Investigation of the effect of berberine on memory and learning in aged rats undergoing sevoflurane anesthesia

BACKGROUND: Sevoflurane is a widely used inhalation anesthetic during surgical procedures. Experimental animal models have demonstrated that exposure to sevoflurane leads to cognitive dysfunction. The molecular mechanisms underlying sevoflurane-induced neurotoxicity, as well as the potential neuroprotective mechanisms of berberine, have not yet been fully elucidated. OBJECTIVES: The current investigation sought to evaluate the effects of berberine on memory and learning in aged rats undergoing sevoflurane anesthesia. MATERIAL AND METHODS: Fifty-six male Sprague Dawley rats aged 20-24 weeks were assigned to 4 groups (n = 14/group): control, berberine, sevoflurane + berberine, and sevoflurane. The control group was exposed to 50% O2 and 50% air at a flow rate of 2 L/min for 6 h. The sevoflurane group underwent inhalation anesthesia with 3% sevoflurane mixed with 50% O2 and 50% air at 2 L/min for 6 h. In the sevoflurane + berberine group, berberine was administered intraperitoneally at a dose of 50 mg/kg/day, starting 1 week before sevoflurane anesthesia. Following these procedures, the Morris water maze (MWM), elevated plus maze (EPM), and novel object recognition tests were conducted. Brain tissues obtained from the remaining 7 rats were preserved for TUNEL staining. The expression levels of the investigated microRNAs and BDNF (brain-derived neurotrophic factor) in the frontal lobe, hippocampus, and plasma were determined using real-time quantitative polymerase chain reaction (qPCR), while BDNF levels were measured using enzyme-linked immunosorbent assay (ELISA). RESULTS: In the berberine group, compared with the sevoflurane group, plasma, frontal lobe, and hippocampal levels of microRNAs 9, 124, and 132 and BDNF were significantly increased, and TUNEL staining revealed a statistically significant reduction in apoptotic bodies. CONCLUSIONS: This study indicates that berberine exerts beneficial effects on memory and learning at the molecular level in the geriatric population.