Antiprotozoal and molluscicidal activities of five Brazilian plants

Abstract

Leishmaniasis, Chagas' disease and schistosomiasis (bilharzia) are parasitic diseases with wide distribution on the American continent, affecting millions of people. In the present study, biological assays for antiprotozoal and molluscicidal activities were carried out with ethanolic extracts of plant species from the Brazilian part of the Upper Paraná River. Crude extracts were obtained by percolation with absolute ethanol from the leaves of Cayaponia podantha Cogn., Nectandra falcifolia (Nees) Castiglioni and Paullinia elegans Cambess., as well as from the aerial parts of Helicteres gardneriana St. Hil. & Naud. and Melochia arenosa Benth., all belonging to genera used in folk medicine. Trypanocidal activity of plants was assayed on epimastigote cultures in liver infusion tryptose. Anti-leishmanial activity was determined over cultures of promastigote forms of the parasite in Schneider's Drosophila medium. Microscopic countings of parasites, after their incubation in the presence of different concentrations of the crude extracts, were made in order to determine the percentage of growth inhibition. C. podantha and M. arenosa, at a concentration of 10 µg/mL, showed 90.4 ± 11.52 and 88.9 ± 2.20% growth inhibition, respectively, of epimastigote forms of Trypanosoma cruzi, whereas N. falcifolia demonstrated an LD 50 of 138.5 µg/mL against promastigote forms of Leishmania (Viannia) braziliensis. Regarding molluscicidal activity, the acute toxicity of the extracts on Biomphalaria glabrata was evaluated by a rapid screening procedure. M. arenosa was 100% lethal to snails at 200 µg/mL and showed an LD 50 of 143 µg/mL. Screening of plant extracts represents a continuous effort to find new antiparasitic drugs.

Evaluación in vitro de la actividad anti Trypanosoma cruzi de aceites esenciales de diez plantas medicinales

“…Se ha reportado que el extracto de la hoja de B. dracunculifolia, a una concentración de 3 mg/mL, produjo 100% de lisis de formas tripomastigotes de T. cruzi (13) ; los extractos y fracciones de A. amazonicus mostraron lisis de las formas tripomasigotes de T. cruzi in vitro (14) ; otros investigadores también han demostrado el efecto tripanocida de diversos extractos vegetales (10,15,16) , así como de diversas estructuras terpénicas contra uno o todos los estadíos de T. cruzi (17)(18)(19)(20) . También han mostrado efecto tripanocida algunos alcaloides (21)(22)(23) , flavonoides (24)(25)(26) , lignanos (27) y artemisininas (28) .…”

Medicinal plants and their bioactive constituents: A review of bioactivity against Schistosoma mansoni

“…Extracts were obtained from the leaves of Cayaponia podantha, Nectandra falcifolia, Castiglioni and Paullinia elegans, as well as the aerial parts of Helicteres gardneriana, Melochia arenosa, all belonging to the genera used in popular medicine. Regarding to molluscicidal activity, acute toxicity of M. arenosa in B. glabrata was lethal to 100% (Truiti et al, 2005).…”

Employing photoacoustic spectroscopy in the evaluation of the skin permeation profile of emulsion containing antioxidant phenolic-rich extract ofMelochia arenosa

“…In those studies, the extract of Melochia arenosa Benth. (Malvaceae) presented antimicrobial activity (Truiti et al, 2005(Truiti et al, , 2006 and the preliminary phytochemical investigation carried out by standard methods indicated the presence of phenolic compounds. These compounds also have been found in species of the genus, such as M. corchorifolia L., M. chamaedrys A.…”