Acaricidal activity of synthetic spilanthol derivative against ticks of medical and veterinary importance

Author(s)

Anholeto, Luis Adriano ; Brancaglion, Guilherme Andrade ; dos Santos, Danilo Martins ; Kapritchkoff, Rafaela Tami Ikeda ; Castro, Karina Neoob de Carvalho ; Canuto, Kirley Marques ; Rodrigues, Rodney Alexandre Ferreira ; Correa, Daniel Souza ; Chagas, Ana Carolina de Souza ; Pastre, Julio Cezar

• Document type: Journal article
• Source: Veterinary Parasitology; v. 327, p. 9-pg., 2024-01-25.

Abstract

The ANESPSAT, a synthetic spilanthol derivative, and its nanoformulation were evaluated against Rhipicephalus microplus and Amblyomma sculptum ticks. ANESPSAT activity was compared with spilanthol and derivatives (ANESPE and others). The compound was synthesized in a gram -scale by a 2 -step process, comprising a direct ester amidation and a Horner -Wadsworth- Emmons reaction. The nanoemulsions were produced by coarse homogenization followed by high-energy ultrasonication, in which hydrodynamic diameter, polydispersity index, and zeta potential remained stable. The spilanthol-eugenol hybrid derivatives did not show significant acaricidal activity. ANESPE killed 83% of the R. microplus larvae at 30 mg.mL(-1), while ANESPSAT killed 97% at 0.5 mg. mL(-1), showing to be the most active compound. Spilanthol and ANESPSAT had similar high mortality rates for tick larvae, with LC50 values of 0.10 and 0.14 mg.mL(-1) for R. microplus larvae, and 0.04 and 0.48 mg.mL(-1) for A. sculptum larvae, respectively. The efficacy of spilanthol was lower against R. microplus engorged females when compared with ANESPSAT, which was highly effective (>98%) against R. microplus engorged females. The nanoemulsion with ANESPSAT was effective against tick females, preventing egg laying and achieving 100% efficacy at 2.5 mg.mL(-1). Spilanthol had only 59% efficacy at 10 mg.mL(-1). The results suggest that ANESPSAT, a natural product derivative, could be used in novel formulations for tick management that might be safer and environmentally friendly. (AU)

• FAPESP's process: 22/00776-8 - Determination of the relationship between ovine ²-globin haplotypes and resistance to infection by Haemonchus contortus in Santa Inês, Texel and White Dorper breeds
• Grantee: Rafaela Tami Ikeda Kapritchkoff
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 21/10004-0 - Nanotechnology applied for the development of botanical acaricides and repellents against ticks of medical and veterinary importance.
• Grantee: Luís Adriano Anholeto
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 21/06661-5 - Enabling technologies for the sustainable chemical synthesis of platform molecules, new chemicals and bioactive compounds
• Grantee: Júlio Cezar Pastre
• Support Opportunities: Program for Research on Bioenergy (BIOEN) - Young Investigators Grants - Phase 2
• FAPESP's process: 18/22214-6 - Towards a convergence of technologies: from sensing and biosensing to information visualization and machine learning for data analysis in clinical diagnosis
• Grantee: Osvaldo Novais de Oliveira Junior
• Support Opportunities: Research Projects - Thematic Grants
• 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