The Alterations of Blood Glucose and Cognitive Function by Ketone Injection in Mice

Objectives The ketogenic diet is defined as a high‐fat and low‐carbohydrate diet, and has been applied to patients with epilepsy, cancer, dementia and obesity. Mounting evidence suggests that ketogenic diet has an anorexigenic effect regulating carbohydrate metabolism and protecting brain function. However, the effects of ketogenic diet have not been clearly proved. This experiment aimed to examine whether ketone injection affects body weight, food intake, glycemic control and cognitive function in mice. Methods ICR male mice (11 weeks of age) were assigned to either control group or ketone group. β‐hydroxybutyrate (BHB, 300 mg/kg/day) was intraperitoneal injected to ketone group mice for 28 days. After ketone treatment for 28 days, oral glucose tolerance test and nest building test of hippocampus function were performed, and then sacrificed. The serum BHB concentrations were measured using a BHB colorimetric assay kit. Results With the ketone injection, daily food intake and body weight changes were similar between groups. The weights of kidney were significantly increased by 28 days of ketone injection ( P = 0.004), whereas, lung ( P = 0.014) and spleen ( P = 0.046) weights of ketone injection group were significantly lower in comparison with control group. The blood glucose concentrations at 2 hours after a glucose challenge were significantly increased by ketone injection ( P = 0.045). During the nest building test, the control group mice barely touched cotton pad, and the untorn pad weights had a tendency to be high in control group mice. Conclusions In this experiment, ketone injection altered glycemic control after a glucose challenge, and might improve hippocampus function. Collectively, findings of current experiment indicate that ketogenic diet could be beneficial for maintaining cognitive function.