ObjectiveThe antitumor activity of sesquiterpenoid M36 isolated from Myrrha against human hepatoma HepG2 cells was investigated in this study. MethodHepG2 cells were treated with M36 at different concentrations （0， 2， 4， 6， 8， 10 μmol·L^-1）. Firstly， the effects of M36 on the proliferation of human hepatoma HepG2 cells were detected by methyl thiazolyl tetrazolium （MTT）， colony formation assay， and EdU proliferation assay. Hoechst staining， flow cytometry analysis， and Western blot were used to explore the effect of M36 on the apoptosis of human hepatoma HepG2 cells. Acridine orange staining and western blotting were used to examine the effect of M36 on autophagy in HepG2 cells. Finally， Western blot was used to detect protein expression of cancer-related signaling pathways. ResultCompared with the blank group， M36 treatment significantly inhibited the proliferation of human hepatoma HepG2 cells （P<0.01）， and the half inhibitory concentration （IC₅₀） value of M36 for 48 h was 5.03 μmol·L^-1， in a dose- and time-dependent manner. M36 was also able to induce apoptosis and autophagy in human hepatoma HepG2 cells. After treatment with 8 μmol·L^-1 M36 for 48 hours， the apoptosis rate of HepG2 cells was （42.03±9.65）% （P<0.01）. Compared with the blank group， HepG2 cells treated with 4 and 8 μmol·L^-1 M36 for 48 h had a significant increase in cleaved poly ADP-ribose polymerase （cleaved-PARP） protein levels （P<0.01）. Acridine orange staining showed that autophagy was significantly activated in HepG2 cells treated with 4 and 8 μmol·L^-1 M36 for 48 h compared with the blank group （P<0.01）， which was further verified by the up-regulation of microtubule-associated protein 1 light chain 3 Ⅱ （LC3 Ⅱ）. Western blot results showed that compared with the blank group， the levels of phosphorylated extracellular regulated protein kinase （p-ERK）， phosphorylated p38 mitogen-activated protein kinase （p-p38 MAPK）， phosphorylated c-Jun N-terminal kinase （p-JNK）， and its downstream nuclear transcription factors c-Jun and p-c-Jun protein were significantly increased in M36 group （P<0.05， P<0.01）. The mechanism may be related to the up-regulation of MAPK signaling pathway. ConclusionThe sesquiterpenoid M36 isolated from Myrrha inhibits the proliferation of human hepatoma HepG2 cells and promotes apoptosis and autophagy， which may be related to the activation of the MAPK signaling pathway.

Objective To investigate the effects of pre-electroacupuncture(EA)on spatial learning and memory,the locus coeruleus-hippocampal neural circuit,and neuroinflammation in Alzheimer's disease(AD)-like rats,and to explore the possible mechanism of pre-EA in preventing and treating AD.Methods Thirty-six male SD rats were divided into the normal,model,EA,and sham EA groups using the random number table method,with nine rats per group.An AD-like rat model was prepared through intraperitoneal injection of 120 mg/(kg·d)D-galactose for eight consecutive weeks.After daily intraperitoneal injection,the rats in the EA group underwent EA stimulation at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints with a continuous wave,frequency of 50 Hz,and a current of 1 mA for 20 min once a day for 8 weeks.The sham EA group was only superficially punctured to the subcutaneous tissue at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints without electricity,and the rest of the operations were the same as those in the EA group.The Morris water maze experiment was then used to evaluate the spatial learning and memory of the rats.Immunofluorescence labeling was used to detect dopamine β hydroxylase and c-Fos co-localization in the locus coeruleus of noradrenergic neurons,as well as glial fibrillary acidic protein and tumor necrosis factor-α(TNF-α)co-localization in the CA1 area of the hippocampus of astrocytes.Western blotting was used to measure the protein expressions of norepinephrine(NE),β2-adrenergic receptor(β2AR),β-inhibitory protein 2(β-arrestin2),nuclear transcription factor-κB(NF-κB)inhibitory factor protein α(IκBα),and NF-κB in the hippocampus of rats.An enzyme-linked immunosorbent assay was used to detect the TNF-α,interleukin-1β(IL-1β),and interleukin-6(IL-6)contents in hippocampal tissue.Results Compared with the normal group,the average escape latency of the model group rats was prolonged,and the times of crossing platform and exploration time in the target quadrant were reduced(P<0.01),while the EA intervention can shorten the average escape latency and increase the times of crossing platform and exploration time in the target quadrant(P<0.01).Compared with the normal group,the expression of co-located noradrenergic neurons in the model group decreased,co-located astrocytes increased(P<0.01);NE,β2AR,β-arrestin2,and IκBα protein expression decreased(P<0.01),NF-κB protein expression increased(P<0.01);the contents of TNF-α,IL-1β,and IL-6 increased(P<0.01).Compared with the model group,the EA group showed an increase in the expression of co-located noradrenergic neurons,a decrease in co-located astrocytes(P<0.01),an increase in NE,β2AR,β-arrestin2,and IκBα protein expressions(P<0.01),a decrease in NF-κB protein expression(P<0.01),and a decrease in TNF-α,IL-1β,and IL-6 levels(P<0.01).No significant difference was observed in the above indicators between the model and sham EA groups.Conclusion Pre-EA at"Neiguan"(PC6)and"Jianshi"(PC5)can alleviate learning and memory dysfunction,alleviate noradrenergic neuronal loss in the locus coeruleus,inhibit astrocyte activation,protect the locus coeruleus-hippocampal neural circuit,and may be associated with inhibiting β2AR/β-arrestin2/NF-κB inflammatory pathway activation.

Objective To investigate the effects of pre-electroacupuncture(EA)on spatial learning and memory,the locus coeruleus-hippocampal neural circuit,and neuroinflammation in Alzheimer's disease(AD)-like rats,and to explore the possible mechanism of pre-EA in preventing and treating AD.Methods Thirty-six male SD rats were divided into the normal,model,EA,and sham EA groups using the random number table method,with nine rats per group.An AD-like rat model was prepared through intraperitoneal injection of 120 mg/(kg·d)D-galactose for eight consecutive weeks.After daily intraperitoneal injection,the rats in the EA group underwent EA stimulation at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints with a continuous wave,frequency of 50 Hz,and a current of 1 mA for 20 min once a day for 8 weeks.The sham EA group was only superficially punctured to the subcutaneous tissue at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints without electricity,and the rest of the operations were the same as those in the EA group.The Morris water maze experiment was then used to evaluate the spatial learning and memory of the rats.Immunofluorescence labeling was used to detect dopamine β hydroxylase and c-Fos co-localization in the locus coeruleus of noradrenergic neurons,as well as glial fibrillary acidic protein and tumor necrosis factor-α(TNF-α)co-localization in the CA1 area of the hippocampus of astrocytes.Western blotting was used to measure the protein expressions of norepinephrine(NE),β2-adrenergic receptor(β2AR),β-inhibitory protein 2(β-arrestin2),nuclear transcription factor-κB(NF-κB)inhibitory factor protein α(IκBα),and NF-κB in the hippocampus of rats.An enzyme-linked immunosorbent assay was used to detect the TNF-α,interleukin-1β(IL-1β),and interleukin-6(IL-6)contents in hippocampal tissue.Results Compared with the normal group,the average escape latency of the model group rats was prolonged,and the times of crossing platform and exploration time in the target quadrant were reduced(P<0.01),while the EA intervention can shorten the average escape latency and increase the times of crossing platform and exploration time in the target quadrant(P<0.01).Compared with the normal group,the expression of co-located noradrenergic neurons in the model group decreased,co-located astrocytes increased(P<0.01);NE,β2AR,β-arrestin2,and IκBα protein expression decreased(P<0.01),NF-κB protein expression increased(P<0.01);the contents of TNF-α,IL-1β,and IL-6 increased(P<0.01).Compared with the model group,the EA group showed an increase in the expression of co-located noradrenergic neurons,a decrease in co-located astrocytes(P<0.01),an increase in NE,β2AR,β-arrestin2,and IκBα protein expressions(P<0.01),a decrease in NF-κB protein expression(P<0.01),and a decrease in TNF-α,IL-1β,and IL-6 levels(P<0.01).No significant difference was observed in the above indicators between the model and sham EA groups.Conclusion Pre-EA at"Neiguan"(PC6)and"Jianshi"(PC5)can alleviate learning and memory dysfunction,alleviate noradrenergic neuronal loss in the locus coeruleus,inhibit astrocyte activation,protect the locus coeruleus-hippocampal neural circuit,and may be associated with inhibiting β2AR/β-arrestin2/NF-κB inflammatory pathway activation.

Objective To investigate the effects of pre-electroacupuncture(EA)on spatial learning and memory,the locus coeruleus-hippocampal neural circuit,and neuroinflammation in Alzheimer's disease(AD)-like rats,and to explore the possible mechanism of pre-EA in preventing and treating AD.Methods Thirty-six male SD rats were divided into the normal,model,EA,and sham EA groups using the random number table method,with nine rats per group.An AD-like rat model was prepared through intraperitoneal injection of 120 mg/(kg·d)D-galactose for eight consecutive weeks.After daily intraperitoneal injection,the rats in the EA group underwent EA stimulation at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints with a continuous wave,frequency of 50 Hz,and a current of 1 mA for 20 min once a day for 8 weeks.The sham EA group was only superficially punctured to the subcutaneous tissue at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints without electricity,and the rest of the operations were the same as those in the EA group.The Morris water maze experiment was then used to evaluate the spatial learning and memory of the rats.Immunofluorescence labeling was used to detect dopamine β hydroxylase and c-Fos co-localization in the locus coeruleus of noradrenergic neurons,as well as glial fibrillary acidic protein and tumor necrosis factor-α(TNF-α)co-localization in the CA1 area of the hippocampus of astrocytes.Western blotting was used to measure the protein expressions of norepinephrine(NE),β2-adrenergic receptor(β2AR),β-inhibitory protein 2(β-arrestin2),nuclear transcription factor-κB(NF-κB)inhibitory factor protein α(IκBα),and NF-κB in the hippocampus of rats.An enzyme-linked immunosorbent assay was used to detect the TNF-α,interleukin-1β(IL-1β),and interleukin-6(IL-6)contents in hippocampal tissue.Results Compared with the normal group,the average escape latency of the model group rats was prolonged,and the times of crossing platform and exploration time in the target quadrant were reduced(P<0.01),while the EA intervention can shorten the average escape latency and increase the times of crossing platform and exploration time in the target quadrant(P<0.01).Compared with the normal group,the expression of co-located noradrenergic neurons in the model group decreased,co-located astrocytes increased(P<0.01);NE,β2AR,β-arrestin2,and IκBα protein expression decreased(P<0.01),NF-κB protein expression increased(P<0.01);the contents of TNF-α,IL-1β,and IL-6 increased(P<0.01).Compared with the model group,the EA group showed an increase in the expression of co-located noradrenergic neurons,a decrease in co-located astrocytes(P<0.01),an increase in NE,β2AR,β-arrestin2,and IκBα protein expressions(P<0.01),a decrease in NF-κB protein expression(P<0.01),and a decrease in TNF-α,IL-1β,and IL-6 levels(P<0.01).No significant difference was observed in the above indicators between the model and sham EA groups.Conclusion Pre-EA at"Neiguan"(PC6)and"Jianshi"(PC5)can alleviate learning and memory dysfunction,alleviate noradrenergic neuronal loss in the locus coeruleus,inhibit astrocyte activation,protect the locus coeruleus-hippocampal neural circuit,and may be associated with inhibiting β2AR/β-arrestin2/NF-κB inflammatory pathway activation.

AIM:To explore the molecular mecha-nism of Fuyangjing gel in the treatment of chronic eczema rats model based on janus protein kinase 1(JAK1)/signal transducer and activator of transcrip-tion 5(STAT5)signaling pathway.METHODS:Thirty-six SPF Wistar rats were randomly divided into nor-mal group,model group,Qingpeng ointment group,Fuyangjing gel low,medium and high dose groups.Except the normal group,the other groups of rats were treated with 2,4-dinitrochlorophenone solution to induce chronic eczema-like lesions on the back.After 3 weeks of modeling,Qingpeng ointment group and Fuyangjing gel low,medium and high dose groups were respectively treated with corresponding drugs.The model group was smeared with blank gel matrix once a day for 2 weeks,while the normal group was not treated.The severity and pathological changes of back le-sions in chronic eczema rats were observed.The ex-pression of phosphorylated protein tyrosine kinase 1(p-JAK1)and phosphorylated signal transduction and transcriptional activator 5(p-STAT5)in rat dor-sal skin was detected by Western blot.Detection of thymic stromallymphopietin(TSLP),JAK1,STAT5,in-terleukin-10(IL-10)and IL-17 mRNA expression lev-els in rat back skin by qRT-PCR;The levels of IL-4,IL-6,IL-10,IL-13 and IL-17 in serum of rats were deter-mined by enzyme-linked immunosorbent assay(ELI-SA).RESULTS:Compared with normal group,the se-rum levels of IL-4,IL-6,IL-13 and IL-17 in model group were significantly increased,while IL-10 lev-els were significantly decreased(P＜0.05).The ex-pression levels of p-JAK1,p-STAT5 protein and TSLP,JAK1,STAT5 and IL-17 mRNA in back lesions were significantly increased,while IL-10 mRNA levels were significantly decreased(P＜0.05).Compared with model group,serum levels of IL-4,IL-6,IL-13 and IL-17 in Qingpeng ointment group and Fuy-angjing gel low,medium and high dose groups were significantly decreased,while IL-10 levels were significantly increased(P＜0.05).The expres-sion levels of p-JAK1,p-STAT5 protein and TSLP,JAK1,STAT5 and IL-17 mRNA in back lesions were significantly decreased,while the mRNA levels of IL-10 were significantly increased(P＜0.05).The serum levels of IL-4,IL-6,IL-13 and IL-17 in Qingpeng oint-ment group were decreased,while IL-10 levels were increased(P＜0.05).The expression levels of p-JAK1,p-STAT5 protein and TSLP,JAK1,STAT5 and IL-17 mRNA in back lesions were decreased,while the mRNA levels of IL-10 were increased(P＜0.05).Com-pared with Qingpeng ointment group,there were no significant differences in serum levels of IL-4,IL-6,IL-10,IL-13 and IL-17 in Fuyangjing gel high-dose group(P＞0.05).There were no significant differenc-es in the expression levels of p-JAK1,p-STAT5 pro-tein and TSLP,JAK1,STAT5,IL-10 and IL-17 mRNA in back lesions(P＞0.05).CONCLUSION:Fuyangjing gel may play a role in the treatment of chronic eczema by regulating the expression of JAK1/STAT5 signal-ing pathway related inflammatory factors,proteins and genes.

Objective To investigate the effects of pre-electroacupuncture(EA)on spatial learning and memory,the locus coeruleus-hippocampal neural circuit,and neuroinflammation in Alzheimer's disease(AD)-like rats,and to explore the possible mechanism of pre-EA in preventing and treating AD.Methods Thirty-six male SD rats were divided into the normal,model,EA,and sham EA groups using the random number table method,with nine rats per group.An AD-like rat model was prepared through intraperitoneal injection of 120 mg/(kg·d)D-galactose for eight consecutive weeks.After daily intraperitoneal injection,the rats in the EA group underwent EA stimulation at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints with a continuous wave,frequency of 50 Hz,and a current of 1 mA for 20 min once a day for 8 weeks.The sham EA group was only superficially punctured to the subcutaneous tissue at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints without electricity,and the rest of the operations were the same as those in the EA group.The Morris water maze experiment was then used to evaluate the spatial learning and memory of the rats.Immunofluorescence labeling was used to detect dopamine β hydroxylase and c-Fos co-localization in the locus coeruleus of noradrenergic neurons,as well as glial fibrillary acidic protein and tumor necrosis factor-α(TNF-α)co-localization in the CA1 area of the hippocampus of astrocytes.Western blotting was used to measure the protein expressions of norepinephrine(NE),β2-adrenergic receptor(β2AR),β-inhibitory protein 2(β-arrestin2),nuclear transcription factor-κB(NF-κB)inhibitory factor protein α(IκBα),and NF-κB in the hippocampus of rats.An enzyme-linked immunosorbent assay was used to detect the TNF-α,interleukin-1β(IL-1β),and interleukin-6(IL-6)contents in hippocampal tissue.Results Compared with the normal group,the average escape latency of the model group rats was prolonged,and the times of crossing platform and exploration time in the target quadrant were reduced(P<0.01),while the EA intervention can shorten the average escape latency and increase the times of crossing platform and exploration time in the target quadrant(P<0.01).Compared with the normal group,the expression of co-located noradrenergic neurons in the model group decreased,co-located astrocytes increased(P<0.01);NE,β2AR,β-arrestin2,and IκBα protein expression decreased(P<0.01),NF-κB protein expression increased(P<0.01);the contents of TNF-α,IL-1β,and IL-6 increased(P<0.01).Compared with the model group,the EA group showed an increase in the expression of co-located noradrenergic neurons,a decrease in co-located astrocytes(P<0.01),an increase in NE,β2AR,β-arrestin2,and IκBα protein expressions(P<0.01),a decrease in NF-κB protein expression(P<0.01),and a decrease in TNF-α,IL-1β,and IL-6 levels(P<0.01).No significant difference was observed in the above indicators between the model and sham EA groups.Conclusion Pre-EA at"Neiguan"(PC6)and"Jianshi"(PC5)can alleviate learning and memory dysfunction,alleviate noradrenergic neuronal loss in the locus coeruleus,inhibit astrocyte activation,protect the locus coeruleus-hippocampal neural circuit,and may be associated with inhibiting β2AR/β-arrestin2/NF-κB inflammatory pathway activation.

Objective To investigate the effects of pre-electroacupuncture(EA)on spatial learning and memory,the locus coeruleus-hippocampal neural circuit,and neuroinflammation in Alzheimer's disease(AD)-like rats,and to explore the possible mechanism of pre-EA in preventing and treating AD.Methods Thirty-six male SD rats were divided into the normal,model,EA,and sham EA groups using the random number table method,with nine rats per group.An AD-like rat model was prepared through intraperitoneal injection of 120 mg/(kg·d)D-galactose for eight consecutive weeks.After daily intraperitoneal injection,the rats in the EA group underwent EA stimulation at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints with a continuous wave,frequency of 50 Hz,and a current of 1 mA for 20 min once a day for 8 weeks.The sham EA group was only superficially punctured to the subcutaneous tissue at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints without electricity,and the rest of the operations were the same as those in the EA group.The Morris water maze experiment was then used to evaluate the spatial learning and memory of the rats.Immunofluorescence labeling was used to detect dopamine β hydroxylase and c-Fos co-localization in the locus coeruleus of noradrenergic neurons,as well as glial fibrillary acidic protein and tumor necrosis factor-α(TNF-α)co-localization in the CA1 area of the hippocampus of astrocytes.Western blotting was used to measure the protein expressions of norepinephrine(NE),β2-adrenergic receptor(β2AR),β-inhibitory protein 2(β-arrestin2),nuclear transcription factor-κB(NF-κB)inhibitory factor protein α(IκBα),and NF-κB in the hippocampus of rats.An enzyme-linked immunosorbent assay was used to detect the TNF-α,interleukin-1β(IL-1β),and interleukin-6(IL-6)contents in hippocampal tissue.Results Compared with the normal group,the average escape latency of the model group rats was prolonged,and the times of crossing platform and exploration time in the target quadrant were reduced(P<0.01),while the EA intervention can shorten the average escape latency and increase the times of crossing platform and exploration time in the target quadrant(P<0.01).Compared with the normal group,the expression of co-located noradrenergic neurons in the model group decreased,co-located astrocytes increased(P<0.01);NE,β2AR,β-arrestin2,and IκBα protein expression decreased(P<0.01),NF-κB protein expression increased(P<0.01);the contents of TNF-α,IL-1β,and IL-6 increased(P<0.01).Compared with the model group,the EA group showed an increase in the expression of co-located noradrenergic neurons,a decrease in co-located astrocytes(P<0.01),an increase in NE,β2AR,β-arrestin2,and IκBα protein expressions(P<0.01),a decrease in NF-κB protein expression(P<0.01),and a decrease in TNF-α,IL-1β,and IL-6 levels(P<0.01).No significant difference was observed in the above indicators between the model and sham EA groups.Conclusion Pre-EA at"Neiguan"(PC6)and"Jianshi"(PC5)can alleviate learning and memory dysfunction,alleviate noradrenergic neuronal loss in the locus coeruleus,inhibit astrocyte activation,protect the locus coeruleus-hippocampal neural circuit,and may be associated with inhibiting β2AR/β-arrestin2/NF-κB inflammatory pathway activation.

Objective To investigate the effects of pre-electroacupuncture(EA)on spatial learning and memory,the locus coeruleus-hippocampal neural circuit,and neuroinflammation in Alzheimer's disease(AD)-like rats,and to explore the possible mechanism of pre-EA in preventing and treating AD.Methods Thirty-six male SD rats were divided into the normal,model,EA,and sham EA groups using the random number table method,with nine rats per group.An AD-like rat model was prepared through intraperitoneal injection of 120 mg/(kg·d)D-galactose for eight consecutive weeks.After daily intraperitoneal injection,the rats in the EA group underwent EA stimulation at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints with a continuous wave,frequency of 50 Hz,and a current of 1 mA for 20 min once a day for 8 weeks.The sham EA group was only superficially punctured to the subcutaneous tissue at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints without electricity,and the rest of the operations were the same as those in the EA group.The Morris water maze experiment was then used to evaluate the spatial learning and memory of the rats.Immunofluorescence labeling was used to detect dopamine β hydroxylase and c-Fos co-localization in the locus coeruleus of noradrenergic neurons,as well as glial fibrillary acidic protein and tumor necrosis factor-α(TNF-α)co-localization in the CA1 area of the hippocampus of astrocytes.Western blotting was used to measure the protein expressions of norepinephrine(NE),β2-adrenergic receptor(β2AR),β-inhibitory protein 2(β-arrestin2),nuclear transcription factor-κB(NF-κB)inhibitory factor protein α(IκBα),and NF-κB in the hippocampus of rats.An enzyme-linked immunosorbent assay was used to detect the TNF-α,interleukin-1β(IL-1β),and interleukin-6(IL-6)contents in hippocampal tissue.Results Compared with the normal group,the average escape latency of the model group rats was prolonged,and the times of crossing platform and exploration time in the target quadrant were reduced(P<0.01),while the EA intervention can shorten the average escape latency and increase the times of crossing platform and exploration time in the target quadrant(P<0.01).Compared with the normal group,the expression of co-located noradrenergic neurons in the model group decreased,co-located astrocytes increased(P<0.01);NE,β2AR,β-arrestin2,and IκBα protein expression decreased(P<0.01),NF-κB protein expression increased(P<0.01);the contents of TNF-α,IL-1β,and IL-6 increased(P<0.01).Compared with the model group,the EA group showed an increase in the expression of co-located noradrenergic neurons,a decrease in co-located astrocytes(P<0.01),an increase in NE,β2AR,β-arrestin2,and IκBα protein expressions(P<0.01),a decrease in NF-κB protein expression(P<0.01),and a decrease in TNF-α,IL-1β,and IL-6 levels(P<0.01).No significant difference was observed in the above indicators between the model and sham EA groups.Conclusion Pre-EA at"Neiguan"(PC6)and"Jianshi"(PC5)can alleviate learning and memory dysfunction,alleviate noradrenergic neuronal loss in the locus coeruleus,inhibit astrocyte activation,protect the locus coeruleus-hippocampal neural circuit,and may be associated with inhibiting β2AR/β-arrestin2/NF-κB inflammatory pathway activation.

Objective To investigate the effects of pre-electroacupuncture(EA)on spatial learning and memory,the locus coeruleus-hippocampal neural circuit,and neuroinflammation in Alzheimer's disease(AD)-like rats,and to explore the possible mechanism of pre-EA in preventing and treating AD.Methods Thirty-six male SD rats were divided into the normal,model,EA,and sham EA groups using the random number table method,with nine rats per group.An AD-like rat model was prepared through intraperitoneal injection of 120 mg/(kg·d)D-galactose for eight consecutive weeks.After daily intraperitoneal injection,the rats in the EA group underwent EA stimulation at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints with a continuous wave,frequency of 50 Hz,and a current of 1 mA for 20 min once a day for 8 weeks.The sham EA group was only superficially punctured to the subcutaneous tissue at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints without electricity,and the rest of the operations were the same as those in the EA group.The Morris water maze experiment was then used to evaluate the spatial learning and memory of the rats.Immunofluorescence labeling was used to detect dopamine β hydroxylase and c-Fos co-localization in the locus coeruleus of noradrenergic neurons,as well as glial fibrillary acidic protein and tumor necrosis factor-α(TNF-α)co-localization in the CA1 area of the hippocampus of astrocytes.Western blotting was used to measure the protein expressions of norepinephrine(NE),β2-adrenergic receptor(β2AR),β-inhibitory protein 2(β-arrestin2),nuclear transcription factor-κB(NF-κB)inhibitory factor protein α(IκBα),and NF-κB in the hippocampus of rats.An enzyme-linked immunosorbent assay was used to detect the TNF-α,interleukin-1β(IL-1β),and interleukin-6(IL-6)contents in hippocampal tissue.Results Compared with the normal group,the average escape latency of the model group rats was prolonged,and the times of crossing platform and exploration time in the target quadrant were reduced(P<0.01),while the EA intervention can shorten the average escape latency and increase the times of crossing platform and exploration time in the target quadrant(P<0.01).Compared with the normal group,the expression of co-located noradrenergic neurons in the model group decreased,co-located astrocytes increased(P<0.01);NE,β2AR,β-arrestin2,and IκBα protein expression decreased(P<0.01),NF-κB protein expression increased(P<0.01);the contents of TNF-α,IL-1β,and IL-6 increased(P<0.01).Compared with the model group,the EA group showed an increase in the expression of co-located noradrenergic neurons,a decrease in co-located astrocytes(P<0.01),an increase in NE,β2AR,β-arrestin2,and IκBα protein expressions(P<0.01),a decrease in NF-κB protein expression(P<0.01),and a decrease in TNF-α,IL-1β,and IL-6 levels(P<0.01).No significant difference was observed in the above indicators between the model and sham EA groups.Conclusion Pre-EA at"Neiguan"(PC6)and"Jianshi"(PC5)can alleviate learning and memory dysfunction,alleviate noradrenergic neuronal loss in the locus coeruleus,inhibit astrocyte activation,protect the locus coeruleus-hippocampal neural circuit,and may be associated with inhibiting β2AR/β-arrestin2/NF-κB inflammatory pathway activation.

Objective To investigate the effects of pre-electroacupuncture(EA)on spatial learning and memory,the locus coeruleus-hippocampal neural circuit,and neuroinflammation in Alzheimer's disease(AD)-like rats,and to explore the possible mechanism of pre-EA in preventing and treating AD.Methods Thirty-six male SD rats were divided into the normal,model,EA,and sham EA groups using the random number table method,with nine rats per group.An AD-like rat model was prepared through intraperitoneal injection of 120 mg/(kg·d)D-galactose for eight consecutive weeks.After daily intraperitoneal injection,the rats in the EA group underwent EA stimulation at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints with a continuous wave,frequency of 50 Hz,and a current of 1 mA for 20 min once a day for 8 weeks.The sham EA group was only superficially punctured to the subcutaneous tissue at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints without electricity,and the rest of the operations were the same as those in the EA group.The Morris water maze experiment was then used to evaluate the spatial learning and memory of the rats.Immunofluorescence labeling was used to detect dopamine β hydroxylase and c-Fos co-localization in the locus coeruleus of noradrenergic neurons,as well as glial fibrillary acidic protein and tumor necrosis factor-α(TNF-α)co-localization in the CA1 area of the hippocampus of astrocytes.Western blotting was used to measure the protein expressions of norepinephrine(NE),β2-adrenergic receptor(β2AR),β-inhibitory protein 2(β-arrestin2),nuclear transcription factor-κB(NF-κB)inhibitory factor protein α(IκBα),and NF-κB in the hippocampus of rats.An enzyme-linked immunosorbent assay was used to detect the TNF-α,interleukin-1β(IL-1β),and interleukin-6(IL-6)contents in hippocampal tissue.Results Compared with the normal group,the average escape latency of the model group rats was prolonged,and the times of crossing platform and exploration time in the target quadrant were reduced(P<0.01),while the EA intervention can shorten the average escape latency and increase the times of crossing platform and exploration time in the target quadrant(P<0.01).Compared with the normal group,the expression of co-located noradrenergic neurons in the model group decreased,co-located astrocytes increased(P<0.01);NE,β2AR,β-arrestin2,and IκBα protein expression decreased(P<0.01),NF-κB protein expression increased(P<0.01);the contents of TNF-α,IL-1β,and IL-6 increased(P<0.01).Compared with the model group,the EA group showed an increase in the expression of co-located noradrenergic neurons,a decrease in co-located astrocytes(P<0.01),an increase in NE,β2AR,β-arrestin2,and IκBα protein expressions(P<0.01),a decrease in NF-κB protein expression(P<0.01),and a decrease in TNF-α,IL-1β,and IL-6 levels(P<0.01).No significant difference was observed in the above indicators between the model and sham EA groups.Conclusion Pre-EA at"Neiguan"(PC6)and"Jianshi"(PC5)can alleviate learning and memory dysfunction,alleviate noradrenergic neuronal loss in the locus coeruleus,inhibit astrocyte activation,protect the locus coeruleus-hippocampal neural circuit,and may be associated with inhibiting β2AR/β-arrestin2/NF-κB inflammatory pathway activation.