Avaliação da atividade diurética e segurança do uso da Equisetum arvense L. (Cavalinha) em humanos saudáveis

Abstract

Treatment with medicinal plants is described for centuries as part of traditional medicine and the interest for herbal products is growing consistently in present days. Equisetum arvense (horsetail) has a long traditional use in several countries and in Brazil its marketing is regulated. However, the existence of studies on its pharmacological effects and safety of use is questioned. The present study aims to combine to the traditional use and official regulations, new clinical data on the diuretic effect, safety and acute effects on kidney function of E. arvense. Primarily we preceded a literature review with searches by uniterm "Equisetum arvense" in the databases of PubMed, LILACS, SciELO, BVS, Cochrane, and Scopus. At the same time a double-blind randomized clinical trial randomly distributed 36 male healthy volunteers in 6 groups (n = 6), who have gone through a 3 stages treatment. Alternately for 4 days in a row, where given the drug tested, placebo or hydrochlorothiazide, separated by 10 days of wash out. The literature review showed that, despite of a well-documented traditional use and the regulation in some countries, studies on E. arvense are still incomplete for a well-established medical use, based on proven effectiveness and acceptable level of safety, necessitating more research mainly on the clinic area. In the clinical study, the extract of E. arvense demonstrated better acute diuretic effect than negative control and similar to hydrochlorothiazide (25 mg), without significant changes in elimination of electrolytes or urinary catabolites, and no signs of acute toxicity, hepatic, renal or cardiac. Further researches are needed to better clarification of the mechanism of action diuretic, as well as other possible pharmacological actions of this phytomedicine.