Avaliação da eficácia terapêutica da mentha crispa no tratamento da giardíase

Abstract

Giardia lamblia infection is endemic in lots of parts of the world. It is estimated that around 200 million of people are parasitized every year, being the disease an important reason for morbidity in the entire world. Current treatment for Giardia infection in humans involves the use of lots of medication. Phitotherapics formulated with Mentha crispa has been used also as giardicides, however its efficacy was not yet established. Hence, the aim of the present study was to evaluate the therapeutic efficacy of Mentha crispa in giardiasis. Initially the research constituted a transversal study for selection of subjects with giardiasis, as well as for determination of prevalence of the main intestinal parasitosis. Afterwards it was realized a double-blind, randomized clinical trial with active control to verify the therapeutic efficacy of Mentha crispa in giardiasis. Coprological samples of 1622 patients from both sexes and 5-year old minimum age were collected for the period May, 2005 to May, 2007 for serial coproscopy examination. It was selected 96 patients with Giardia lamblia who were randomly distributed into two groups: Secnidazol, constituted by 50 patients, who were treated with 2 g of secnidazol (Secnidal®); and Mentha crispa, constituted by 46 subjects treated with 24 mg of Mentha crispa (Giamebil®). Treatments were administrated in a single dose orally. After 7 days, cure was evaluated by immunoenzymatic assay (ELISA) in a freshly fecal sample. In addition, subjects were asked for possible side effects, and they answered a questionnaire about hidrosanitary and socioeconomics aspects. Transversal study results showed 47.78% of prevalence of enteroparasitosis in general. More prevalent protozoa were: Endolimax nana (20.47%), Entamoeba coli (18.56%), Giardia lamblia (7.83%), and Entamoeba histolytica (2.22%). Among helminthes, the most prevalent were: Ascaris lumbricoides (10.36%) and Trichocephalus trichiurus (2.59%). During the analysis of the clinical trial, it was found that the cure rate observed in the Secnidazol group (84.00%) was significantly higher (P = 0.0002) than that observed in Mentha crispa group (47.83%). The medications were well tolerated once it was observed only three low intensity adverse events. It was verified that the occurrence of abdominal pain was significantly higher in Mentha crispa group. However, the report of metallic taste was significantly higher in Secnidazol group. On the other side, the occurrence of nausea did not differ significantly between the groups. The data from socioeconomic questionnaire corroborated the relation between poverty, low schoolarity, absence of sanitation, and the occurrence of Giardia lamblia infection. It follows therefore that, at the dose used, the giardicide effect of Mentha crispa is lower than the secnidazol.