Effect of NC on the cognitive function of STZ‐induced diabetic rats in MWM test. Diabetic rats were treated with RAP (1 mg/kg/day, IP), NC (100 mg/kg/day, IP), NC (100 mg/kg/day, IP) + CQ (40 mg/kg/day, IP), NC (100 mg/kg/day, IP) + 3‐MA (1.5 mg/kg/day, IP) for 35 consecutive days. MWM test was used to evaluate the cognitive function of rats. The latency to find platform in acquisition phase was analyzed (A). The percentage of time spent in the target quadrant (B) and the times across invisible platform were analyzed (C). The data are expressed as mean ± SEM (n = 10‐14 per group). *P < 0.05, **P < 0.01, compared with the DM group; #
P < 0.05 compared with the DM + NC group