In vitro study of ivermectin efficiency against the cattle tick, Rhipicephalus (Boophilus) annulatus, among cattle herds in El-Beheira, Egypt

Abstract

Background and aim: Ivermectin (IVM) has been used in veterinary practice to control different parasitic infestations over the past two decades. This study aimed to re-assess the acaricidal effects of IVM, as well as to evaluate its efficacy against Rhipicephalus (Boophilus) annulatus by determining the mortality rate, γ-aminobutyric acid (GABA) level, and oxidative/antioxidative homeostasis (malondialdehyde [MDA] levels and glutathione S-transferase [GST] activities).

Materials and methods: Adult female Rhipicephalus (Boophilus) annulatus were picked from cattle farms in El-Beheira Governorate, Egypt. Ticks were equally allocated to seven experimental groups to assess the acaricidal potential of IVM chemotherapeutics in controlling R. (B.) annulatus. IVM was prepared at three concentrations (11.43, 17.14, and 34.28 µM of IVM).

Results: Mortality rate was calculated among the treated ticks. In addition, GABA, GST, and MDA biomarker levels were monitored. The data revealed a noticeable change in GST activity, a detoxification enzyme found in R. (B.) annulatus, through a critical elevation in mortality percentage.

Conclusion: IVM-induced potent acaricidal effects against R. (B.) annulatus by repressing GST activity for the initial 24 h after treatment. Collectively, this paper reports the efficacy of IVM in a field population of R. (B.) annulatus in Egypt.

Keywords: Rhipicephalus (Boophilus) annulatus; acaricidal; glutathione S-transferase; ivermectin; malondialdehyde; γ-aminobutyric acid.

Figure-1

Map of the study regions (A and B), El-Beheira Governorate, Egypt [Source: Google map].

Figure-2

The mortality rates of treatment groups; ivermectin (IVM) A (IVM 10 mg/mL) and IVM B (IVM 10 mg plus clorsulon 100 mg/mL); groups were analyzed by two-way ANOVA. *p<0.05 and **p<0.01 and ***p<0.001; IVM A-I versus IVM B-I; IVM A-II versus IVM B-II and IVM A-III versus IVM B-III groups by an unpaired t-test.

Figure-3

γ-aminobutyric acid levels in Rhipicephalus (Boophilus) annulatus in the control, ivermectin (IVM) A (IVM 10 mg/mL), and IVM B (IVM 10 mg plus clorsulon 100 mg/mL) groups. *p<0.05 versus control, analyzed by two-way ANOVA.

Figure-4

Glutathione S-transferase activities in Rhipicephalus (Boophilus) annulatus of the control, ivermectin (IVM) A (IVM 10 mg/mL), and IVM B (IVM 10 mg plus clorsulon 100 mg/mL) groups. *p<0.05, **p<0.01, and ***p<0.001 versus control, analyzed by two-way ANOVA. ⁺⁺p<0.01 IVM A-I versus IVM B-I; ^xxxp<0.001 IVM A-II versus IVM B-II, and^##p<0.01 IVM A-III versus IVM B-III groups by unpaired t-test analysis.

Figure-5

Malondialdehyde levels in Rhipicephalus (Boophilus) annulatus of control, ivermectin (IVM) A (IVM 10 mg/mL), and IVM B (IVM 10 mg plus clorsulon 100 mg/mL) groups. *p<0.05 and **p<0.01 versus control, analyzed by two-way ANOVA. ⁺p<0.05 IVM A-I versus IVM B-I groups by unpaired t-test analysis.