Neuroprotective effect of nobiletin on cognitive dysfunction rats after sevoflurane anesthesia / 中华行为医学与脑科学杂志

Objective:To study the neuroprotective effect of nobiletin on the symptoms of postoperative cognitive impairment (POCD) induced by sevoflurane inhalation.Methods:Twenty-four aged SD rats (12 female mice and 12 male mice) were divided into three groups randomly: control group ( n=8), surgery group ( n=8) and surgery + nobiletin group ( n=8), with 4 females and 4 males in each group.The rats in surgery group and surgery+ nobiletin group were given normal saline(0.1 ml/10 g, once a day) and nobiletin(100 mg/kg, once a day) intragastrically for 6 weeks.Then the rats were anesthetized by sevoflurane and treated by abdominal exploration surgery, and then continued gavage for 1 week.The rats in control group were given normal saline(0.1 ml/10 g, once a day) intragastrically for 7 weeks without anesthesia or surgery.Sevoflurane inhalation anesthesia and abbreviated laparotomy were not done for control group.Morris water maze and open field experiment were used to measure the memory and cognitive ability and the independent exploration ability respectively.The changes of α-band electroencephalogram (EEG) were recorded by multi-channel physiological signal acquisition and processing system.The concentration of S100β, a marker of neurological impairment was detected by ELISA.Western blot was used to detect the expression level of IBA-1 in microglia.SPSS 20.0 software was used to analyze the data. Results:There were no significant differences in Morris water maze, positioning cruise test and open field test among the groups before operation (all P>0.05). The differences were statistically significant among the groups 7 days after operation (all P<0.05). Compared with the control group (the escape latency, path length and cross platform times were ((20.37±1.11)s, (552.37±14.19)cm, (6.75±0.43)times respectively), the escape latency ((40.87±2.03)s) and path length ((1 258.62±19.53)cm) of rats in surgery group were significantly longer (both P<0.01), and the cross platform times ((2.12±0.33)times) significantly reduced ( P<0.01). The differences between surgery + nobiletin group ((22.37±1.11)s, (584.50±10.90)cm, (6.62±0.48)times) and control group were not significant (all P>0.05). The open field experiment showed that the movement distance, the crossed square number, and activity times in surgery group ((1.78±0.55) m, (4.75±0.50), (14.87±0.33) times) decreased significantly compared with those in control group ((3.73±0.07) m, (11.10±0.78), (51.12±0.78) times, all P<0.01). No significant difference was found between surgery + nobiletin group ((3.76±0.07)m, (10.75±0.66), (50.75±0.43)times) and control group(all P>0.05). Before anesthesia, there was no significant difference in the power ratio of α-band among the three groups ( P>0.05), but the differences during anesthesia and operation were significant ( F=72.58, 101.50, P<0.01). During anesthesia and operation, the power ratio of α-band in anesthesia and in surgery group (2.51±0.04, 2.14±0.03) were significantly lower (both P<0.01) than those in control group (3.49±0.03, 3.49±0.03), while there was no obvious changes (both P>0.05) in the surgery + nobiletin group (3.50±0.04, 3.51±0.04). There were significant differences in Bcl-2 protein expression and caspase 3/7 protein activity among the three groups ( F=5.21, 7.84, P<0.01). Compared with control group (1.00±0.02, 1 557.46±3.63), Bcl-2 of rats in the surgery group(0.40±0.05) were significantly lower and Caspase3/7 expression of surgery group (3 689.58±10.46) was significantly higher (both P<0.01), while the rats in the surgery + nobiletin group had no significant difference in both Bcl-2 level (1.03±0.06) and caspase 3/7 activities (1 805.28±6.17, both P>0.05). The difference of S100 β protein expression was significant among the three groups ( F=490.80, P<0.01). Compared with the control group ((0.18±0.01)μg/L), the concentration of S100β protein in the surgery group ((2.13±0.02)μg/L) decreased ( P<0.01), while there was no significant difference in the surgery + nobiletin group ((0.16±0.01) μg/L, P>0.05). The expression levels of IBA-1 protein ( F=10.83) and TNF-α, IL-1, IL-1β and IL-6 ( F=996.20, 221.40, 73.02, 174.13) were significantly different among the three groups (all P<0.01). The expression level of the neuroglial marker IBA-1 in the surgery group(1.36±0.02) was significantly higher than that in the control group (1.00±0.01, P<0.01), while the surgery + nobiletin group (1.03±0.01) had no significant different compared with control group ( P>0.05). The levels of inflammatory factors, including TNF-α, IL-1, IL-1β and IL-6, in the brain of rats treated with nobiletin ((49.06±3.63)pg/mg, (2.09±0.43)pg/mg, (16.27±0.80)pg/mg, (2.11±0.19)pg/mg) were significantly lower than those in the surgery group((145.10±6.46)pg/mg, (5.67±0.43)pg/mg, (27.88±3.43)pg/mg, (4.74±0.32)pg/mg, all P<0.01). Conclusion:Nobiletin can obviously alleviate POCD symptoms caused by sevoflurane inhalation anesthesia.

Changes in electroencephalogram during cognitive dysfunction induced by multiple inhalation of sevoflurane anesthesia in aged rats / 中华麻醉学杂志

Objective:To evaluate the changes in electroencephalogram (EEG) during cognitive dysfunction induced by multiple inhalation of sevoflurane anesthesia in aged rats.Methods:Twenty-one SPF healthy male Sprague-Dawley rats, aged 20-22 months, weighing 450-550 g, were divided into 2 groups using a random number table method: control group (group C, n=8) and repeated inhalation of sevoflurane anesthesia group (group S, n=13). In group S, the rats were put into an anesthesia box and inhaled a mixture of 3% sevoflurane and 30% oxygen for anesthesia, the oxygen flow rate was set at 3 L/min, maintaining for 3 h, and anesthesia was performed once every week for 3 times in total.The rats only inhaled a mixture of 70% air and 30% oxygen in group C. Two weeks later, cognitive function was assessed using Morris water maze test, the EEG was collected and analyzed by the multi-channel physiological signal system, and the recording time of EEG signal was 30 min.The rats were sacrificed, and the brains were collected for determination of the count of apoptotic nerve cells (by TUNEL staining), and the apoptotic rate of nerve cells was calculated. Results:Compared with group C, the escape latency was significantly prolonged at 3rd and 4th days of training, the number of crossing the original platform was decreased at 5th day, the percentage of high-frequency waves was decreased, the percentage of low-frequency waves was increased, and the apoptosis rate of nerve cells was increased in group S ( P<0.05). Conclusion:The percentage of high-frequency waves is decreased, and the percentage of low-frequency waves is increased during cognitive dysfunction induced by multiple inhalation of sevoflurane anesthesia, which may be related to apoptosis in nerve cells of aged rats.

Blockage of PD-L1/PD-1 pathway for enhancing the chemotherapeutic efficacy of cisplatin / 实用医学杂志

Objective To explore the anti-tumor effect and the influence of antitumor immunity of PD-L1/PD-1 blocked by PD-1 antibody combined with cisplatin. Methods Tumor models were established by injecting TC-1 cells into C57BL/6 mice, and the mice were divided into four groups (n = 4). The tumor growth curves and survival curves were drawn to observe the anti-tumor effect. The tumors were then removed; and the PD-L1 and CD8+ T cells were analyzed by immunohistochemical method. Results The anti-tumor effect was greater in the cisplatin group , PD-1 antibody group , and PD-1 antibody plus cisplatin group than in the control group (P < 0.05). Expression of PD-L1 in the tumor tissues was markedly increased in the cisplatin group and it was obviously decreased in the combination group (P < 0.05). CD8+ T cells decreased in the cisplatin group; and expression of CD8+ T cells was significantly increased the combination group (P < 0.05). Conclusion The anti-tumor effect and anti-tumor immunity of cisplatin are enhanced by blocking PD-L1/PD-1 pathway with PD-1 antibody.

Effect of pre-amputation pain block on the spinal and anterior cingulated cortex NMDA receptor activation in amputated rats / 中南大学学报(医学版)

OBJECTIVE@#To investigate the effect of pre-amputation pain block on the N-methyl-D-aspartate receptor activation in the central nervous system of amputated rats, and the association between pre-amputation pain block and chronic amputation-related pain.@*METHODS@#Thirty-six adult male SD rats were randomly assigned to an NA group (n=12), a PA group (n=12) and a PAB group (n=12). Group NA was intraplantarly injected saline l00 μL while group PA and group PAB were intraplantarly injected complete Freund adjuvant (CFA) 100 μL. The sciatic nerve of group NA and group PA were freed from surrounding tissue, and that of group PAB was blocked by bupivacaine under pentobarbital sodium anesthesia 5 days after the injection. Thermal withdrawal latency (TWL) was measured before and after the injection. All rats were amputated at the scheduled survival time. The expression of N-methyl-D-aspartate receptor (NR2B) was measured by immunohistochemistry in L4-6 of the spinal cord and the anterior cingulated cortex 7 days after the amputation procedure.@*RESULTS@#The TWL after intraplantar administration of CFA in group PA and group PAB decreased significantly compared with the baseline value (P<0.05), while the saline treated control group remained unchanged. Besides the basic value, the TWL of group PA was shorter than that of group NA at the above-mentioned time-points (P<0.05). Compared with the basic value and group NA, the TWL of group PAB after the block increased significantly (P<0.05). Compared with group NA and group PAB, group PA had a remarkably high expression of NR2B (P<0.05), while there was no difference between group PA and group PAB.@*CONCLUSION@#Pre-amputation pain may activate N-methyl-D-aspartate receptor of the central nervous system, which may lead acute postoperative pain to chronic pain. It is necessary to treat pre-amputation pain.

Chronic ethanol exposure and withdrawal alter the expression of actin-binding protein and cyclin-dependent kinase-5 in rat brain / 中华行为医学与脑科学杂志

Objective To investigate the effects of chronic ethanol exposure and withdrawal on the expression of actin-binding protein cofilin,p-cofilin and cyclin-dependent kinase-5 (cdk5) in the nucleus accumbens and striatum in rat brain.Methods Twenty-four male SD rats were randomly divided into one control group and three experimental groups.In the experimental groups,ethanol was administered in drinking water at the concentration of 6％ (V/V) for two months.Rats in control group drank normal drinking water.After two months ethanol was removed and ethanol withdrawal syndromes were evaluated.Rats were sacrificed on withdrawal 0 h,withdrawal 6 h and withdrawal 2 d.The expression levels of cofilin,p-cofilin(ser3)and cdk5 in the rat brain were measured by immunohistochemistry methods.Results Withdrawal syndrome scores of ethanol fed rats were obviously higher than those of control rats after ethanol was removed,the highest score occurred at 6 h after ethanol withdrawal.In the nucleus accumbens area of rat brain,the levels of cofilin on withdrawal 0 h significantly decreased compared with control group ((0.31±0.05),(0.39± 0.05),P＜ 0.05).The levels of cdk5 on withdrawal 0 h and withdrawal 6 h significantly increased compared with control group((0.36±0.07),(0.34±0.07),(0.25±0.05),P＜0.05).In the striatum of rat brain,the levels of cofilin on withdrawal 0 h significantly decreased compared with control group ((0.26±0.04),(0.34±0.05),P＜0.05).The levels of p-cofilin on withdrawal 6 h significantly increased compared with control group((0.43±0.06),(0.30±0.06),P＜0.01).The levels of cdk5 on withdrawal 0 h significantly increased compared with control group((0.35±0.06),(0.26±0.05),P＜0.05),and the levels of cofilin on withdrawal 6 h significantly decreased compared with control group((0.37±0.06),(0.26±0.05),P＜0.01).Conclusion Chronic ethanol exposure can induce the development of ethanol dependence,and it accompanies with changes in the expression of actin-binding protein and cdk5 in the brain of rats.

Effect of preamputation pain on the behavioral changes and spinal astrocytic activation in amputated rats / 中南大学学报(医学版)

OBJECTIVE@#To determine the effect of preamputation pain on the behavioral response and astrocytic activation in the spinal cord of amputated rats, and to assess the association between preamputation pain and chronic amputation-related pain.@*METHODS@#A total of 84 adult male SD rats were randomly distributed into an NA group (n=42) and a PA group (n=42). The NA group was intraplantarly injected with saline 100 μL, while the PA group was intraplantarly injected with complete Freund's adjuvant (CFA) 100 μL in both cases at 7 d before the amputation. Thermal withdrawal latency (TWL) was measured before the injection and at 1, 3, 5, and 7 d after the injection. All rats were amputated on the 7th day. The TWL, diet and water intake were measured on 1, 3, 5, 7, 10, 14, 17, 21, and 28 d after the amputation. Expression of glial fibrillary acidic protein (GFAP) in the L4-6 of spinal cord was measured by immunohistochemistry before the saline/ CFA injection, 7 d after the injection and 1, 3, 5, 7, 10 d after the amputation..@*RESULTS@#The TWL significantly decreased on 1, 3, 5, and 7 d after the intraplantar administration of CFA compared with the basic value in the PA group (P0.05). In addtions to the basic value, the TWL of the PA group was shorter than that of the NA group at the above-mentioned time-points (P<0.05). Compared with the preoperative level, the diet and water intake decreased significantly after the amputation in both groups, but recovered to the preoperative levels, by 3 d after the amputation in the NA group, and by 5 d after the amputation in the PA group. Compared with the TWL of the residual limb on the day of amputation, the TWL of the residual limb increased significantly 3 d after the amputation and remained elevated until 28 d after the amputation in the NA group (P<0.05), while there was no difference between each time point after the amputation and the day of the amputation in the PA group. Compared with the basic value, there was an obviously high expression of GFAP in the NA group beginning on the day of amputation and in the PA group 7 d after the CFA injection (P<0.05). After the amputation, the expression of GFAP was significantly higher in the PA group (P<0.05).@*CONCLUSION@#Preamputation pain delays the recovery and activates the spinal astrocytes which may turn the acute postoperative pain into a chronic one.