Antiprotozoal and molluscicidal activities of five Brazilian plants.

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 microg/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 LD50 of 138.5 microg/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 microg/mL and showed an LD50 of 143 microg/mL. Screening of plant extracts represents a continuous effort to find new antiparasitic drugs.

Efficacy of components from leaves of Calophyllum brasiliense against Leishmania (Leishmania) amazonensis.

Leishmanicide potential of Calophyllum brasiliense leaves on promastigote and amastigote of Leishmania (Leishmania) amazonensis is evaluated. The LD(50) of dichloromethane extract and hexane fraction for promastigotes was respectively 40 microg/ml and 20 microg/ml. In mouse peritoneal macrophages infected with Leishmania amastigotes the Infection Index decreased respectively 100% and 84.2% in 80 microg/ml and 40 microg/ml concentrations of dichloromethane extract. Hexane fraction decreased infection index respectively by 98.7% and 91.3% within the same concentrations. It was found that pretreatment with dichloromethane extract or with hexane fraction of experimentally infected BALB/c mice decrease the volume of the lesions by L. (L.) amazonensis. Moreover, animals treated topically also revealed healing lesions. Besides, the parasite load in the animals' popliteal lymph nodes was significantly reduced in treated animals, showing that plant components actually control infection. Results show that crude extract and hexane fraction of C. brasiliense reveal a significant in vitro and in vivo leishmanicide activity.

Antileishmanial activity of indole alkaloids from Aspidosperma ramiflorum.

The present study was designated to evaluate the antileishmanial activity of acid and basic fractions that were obtained after acid-basic extraction, from ethanolic 70% crude extract and pure compounds from the stem bark of Aspidosperma ramiflorum. The basic alkaloidal fraction presented a good activity against the extracellular form (promastigotes) of Leishmania (L.) amazonensis (LD(50) value<47 microg/ml). Based on these findings, the basic fraction was fractionated on silica gel column chromatography in a bioassay-guided fractionation affording individual purified ramiflorines A and B. Both ramiflorines A and B showed significant activity against Leishmania (L.) amazonensis (LD(50) values of 16.3+/-1.6 microg/ml and 4.9+/-0.9 microg/ml, respectively). Our results are promising, showing that these compounds are biologically active against Gram-positive bacteria.

Germinação, vigor e sanidade de sementes de fava d'anta (Dimorphandra mollis Benth. ) obtidas de frutos coletados no solo e na planta / Germination, vigor and sanity of "fava d'anta" (Dimorphandra mollis Benth. ) seeds obtained from fruits collected both in the soil and in the plant

O objetivo do trabalho foi avaliar a qualidade fisiológica e sanitária das sementes obtidas a partir de frutos maduros coletados no solo e nas plantas de fava d'anta, espécie medicinal nativa do Cerrado, ameaçada de extinção, cujos frutos são ricos em rutina. O delineamento experimental empregado foi o inteiramente casualizado, com 10 repetições. Cada repetição foi constituída de uma caixa gerbox contendo 15 sementes cada. A qualidade fisiológica foi determinada por meio de testes de germinação e vigor, avaliando-se a porcentagem de germinação, o índice de velocidade de germinação (IVG) e a massa seca das raízes primárias. A qualidade sanitária foi determinada pela identificação dos microorganismos patogênicos associados às sementes, bem como pela porcentagem de ocorrência destes em cada parcela. Os fungos identificados nas sementes pertencem aos gêneros Fusarium, Alternaria, Aspergillus, Cladosporium, Colletrotrichum, Helminthosporium, Nigrospora, Penicillum, Phoma e Phomopsis. Sementes oriundas de frutos coletados no solo foram mais contaminadas por agentes patogênicos e apresentaram germinação (56,67 por cento), vigor e sanidade inferiores às sementes obtidas de frutos coletados na planta.

The aim of this work was to evaluate the physiological and sanitary quality of seeds obtained from mature fruits collected in the soil and in "fava d'anta" plants. Dimorphandra mollis constitutes an endangered medicinal species native to cerrado and presents fruits rich in rutin. The experimental design was completely randomized, with 10 replicates. Each replicate consisted of a gerbox containing 15 seeds each. Physiological quality was assessed through germination and vigor tests by evaluating germination percentage, germination velocity index (GVI), and primary root dry matter. Sanitary quality was evaluated by identifying pathogenic microorganisms associated with the seeds, as well as their occurrence percentage in each plot. The identified fungi belonged to the genera Fusarium, Alternaria, Aspergillus, Cladosporium, Colletotrichum, Helminthosporium, Nigrospora, Penicillium, Phoma and Phomopsis. Seeds from fruits collected in the soil were more contaminated by pathogenic agents and presented lower germination (56.67 percent), vigor and health than seeds from fruits collected in the plant.

Antiprotozoal and molluscicidal activities of five Brazilian plants

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 æg/mL, showed 90.4 ± 11.52 and 88.9 ± 2.20 percent growth inhibition, respectively, of epimastigote forms of Trypanosoma cruzi, whereas N. falcifolia demonstrated an LD50 of 138.5 æg/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 percent lethal to snails at 200 æg/mL and showed an LD50 of 143 æg/mL. Screening of plant extracts represents a continuous effort to find new antiparasitic drugs.