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The objective of the present study was to evaluate the efficacy of curcumin, an antioxidant found in turmeric (Curcuma longa) powder (TMP), to ameliorate changes in gene expression in the livers of broiler chicks fed aflatoxin B(1) (AFB(1)). Four pen replicates of 5 chicks each were assigned to each of 4 dietary treatments, which included the following: A) basal diet containing no AFB(1) or TMP (control), B) basal diet supplemented with TMP (0.5%) that supplied 74 mg/kg of curcumin, C) basal diet supplemented with 1.0 mg of AFB(1)/kg of diet, and D) basal diet supplemented with TMP that supplied 74 mg/kg of curcumin and 1.0 mg of AFB(1)/kg of diet. Aflatoxin reduced (P < 0.05) feed intake and BW gain and increased (P < 0.05) relative liver weight. Addition of TMP to the AFB(1) diet ameliorated (P < 0.05) the negative effects of AFB(1) on growth performance and liver weight. At the end of the 3-wk treatment period, livers were collected (6 per treatment) to evaluate changes in the expression of genes involved in antioxidant function [catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione S-transferase (GST)], biotransformation [epoxide hydrolase (EH), cytochrome P450 1A1 and 2H1 (CYP1A1 and CYP2H1)], and the immune system [interleukins 6 and 2 (IL-6 and IL-2)]. Changes in gene expression were determined using the quantitative real-time PCR technique. There was no statistical difference in gene expression among the 4 treatment groups for CAT and IL-2 genes. Decreased expression of SOD, GST, and EH genes due to AFB(1) was alleviated by inclusion of TMP in the diet. Increased expression of IL-6, CYP1A1 and CYP2H1 genes due to AFB(1) was also alleviated by TMP. The current study demonstrates partial protective effects of TMP on changes in expression of antioxidant, biotransformation, and immune system genes in livers of chicks fed AFB(1). Practical application of the research is supplementation of TMP in diets to prevent or reduce the effects of aflatoxin in chicks fed aflatoxin-contaminated diets.

Exposure to ergot alkaloids in endophyte-infected fescue (E+) is associated with impaired animal productivity, especially during heat stress, which is commonly referred to as fescue toxicosis. To elucidate the pathogenesis of this condition, the effects of short-term heat stress (HS) on hepatic gene expression in rats exposed to endophytic ergot alkaloids were evaluated. Rats implanted with telemetric transmitters to continuously measure core temperature were fed an E+ diet and maintained under thermoneutral (TN) conditions (21 degrees C) for 5 d, followed by TN or 31 degrees C (HS) conditions for 3 d. Feed intake (FI) and BW were monitored daily. The E+ and HS-induced alterations in hepatic genes were evaluated using DNA microarrays and PCR analyses. Hepatic antioxidant enzyme activities, as well as the incidence of apoptosis, were determined. As expected, intake of E+ reduced FI and BW from pretreatment levels under TN conditions, with greater reductions during short-term HS. Genes involved in gluconeogenesis and apoptosis were upregulated, whereas genes associated with oxidative phosphorylation, xenobiotic metabolism, antioxidative mechanisms, immune function, cellular proliferation, and chaperone activity were all downregulated with short-term HS. Hepatocytic apoptosis was increased and antioxidant enzyme activity decreased in the livers of rats exposed to HS. The hypothesized, exacerbating effects of HS on the direct, endophytic toxin-related and indirect, reduced caloric intake-associated alterations in hepatic gene expression were clearly demonstrated in rats and may help to elucidate the pathogenesis of fescue toxicosis in various animal species.

The objective of this study was to determine the effects of dietary aflatoxin B1 (AFB1) on hepatic gene expression in male broiler chicks. Seventy-five 1-d-old male broiler chicks were assigned to 3 dietary treatments (5 replicates of 5 chicks each) from hatch to d 21. The diets contained 0, 1 and 2 mg of AFB1/kg of feed. Aflatoxin B1 reduced (P<0.05) feed intake, BW gain, serum total proteins, and serum Ca and P, but increased (P<0.01) liver weights in a dose-dependent manner. Microarray analysis was used to identify shifts in genetic expression associated with the affected physiological processes in chicks fed 0 and 2 mg of AFB1/kg of feed to identify potential targets for pharmacological/toxicological intervention. A loop design was used for microarray experiments with 3 technical and 4 biological replicates per treatment group. Ribonucleic acid was extracted from liver tissue, and its quality was determined using gel electrophoresis and spectrophotometry. High-quality RNA was purified from DNA contamination, reverse transcribed, and hybridized to an oligonucleotide microarray chip. Microarray data were analyzed using a 2-step ANOVA model and validated by quantitative real-time PCR of selected genes. Genes with false discovery rates less than 13% and fold change greater than 1.4 were considered differentially expressed. Compared with controls (0 mg of AFB1/kg), various genes associated with energy production and fatty acid metabolism (carnitine palmitoyl transferase), growth and development (insulin-like growth factor 1), antioxidant protection (glutathione S transferase), detoxification (epoxide hydrolase), coagulation (coagulation factors IX and X), and immune protection (interleukins) were downregulated, whereas genes associated with cell proliferation (ornithine decarboxylase) were upregulated in birds fed 2 mg of AFB1/kg. This study demonstrates that AFB1 exposure at a concentration of 2 mg/kg results in physiological responses associated with altered gene expression in chick livers.