Effects of Isoliquiritigenin on Cognitive Function after Ketamine Anesthesia in Elderly Rats and the Mechanisms

This study aimed to investigate the effects of isoliquiritigenin (ISL) on cognitive function after ketamine anesthesia in elderly rats and the mechanisms. Fifty rats were randomly divided into control, model and 10, 20, and 40 mg/kg ISL groups, 10 rats in each group. The model and ISL groups received the ketamine anesthesia. Then, the 10, 20, and 40 mg/kg ISL groups received the ISL treatment, with dosage of 10, 20, and 40 mg/kg, respectively. The behavioral changes of rats were observed. The Morris water maze experiment was performed. The oxidative stress indexes, inflammatory factors and Tau protein, and amyloid beta-protein (A beta) expressions in hippocampus were determined. Results showed that, compared with model group, in 40 mg/kg ISL group the time of loss of righting reflex and duration of post-loss of righting reflex ataxia of rats were significantly decreased, the escape latency was significantly decreased, the original quadrant residence time and traversing times were significantly increased, the hippocampal superoxide dismutase and glutathione levels were significantly increased, the hippocampal malondialdehyde, tumor necrosis factor-alpha and interleukin-1 levels were significantly decreased, and the hippocampal Tau protein and amyloid beta-protein expression levels were significantly decreased. In conclusion, ISL can alleviate the cognitive impairment after ketamine anesthesia in elderly rats. The mechanisms may be related to its resistance of oxidative stress and inflammatory response and inhibition of Tau protein and A beta expressions in hippocampus.