Alpha-Pinene Ameliorates Memory Deficits in 3-Nitropropionic Acid-Induced Rat Model of Huntington's Disease

Memory impairment is one of the cognitive symptoms in Huntington's disease (HD) which appears before motor dysfunction in patients. Various molecular mechanisms, including disruptions in neurotrophins levels, are involved in the occurrence of memory problems in HD. Alpha-pinene (APN), a member of the monoterpene family, exhibited beneficial effects in animal models of neurodegenerative disorders. As a result, this study assessed the impact of APN on memory in the 3-nitropropionic acid (3-NP) induced model of HD in rats. Male Wistar rats received saline, 3-NP to model HD, or APN (1, 5, or 10 mg/kg) plus 3-NP for 21 days to assess APN's effects. Working and spatial memory were examined by the Y-maze and Morris-water-maze (MWM) tests. The mRNA levels of neurotrophins and their receptors in the brain cortex and hippocampus of the rats were quantitatively assessed through Reverse Transcription Quantitative Polymerase Chain Reaction (RT-qPCR) analysis. The results showed that APN, at all three doses, significantly prevented the disease phenotype induced by 3-NP administration. In addition, APN treatment elevated the gene expression levels of BDNF, TrkA, TrkB, and CREB, while significantly decreasing P75 NTR showing a dose-dependent effect in the brain cortex and hippocampus, compared to the 3-NP group. These findings suggest that APN alleviates 3-NP-induced memory deficits by enhancing neurotrophins and their receptor levels in an animal model of HD.