Laboratory of Neurodegenerative Diseases, School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region; State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong Special Administrative Region. Electronic address: [Email]
Propofol and dexmedetomidine are commonly used in clinical situations where neuroinflammation may be imminent or even established but comparative data on their effects on neuroinflammatory and cognitive parameters are lacking. Using a murine model of neuroinflammation induced by systemic lipopolysaccharide (LPS), this study compared the effects of these two agents on cognitive function, neuroinflammatory parameters, oxidative stress and neurotransmission. Male adult C57BL/6 N mice were anaesthetised with propofol or dexmedetomidine prior to intraperitoneal injection of LPS. Cognitive and motor function were assessed by the Y-maze and Rotarod tests respectively. Inflammatory responses were evaluated by relative levels of cytokine mRNA and immunoreactivity of glia cells. LPS caused a marked elevation in IL-1β and TNF-α levels both peripherally and in the brain, together with microglia activation (p < 0.05) and cognitive impairment. These changes were accompanied by an increase in 8-hydroxy-2'-deoxyguanosine (8-OHdG) (p < 0.05). Dexmedetomidine attenuated microglia activation (p < 0.05) and the elevation in 8-OHdG level (p < 0.05). Propofol did not affect cognition. However, both drugs lowered the number of vesicular glutamate transporter 1 (VGLUT 1), but was associated with higher levels of apoptosis and 8-OHdG (p < 0.05). Data from this study suggest dexmedetomidine and propofol have different anti-neuroinflammatory and neuroprotective profiles. However, neither drug can fully attenuate the effects of LPS induced cognitive impairment.