Abstract

The aim of the study was to evaluate the ovicidal and larvicidal efficacy of hexane and ethanolic extracts of Chenopodium ambrosioides (Chenopodiaceae) leaves on the eggs and larvae of Heligmosomoides bakeri in vitro. The eggs of the parasite were obtained from feaces of artificially infected mice, and after 3 and 4 to 5 days incubation at 25°C, L1 and L2 larvae were obtained respectively. The different stages were exposed to 5 concentrations (0.625, 1.25, 2.5, 3.75 and 5 mg.ml-1) and expositions periods were 48 and 24 h for eggs and larvae respectively. Distilled water, 10% gelatine and mebendazole were used in bioassay as negative and positive controls respectively. The hexane and ethanolic extracts of C. ambrosioides had a negative effect on the development of embryos, hatching rate and larval survival of H. bakeri. 61.59 and 39.06% embryonation rates were obtained at 3.75 and 5 mg.ml-1 for hexane extract while 0% hatching rate was obtained at concentration of 5 mg.ml-1 with the same extract. The 50% inhibitory concentration (IC50) on embryonation was 2.84 and 13.53 mg.ml-1 for hexane and ethanolic extracts respectively while the same values were 0.966 and 1.4 mg.ml-1 on embryonated eggs respectively. At the highest concentration larvicidal activity was 100% on both L1 and L2 larvae. As concern larval mortality, the LC50 obtained with hexane and ethanolic extracts and mebendazole was 2.963, 5.208 and 2.243 for L1 larvae and 0.8, 1.661 and 1.602 for L2 larvae respectively. These data show that both extracts of C. ambrosioides possess nematicidal activity justifying its use as worm medicine all over the world.

Key words: Anthelmintic, Chenopodium ambrosioides, extracts, Heligmosomoides bakeri.