Veterinary Parasitology 197 (2013) 374–378 Contents lists available at ScienceDirect Veterinary Parasitology jou rn al h om epa ge: www.elsevier.com/locate/vetpar Short communication Thymus capitatus from Tunisian arid zone: Chemical composition and in vitro anthelmintic effects on Haemonchus contortus Ramzi Boubaker Elandalousi a,∗,1 , Hafidh Akkari b,1 , Fatma B’chir c , Mohamed Gharbi b , Moez Mhadhbi b , Soufia Awadi d , Mohamed Aziz Darghouth b a Laboratoire d’épidémiologie et microbiologie vétérinaires, Institut Pasteur de Tunis and Institut supérieur de biotechnologie, Université de la Manouba, BiotechPôle, BP-66, 2020 Sidi Thabet, Tunisia b Laboratoire de Parasitologie, Université de la Manouba, École Nationale de Médecine Vétérinaire de Sidi Thabet, 2020 Sidi Thabet, Tunisia c Laboratoire des substances naturelles, Institut National de Recherche et d’Analyse physico-chimique – Pôle Technologique Sidi Thabet, 2020, Tunisia d Abattoir régional de Béja, 9000 Béja, Tunisia a r t i c l e i n f o Article history: Received 4 January 2013 Received in revised form 7 May 2013 Accepted 15 May 2013 Keywords: Thymus capitatus Anthelmintic Haemonchus contortus Tunisia a b s t r a c t The increasing prevalence of anthelmintic resistant strains of helminths, the drug residues in animal products and the high cost of conventional anthelmintics has created an inter- est in studying medicinal plants as an alternative source of anthelmintics. Thymus capitatus (Lamiales: Lamiaceae) is used traditionally by people as spices and reported to possess some biological effects. The objective of this study is to evaluate the anthelmintic efficacy of T. capitatus in comparison to albendazole against the gastrointestinal nematodes of sheep. To fulfil the objectives, in vitro anthelmintic activities of crude aqueous and crude ethanolic extracts of aerial parts of T. capitatus were investigated on the eggs and adults of the nema- tode parasite Haemonchus contortus. Both extract types of T. capitatus completely inhibited egg hatching at a concentration close to 2 mg/ml. LC 50 of ethanolic extract of T. capitatus was 0.368 mg/ml while that of aqueous extract was 6.344 mg/ml (p < 0.05). The ethanolic extract showed higher in vitro activity against adult parasites than the aqueous one in terms of the paralysis and/or death of the worms at different hours post-treatment. Dose dependent effect was observed for both extracts. Chemical analyses revealed that the overall profile of both extracts was dominated by oxygenated constituents. In addition, ethanolic extract is mainly composed of phenols among which thymol (71.22%) and camphor (17.18%). As far as the literature could be ascertained, this is the first publication on anthelmintic activity of T. capitatus. The results of the present study suggest that T. capitatus extracts are a promising alternative to the commercially available anthelmintics like albendazole for the treatment of small ruminants’ gastrointestinal nematodes. © 2013 Elsevier B.V. All rights reserved. ∗ Corresponding author. Tel.: +216 20 505 789; fax: +216 71 537 044. E-mail address: ramzi.b.landolsi@gmail.com (R. Boubaker Elandalousi). 1 These authors contributed equally to this study. 1. Introduction Gastrointestinal parasitism with nematodes (especially Haemonchus contortus) has been classified as a major health and welfare problem for small ruminants, particularly in the tropics and sub-tropical countries (Hoste et al., 2005). 0304-4017/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.vetpar.2013.05.016