ORIGINAL PAPER Ovicidal and larvicidal activity of crude extracts of Melia azedarach against Haemonchus contortus (Strongylida) Chinnaperumal Kamaraj & Abdul Abdul Rahuman & Asokan Bagavan & Mohamed Jamal Mohamed & Gandhi Elango & Govindasamy Rajakumar & Abdul Abduz Zahir & Thirunavukkarasu Santhoshkumar & Sampath Marimuthu Received: 10 December 2009 / Accepted: 13 January 2010 / Published online: 23 February 2010 # Springer-Verlag 2010 Abstract The rapid development of anthelmintic resis- tance, associated with the high cost of the available anthelmintic drugs, has limited the success of gastrointes- tinal nematodiosis control in sheep and goats and thus created interest in studying medicinal plants as an alterna- tive source of anthelmintics. The aim of this study was carried out to evaluate the anthelmintic activity of the leaves and seed aqueous and hydro-alcoholic extracts of Melia azedarach L. (Meliaceae) were tested for in vitro ovicidal and larvicidal activity against Haemonchus con- tortus (Strongylida). Both extracts were evaluated at five concentrations: 12.5, 6.2, 3.12, 1.56, and 0.78 mg/ml. The leaves aqueous and hydro-alcoholic extracts inhibited 99.4% and 100% of the egg hatching and 100% of larval development at 12.5 mg/ml, respectively. In a similar way, the leaves hydro-alcoholic extract was the most active on egg inhibition (ED 50 =1.97 and ED 90 =5.05 mg/ml), leaves and seed aqueous and hydro-alcoholic extracts showed the best inhibition of larval development (ED 50 =3.01, 2.43, 3.17, 2.40, and ED 90 =10.53, 8.14, 11.94, and 8.19 mg/ml), respectively. These results suggest that utilization of M. azedarach extracts is useful in the control of H. contortus. Introduction Gastrointestinal nematodes remain a major constraint for the breeding of small ruminants both in developed and developing countries. The usual mode of control of these parasitic diseases was based on the repeated, strategic use of drug treatment impaired by the increasing development and resistance against a number of anthelmintics in worm populations. This worldwide problem explains the current interest in the search for alternative solutions in order to reduce on chemotherapy (Waller 1999). In particular, there is renewed interest in ethnoveterinary medicine and plants with anthelmintic properties in both temperate and tropical counties (Hammond et al. 1997; Waller et al. 2001). Compared with other parasitic nematodes, Haemonchus contortus is a highly pathogenic parasite of small ruminants and is capable of causing acute disease and high mortality in all classes of live stock. Haemonchosis is characterized by hemorrhagic anemia attributable to blood loss via the bloodsucking activities of worms in the abomasum (Allonby and Urquhart 1975; Urquhart et al. 1996). Commercial anthelmintics have been used for some decades throughout the world to minimize the losses caused by helminth infections. However, the threats of anthelmintic resistance, risk of residue, availability, and high cost especially to farmers of low income in developing countries have led to the need of other alternative control methods (Baker et al. 1992). Options like biological control, vaccine, and tradi- tional medicinal plants are being examined in different parts of the world (Bain 1999; Chandrawathani et al. 2003; Githiori 2004). Screening and proper evaluation of the claimed medicinal plants could offer the possible alternatives that may both be sustainable and environmentally acceptable. In this context, leaves and seeds of Melia azedarach were selected based on the reported anthelmintic properties (Hördegen et al. 2003; Maciel et al. 2006). M. azedarach L. is known as Chinaberry or Persian lilac tree, and it is a deciduous tree that is native to northwestern India and has long been recognized for its insecticidal C. Kamaraj : A. A. Rahuman (*) : A. Bagavan : M. J. Mohamed : G. Elango : G. Rajakumar : A. A. Zahir : T. Santhoshkumar : S. Marimuthu Unit of Bioactive Natural Products, Post Graduate and Research Department of Zoology, C. Abdul Hakeem College, Melvisharam 632 509 Vellore District( Tamil Nadu, India e-mail: abdulrahuman6@hotmail.com Parasitol Res (2010) 106:1071–1077 DOI 10.1007/s00436-010-1750-0