A New Dipeptide H-MGL Partially Ameliorating Memory Impairment in an STZ-induced Alzheimer Model in Male Rats.

Introduction: Alzheimer disease (AD) is a progressive neurodegenerative disorder that is identified by the gradual decline in memory and cognitive function. It is classified by the deposition of Aβ plaques, the build-up of intracellular neurofibrillary tangle (NFT), and neuron loss. Neurotrophic factors play a critical role in the treatment of AD. However, utilizing such neurotrophins has encountered certain difficulties and side effects. Novel technological advancements prioritize innovative dipeptide usage, which offers fewer side effects. Methods: The present study endeavors to analyze the compound hexamethylenediamide bis-(N-monosuccinyl-glutamyl-lysine) (lab name: H-MGL), a newly discovered neurotrophin mimetic dipeptide, to alleviate memory impairment in an intracerebroventricular single dose streptozotocin (STZ)-induced Alzheimer model in rats. We arranged 4 groups: Sham and groups receiving STZ and STZ + H-MGL (1 and 2 mg/kg). The H-MGL was administered consecutively for 14 days following the STZ injection. Then, the Morris water maze test was performed. Results: The findings suggest that administration of STZ caused a significantly increment in mean escape latency and mean traveled distance in acquisition days. H-MGL at a 1 mg/kg dosage failed to yield any notable improvement in rats compared to STZ. By contrast, 2 mg/kg of H-MGL dosage led to a significant decrease in the latency to first platform crossing and frequency of platform crossings. Conclusion: Consequently, the findings above have engendered the notion that H-MGL partially ameliorates cognitive impairment, so it may hold promise for having low side effects to alleviate cognitive deficits in AD or potentially decrease the symptoms associated with its progression.