Overview
ElMosbah and colleagues used oral aluminum chloride to induce Alzheimer’s-like pathology in rats, then compared oral versus intranasal rivastigmine-loaded chitosan nanoparticles. This is in-scope lane a4 toxicology evidence for aluminum neurotoxicity and treatment response. It is not consumer-product occurrence evidence and does not report aluminum concentrations in food, water, or tissue.
Key numbers
The model used 30 adult male albino rats weighing 200-250 g. Rats acclimatized for 7 days before the experiment.
The experimental design section reports these exposure and treatment values:
| Group or phase | Exposure/treatment | Duration or grouping |
|---|---|---|
| Negative control | Distilled water orally | Daily |
| Oral RS-CSNPs group | 1 mL rivastigmine-loaded chitosan nanoparticle dispersion containing 0.13 mg rivastigmine | Daily |
| Nasal RS-CSNPs group | Rivastigmine-loaded chitosan nanoparticle dispersion intranasally | Daily |
| Disease induction | AlCl3 at 100 mg/kg/b.wt orally | Daily for 90 days |
| AlCl3 positive control subgroup | No rivastigmine nanoparticle treatment after induction | 5 rats |
| AlCl3 + oral RS-CSNPs subgroup | 1 mL RS-CSNPs containing 0.13 mg rivastigmine orally | Daily for 75 days |
| AlCl3 + nasal RS-CSNPs subgroup | RS-CSNPs intranasally | Daily for 75 days |
The methods report chitosan solutions prepared at 0.5%, 0.7%, 1%, 1.2%, and 1.4% w/v, and sodium tripolyphosphate solutions prepared at 0.6%, 0.8%, 1%, 1.2%, and 1.4% w/v. Tween 80 was added at a constant ratio of 0.2 mL.
Table 1 gives real-time PCR primer product sizes:
| Gene | Product size |
|---|---|
| NF-kB | 234 |
| Nrf-2 | 159 |
| Caspase-3 | 158 |
| beta-Act | 297 |
The results state that viable neuron percentage was significantly reduced in the AlCl3 group compared with other groups, and that AlCl3 + nasal RS-CSNPs had significantly higher cell viability and less neuronal degeneration than AlCl3 + oral RS-CSNPs. The figure with neuron viability percentages is graphical; exact numeric percentages are not reported in extractable text.
The qPCR results state that Caspase-3 and NF-kB expression were significantly up-regulated in the AlCl3 group compared with treated and control groups, while Nrf-2 was significantly down-regulated in the AlCl3 group. The source reports that Caspase-3 transcript fold change was significantly lower in AlCl3 + nasal RS-CSNPs than in AlCl3 + oral RS-CSNPs, while NF-kB and Nrf-2 did not significantly differ between the two treated AlCl3 subgroups. The fold-change values are shown in bar charts and are not printed as exact text values.
Methods (brief)
The study was conducted in the Pathology Department, Faculty of Veterinary Medicine, Cairo University. Brain, nasal mucosa, stomach, intestine, and liver were fixed in 10% neutral buffered formalin, embedded in paraffin, sectioned at 3-4 um, and stained with H&E. Cresyl violet (Nissl) staining was used to quantify viable neurons in cerebral cortical regions. Phosphorylated tau expression was assessed by immunohistochemistry using a 1:100 phosphorylated tau antibody. Gene expression for Caspase-3, NF-kB, and Nrf-2 was measured by real-time PCR and normalized to beta-actin.
Related evidence
Update history
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