Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 12, 2012
Publication Date: N/A
The use of "green" processes for the synthesis of nanoparticles is a new branch of nanotechnology. However, knowledge of the bioactivity of nanoparticles against mosquitoes and malaria parasites is limited. We tested silver nanoparticles (average size 450 nm) bio-reduced in 5% Cassia occidentalis leaf broth (from aqueous 1 mM AgNO3) against the malaria vector Anopheles stephensi, and the malaria parasite Plasmodium falciparum. Toxicity assays against 4th instar Anopheles stephensi larvae, at nanoparticle concentrations of 3 mg/l, 1.50 mg/l, and 0.75 mg/l, indicated median lethal concentrations (LC50) of 0.30 ppm, 0.41 ppm, and 2.12 ppm, respectively. Adult longevity (days) in male and female mosquitoes exposed as larvae to 0.1 ppm silver nanoparticles was reduced by 29 % (p <0.05). The number of eggs laid by females exposed as larvae to 0.1 ppm silver nanoparticles decreased by 32% (p <0.05). When tested in vitro against Plasmodium falciparum, silver nanoparticles inhibited development in chloroquine-resistant and chloroquine-sensitive parasites. Levels of inhibition (sensitive/resistant) at the 25, 50, 75, and 100 µg/ml nanoparticle concentrations were 32.0%/38.9%, 23.5%/30.9%, 11.0%/19.8%, and 6.05%/11.1 %, respectively.