Effects of Decabrominated Diphenyl Ether Exposure on Growth, Meat Characteristics and Blood Profiles in Broilers

A critical review on BDE-209: Source, distribution, influencing factors, toxicity, and degradation

As the most widely used polybrominated diphenyl ether, BDE-209 is commonly used in polymer-based commercial and household products. Due to its unique physicochemical properties, BDE-209 is ubiquitous in a variety of environmental compartments and can be exposed to organisms in various ways and cause toxic effects. The present review outlines the current state of knowledge on the occurrence of BDE-209 in the environment, influencing factors, toxicity, and degradation. BDE-209 has been detected in various environmental matrices including air, soil, water, and sediment. Additionally, environmental factors such as organic matter, total suspended particulate, hydrodynamic, wind, and temperature affecting BDE-209 are specifically discussed. Toxicity studies suggest BDE-209 may cause systemic toxic effects on living organisms, reproductive toxicity, embryo-fetal toxicity, genetic toxicity, endocrine toxicity, neurotoxicity, immunotoxicity, and developmental toxicity, or even be carcinogenic. BDE-209 has toxic effects on organisms mainly through epigenetic regulation and induction of oxidative stress. Evidence regarding the degradation of BDE-209, including biodegradation, photodegradation, Fenton degradation, zero-valent iron degradation, chemical oxidative degradation, and microwave radiation degradation is summarized. This review may contribute to assessing the environmental risks of BDE-209 to help develop rational management plans.

Curcumin alleviates spleen immunotoxicity induced by decabrominated diphenyl ethers (BDE-209) by improving immune function and inhibiting inflammation and apoptosis in broilers

This study was conducted to assess the mitigating effects of curcumin (Cur) on immunotoxicity in the spleen of broilers induced by the polybrominated diphenyl ether BDE-209. Eighty one-day-old broilers were allocated to the following four groups: control group, BDE-209 (0.4 g/kg) group, BDE-209 (0.4 g/kg) + Cur (0.3 mg/kg) group, and Cur (0.3 mg/kg) group. Growth performance, immunological function, inflammation, and apoptosis were assessed after 42 days of treatment. The findings demonstrate that firstly, Cur restored spleen damage caused by BDE-209 by increasing body weight, decreasing feed-to-gain ratio, correcting the spleen index, and improving the histopathological structure of the spleen. Secondly, Cur relieved BDE-209-induced immunosuppression by increasing the levels of the immunoglobulins IgG, IgM, and IgA in the serum, as well as the levels of white blood cells and lymphocytes. The levels at which GATA binding protein 3, T-box expressed in T cells, interferon-γ, and interleukin (IL)- 4 are expressed were controlled. The ratio of T helper (Th) type 1 (Th1) to Th2 cells in the spleen of broilers was also controlled. Thirdly, Cur reduced the expression of Toll like receptor (TLR) 2, TLR4, nuclear factor (NF)-κB, IL-8, IL-6, and IL-1β, which alleviated BDE-209-induced inflammation in broilers. Cur reduced BDE-209-induced apoptosis by increasing the expression of the bcl-2 protein, decreasing the expression of cleaved caspase-3 and bax proteins, decreasing the bax/bcl-2 protein ratio, and decreasing the mean optical density of TUNEL. These results suggest that Cur protects broiler spleens from BDE-209-induced immunotoxicity via modulating humoral immunity, the equilibrium between Th1 and Th2 cells, the TLRs/NF-κB inflammatory pathway, and the apoptotic pathway.

High Dietary Organic Iron Supplementation Decreases Growth Performance and Induces Oxidative Stress in Broilers

Although Iron (Fe) is an essential nutrient that plays a vital role in respiratory processes, excessive Fe in the diet can affect the health of broilers. We investigated the effects of diet supplemented with high levels of iron chelates with lysine and glutamic acid (Fe−LG) on the growth performance, serum biochemical parameters, antioxidant status, and duodenal mRNA expression of Fe transporters in broilers. A total of 800 1-day-old male Arbor Acres broilers were assigned to 5 groups, with 8 replicates each. Broilers were fed a corn−soybean meal basal diet or basal diets supplemented with 40, 80, 400, or 800 mg Fe/kg as Fe−LG for 6 weeks. The body weight (BW) was increased in the 80 mg Fe/kg treatment group, but decreased in the 800 mg Fe/kg treatment group on day 21. During days 1−21, compared with the control group, the supplementation of the 80 mg Fe/kg increased the average daily gain (ADG) and average daily feed intake (ADFI); however, the supplementation of the 800 mg Fe/kg group decreased the ADG and increased the FCR in broilers (p < 0.05). The heart, liver, spleen, and kidney indices were reduced in the 800 mg Fe/kg treatment group (p < 0.05). The supplementation of the 800 mg Fe/kg group increased the serum aspartate aminotransferase activity and the levels of creatinine and urea nitrogen on day 42 (p < 0.05). The broilers had considerably low liver total superoxide dismutase activity and total antioxidant capacity in the 800 mg Fe/kg treatment group (p < 0.05). Serum and liver Fe concentrations were elevated in the 400 and 800 mg Fe/kg treatment groups, but were not affected in the 40 and 80 mg Fe/kg treatment groups. The duodenal Fe transporters divalent metal transporter 1 (DMT1) and ferroportin 1 (FPN1) were downregulated in the Fe−LG treatment groups (p < 0.05). We conclude that a high dietary supplement of 800 mg Fe/kg in broilers leads to detrimental health effects, causing kidney function injury and liver oxidative stress.