| Objectives To observe the effect of berberine on the cognitive function of wild-type and NRF2 gene knockout type diabetic mice,and to explore the possible mechanism of berberine improving the cognitive function of mice.Methods 1 Sixty male wild-type ICR mice were selected and randomly divided into wild control group(NC),wild control+berberine group(NC+BBR),wild diabetes group(DM),and wild diabetes+berberine group(DM+BBR).Type 2 diabetes mellitus model was established by high fat diet combined with streptozotocin injection.Treatment group mice gastric berberine 50 mg/kg per day,the rest of the mice given amount of 0.5% sodium hydroxy methyl cellulose solution.After 8 weeks,the mice were tested for fasting blood glucose and body weight,water maze experiment was used to judge the cognitive ability of mice,Nissl staining method was used to observe the effect of berberine on hippocampal tissue morphology,hippocampal MDA level was measured,and the expression of Nrf2、HO-1 and NQO1 were measured by RT-PCR,Western blot was used to detect the protein expression of Nrf2,HO-1,NQO1,Bcl-2,Bax,and Caspase3.2 Sixty Nrf2 knockout mice were selected and randomly divided into knockout control group(KO-NC),knockout control+berberine group(KO-NC+BBR),knockout diabetes group(KO-DM),Knock-out diabetes+berberine group(KO-DM+BBR),apply the same method to establish a model and intervene,water maze experiment was used to judge the cognitive ability of mice,RT-PCR and Western blot was used to detect the protein expression of Nrf2,HO-1,NQO1.Results 1 After 8 weeks of berberine,compared with DM group,the fasting blood glucose level and body weight of mice in DM+BBR group were reduced(P<0.01).2 The results of the Morris water maze experiment showed that from the second day of the experiment,compared with the NC group,the escape latency of the DM group was prolonged(P<0.05).Compared with the KO-DM+BBR group,the escape latency of the DM+BBR group was shortened(P<0.05).From the third day of the experiment,compared with DM group,the escape latency of DM+BBR group was shortened(P<0.05).On the 5th day of the experiment,the KO-DM group increased the escape latency compared with the DM group(P<0.05).After the platform was removed on the 6th day,compared with the NC group,the number of times of crossing the platform and the staying time in the platform quadrant of the DM group decreased(P<0.05).Compared with the DM group,the number of platforms and the staying time in the platform quadrant of the KO-DM group were both reduced(P<0.05).Compared with the DM group and the KO-DM+BBR group,the number of crossing the platform and the staying time in the platform quadrant of the DM+BBR group increased(P<0.05).3 Nissl staining of the mice hippocampus showed that the hippocampal cells of the control group were neatly arranged,the intercellular space and morphology were normal,and the nucleolus was clear;the hippocampal cells of the DM group were irregularly arranged,the cells were scattered,the gaps were enlarged,and the cells were shrunk,the structure was obviously damaged,and nuclear pyknosis occurs;the damage of hippocampal neurons in DM+BBR group is reduced.Comparing the relative cell numbers of the mouse hippocampus,it was found that compared with the NC group,the hippocampal cell counts of the DM group decreased,and the hippocampal cell counts increased after the intervention of berberine(P<0.01).4 Compared with the NC group,the MDA level in the hippocampal neurons of the DM group increased(P<0.01).Compared with the DM group,the MDA content of the KO-DM group was significantly higher.After8 weeks of berberine intervention,the MDA content of the DM+BBR group was lower than that of the DM group(P<0.01),while there was no significant difference in the KO-DM group and the KO-DM+BBR group(P>0.05).5 The expression of Bcl-2,Bax and Caspase3 in mice was detected by Western blot.The results showed that Bcl-2 expression in hippocampus of DM group was significantly reduced,Bax and Caspase-3 expression increased(P<0.01),while Bcl-2 expression in DM + BBR group was increased,Bax and Caspase-3 expression decreased(P<0.01).6 RT-PCR was used to detect the effect of berberine on the m RNA expression of Nrf2,HO-1 and NQO1 in hippocampus of mice.Compared with the control group,the m RNA expression of Nrf2,HO-1 and NQO1 in DM group was decreased(P<0.01),while the m RNA expression of Nrf2,HO-1 and NQO1 in hippocampus of DM + BBR group was increased(P<0.01).Compared with DM group,Nrf2 gene was not expressed in KO-DM group,and the expression of HO-1 and NQO1 was significantly decreased(P<0.01).After treatment with berberine,HO-1 and NQO1 expression in KO-DM+BBR group had no difference compared with that in KO-DM group(P>0.05).7 Western blott was used to detect the expression of Nrf2,HO-1 and NQO1 in hippocampus of mice.The results showed that the protein expression of Nrf2,HO-1 and NQO1 in hippocampus of mice in DM group was significantly lower than that in NC group(P<0.01).After 8 weeks of berberine intervention,the protein expression of Nrf2,HO-1 and NQO1 in hippocampus of mice in DM + BBR group was higher than that in DM group(P<0.01).Further detection of the expression of Nrf2,HO-1 and NQO1 in Nrf2 knockout mice showed that compared with DM group,Nrf2 gene was almost not expressed in KO-DM group,and the expression of HO-1 and NQO1 was significantly decreased(P<0.01).After treatment with berberine,HO-1 and NQO1 expression in KO-DM+BBR group had no difference compared with that in KO-DM group(P>0.05).Conclusions 1 Type 2 diabetic mice have cognitive dysfunction,berberine can improve the cognitive ability of mice.2 Berberine can improve the cognitive dysfunction of type 2diabetic mice by reducing the oxidative stress and apoptosis of hippocampus in mice.3Berberine can protect the cognitive impairment of type 2 diabetes by activating Nrf2 pathway and up regulating the expression of HO-1 and NQO1.Figure 17;Table 2;Reference 143... |
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