Lack of the effect of mycotoxins-aflatoxin B1 and ochratoxin A on some functions of rat adipocytes

Curcumin Mitigates Oxidative Damage in Broiler Liver and Ileum Caused by Aflatoxin B1-Contaminated Feed through Nrf2 Signaling Pathway

This experiment aimed to investigate the mitigating effect of CUR on the growth performance and liver and intestinal health of broilers fed AFB1-contaminated diets. In this study, 320 one-day-old healthy male Arbor Acres (AA) broilers were randomly divided into four groups, including the Control group (fed the basal diet), the AFB1 group (fed the AFB1-contaminated diet containing 1 mg/kg AFB1), the AFB1+CUR group (fed the AFB1-contaminated diet with 500 mg/kg CUR), and the CUR group (fed the basal diet containing 500 mg/kg CUR), with eight replicates of ten animals per group and a 28 d experimental period. In terms of the growth performance, the addition of 500 mg/kg CUR significantly improved AFB1-induced significant reductions in the final body weight on day 28 and mean daily gain (p < 0.05) and increased the ratio of the mean daily feed intake to mean daily weight gain in broilers (p < 0.05). In terms of liver health, significant improvements in liver histological lesions occurred in broilers in the AFB1+CUR group compared to the AFB1 group, with significantly higher glutathione peroxidase (GSH-Px), catalase (CAT), and total superoxide dismutase (T-SOD) activities (p < 0.05) and significantly higher levels of nuclear factor erythroid 2-related factor 2 (Nrf2), Kelch-like ECH-associated protein 1 (Keap-1), heme oxygenase 1 (HO-1), and NAD(P)H quinone oxidoreductase 1 (NQO-1) gene expression (p < 0.05). In terms of intestinal health, CUR addition significantly increased the relative length of ileum (p < 0.05), significantly elevated the height of ileal villi (p < 0.05), significantly reduced D-Lactate (D-LA) and diamine oxidase (DAO) activities in broiler serum (p < 0.05), significantly increased GSH, CAT, and T-SOD activities in ileal tissues (p < 0.05), and significantly elevated the expression of Nrf2, HO-1, and NQO-1 genes (p < 0.05) compared to the AFB1 group. In conclusion, CUR showed a protective effect against damage to the liver and intestine caused by AFB1 in broilers through the Nrf2 signaling pathway, thereby improving the growth performance of broilers exposed to AFB1.

The multiple biotoxicity integrated study in grass carp (Ctenopharyngodon idella) caused by Ochratoxin A: Oxidative damage, apoptosis and immunosuppression

Ochratoxin A (OTA) is a common hazardous food contaminant that seriously endangers human and animal health. However, limited study is focused on aquatic animal. This research investigated the multiple biotoxicity of OTA on spleen (SP) and head kidney (HK) in grass carp and its related mechanism. Our data showed that, dietary supplemented with OTA above 1209 μg/kg caused histopathological damages by decreasing the number of lymphocytes and necrotizing renal parenchymal cells. Meanwhile, OTA caused oxidative damage and reduced the isoforms mRNAs transcripts of antioxidant enzymes (e.g., GPX1, GPX4, GSTO) partly due to suppressing NF-E2-related factor 2 (Nrf2). OTA triggered apoptosis through mitochondria and death receptor pathway potentially by p38 mitogen-activated protein kinase (p38MAPK) activation. Besides, OTA exacerbated inflammation by down-regulation of anti-inflammatory factor (e.g., IL-10, IL-4) and up-regulations of pro-inflammatory factors (e.g., TNF-α, IL-6), which could be ascribed to signaling meditation of Janus kinase / signal transducer and activator of transcription (JAK/STAT). Additionally, the safe upper limits of OTA were estimated to be 677.6 and 695.08 μg/kg based on the immune-related indexes (C3 contents in the SP and LZ activities in the HK, respectively). Our study has provided a wide insight for toxicological assessment of feed pollutant in aquatic animals.

Diabetogenic Effects of Ochratoxin A in Female Rats

In this study, the diabetogenic effects of long term Ochratoxin A (OTA) administration in rats were investigated, and its role in the etiology of diabetes mellitus (DM) was examined utilizing 42 female Wistar rats for these purposes. The rats were divided into three different study and control groups according to the duration of the OTA administration. The rats received 45 μg OTA daily in their feed for 6, 9 and 24 weeks, respectively. Three control groups were also used for the same time periods. Blood and pancreatic tissue samples were collected during the necropsy at the end of the 6, 9 and 24 weeks. The plasma values of insulin, glucagon and glucose were determined for the study and control groups. Pancreatic lesions were evaluated via histopathological examination and insulin and glucagon expression in these lesions was subsequently determined using immunohistochemical methods. Statistically significant decreases in insulin levels were observed, in contrast to increases in blood glucagon and glucose levels. Histopathological examinations revealed slight to moderate degeneration in Langerhans islet cells in all OTA-treated groups. Immunohistochemistry of pancreatic tissue revealed decreased insulin and increased glucagon expression. This study demonstrated that OTA may cause pancreatic damage in the Langerhans islet and predispose rats to DM.

Leptin in hepatocellular carcinoma

The risk factors for hepatocellular carcinoma (HCC) development have been established, and include chronic hepatitis B and C, heavy alcohol consumption, and aflatoxins. In fact, 5%-30% of patients with HCC still lack a readily identifiable risk factor. It has been reported that the majority of ‘‘cryptogenic’’ HCC may be attributed to nonalcoholic fatty liver disease, the hepatic presentation of the metabolic syndrome (MS). Obesity is associated with the development of the MS. Recently, adipose tissue has been considered as an endocrine organ because of its capacity to secrete a variety of cytokines, which are collectively known as the adipokines. Leptin, the product of the obese gene, is mainly produced by adipose tissue. Since leptin was first characterized in 1994, accumulated literature has demonstrated the involvement of this adipokine in several areas of human physiology. After binding to its receptor, leptin initiates a cascade of signaling events and subsequent cellular effects. In addition to being the regulatory mediator of energy homeostasis, several in vitro studies have demonstrated the fibrogenic role of leptin in the liver. Furthermore, the deregulated expression of leptin and its receptor have been demonstrated to be associated with a variety of metabolic disorders as well as human cancers. Most importantly, direct evidence supporting the inhibitory and/or activating role of leptin in the process of carcinogenesis and progression of human HCC has been accumulating rapidly. This review aims to provide important insights into the potential mechanisms of leptin in the development of HCC. Hopefully, further investigations will shed light on a new therapeutic target in HCC.