Effet chez le porcelet d'une exposition à un régime co-contaminé en ...

TRAVAIL EXPERIMENTALINTRODUCTIONFumonisins are a family of mycotoxins produced by Fusarium verticillioides (formerly F.moniliforme), which are common fungal contaminants of corn and some other grains (Marasas,2001). Fumonisins exert complex biological effects. The toxic effects of fumonisins range fromhepatotoxicity and renal toxicity to species-specific effects such as pulmonary edema in pigs andleukoencephalomalacia in horses (Voss et al., 2007). In humans, exposure to fumonisins has beenlinked to esophageal cancer and neural tube defects (Voss et al., 2007; Waes et al., 2005). The effectof low doses has been lesser investigated but revealed reduced performance, pathologicalalterations of the lungs and an increase in intestinal colonization by opportunistic pathogenicbacteria in piglets (Rotter et al., 1996b; Halloy et al., 2005; Oswald et al., 2003; Haschek et al., 2001).Fumonisins are structurally similar to sphingoid bases, and were determined to be potentinhibitors of sphinganine N-acyl transferase (ceramide synthase) (Wang et al., 1991). Research sincethis discovery has provided substantial evidence that the toxicity and carcinogenicity of fumonisins isrelated to the disruption of sphingolipid metabolism that occurs as a result of inhibition of ceramidesynthase (Riley et al., 1993, 1994a; Voss et al., 2007).As much as 59% of the corn and corn-based products worldwide have been estimated to becontaminated with variable amounts of fumonisin B1 (FB1), the most prevalent of the fumonisinsubspecies (Desai et al., 2002; Haschek et al., 2001), and therefore, it is not surprising that livestockfarming and feed processing industries are interested in efficient and applicable methods forreducing fumonisin concentrations in animal feed. Most physical and chemical methods, such asthermal food processing, ammoniation or alkali treatment, reduce but do not completely eliminatefumonisins present in feed samples (Norred et al., 1991; Sydenham et al., 1995; Visconti et al., 1996).Besides, most of the methods are difficult to implement into the production process. New approachconsists to find organism or enzymes able to metabolize fumonisins and that could lead to theformation of hydrolyzed fumonisins (HFB) (Heinl et al., 2010).Except in one case in which FB1 metabolism led to a modest amount of HFB1 in vervet monkeys(Shephard et al., 1994), hydrolysis of fumonisins occurs after the well known alkali treatment namednixtamalization. This process is widely used in regions such as Central and South America, to producetortillas or other corn products made from corn cooked and steeped in a lime solution (Dombrink-Kurtzman et al., 2000; Palencia et al., 2003; Cortez-Rocha et al., 2002).As never investigated in domestic animals, we proposed in the present study to compare thetoxicity of fumonisin B1 (FB1) and hydrolyzed fumonisin B1 (HFB1) in piglets orally exposed tomoderate doses. In terms of toxicity assessment, we also reported effects of these treatments at the128