Evaluation of Larvicidal andin Vitro. Antiparasitic Activities of Plants in a Biodiversity Plot in the Altos de Campana National Park, Panama

Abstract

This TDR=WHO project was carried out from 2003 to 2005 in an 0.1-ha biodiversity plot in the Altos de Campana National Park to discover novel active antiparasitic and larvicidal compounds in Panamanian plants. One-hundred-fifty organic plant extracts representing 43 families, 73 genera, and 93 species were tested in a panel of antimalarial (Plasmodium falciparum W2, chloroquine resistant), antileishmanial (Leishmania mexicana amastigotes), antitrypanosomal (Trypanosoma cruzi trypomastigotes), and larvicidal (Aedes aegypti) screens. Of these 150 plant extracts, two (1.3%) (Talisia nervosa and Topobea parasitica) showed significant antimalarial activity (IC 50 values <10 mg=ml), two (1.3%) (Cestrum megalophyllum and Zanthoxylum acuminatum) weak antileishmanial activity (IC 50 values ranging from 10 to 20 mg=ml), one (0.6%) (Zanthoxylum acuminatum) weak antitrypanosomal activity (IC 50 values ranging from 10 to 20 mg=ml), and one (0.6%) (Piper fimbriulatum) larvicidal activity (LC 100 values <30 mg=ml). Ethyl gallate (1) and methyl gallate (2) were isolated from stems of Talisia nervosa by bioassay-guided fractionation. Both (1) and (2) showed weak in vitro antiplasmodial activity against P. falciparum (IC 50 35.3 mM and IC 50 38.0 mM, respectively), but both compounds were less active than chloroquine (IC 50 0.088 mM). Moreover, compounds (1) (IC 50 33.1 mM) and (2) (IC 50 33.6 mM) showed weakly antileishmanial activity (miltefosine: IC 50 0.5 mM), but they were not cytotoxic to Vero mammalian cells.

Plants used by native Amazonian groups from the Nanay River (Peru) for the treatment of malaria

“…In fact, biomineralization is a Plasmodium specific process in which FP (that is lethal for the parasite) is derived from the digestion of haemoglobin that is converted to haemozoin, and can explain drugs pharmacological properties. The analysis of (Renapurkar and Sutar, 1989;Misra et al, 1991;Muñoz et al, 2000;Zirihi et al, 2005;Calderon et al, 2006;De Mesquita et al, 2007;and Table 1). Nonetheless, it is important to remind that nonactivity of plant extracts in vitro must not be interpreted as in vivo inactivity against malaria for different reasons, as the biological and phytochemical limits of the test (due to biodistribution and extraction process), or because of the nonevaluated effects of the remedies (symptomatic medicine or drug effects depending from the cultural construction of the efficacy of the remedy, etc.).…”

Almiramides A−C: Discovery and Development of a New Class of Leishmaniasis Lead Compounds

“…19 Leishmaniasis bioassays were performed using a method previously employed in our laboratory, based on parasite DNA fluorescence. 20 In this latter assay, amphotericin B was used as the positive control and had an IC 50 of 80 ng/mL. Cytotoxicity bioassays were performed following an 3-[4,5- dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) cell proliferation assay protocol with green monkey Vero kidney cells.…”

Fragment-Based Screening of a Natural Product Library against 62 Potential Malaria Drug Targets Employing Native Mass Spectrometry

“…Compounds 5 , 65 6 , 65 7 , 66 9 , 67 27 , 68 85 69 have previously been reported to have anti-Plasmodial activity. Compound 9 had weak activity against P. falciparum 3D7 (61% inhibition at 100 μM) but had a previously reported IC 50 of 9 μM against chloroquine-sensitive (D6, Sierra Leone) and chloroquine-resistant (W2) lines of P. falciparum.…”