Evaluation of ovicidal and larvicidal activity of ten plant extracts against Ancylostoma spp.

Abstract

Several investigations have highlighted coproparasitological Ancylostoma spp. as the helminth species that most frequently parasitize the domestic dog, causing possible damage to the host such as irritability, anorexia, severe anemia and death. Hookworms are intestinal parasites that spend part of their life cycle in the soil, with short periods for egg hatching and larval maturation. It is essential that these two processes occur, so that the parasites may reach their infective stage. The present study aimed to evaluate the in vitro ovicidal and larvicidal properties of extracts from toxic plants collected in the Paraíba Valley region, Brazil, against Ancylostoma spp. Hydroalcoholic extracts were obtained from 10 plants, by the Soxhlet method, concentrated by solvent evaporation, and the final concentration of extract was adjusted to 10% of the crude extract. Fecal samples from naturally infected dogs were used, from which hookworm eggs were purified, and in parallel culture of larvae was performed using the method of Harada-Mori. Between the plants evaluated, four showed promising results, namely: Allamanda cathartica L. (Apocynaceae), Nerium
oleander L. (Apocynaceae), Mirabilis jalapa L. (Nyctaginaceae) and Brugmansia suaveolens Willd. (Solanaceae), particularly the last two, which showed 100% larvicidal activity at a dilution of 12.5mg/ml, thereby demonstrating the potential use of these extracts for environmental decontamination and the control of Ancylostoma spp. larvae.