Anthelmintic potential of essential oils and their components against caprine multi-drug resistant gastrointestinal nematodes of Punjab

The growing widespread emergence of multi-anthelmintic resistance in Punjab state, India has become a major concern in small ruminants, where gastrointestinal nematodes severely affects productivity and their control still heavily relies on the administration of synthetic broad-spectrum anthelmintics. However, the selection for resistance, chemical residues in milk and meat, environmental impact and limitations in organic livestock farming has led to exploration of alternative control strategies. The anthelmintic potential of selected essential oils (EOs) viz. cinnamon (Cinnamomum verum), clove (Syzygium aromaticum), garlic (Allium sativum), lemongrass (Cymbopogon citratus) and peppermint (Mentha piperita) oil as well as essential oil components (EOCs) like cinnamaldehyde, citral, eugenol, menthol and limonene was evaluated by in vitro tests against a caprine gastrointestinal nematode (GIN) population resistant to benzimidazoles, levamisole and ivermectin. The data generated were subjected to probit regression analysis and lethal concentration (LC) values were calculated. Among the tested EOs, garlic and cinnamon oils exhibited the strongest ovicidal activity with respective LC50 (95% CI) values of 36.47 (33.7-38.8) and 39.76 (30.5-50.2) ppm while for EOCs, cinnamaldehyde and eugenol revealed the lowest values, as 68.53 (54.3-83.3) and 114.61 (102.1-127.9) ppm. The findings indicate that selected EOs and EOCs may serve as promising natural alternatives to control multi-resistant GINs in small ruminants.