Estudo farmacognóstico e atividade antimicrobiana in vitro de folhas de Zanthoxylum fagara (L.) Sarg

Introduction: Zanthoxylum fagara (L.) Sarg. is a medicinal species used by the Cuban population, which has scarce scientific reports. Objective: To evaluate the in vitro antimicrobial activity of Z. fagara leaves. Methodology: Pharmacognostic parameters were determined as established in the WHO standard for plant materials. The in vitro antimicrobial activity for colorimetric microdilution methods was determined to a hydroalcoholic extract obtained by percolation. The physical-chemical parameters, qualitative chemical composition, as well as its content of phenols and total flavonoids were determined for the extract by the Folin-Ciocalteu method and aluminum chloride respectively. Results: The pharmacognostic parameters obtained were: residual moisture (11.5%), total ashes (7.91%), water-soluble ashes (2.64%) and extractable substance (water, 30%, 50%, 70% and 90%). The following metabolites were identified: alkaloids, triterpenes and steroids, essential oils, flavonoids, carbohydrates, phenols and tannins. The 70% hydroalcoholic extract had a characteristic odor, a greenish-yellow color, relative density of 0.9244 ± 0.0651%; pH of 5.97%, refractive index of 1.3605% and total solids of 21.4 mg/100 mL. The content of total phenols and flavonoids was 14.73 µg of gallic acid/mg and 3.11 µg of quercetin/mg respectively. The extract was not active against bacteria and fungi, however, it exhibited potent activity against parasites, with Trypanosoma brucei (IC50 = 2.48) being the most sensitive. Conclusion: The results show the antiparasitic potential of Z. fagara leaves.