In vitro investigation of Brazilian Cerrado plant extract activity against Plasmodium falciparum, Trypanosoma cruzi and T. brucei gambiense

Abstract

The threatened Brazilian Cerrado biome is an important biodiversity hotspot but still few explored that constitutes a potential reservoir of molecules to treat infectious diseases. We selected eight Cerrado plant species for screening against the erythrocytic stages of Plasmodium falciparum, human intracellular stages of Trypanosoma cruzi and bloodstream forms of T. brucei gambiense, and for their cytotoxicity upon the rat L6-myoblast cell line. Bioassays were performed with 37 hexane, ethyl acetate and ethanol extracts prepared from different plant organs. Activities against parasites were observed for 24 extracts: 9 with anti-P. falciparum, 4 with anti-T. cruzi and 11 with anti-T. brucei gambiense activities. High anti-protozoal activity (IC50 values < 10 μg/mL) without obvious cytotoxicity to L6 cells was observed for eight extracts from plants: Connarus suberosus, Blepharocalyx salicifolius, Psidium laruotteanum and Myrsine guianensis. Overall, studies of plant extracts will contribute to increase the biodiversity knowledge essential for Cerrado conservation and sustainable development.

Brazilian cerrado Qualea grandiflora Mart. leaves exhibit antiplasmodial and trypanocidal activities In vitro

“…For the [ 3 H] hypoxanthine incorporation assay, in vitro extract susceptibility was measured as described by Desjardins and Guillon[ 20 21 ] as routinely performed. [ 22 ] The results were expressed as the means determined from three independent experiments. Stock solution of CQ was prepared in purified water (Milli-Q grade) at 10 mM and was used as antimalarial drug control.…”

“…Extract assays were based on the conversion of a redox-sensitive dye (Resazurin sodium salt, SIGMA) to a fluorescent product by viable cells. [ 22 25 26 ]…”

“…IC 50 and IC 90 values were determined from the dose–response curves with extract concentrations ranging from 100 to 0.05 μg/mL as described. [ 22 ] The results were the mean values ± the SDs. Stock solution of pentamidine was prepared in DMSO at 10 mM and used as drug control.…”

“…Cytotoxicity was determined using the colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide,[ 27 ] and the reduction percentages were measured by absorbance at 540 nm as described. [ 22 ] The concentrations causing 50% (TC 50 ) and 90% (TC 90 ) of cell growth inhibition were obtained from the drug concentration–response curves. The results were expressed as the mean values ± SDs determined from three independent experiments.…”

Scents from Brazilian Cerrado: chemical composition of the essential oil from Psidium laruotteanum Cambess (Myrtaceae)

“…The anti-parasitic activity of extracts (hexane, ethyl acetate and ethanol) from P. laruotteanum was evaluated for Plasmodium falciparum, Trypanosoma cruzi and T. brucei gambiense (6). The ethyl acetate extract from the stems was found to be active against P. falciparum (IC 50 : 16.3 μg/mL), while the hexane and ethyl acetate extracts from the leaves showed activity against T. brucei gambiense (IC 50 : 3.9 μg/mL, and 6.8 μg/mL, respectively).…”