Acaricides containing zein nanoparticles: A tool for a lower impact control of the cattle tick Rhipicephalus microplus

Author(s)

Figueiredo, Amanda ; Anholeto, Luis Adriano ; Cola, Diego Faria ; Fantatto, Rafaela Regina ; Gainza, Yousmel Aleman ; dos Santos, Isabella Barbosa ; Vicozzi, Gabriel Pedroso ; Avila, Daiana Silva ; Fraceto, Leonardo Fernandes ; Chagas, Ana Carolina de Souza

• Document type: Journal article
• Source: Veterinary Parasitology; v. 318, p. 11-pg., 2023-04-11.

Abstract

Nanoformulations containing zein nanoparticles (ZN) can promote the stability and protection of molecules with acaricidal activity. The present study sought to develop nanoformulations with ZN associated with cypermethrin (CYPE) + chlorpyrifos (CHLO) + a plant compound (citral, menthol or limonene), characterize them, and verify their efficacy against Rhipicephalus microplus ticks. Additionally, we aimed to assess its safety in nontarget nematodes found in soil at a site subjected to contamination by acaricides. The nanoformulations were char-acterized by dynamic light scattering and nanoparticle tracking analysis. Nanoformulations 1 (ZN+CYPE+-CHLO+citral), 2 (ZN+CYPE+CHLO+menthol), and 3 (ZN+CYPE+CHLO+limonene) were measured for diameter, polydispersion, zeta potential, concentration, and encapsulation efficiency. Nanoformulations 1, 2, and 3 were evaluated in a range from 0.004 to 0.466 mg/mL on R. microplus larvae and caused mortality > 80% at concentrations above 0.029 mg/mL. The commercial acaricide Colosso (R) (CYPE 15 g + CHLO 25 g + citronellal 1 g) was evaluated also from 0.004 to 0.512 mg/mL and resulted in 71.9% larval mortality at 0.064 mg/mL. Formulations 1, 2, and 3 at 0.466 mg/mL showed acaricidal efficacy of 50.2%, 40.5%, and 60.1% on engorged females, respectively, while Colosso (R) at 0.512 mg/mL obtained only 39.4%. The nanoformulations exhibited long residual period of activity and lower toxicity to nontarget nematodes. ZN was able to protect the active compounds against degradation during the storage period. Thus, ZN can be an alternative for the development of new acaricidal formulations using lower concentrations of active compounds. (AU)

• FAPESP's process: 19/20185-1 - Antiparasitic and antimicrobial activity of spilanthol: study of the effects on ticks of medical and veterinary importance and against pathogens transmitted by them
• Grantee: Luís Adriano Anholeto
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 18/16070-1 - Study of the impact of gastrointestinal nematodes infection on the performance of Morada Nova Lambs for development of a targeted selective treatment
• Grantee: Isabella Barbosa dos Santos
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 17/13249-8 - Nanotechnology applied to elaboration of synthetic acaricides associated with plant isolates for the control of Rhipicephalus (b.) microplus
• Grantee: Amanda Figueiredo
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 17/21004-5 - Agriculture, micro/nanotechnology and environment: from evaluation of the mechanisms of action to studies of transport and toxicity
• Grantee: Leonardo Fernandes Fraceto
• Support Opportunities: Research Projects - Thematic Grants