In vitro anthelmintic activity of Zanthoxylum simulans essential oil against Haemonchus contortus

The need for new anthelmintic agents with low impact on the environment is becoming urgent. Phytotherapy is an alternative method to control gastrointestinal nematodes in small ruminants. This study aims to determine the composition of Zanthoxylum simulans essential oil (ZSEO) and evaluate the in vitro ovicidal and larvicidal effects of ZSEO on Haemonchus contortus using egg hatch assay, larval development assay (LDA), and larval migration inhibition assay (LMIA). The chemical composition of ZSEO was determined through gas chromatography and mass spectrometry and 94 compounds were identified from the ZSEO. The major constituents of ZSEO were borneol (18.61%), β-elemene (10.87%). ZSEO and borneol both at 40 mg/mL inhibited larval hatching by 100%, with LC50 values of 3.98 and 1.50mg/mL, respectively. The LC50 value of β-elemene was not determined because of its insufficient activity. The results of LDA showed that ZSEO, borneol, and β-elemene all at 40 mg/mL inhibited larval development by 99.8%, 100%, and 55.4%, respectively, and exhibited dose-dependent responses with LC50 values of 4.02, 1.99, and 32.17 mg/mL, respectively. The results of LMIA showed that ZSEO, borneol, and β-elemene all at 40 mg/mL inhibited larval migration by 74.3%, 97.0%, and 53.2%, respectively. ZSEO presented ovicidal and larvicidal activities in vitro. Therefore, Zanthoxylum may be an alternative source of anthelmintic agents to control gastrointestinal nematodes in sheep.