Prolonged mosquitocidal activity of Siparuna guianensis essential oil encapsulated in chitosan nanoparticles

Abstract

Background The use of synthetic insecticides is one of the most common strategies for controlling disease vectors such as mosquitos. However, their overuse can result in serious risks to human health, to the environment, as well as to the selection of insecticidal resistant insect strains. The development of efficient and eco-friendly insect control is urgent, and essential oils have been presented as potential alternatives to synthetic insecticides. Moreover, nanoencapsulation techniques can enhance their efficiency by protecting from degradation and providing a controlled release rate. Results We assessed the potential of chitosan nanoparticles in encapsulating Siparuna guianensis essential oil, and maintaining its efficiency and prolonging its activity for the control of Aedes aegypti larvae. The encapsulation was characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA), with an encapsulation efficiency ranging from 84.8% to 88.0%. Toxicity studies have demonstrated efficacy against mosquito larvae over 50% for 19 days with 100% mortality during the first week. This persistent action is presumably due to the enhanced contact and slow and maintained release conferred by chitosan nanoparticles. Furthermore, the exposure of aquatic non-target organisms (e.g. embryos and small adult fishes) revealed adequate selectivity of these nanoparticles. Conclusions The encapsulation of S . guianensis essential oil in chitosan nanoparticles showed promising potential as a larvicide control alternative and should be considered within strategies for fighting Ae . aegypti .

Essential Oils and Mono/bi/tri-Metallic Nanocomposites as Alternative Sources of Antimicrobial Agents to Combat Multidrug-Resistant Pathogenic Microorganisms: An Overview

“…Scandorieiro et al [201] reported that the combination of silver NPs with Origanum vulgare EO resulted in synergistic antimicrobial activities against E. coli, A. baumannii, and S. aureus. Similarly, hydroxyapatite NPs with peppermint EO against S. aureus, E. faecium, E. coli, P. aeruginosa, and C. parapsilosis [202], olive EO with lipid nanoparticles against P. pyogenes and S. aureus [203], Siparuna guianensis EO with chitosan NPs against A. aegypti [187] showed enhanced antimicrobial effects. In addition, rosemary and oregano EOs, with silver and zinc oxide NPs incorporated into pullulan films were effective against pathogenic microorganisms such as S. aureus, L. monocytogenes, E. coli, and S. typhimurium [196], cinnamon EO with chitosan NPs against E. coli and S. aureus [204] also had synergistic antimicrobial activities.…”

“…Soybean oil with sodium dodecyl sulfate against S. aureus as nanoemulsion [181], Schinus molle with chitosan against Aspergillus parasiticus as nanoprecipitation [182], Zataria multiflora with lipid phase (glyceryl monostearat) and precirol against Aspergillus ochraceus, Aspergillus niger, Aspergillus flavus, Alternaria solani, Rhizoctonia solani, and Rhizopus stolonifer as solid-lipid nanoparticles [183]. In addition, Gaultheria procumbens with chitosan-cinnamic acid microgel against A. flavus as microencapsulation [184], Thymus capitatus with sodium dodecyl sulfate against E. coli and B. subtilis as nanoencapsulation [185], cardamom EO with chitosan against E. coli and S. aureus as nanocomposites [186], and Siparuna guianensis with chitosan against larvicide Aedes aegypti as nanoencapsulation [187].…”

Rethinking biorational insecticides for pest management: unintended effects and consequences

“…Insect control measures, such as the control of agricultural insect pests and aquatic insects that transmit human diseases, are becoming a cause of contamination of aquatic environments with biorational insecticides . Indeed, there is growing evidence of high activity of botanicals against mosquitos with no effects or even stimulatory effects on aquatic predators of mosquito larvae . In contrast, other categories of biorational insecticides can cause adverse effects on non‐target aquatic organisms .…”

Nanosystems for the Encapsulation of Natural Products: The Case of Chitosan Biopolymer as a Matrix

“…For example, heat exposure of EOs may cause epimerization, oxidation, and degradation of some of their chemical compounds. Their sensitivity can also lead to adverse effects in humans such as hypersensitivity reaction and allergic dermatitis due to the chemical conversion of some constituents after atmospheric exposure [ 3 , 119 , 176 , 177 , 178 , 179 , 180 , 181 ]. Another problem is the high volatility of EOs [ 116 ] and one more limitation is their irregular dispersion in food industry use [ 2 ].…”