Multi-Targeting Intranasal Nanoformulation as a Therapeutic for Alzheimer's Disease

Area of Science:

• Neuroscience
• Pharmacology
• Biochemistry

Background:

• Alzheimer's disease (AD) is characterized by cognitive deficits and neuropathologies.
• Melatonin, insulin, and THC individually show potential in reversing AD-related symptoms in mouse models.
• A novel nanoformulation combines these agents for potential synergistic effects.

Purpose of the Study:

• To evaluate the therapeutic efficacy of a long-term intranasal nanoformulation of melatonin, insulin, and THC (MIT) in aged APP/PS1 transgenic mice.
• To assess the impact of MIT treatment on spatial memory, amyloid-beta (Aβ) load, tauopathy, and mitochondrial function in an AD mouse model.

Main Methods:

• Aged APP/PS1 mice received daily intranasal MIT (0.04 mg/kg melatonin, 0.008 mg/kg insulin, 0.02 mg/kg THC) for 3 months.
• Spatial memory was evaluated using the radial arm water maze (RAWM) test.
• Brain tissues were analyzed for Aβ load, tau phosphorylation, and mitochondrial protein expression (CKMT1, Mfn2, Opa1, Parkin).

Main Results:

• MIT treatment significantly improved spatial learning and memory in APP/PS1 mice.
• MIT significantly reduced tau phosphorylation and the expression of CKMT1, a marker of mitochondrial dysfunction.
• MIT modulated mitochondrial dynamics by decreasing Mfn2 and Opa1 expression and increasing Parkin, suggesting enhanced mitophagy.

Conclusions:

• This study demonstrates the first successful use of an MIT nanoformulation to enhance spatial memory in an AD mouse model.
• The MIT nanoformulation exerts multi-targeting effects on Aβ production, tau phosphorylation, and mitochondrial dynamics.
• MIT presents a promising, safe, and effective therapeutic candidate for Alzheimer's disease.