Effect Of Butylphthalide On The Neurotoxicity Of Ketamine In Mice During Development And Its Mechanism

Objective: To study the effect of butylphthalide on neurotoxic mice induced by ketamine and its mechanism of actionMethods: Forty-four healthy C57/BL6 mice at the age of 7 days were divided into four groups according to random number scale: control group(group C),ketamine group(group K),low-dose butylphthalide group(group L)and high-dose butylphthalide group(group H).Mice in group K were intraperitoneally injected with ketamine 75 mg/kg,mice in group L were intraperitoneally injected with ketamine 75 mg/kg+ butylphthalide 80 mg/kg,mice in group H were intraperitoneally injected with ketamine 75 mg/kg+butylphthalide 160 mg/kg,and mice in group C were intraperitoneally injected with 5 μL normal saline.Intraperitoneal injection was given once daily for three consecutive days.During anesthesia,mice were placed in an incubator to maintain the temperature at 26-28 ℃ and oxygen supply at a low flow rate of 2 L/min.The changes of respiration,skin and mucosa were closely observed during anesthesia.After the end of general anesthesia,mice in each group were put back into the cage to continue feeding.After 24 hours after the last administration,6 mice in each group were taken from the amputated head and hippocampal tissues were collected.The expressions of PI3 K,Akt,p-PI3 K,p-Akt and autophagy related indexes LC3 and Beclin-1 were detected by Western blot.The other mice were tested by water maze test at 30 days of age to detect their learning and memory ability.After the water maze test,the morphology of hippocampal cells in each group was observed by HE staining.Results: 1.The results of the water maze showed that there were statistically significant differences in the escape latency between each group during the navigation experiment(P<0.05),with the increase of training days,the escape latency of mice in each group showed a downward trend.Compared with group C,the escape latency of mice in group K was significantly prolonged from day 2 to day 5,and the difference was statistically significant(P<0.01),compared with group K,the escape incubation period of group L and group H was shortened on day 4-5,and the difference was statistically significant(P<0.05),there was no significant difference in escape latency between group L and group H(P>0.05).In the space exploration experiment,compared with group C,the percentage of target quadrant residence time and platform crossing times of mice in group K were significantly decreased(P<0.01),the percentage of target quadrant residence time and platform crossing times of group L were significantly decreased(P<0.01),the percentage of target quadrant residence time and platform crossing times of group H had no significant difference(P>0.05),the percentage of target quadrant residence time and platform crossing times in group L were increased compared with group K(P<0.05),the percentage of target quadrant residence time and platform crossing times in group H were significantly increased(P<0.01).Compared with group L,the percentage of target quadrant residence time and platform crossing times of group H were increased(P<0.05).2.HE results show that:The hippocampal neurons of control group were intact and closely arranged.Hippocampal neurons in ketamine group were arranged disorderly and some neurons were missing.Compared with the ketamine group,the hippocampal neurons in the low-dose and high-dose butylphthalide groups were improved in terms of cell integrity,disordered arrangement and neuron deletion.3.Western blot results showed that:There was no significant difference in PI3 K and AKT protein among all groups(P>0.05);Compared with the control group,p-PI3 K and p-AKT proteins were decreased in the ketamine group(P<0.01),LC3 and Becline-1were increased(P<0.01),P-PI3 K and P-AKT in L group were decreased(P<0.01),Beclin-1 and LC3 were increased(P<0.05),p-PI3K(P<0.01)and p-AKT(P<0.05)in group H were increased compared with that in group K,Beclin-1 was significantly decreased(P<0.01),LC3 decreased(P<0.05),compared with group L,p-PI3 K in group H was significantly increased(P<0.01).Conclusion:1.Butylphthalide can ameliorate the neurotoxic effect of ketamine on developing mice.2.The mechanism of butylphthalide improving the neurotoxicity of ketamine may be related to the activation of PI3K/ Akt pathway and the inhibition of autophagy.3.There was no significant abnormality in the improvement of neurotoxicity in mice by high-dose and low-dose butylphthalide.