目的 通过研究肉桂酸对db/db小鼠肝脏PI3K/AKT/FoxO1信号通路的影响，探讨其在肝脏胰岛素抵抗方面的作用机制。方法 连续两日同一时间测空腹血糖，并参考体重用随机分层抽样法将18只db/db小鼠分为模型组、吡格列酮组和肉桂酸组，正常组为同周龄db/m + 小鼠，每组6只，分别给予肉桂酸溶液与等量DMSO灌胃4周。Elisa法检测血清胰岛素水平，全自动生化分析仪检测血清甘油三酯（TG）、总胆固醇（TC）、谷丙转氨酶（ALT）、谷草转氨酶（AST）和游离脂肪酸（FFA），Western blot法检测肝脏组织PI3K、AKT、FoxO1的蛋白表达。结果 肉桂酸可降低db/db小鼠空腹血糖水平及血清ALT、AST、TG、TC和FFA的水平；其亦可上调肝脏组织PI3K、p-FoxO1、p-AKT蛋白表达水平，下调FoxO1蛋白表达水平。结论 肉桂酸可以改善db/db小鼠的空腹葡萄糖水平，调节血脂及改善胰岛素抵抗，其作用机制可能是通过激活PI3K/AKT/FoxO1信号通路来实现的。

Objective To investigate the effects of cinnamic acid on the PI3K/AKT/FoxO1 signaling pathway in the liver of db/db mice, and to explore its mechanism of action on liver insulin resistance.Methods Fasting blood glucose was measured at the same time for two consecutive days, and 18 db/db mice were divided into model group, pioglitazone group and cinnamic acid group by random stratified sampling with reference to body weight. The normal group was db/m + mice of the same age, with 6 rats in each group. They were given cinnamic acid solution and the same amount of DMSO by gavage for 4 weeks. ELISA method was used to detect serum insulin level. Automatic biochemical analyzer was used to detect serum TC, TG, ALT, AST and FFA, and Western blot method was used to detect the protein expression of liver tissue PI3K, AKT and FoxO1.Results Cinnamic acid can reduce fasting blood glucose levels and serum ALT, AST, TG, TC and FFA levels in db/db mice; it can also up-regulate liver tissue PI3K, p-FoxO1, p-AKT protein expression levels, and down-regulate FoxO1 protein expression level.Conclusion Cinnamic acid can improve fasting glucose levels in db/db mice, regulate blood lipids and improve insulin resistance. Its mechanism of action may be achieved by activating the PI3K/AKT/FoxO1 signaling pathway.