Rosemary inhalation improves the behavior and cognition of vascular cognitive impairment rats by regulating SIRT1/mTOR pathway-mediated cell apoptosis and autophagy

Abstract

Objective(s): Vascular cognitive impairment (VCI) is a major cause of behavioral and cognitive abnormalities and dementia, but there are currently no specific drugs for VCI. Rosemary oil has been found to have a role in cognitive function. This study aims to evaluate whether inhalation of rosemary can improve learning and memory in VCI rats by regulating neuronal apoptosis and autophagy. Materials and Methods: Male SD rats were used to establish a VCI rat model by bilateral common carotid artery ligation. The rats were intervened with rosemary essential oil inhalation and EX527 injection. Cognitive function was evaluated by the Morris water maze test two weeks after the operation. The pathological changes of hippocampal tissue (HE, Nissl, TEM, TUNEL) and protein expression (WB) were analyzed. Results: Compared with the sham group, the VCI group exhibited cognitive deficits, neuronal loss, mitochondrial damage, and increased neuronal apoptosis (P<0.001). The levels of caspase-3, LC3B, and p-mTOR/mTOR in the hippocampal tissue were significantly elevated (P<0.0001, P<0.01, P<0.01), while the protein level of SIRT1 was significantly reduced (P<0.01). Compared with the VCI group, the rosemary group showed improved cognitive ability, ameliorated neuronal damage, and reduced neuronal apoptosis (P<0.05). The levels of caspase-3, LC3B, and p-mTOR/mTOR were decreased (P<0.0001, P<0.01, P<0.05), while the level of SIRT1 was increased (P<0.05). However, intervention with EX527 attenuated this protective effect. Conclusion: Rosemary inhalation can improve behavior and cognition in VCI rats by regulating SIRT1/mTOR pathway-mediated cell apoptosis and autophagy.