Involvement of oxidative stress in subacute toxicity induced by fumonisin B1 in broiler chicks

Abstract

Fumonisin B1 (FB1) is a mycotoxin produced by Fusarium spp. It has been reported to be a potential cause of liver cancer in rats and esophageal cancer in humans. The underlying mechanisms of FB1 toxicity are thought to be related to the inhibition of ceramide synthase, causing an accumulation of sphingosine (SO) and sphinganine (SA), which in turn may cause tissue functional impairment and the development of oxidative stress. Therefore, in this study, we investigate the effects of an FB1-contaminated diet on markers of oxidative stress in chick liver. A total of 24 male broiler chicks (Cobb 500) were fed a standard control diet or a diet contaminated with FB1 (100mg/kg) for 21 days, starting on postnatal day one. The feed and animals were weighed on days 0, 7, 14 and 21 to estimate the feed conversion ratio, and at 21 days, the liver weight and liver relative weight were determined. At the end of the experiment, samples of blood and liver were collected. The blood was used to quantify the SA/SO ratio, and the liver was used to determine the activity of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST); ascorbic acid levels (VitC), non-protein thiol (NPSH) levels and TBARS content were also determined. The FB1 diet increased the liver weight, liver relative weight, feed conversion and SA/SO ratio. Furthermore, hepatic TBARS levels, Vit C content and CAT activity were also increased. Conversely, the activities of SOD, GST and NPSH levels, in the liver were not altered by the mycotoxin-contaminated diet. In summary, we showed that subacute exposure of broiler chicks to FB1 induced liver oxidative stress concomitantly with SA/SO accumulation.

Keywords: Ascorbic acid; Catalase; Feed conversion; Liver; Mycotoxin; TBARS.