The effects of polyvinyl alcohol-coated selenium nanoparticles on memory impairment in rats.

Some mineral elements exert beneficial neuroprotection, especially in the form of nanoparticles. The aim of the present study was to evaluate the effects of selenium nanoparticles (SeNPs) and polyvinyl alcohol (PVA)-coated SeNPs (PVA-SeNPs) on Alzheimer's disease (AD) in a rat model of AD. Twenty-eight rats were randomly divided into four groups of seven rats: control, Alz, Alz + Se, and Alz + Se-PV groups. PVA-SeNPs and SeNPs were chemically synthesized and orally administrated (0.4 mg/kg) to the AD rats for one month. AD was induced by an intracerebroventricular (ICV) injection of streptozotocin (STZ). The memory function was assessed by the novel object recognition (NOR) and passive avoidance learning (PAL) tests. The expression of hippocampal brain-derived neurotrophic factor (BDNF) and stress oxidative markers (MDA and TAC), and the number of amyloid-beta (Aß) plaques were assessed using ELISA kits, biochemical methods, and Congo red staining, respectively. The results of the behavioral tests showed that the discrimination index in the NOR test increased in the Alz + PVA-SeNPs group compared to the Alz group. Memory performance in the PAL task improved in the PVA-SeNPs and SeNPs groups compared to the Alz group. The level of the BDNF in both of the Alz treatment groups (PVA-SeNPs and SeNPs) showed a significant increase compared to the Alz group. MDA levels and Aß plaques decreased in both NPs-treated Alz groups, while TAC levels decreased in all Alz groups. PVA-SeNPs were more effective than SeNPs in the improvement of the cognition deficit. The results suggest that PVA-SeNPs improve the cognition and memory deficit induced by an ICV injection of STZ through a decrease in the number of Aß plaques and malondialdehyde levels and an increase in the BDNF levels.

Deferoxamine preconditioning enhances the protective effects of stem cells in streptozotocin-induced Alzheimer's disease.

AIMS: Stem cell-based therapy is one of the promising strategies in the treatment of Alzheimer's disease (AD), but the short lifespan and low homing of transplanted cells continue to be a major obstacle in this method. Preconditioning of stem cells before transplantation could increase cell therapy efficiency. Herein, we examined whether the treatment of stem cells with deferoxamine (DEF) prior to graft could enhance the neuroprotective effects of stem cells in the streptozotocin (STZ)-treated male rats. MATERIALS AND METHODS: After induction of the AD model, the rats were transplanted with DEF-preconditioned Adipose-derived mesenchymal stem cells (AMSCs) or untreated cells. Memory function, antioxidant capacity, cell density, and homing of transplanted cells were assessed using Morris water maze and shuttle box tasks as well as biochemical and histochemical methods. KEY FINDINGS: Transplantation of AMSCs caused a memory improvement when compared to the AD model. The injection of DEF-preconditioned AMSCs was more effective in improving learning and memory than the untreated cells through an increase in the antioxidant capacity. Moreover, the homing of transplanted cells was higher in the rats that received the preconditioned cells than that of the naïve cell-injected group. SIGNIFICANCE: It seems that the transplantation of DEF-treated cells may increase the efficiency of stem cells via an increase in the antioxidant capacity.

Synergistic effects of adipose-derived mesenchymal stem cells and selenium nanoparticles on streptozotocin-induced memory impairment in the rat.

AIMS: Memory impairment is determined to be the most well-known symptom of Alzheimer's disease (AD). Although cell therapy seems is an efficient therapeutic strategy to attenuate the AD-related memory impairment, transplanted cells have a short lifespan and do not survive long term in the recipient animals. Herein, we investigated whether the combination therapy of Selenium nanoparticles (SeNPs) and stem cells attenuates the neurotoxicity in an AD animal model. MATERIAL AND METHODS: The adipose-derived mesenchymal stem cells (AMSCs) were transplanted in the AD model. In addition to cell injections, the animals also received oral administration of SeNPs (0.4 mg/kg) for one month. Recognition memory, cell survival, and BDNF concentration were assessed using the novel object recognition task, immunofluorescence, and ELISA methods. KEY FINDINGS: Our results showed that the combined therapy was more effective in increasing the discrimination index than the administering SeNPs or AMSCs alone. Moreover, SeNPs and stem cells together had the greatest effects in reducing the deposition of Aß and increasing the concentration of BDNF. Ultimately, the survival and proliferation of transplanted cells were more in the group that received stem cells besides SeNPs. SIGNIFICANCE: Taken together, it seems that the transplantation of MSCs combined with SeNPs could achieve better results in the neuroprotection in the AD model than a conventional treatment of SeNPs or stem cells alone.