Korean J Parasitol.  2016 Aug;54(4):415-421. 10.3347/kjp.2016.54.4.415.

Antiplasmodial and Cytotoxic Activities of Toad Venoms from Southern Amazon, Brazil

• Banfi FF
• Guedes KD
• Andrighetti CR
• Aguiar AC
• Debiasi BW
• Noronha JD
• Rodrigues
• Júnior GM
• Sanchez BA

• KMID: 2353570
• DOI: http://doi.org/10.3347/kjp.2016.54.4.415

Abstract

The drug-resistance of malaria parasites is the main problem in the disease control. The huge Brazilian biodiversity promotes the search for new compounds, where the animal kingdom is proving to be a promising source of bioactive compounds. The main objective of this study was to evaluate the antiplasmodial and cytotoxic activity of the compounds obtained from the toad venoms of Brazilian Amazon. Toad venoms were collected from the secretion of Rhinella marina and Rhaebo guttatus in Mato Grosso State, Brazil. The powder was extracted at room temperature, yielding 2 extracts (RG and RM) and a substance ('1') identified as a bufadienolide, named telocinobufagin. Growth inhibition, intraerythrocytic development, and parasite morphology were evaluated in culture by microscopic observations of Giemsa-stained thin blood films. Cytotoxicity was determined against HepG2 and BGM cells by MTT and neutral red assays. The 2 extracts and the pure substance ('1') tested were active against chloroquine-resistant Plasmodium falciparum strain, demonstrating lower ICâ‚…â‚€ values. In cytotoxic tests, the 2 extracts and substance '1' showed pronounced lethal effects on chloroquine-resistant P. faciparum strain and low cytotoxic effect, highlighting toad parotoid gland secretions as a promising source of novel lead antiplasmodial compounds.

Keyword

Plasmodium falciparum; antiplasmodial effect; toad venom; bufadienolide; malaria chemotherapy

MeSH Terms

Amphibian Venoms*
Animals
Biodiversity
Brazil*
Bufo marinus
Malaria
Neutral Red
Parasites
Plasmodium falciparum
Amphibian Venoms
Neutral Red