Iron biodistribution profile changes in the rat spleen after administration of high-fat diet or iron supplementation and the role of curcumin

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.

Time-dependent biodistribution profiles and reaction of polyethylene glycol-coated iron oxide nanoclusters in the spleen after intravenous injection in the mice

Polyethylene glycol (PEG) is widely used polymer in the field of pharmaceutics, particularly in which related to drug delivery systems (DDS). Surface coating of the nanoparticles (NPs) with PEG (i.e. pegylation) adds novel characteristics that make their use in vivo more effective with lower cytotoxicity. The biodistribution profiles, reaction, and fate of PEG-coated NPs in vivo still unclear and need more detailed studies. Here in this study, we prepared PEG-coated iron oxide nanoclusters (PEG-coated IONCs) to investigate their biodistribution profiles and reactions in spleen after intravenous injection time-dependently. Using Prussian blue staining method as specific histochemical reaction for iron detection in the tissues, the PEG-coated IONCs were observed in a higher ratio in spleen red pulp after 1 day of injection but decreased time-dependently after 10 days and 20 days. Interestingly, PEG-coated IONCs moved from red pulp into the white pulp specially after 20 days of injection. After long time exposure (20 days), higher amount of PEG-coated IONCs was observed in the center of spleen white pulp follicle. Using histological staining, the reaction of PEG-coated IONCs with splenocytes or immune cells induced cellular abnormalities such as, nucleic acid damages, induction of megakaryocytes number, and sever vacuolation in the white pulp area specially after 20 days of injection. Histochemically, the localization of PEG-coated IONCs in the splenic parenchyma induced the level of the collagen fibers particularly after 1 day and 10 days of injection. Interestingly, cellular abnormalities in the splenic red pulp as well as collagen levels decreased after 20 days of injection due to the clearance of PEG-coated IONCs from this area. This data indicated that cytotoxicity produced by the reaction of PEG-coated IONCs in the spleen are reversible specially after 20 days of in the intravenous injection. Understanding the detailed mechanism of the fate and reaction of the coated nanomaterials after intravenous injection is important to design effective and safe DDS based NPs.