Taenia crassiceps: Fatty acids oxidation and alternative energy source in in vitro cysticerci exposed to anthelminthic drugs Marina Clare Vinaud * , Cirlane Silva Ferreira 1 , Ruy de Souza Lino Junior, José Clecildo Barreto Bezerra Tropical Pathology and Public Health, Institute from Federal, University of Goias, 74605-050 Goiania, Goias, Brazil article info Article history: Received 25 July 2008 Received in revised form 23 March 2009 Accepted 27 March 2009 Available online 5 April 2009 Keywords: Cysticerci of Taenia crassiceps Cestode Taeniidae High performance liquid chromatography (HPLC) Taenia crassiceps (T. crassiceps) Original fox (ORF) strain Federal University of Goias (UFG) Albendazole Praziquantel Creatinine Urea excretion Fatty acid oxidation Secreted/excreted (SE) abstract Cysticerci metabolic studies demonstrate alternative pathways responsible for its survival, such as energy sources, fatty acids oxidation and excretion of b-hydroxybutirate, which indicates the capability of energy production from proteins. The aim of this study was to detect alternative metabolic pathways for energy production and its end products in Taenia crassiceps cysticerci in vitro exposed to praziquantel and alben- dazole, in sub lethal doses. Spectrophotometer and chromatographic analysis were performed to detect: propionate, acetate, b-hydroxybutirate, total proteins, urea and creatinine, SE by cysticerci in vitro exposed to praziquantel and albendazole. The drugs influenced the metabolism by inducing the creati- nine phosphate phosphorylation as an alternative energy source, inhibiting the use of proteins and amino acids in the acid nucleic synthesis; and preventing the budding and replication of the cysticerci. This study also highlights the description of urea excretion, which is an important metabolic pathway to excrete toxic products such as ammonia, and the fatty acid oxidation as an alternative energy source in cysticerci exposed to anthelmintic drugs. Ó 2009 Elsevier Inc. All rights reserved. 1. Introduction Taenia crassiceps cysticerci are used as experimental model for cysticercosis caused by the Taenia solium metacestode larvae, pre- senting antigenic and metabolic similarities (Del Arenal et al., 2005; Espindola et al., 2002). Besides, there are reports of human beings, mostly immune-compromised, acting as hosts to T. crassi- ceps in cases of ocular and subcutaneous cysticercosis (Chermette et al., 1995; Maillard et al., 1998). Cysticerci metabolic studies have shown biochemical differ- ences and similarities between this parasite and its mammal host, highlighting the detection of alternative metabolic pathways which are responsible for the helminth survival in several habitats, such as the host tissues or its intestinal lumen (Corbin et al., 1998; Vinaud et al., 2007). Taenia crassiceps cysticerci in vivo present as main energy source glucose molecules, removed from the host, or glycogen stored in the tegument (Willms et al., 2005). However, in the case of low glucose concentrations or metabolic alterations in the hab- itat, the parasite presents alternative energy sources such as fatty acids oxidation and its consequent secretion of b-hydroxybutirate, which indicates the ability of producing energy from lipids stored in its structure or removed from the host, allowing its survival (Vinaud et al., 2007). The detection of this alternative pathways in vitro or its final products, urea and creatinine, have not yet been described in the literature. Praziquantel and albendazole, anthelminthic drugs widely used in cysticercosis treatment, interfere in the glucose uptake of the parasite leading to an alteration in the energy metabolism and the consequent decrease of glycogen stores, resulting in immobil- ity and death of the parasites (Cioli et al., 1995; Nogales-Gaete et al. 2006; Köhler, 2001). However, the action of these drugs in inducing survival through alternative energy metabolism path- ways, in other words, inducing the oxidation of fatty acid is yet to be described. The aim of this study was to detect, through chromatogra- phy and spectrophotometry techniques, the alternative meta- bolic pathways and its final products SE by T. crassiceps cysticerci in vitro exposed to sublethal doses of anthelminthic drugs. 0014-4894/$ - see front matter Ó 2009 Elsevier Inc. All rights reserved. doi:10.1016/j.exppara.2009.03.015 * Corresponding author. Fax: +55 62 3521 1839. E-mail address: mvinaud@yahoo.com.br (M.C. Vinaud). 1 Tropical Medicine post-graduate student. Experimental Parasitology 122 (2009) 208–211 Contents lists available at ScienceDirect Experimental Parasitology journal homepage: www.elsevier.com/locate/yexpr