Plant species used in giardiasis treatment: Ethnopharmacology and in vitroevaluation of anti-Giardia activity

Abstract

The aim of this study was to compile the traditional knowledge about plants used for the treatment of giardiasis, And also to carry out experimental research to evaluate the antiGiardia activity of five species. To reach this objective, 398 interviews were performed using a previously prepared questionnaire, Followed by an in vitro evaluation of giardicidal potential of hydroalcoholic leaf extracts of Anacardium occidentaleL., Chenopodium ambrosioidesL., Passiflora edulisSims, Psidium guajavaL., and Stachytarpheta cayennensis(Rich.) Vahl. Among the interviewed people, 55.53% reported the use of plants to treat diarrhea, the most severe symptom of giardiasis. The results indicated 36 species used by this population for these problems. The use of leaves (72.50%) of a single plant (64.25%) collected from backyards and gardens (44.34%) and prepared by decoction were predominant. The majority of the interviewees (85.52%) attributed their cure to the use of plants. In the experimental tests, all extracts inhibited the growth of Giardia lambliatrophozoites in different intensities: A. occidentaleand P. guajavaextracts elicited a moderate activity (250 ≤ IC 50 ≤ 500 μg/ml), C. ambrosioidesand S. cayennensisextracts evoked a high activity (100 ≤ IC 50 ≤ 250 μg/ml), and P. edulisextract showed very high activity (IC 50 ≤ 100 μg/ml). This study shows that an ethnopharmacological approach is useful in the selection of plant materials with potential giardicidal activity. © 2014 Sociedade Brasileira de Farmacognosia. Published by Elsevier Editora Ltda. All rights reserved.