Punica granatum peel ethanolic extract exhibits acaricidal activity against Rhipicephalus sanguineus: in vitro and in vivo study

Abstract

Objective: To evaluate natural, environmentally safe alternatives for controlling hard ticks in response to emerging resistance against commonly used acaricides. Methods: Punica granatum peel ethanolic extract (PPE) was prepared and then chemically characterized using liquid chromatography-electrospray ionization-tandem mass spectrometry. The adult immersion test was used to evaluate the in vitro anti-tick activity of PPE at the concentrations of 12.5, 25, 50, 100, and 200 mg/mL. The effect of PPE on tick counts and antioxidant activity in artificially infested dogs was assessed for 7 days after application. Results: Chromatographic analysis detected 8 O-glycosylated flavonoids as well as catechin, apigenin, luteolin, and procyanidin. In vitro, immersing adult ticks in 35 mg/mL PPE for 5 min resulted in 50% mortality after 6 hours (LC50). In the in vivo trial, tick-infested dogs sprayed with PPE (35 mg/mL) had significantly lower tick counts than untreated infested controls on days 2, 4, and 7 after treatment, with the maximum count reduction on day 7 (4.67 ± 1.53 in treated dogs vs 81.7 ± 5.0 in controls). In vivo results showed that PPE treatment improved antioxidant activity in tick-infested dogs, increasing glutathione reductase, glutathione peroxidase, and catalase levels while decreasing malondialdehyde. Conclusions: In vivo results showed that PPE treatment improved antioxidant activity in tick-infested dogs, increasing glutathione reductase, glutathione peroxidase, and catalase levels while decreasing malondialdehyde. Clinical Relevance: This study is the first to show the acaricidal activity of PPE against tick species. The results suggest the potential of this botanical byproduct as an alternative to chemical acaricides for tick control.