Acaricide activity of extract and an isolated compound of Lithraea brasiliensis on Rhipicephalus microplus and selectivity actions against a non-target organism

• Published in: Veterinary parasitology Vol. 300; p. 109597
• Main Authors: da Silva Lima, Aldilene, Soares Rocha, Ana Paula, Serejo, Rafaela Silva, de Almeida Lima, Graziela Domingues, de Sousa Lima Neto, José, Machado Ferreira, Maria Clara, Viteri Jumbo, Luis O., Costa-Junior, Lívio Martins, de Oliveira, Eugênio Eduardo, da Rocha, Cláudia Quintino
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.12.2021
• Subjects: Acaricides - pharmacology; Animals; Crude extract; Larva; Larvae control; Lethal Dose 50; Natural acaricides; Plant Extracts - pharmacology; Rhipicephalus; Urushiol II; Natural acaricides; Urushiol II; Crude extract; Larvae control
• ISSN: 0304-4017; 1873-2550
• DOI: 10.1016/j.vetpar.2021.109597

Chemical profile, isolation, and assessment of the acaricide potential of Lithraea brasiliensis. [Display omitted] •The ethanolic extract from Lithraea brasiliensis and isolated compound(urushiol II) are promising control of Rhipicephalus microplus larvae.•For acute toxicity in Artemia salina, the extract showed LC50 >100 μg/mL.•The first study to report the Lithraea brasiliensis acaricide activity on Rhipicephalus microplus larvae. Rhipicephalus microplus, known as the cattle tick, is a cause of great economic losses for dairy cattle farming because of its high frequency of occurrence and the difficulty in controlling it. This research characterized the chemical profile and evaluated the in vitro toxicity of crude Lithraea brasiliensis extract and its isolated compound against acaricide-resistant and acaricide-susceptible R. microplus strains. Acaricidal activity was evaluated using a larval immersion test and the selectivity against non-target organisms was assessed on Artemia salina assay. The chemical investigation by high-performance liquid chromatography coupled with mass spectrometry (i.e., HPLC-MS) analysis showed the presence of hydrolysable tannins as well as urushiol derivatives. Column chromatography (CC) was carried out on the extract to obtain fractions and an isolated compound. The extract exhibited significant activity against acaricide-resistant (LC50 0.64 mg/mL) and acaricide-susceptible (LC50 0.76 mg/mL) strains of R. microplus larvae. The isolated compound from the extract (urushiol II), exhibited LC50 of 1.11 mg/mL for acaricide-resistant larvae. For acute toxicity in A. salina, the extract showed LC50>100 μg/mL. Thus, our findings represent the first effort to demonstrate the potential of L. brasiliensis extract and urushiol II as potential natural acaricides to replace or to be integrated into the conventional control of R. microplus larvae.