In vitro antimalarial activity of six Aspidosperma species from the state of Minas Gerais (Brazil).

Ethnomedicinal informations point to some Aspidosperma species (Apocynaceae) as antimalarial plants in Brazil and have motivated the evaluation of six species which were collected in the state of Minas Gerais: A. cylindrocarpon Müll. Arg., A. parvifolium A. DC., A. olivaceum Müll. Arg., A. ramiflorum Müll. Arg., A. spruceanum Benth. ex Müll. Arg. and A. tomentosum Mart.. A total of 23 extracts of different plant parts in different solvents were assayed in vitro against chloroquine-resistant (W2) and chloroquine-sensitive (3D7) strains of Plasmodium falciparum. All the extracts were shown to be active with IC50 values in the range of 5.0 ± 0 2.8 µg/mL to 65.0 ± 4.2 µg/mL. TLC profile of the extracts revealed the presence of alkaloids in the six species assayed. These results seem to confirm the popular use of Aspidosperma species to treat human malaria in Brazil and seem point to alkaloids as the putative active compounds of the assayed species.

Use of glass beads and CF 11 cellulose for removal of leukocytes from malaria-infected human blood in field settings

Passage of malaria infected blood through a two-layered column composed of acid-washed glass beads and CF 11 cellulose removes white cells from parasitized blood. However, because use of glass beads and CF 11 cellulose requires filtration of infected blood separately through these two resins and the addition of ADP, the procedure is time-consuming and may be inapropriate for use in the field, especially when large numbers of blood samples are to be treated. Our modification of this process yields parasitized cells free of contaminating leukocytes, and because of its operational simplicity, large numbers of blood samples can be processed. Our procedure also compares well with those using expensive commercial Sepacell resins in its ability to separate leukocytes from whole blood. As a test of usefulness in molecular biologic investigations, the parasites obtained from the blood of malaria-infected patients using the modified procedure yield genomic DNA whose single copy gene, the circumsporozite gene, efficiently amplifies by polymerase chain reaction