A human is exposed to a chemical mixture rather than a single chemical, particularly with the wide spread of nanomaterials. Therefore, the present study evaluated the combined exposure of lead acetate (Pb) and zinc oxide-nanoparticles (ZnO-NPs) compared to each metal alone on the thyroid gland of adult rats. A total of 30 adult male albino rats were divided into four groups, group I (control), group II received Pb (10 mg/kg), group III received ZnO-NPs (85 mg/kg) and group IV co-administrated the two metals in the same previous doses. The materials were gavaged for 8 weeks.

Objective The aim of our study is to compare the role of the new natural alternative (Quercetin) with the current iron-chelation therapy (Deferoxamine (DFO)) in the effect of iron overload on small intestinal tissues and to investigate the possible underlying molecular mechanisms of such toxicity. Methods Forty-two adult male albino rats were divided into six groups: control groups, DFO, Quercetin, iron overload, iron overload+DFO, and iron overload+Quercetin groups. Animals received daily intraperitoneal injection of Deferoxamine (125 mg /kg), Quercetin (10 mg/kg), and ferric dextran (200 mg/kg) for 2 weeks. Results Iron overloaded group showed significant increase in serum iron, total iron binding capacity (TIBC), transferrin saturation percentage (TS %) hepcidin (HEPC), serum ferritin, nontransferrin bound iron (NTBI), and small intestinal tissues iron levels. Iron overload significantly increased the serum oxidative stress indicator (MDA) and reduced serum total antioxidant capacity (TAC). On the other hand, iron overload increased IL6 and reduced IL10 in small intestinal tissues reflecting inflammatory condition and increased caspase 3 reactivity indicating apoptosis and increased iNOs expressing cell indicting oxidative stress especially in ileum. In addition, it induced small intestinal tissues pathological alterations. The treatment with Quercetin showed nonsignificant differences as compared to treatment with DFO that chelated the serum and tissue iron and improved the oxidative stress and reduced tissue IL6 and increased IL10 and decreased caspase 3 and iNOs expressing cells in small intestinal tissues. Moreover, it ameliorated the iron overload induced pathological alterations. Conclusion Our study showed the potential role of Quercetin as iron chelator like DFO in case of iron overload induced small intestinal toxicity in adult rats because of its serum and tissue iron chelation, improvement of serum, and small intestinal oxidative stress, ameliorating iron induced intestinal inflammation, apoptosis, and histopathological alterations.

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Chlorpyrifos (CPF) is a chlorinated organophosphate insecticide that is used widely in the world and Egypt. The aim of present work was to study the possible protective role of Propolis on thyroid gland of male rats after chronic exposure of chlorpyrifos. For this purpose, Fifty adult male albino rats were randomized into 5 groups: I, II (Control), III (received Propolis dissolved in 0.5 ml corn oil, 50 mg/kg b.w./day), IV (received CPF dissolved in 0.5 ml corn oil 6.75 mg/kg b.w./ day) and V (received CPF and Propolis at the same previously mentioned doses). Rats were orally treated by gavage for 12 weeks. We found that Chlorpyrifos induced damaging effects in thyroid tissue architecture, thickened collagen fibers between the follicles and decreased periodic acid schiff (PAS) reaction in the colloids. Immunohistochemically, there was weak thyroglobulin (TGB) expression. Besides, it significantly decreased the serum levels of Tri-iodothyronin (T3), Tetraiodothyronin (T4) and Thyroid stimulating hormone (TSH). It depressed reduced glutathione (GSH) content and antioxidant enzyme activities in thyroid tissues with respect to control groups. Furthermore, CPF increased thyroid oxidative stress as manifested by elevated malondialdehyde (MDA) levels. On the other hand, the concurrent administration of Propolis with CPF showed significant improvement in previous changes. Our findings showed that the concurrent oral administration of Propolis with CPF improved the CPF induced oxidative damaging effects in thyroid gland and the antioxidative defense in the rats.

The usage of Titanium Dioxide NanoParticles (TiO2NPs) on a large scale of applications was a reason of a variety of many health problems. The aim of the current study was to evaluate the immune toxic effects of short term administration of TiO2NPs on spleen. Material and Methods: Forty Adult male Rats were equally divided into four groups as follows: Group I: negative control, Group II: positive control, Group III: received TiO2NPs (1200 mg/kg) orally daily for 12 weeks. Group IV: follow up group received TiO2NPs by the same dose, route and for the same duration as TiO2NPs group and then they were left untreated for another 8 weeks. Total leukocytes, differential leukocytic counts, Interleukins IL-2 and IL-10 levels were measured, the spleen sections were examined immunohistochemically for the detection of CD4+ and iNOS expressing cells. Histopathological alterations in the spleen were also evaluated. Moreover, DNA damage was evaluated by comet assay. The results: TiO2NPs exposure for 12 weeks resulted in significant decreased in the total and deferential leukocytic counts, serum interleukins IL-2 as well as IL-10. It caused marked decrease in CD4+T-lymphocytes and increase in iNOS expressing cells indicating oxidative stress in spleen tissues. It also caused histopathological disruption of spleen architecture and produced DNA damage in splenocytes. Discontinuation of TiO2NPs administration for 8 weeks resulted in significant improvement of leukocytes, interleukins, increase in CD4+ T-lymphocytes and decrease in iNOS expressing cells in spleen tissues. Moreover, there was moderate improvement in histopathological alterations and DNA damage. Conclusion:TiO2NPs consumption have immunotoxic effects which may resulted from genetic damage and oxidative stress in the spleen of adult male albino rats which could be improved by its discontinuation for a period of time and it was recommended to increase the period of discontinuation as complete improvement may occur