillus niger , respectively. In qualitative tests for the determination of secondary metabolites, the presence of alkaloids, triterpenes, monoterpenes, steroids, saponins and phenolic compounds were found, which report antimicrobial potential. The methanolic and acetonic extracts from the seeds of both guajes showed significant biological activity on different strains of bacteria and fungi, thus validating the medicinal use of this resource by the Tlayacapan community.