An Umbrella Insight into the Phytochemistry Features and Biological Activities of Corn Silk: A Narrative Review.

Corn silk (Zea mays L.) is the stigma of an annual gramineous plant named corn, which is distributed in many regions worldwide and has a long history of medicinal use. In recent years, with the sustainable development of traditional Chinese medicine, studies of corn silk based on modern technologies, such as GC-MS, LC-MS, and other analytical means, have offered more comprehensive analyses. Phytochemistry studies have shown that the main bioactive components in corn silk include flavonoids, polyphenols, phenolic acids, fatty acids, and terpenoids. Pharmacological studies have shown that corn silk extract has various pharmacological effects, such as reducing blood lipids, lowering blood pressure, regulating blood sugar levels, anti-inflammatory effects, and anti-oxidation effects. In this paper, the related research on corn silk from the past few years is summarized to provide a theoretical reference for the further development and utilization of corn silk.

Ginsenoside CK targeting KEAP1-DGR/Kelch domain disrupts the binding between KEAP1 and NRF2-DLG motif to ameliorate oxidative stress damage.

BACKGROUND: Panax ginseng and Panax notoginseng as traditional Chinese medicines, are widely used in the treatment of qi deficiency, viral or bacterial infection, inflammation and cancer. Ginsenoside CK, an active metabolite of protopanoxadiol among the ginseng saponins, has been shown in previous studies to improve the organism's oxidative balance by regulating the KEAP1-NRF2/ARE pathway, thus slowing the progression of diseases. However, the specific targets and mechanisms of CK in improving oxidative stress remain unclear. PURPOSE: The aim of this study was to determine the potential therapeutic targets and molecular mechanisms of CK in improving oxidative stress injury both in vitro and in vivo. METHODS: LPS was used to induce oxidative damage in RAW 264.7 cells to evaluate the regulatory effects of CK on the KEAP1-NRF2/ARE pathway. Drug affinity responsive target stability technology (DARTS) combined with proteomics was employed to identify CK's potential target proteins. CK functional probe were designed to analyze the target protein using click chemistry. Furthermore, small molecule and protein interaction technologies were used to verify the mechanism, and computer dynamic simulation technology was used to analyze the interaction sites between CK and the target protein. The pharmacological effects and mechanism of CK in improving oxidative damage were verified in vivo by LPS-induced acute injury in mice and physical mechanical injury in rat soft tissues. RESULTS: KEAP1 was identified as the target protein that CK regulates to improve oxidative damage through the KEAP1-NRF2/ARE pathway. CK competitively binds to the DGR/Kelch domain of KEAP1, disrupting the binding between DLG peptide in NRF2 and KEAP1, thereby inhibiting the occurrence of oxidative damage induced by LPS or physical mechanical stress. CONCLUSIONS: CK functions as a natural KEAP1-NRF2 inhibitor, disrupting the binding between KEAP1 and NRF2-DLG motifs by targeting the DGR/Kelch domain of KEAP1, activating the antioxidant transcriptional program of NRF2, and reducing oxidative stress damage.

Anti-neuroinflammation effects of transcutaneous auricular vagus nerve stimulation against depression-like behaviors via hypothalamic α7nAchR/JAK2/STAT3/NF-κB pathway in rats exposed to chronic unpredictable mild stress.

BACKGROUND: Transcutaneous auricular vagus nerve stimulation (taVNS) is a vital neuromodulation for the treatment of depression, but its antidepressant molecular mechanism is unclear. The α7 nicotinic acetylcholine receptor (α7nAchR) is a key mediator of the vagus nerve that mediates its anti-inflammatory efficacy. Here, we investigated whether the antidepressant effect of taVNS in chronic unpredicted mild stress (CUMS)-exposed rats works through the α7nAchR/JAK2/STAT3/NF-κB pathway. METHODS: The depression model was established by CUMS for continuous 6 weeks in rats. From the 4th week of the experiment, CUMS-exposed rats were subjected to taVNS for 3 weeks. To clarify the role of α7nAchR in the antidepressant effect of taVNS, we used α7nAchR-/- gene knockout rats. The sucrose preference test (SPT), open field test (OFT), and forced swimming test (FST) were used to evaluate depression-like behaviors of rats. Immunofluorescent staining was used to observe the morphology of microglia in the hypothalamus. Western blot was used to examine the protein expression of α7nAchR, p-JAK2, p-STAT3, IL-1ß, NF-κB p65, and p-NF-κB p65 in the hypothalamus. RESULTS: Depression-like behaviors in CUMS-exposed rats were manifested by decreased SPT ratio, increased FST immobility time, decreased total distance, vertical movement score, and activity time of OFT. Hypothalamic neuroinflammation in CUMS-exposed rats was manifested by an amoebic-like activated state of microglia, downregulated expression of α7nAchR, p-JAK2, p-STAT3, and upregulated expression of NF-κB p65, p-NF-κB p65, and IL-1ß. TaVNS could significantly reverse the above-mentioned phenomena, but had a poor improvement effect for CUMS-exposed α7nAchR-/- rats. CONCLUSION: The hypothalamic α7nAchR/JAK2/STAT3/NF-κB signaling pathway may play an important role in the antidepressant-like behavior of taVNS.

Astragaloside IV targets PRDX6, inhibits the activation of RAC subunit in NADPH oxidase 2 for oxidative damage.

BACKGROUND: Radix Astragali Mongolici, as a traditional Chinese medicine, is widely used in the treatment of qi deficiency, viral or bacterial infection, inflammation and cancer. Astragaloside IV (AST), a key active compound in Radix Astragali Mongolici, has been shown to reduce disease progression by inhibiting oxidative stress and inflammation. However, the specific target and mechanism of action of AST in improving oxidative stress are still unclear. PURPOSE: This study aims to explore the target and mechanism of AST to improve oxidative stress, and to explain the biological process of oxidative stress. METHODS: AST functional probes were designed to capture target proteins and combined with protein spectrum to analyze target proteins. Small molecule and protein interaction technologies were used to verify the mode of action, while computer dynamics simulation technology was used to analyze the site of interaction with the target protein. The pharmacological activity of AST in improving oxidative stress was evaluated in a mouse model of acute lung injury induced by LPS. Additionally, pharmacological and serial molecular biological approaches were used to explore the underlying mechanism of action. RESULTS: AST inhibits PLA2 activity in PRDX6 by targeting the PLA2 catalytic triad pocket. This binding alters the conformation and structural stability of PRDX6 and interferes with the interaction between PRDX6 and RAC, hindering the activation of the RAC-GDI heterodimer. Inactivation of RAC prevents NOX2 maturation, attenuates superoxide anion production, and improves oxidative stress damage. CONCLUSION: The findings of this research indicate that AST impedes PLA2 activity by acting on the catalytic triad of PRDX6. This, in turn, disrupts the interaction between PRDX6 and RAC, thereby hindering the maturation of NOX2 and diminishing the oxidative stress damage.

Electroacupuncture restores intestinal mucosal barrier through TLR4/NF-κB p65 pathway in functional dyspepsia-like rats.

Functional dyspepsia (FD) is a common functional gastrointestinal disorder with high morbidity. Electroacupuncture (EA) has been applied to treat FD for a long time. The aim of this study was to investigate the effects of EA and its mechanism about intestinal mucosal barrier in rodent model of FD. Male Sprague-Dawley rats were randomly divided into the control group and the model group. Then, the rats in model group were established to the FD model by multifactor interventions. In Experiment 1, qualified FD-like rats were randomly divided into three groups: FD, EA, and acupuncture (AP) groups. The interventions of EA and AP lasted 14 days, food intake, and body weight were recorded every 5 days. In Experiment 2, qualified FD-like rats were randomly divided into five groups: FD, EA, AP, EA + TAK242, and TAK242 groups. The interventions of EA and AP lasted 14 days, while TAK242 injection continued for 6 days. The rats were sacrificed for the measurement of serum Interleukin- 6 (IL-6) and Tumor necrosis factor-α (TNF-α) assayed by ELISA. Western blotting was used to assess the expression of TLR4, Myd88, NF-κB p65, p-NF-κB p65, TRAF6, ZO-1, and occludin in the duodenum. The transmission electron microscope was used to observe the ultrastructure of intestinal epithelial cells. Compared with the rats in the group FD, the rats in EA group had significantly increase of body weight, food intake, and protein expressions of ZO-1 and occludin, while expressions of TLR4, Myd88, NF-κB p65, p-NF-κB p65, TRAF6 in the duodenum and IL-6, and TNF-α in serum were decreased. The EA + TAK242 treatment had similar effects to the EA treatment but with increased potency; compared with EA, AP showed similar but reduced effects. Our data demonstrated that EA is more effective than AP in improving intestine mucosal barrier. The possible mechanisms of EA may involve the TLR4/NF-κB p65 pathway.

Electroacupuncture relieves hyperalgesia by regulating neuronal-glial interaction and glutamate transporters of spinal dorsal horns in rats with acute incisional neck pain.

Objective: Glial cells are involved in the analgesic effect of electroacupuncture (EA) in rats with chronic neurological pain. The objective of this study was to observe the role of neuronal-glial interaction and glutamate (Glu) transporters in EA-induced acute neck pain relief in rats. Materials and methods: Male rats were placed into the following five groups: control, model, EA Futu (LI18), EA Hegu (LI4)-Neiguan (PC6), and EA Zusanli (ST36)-Yanglingquan (GB34). The incisional neck pain model was established by making a longitudinal incision along the midline of the neck. The thermal pain threshold (TPT) was measured using a radiation heat detector. The immunoactivities of glial fibrillary acidic protein (GFAP), ionized calcium-binding adapter molecule 1 (Iba-1), neurokinin-1 receptor (NK-1R), Glu aspartate transporter (GLAST), and Glu transporter-1 (GLT-1) in the dorsal horns (DHs) of the cervico-spinal cord (C2-C5) were detected using immunofluorescence histochemistry. The expression levels of GFAP, Iba-1, GLAST, and GLT-1 mRNAs were determined using quantitative real-time polymerase chain reaction (PCR). Results: The TPT and levels of mRNAs expression and immunoactivity of GLT-1 and GLAST were significantly decreased, and those of Iba-1 and GFAP were significantly increased in the model group than those of the control group (P < 0.05). The activated microgliacytes were gathered around the NK-1R positive neurons, and co-expression of NK-1R and astrocytes was observed in the model group. EA LI18 significantly increased the TPT and expression of GLAST and GLT-1 mRNAs (P < 0.05) and notably decreased the number of Iba-1 positive cells and Iba-l mRNA expression (P < 0.05), whereas GLAST and GLT-1 antagonists inhibited the analgesic effect of EA LI18. However, these effects, except for the downregulation of Iba-1 mRNA, were not observed in the EA ST36-GB34 group. Fewer NK-1R-positive neurons were visible in the spinal DHs in the EA LI18 group, and the co-expression of NK-1R and astrocytes was also lower than that in the three EA groups. Conclusion: Electroacupuncture of LI18 had an analgesic effect in rats with neck incisions, which may be related to its functions in suppressing the neuronal-glial cell interaction through NK-1R and upregulating the expression of GLAST and GLT-1 in the spinal DHs.

The efficacy and safety of transcutaneous auricular vagus nerve stimulation in patients with mild cognitive impairment: A double blinded randomized clinical trial.

BACKGROUND: There are 9.9 million new cases of dementia in the world every year. Short-term conversion rate from mild cognitive impairment (MCI) to dementia is between 20% and 40%, but long-term in 5-10 years ranges from 60% to 100%. It is particularly important to prevent or prolong the development of MCI into dementia. Both auriculotherapy and vagus nerve stimulation are effective on improving cognitive functions. However, there is no double blinded randomized clinical trial to support the effectiveness of transcutaneous electrical stimulation of auricular acupoints in patients with MCI. METHODS: This randomized controlled trial involved patients with MCI, aged from 55 to 75 years old. Patients were randomly allocated to transcutaneous auricular vagus nerve stimulation (taVNS) group or sham taVNS group. In the taVNS group, two auricular acupoints were stimulated, including heart (concha, CO15) and kidney (CO10), which are in the distribution of vagus nerve. While in the sham taVNS group, two other auricular acupoints were stimulated, including elbow (scaphoid fossa, SF3) and shoulder (SF4,5), which are out of the distribution of vagus nerve. The primary outcome was the Montreal cognitive assessment-basic, MOCA-B. The secondary outcomes included auditory verbal learning test-HuaShan version (AVLT-H), shape trails test A&B (STT-A&B), animal fluence test (AFT), Boston naming test (BNT), Pittsburgh sleep quality index (PSQI), rapid eye movement sleep behavior disorder screening questionnaire (RBDSQ), Epworth sleepiness scale (ESS) and functional activities questionnaire (FAQ). These outcome measures were taken at baseline, 24 weeks later. RESULTS: After 24 weeks of intervention, the data of 52 patients were intended for analysis. After intervention, there was significant difference in the overall scores of MoCA-B between taVNS group and sham taVNS group (p = 0.033 < 0.05). In taVNS group, compared with before intervention, the overall scores of MOCA-B increased significantly after intervention (p < 0.001). As for N5 and N7, the two sub-indicators of AVLT-H, in taVNS group, compared with before intervention, both N5 and N7 increased significantly after intervention (both ps < 0.001). As for STTB, in taVNS group, compared with before intervention, STTB was significantly reduced after intervention (p = 0.016). For BNT, in taVNS group, compared with before intervention, BNT increased significantly after intervention (p < 0.001). In taVNS group, compared with before intervention, PSQI, RBDSQ, ESS and FAQ decreased significantly after intervention (p = 0.002, 0.025, <0.001, 0.006 respectively). 1 patient with a history of tympanic membrane perforation in taVNS group was reported with mild adverse reactions which disappeared a week after termination of taVNS. The intervention of taVNS is effective on increasing the overall scores of MoCA-B, N5 and N7. CONCLUSION: The clinical trial demonstrated that taVNS can improve cognitive performance in patients with MCI. This inexpensive, effective and innovative method can be recommended as a therapy for more patients with MCI in the prevention or prolonging of its development into dementia, but it is still required to be further investigated. TRIAL REGISTRATION: http://www.chictr.org.cn. (ID: ChiCTR2000038868).

Ursolic acid inhibits the cholesterol biosynthesis and alleviates high fat diet-induced hypercholesterolemia via irreversible inhibition of HMGCS1 in vivo.

BACKGROUND: In hypercholesteremia, the concentrations of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) are enhanced in serum, which is strongly associated with an increased risk of developing atherosclerosis. Ursolic acid (UA), a pentacyclic terpenoid carboxylic acid, was found to alleviate hypercholesterolemia and hypercholesterolemia-induced cardiovascular disease. However, the specific targets and molecular mechanisms related to the effects of UA in reducing cholesterol have not been elucidated. PURPOSE: In this study, we aimed to illustrate the target of UA in the treatment of hypercholesterolemia and to reveal its underlying molecular mechanism. METHODS: Nontargeted metabolomics was conducted to analyze the metabolites and related pathways that UA affected in vivo. The main lipid metabolism targets of UA were analyzed by target fishing and fluorescence colocalization in mouse liver. Molecular docking, in-gel fluorescence scan and thermal shift were assessed to further investigate the binding site of the UA metabolite with HMGCS1. C57BL/6 mice were fed a high-fat diet (HFD) for 12 weeks to induce hypercholesteremia. Liver tissues were used to verify the cholesterol-lowering molecular mechanism of UA by targeted metabolomics, serum was used to detect biochemical indices, and the entire aorta was used to analyze the formation of atherosclerotic lesions. RESULTS: Our results showed that hydroxy­3-methylglutaryl coenzyme A synthetase 1 (HMGCS1) was the primary lipid metabolism target protein of UA. The UA metabolite epoxy-modified UA irreversibly bonds with the thiol of Cys-129 in HMGCS1, which inhibits the catalytic activity of HMGCS1 and reduces the generation of precursors in cholesterol biosynthesis in vivo. The contents of TC and LDL-C in serum and the formation of the atherosclerotic area in the entire aorta were markedly reduced with UA treatment in Diet-induced hypercholesteremia mice. CONCLUSION: UA inhibits the catalytic activity of HMGCS1, reduces the generation of downstream metabolites in the process of cholesterol biosynthesis and alleviates Diet-induced hypercholesteremia via irreversible binding with HMGCS1 in vivo. It is the first time to clarify the irreversible inhibition mechanism of UA against HMGCS1. This paper provides an increased understanding of UA, particularly regarding the molecular mechanism of the cholesterol-lowering effect, and demonstrates the potential of UA as a novel therapeutic for the treatment of hypercholesteremia.

[Transcutaneous auricular vagus nerve stimulation promotes gastric motility by up-rgulating α7nAChR and suppressing NF-κB p65 expression in duodenum in rats with functional dyspepsia].

OBJECTIVE: To study the effect of transcutaneous auricular vagus nerve stimulation (taVNS) on gastric sensitivity and motility in rats with functional dyspepsia (FD), so as to explore its underlying mechanism in improving FD. METHODS: A total of 48 young SD rats were randomly divided into control (n=10), model (n=9), taVNS (n=9), subdiaphragmatic vagus nerve stimulation (SDVNS, n=9) and sham SDVNS (n=7) groups. The FD model was established by gavage of 0.1% iodoa-cetamide+2% glucose, once daily for 6 days. Rats in the taVNS group received taVNS (0.5 mA) of optopoint "Heart" and "Stomach" for 30 min, once daily for 14 days, while rats in the SDVNS group received subdiaphragmatic vagus nerve stimulation through the implanted electrode, and those of the sham SDVNS group received only application of the same electrodes without electrical stimulation. Electromyogram (EMG) of the cervical trapezius muscle (reflecting gastric sensitivity) was recorded before and after intragastric expansion via an air ballon and the gastric emptying rate was calculated for assessing the gastric motility. The contents of acetylcholine (ACh), nicotinic acetylcholine receptor α7 subunit (α7nAChR), interleukin-6 (IL-6), interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α) in the duodenum tissue were detected by enzyme-linked immunosorbent assay (ELISA). The expression of nuclear factor kappa B (NF-κB) p65 in the duodenum tissue was determined by Western blot. RESULTS: In comparison with the control group, the EMG change rate at intragastric pressure levels of 40, 60 and 80 mm Hg, expression of NF-κB p65 protein, and contents of IL-6, IL-1ß and TNF-α were significantly increased (P<0.05,P<0.01, P<0.001), while the gastric emptying rate, ACh and α7nAChR contents considerably decreased (P<0.05, P<0.001) in the model group. After interventions, the EMG change rate, contents of IL-6, IL-1ß and TNF-α, and expression of NF-κB p65 were notably decreased (P<0.05, P<0.01, P<0.001), and the gastric emptying rate, ACh and α7nAChR contents obviously increased (P<0.05, P<0.001) in both taVNS and SDVNS groups relevant to the model group. In comparison with the sham SDVNS group, the EMG change rate, contents of IL-6, IL-1ß and TNF-α, and expression of NF-κB p65 were notably decreased (P<0.01, P<0.05,P<0.001), and the gastric emptying rate, ACh and α7nAChR contents obviously increased (P<0.01, P<0.001) in the both SDVNS and taVNS groups. CONCLUSION: taVNS can reduce gastric sensitivity and promote gastric emptying in FD model rats, which may be closely related to its functions in up-regulating ACh and α7nAChR contents and inhibiting the activation of NF-κB p65 signaling in the duodenum.

Polysaccharides from Medicine and Food Homology Materials: A Review on Their Extraction, Purification, Structure, and Biological Activities.

Medicine and food homology (MFH) materials are rich in polysaccharides, proteins, fats, vitamins, and other components. Hence, they have good medical and nutritional values. Polysaccharides are identified as one of the pivotal bioactive constituents of MFH materials. Accumulating evidence has revealed that MFH polysaccharides (MFHPs) have a variety of biological activities, such as antioxidant, immunomodulatory, anti-tumor, hepatoprotective, anti-aging, anti-inflammatory, and radioprotective activities. Consequently, the research progress and future prospects of MFHPs must be systematically reviewed to promote their better understanding. This paper reviewed the extraction and purification methods, structure, biological activities, and potential molecular mechanisms of MFHPs. This review may provide some valuable insights for further research regarding MFHPs.

Toward Diverse or Standardized: A Systematic Review Identifying Transcutaneous Stimulation of Auricular Branch of the Vagus Nerve in Nomenclature.

OBJECTIVES: After 20 years of development, there is confusion in the nomenclature of transcutaneous stimulation of the auricular branch of the vagus nerve (ABVN). We performed a systematic review of transcutaneous stimulation of ABVN in nomenclature. MATERIALS AND METHODS: A systematic search of the literature was carried out, using the bibliographic search engine PubMed. The search covered articles published up until June 11, 2020. We recorded the full nomenclature and abbreviated nomenclature same or similar to transcutaneous stimulation of ABVN in the selected eligible studies, as well as the time and author information of this nomenclature. RESULTS: From 261 studies, 67 full nomenclatures and 27 abbreviated nomenclatures were finally screened out, transcutaneous vagus nerve stimulation and tVNS are the most common nomenclature, accounting for 38.38% and 42.06%, respectively. In a total of 97 combinations of full nomenclatures and abbreviations, the most commonly used nomenclature for the combination of transcutaneous vagus nerve stimulation and tVNS, accounting for 30.28%. Interestingly, the combination of full nomenclatures and abbreviations is not always a one-to-one relationship, there are ten abbreviated nomenclatures corresponding to transcutaneous vagus nerve stimulation, and five full nomenclatures corresponding to tVNS. In addition, based on the analysis of the usage habits of nomenclature in 21 teams, it is found that only three teams have fixed habits, while other different teams or the same team do not always use the same nomenclature in their paper. CONCLUSIONS: The phenomenon of confusion in the nomenclature of transcutaneous stimulation of ABVN is obvious and shows a trend of diversity. The nomenclature of transcutaneous stimulation of ABVN needs to become more standardized in the future.

[Effect of transcutaneous auricular vagus nerve stimulation on the expressions of GFAP and MAP2 in ischemic penumbra of rats with middle cerebral artery ischemia].

OBJECTIVE: To observe the effects of transcutaneous auricular vagus nerve stimulation (taVNS) on the motor function and the expression of glial fibrillary acidic protein (GFAP) and microtubule associated protein 2 (MAP2) in cerebral ischemic penumbra of rats with middle cerebral artery occlusion (MCAO) and explore the mechanism of taVNS in the improvement of motor function in MCAO rats. METHODS: A total of 48 male SD rats were randomized into a sham-operation group, a model group, a transcutaneous auricular non-vagus nerve stimulation (tnVNS) group and a taVNS group, with 12 rats in each group. The suture-occluded method was adopted to prepare MCAO rat model. The auricular rim was stimulated in the tnVNS group and the concha stimulated in the taVNS group, 2 mA in intensity, 10 Hz in frequency, 30 min each time, once a day, for 14 days consecutively. The nerve functional assessment was recorded in each group. The expressions of nicotinic acetylcholine receptor (α7nAchR) in the cerebral ischemic penumbra and the spleen were detected by using Western blot. With the immunofluorescence, the expressions of GFAP and MAP2 were detected. RESULTS: After modeling, compared with the sham-operation group, the nerve functional score was increased in the model group, the tnVNS group and the taVNS group (P<0.01), suggesting the success of modeling. After treatment, the score was increased in the model group (P<0.01) as compared with the sham-operation group. Compared with the model group, the neurological deficit score was reduced in the taVNS group (P<0.01). Compared with the sham-operation group, GFAP expression was increased and MAP2 expression was reduced remarkably in the cerebral ischemic penumbra in the model group (P<0.05). In comparison with the model group, GFAP expression was reduced, while MAP2 expression was increased remarkably in the cerebral ischemic penumbra in the taVNS group (P<0.05). There were no significant differences in the abovementioned indexes between the model group and tnVNS group (P>0.05). The differences in the expression of α7nAchR in the cerebral ischemic penumbra and the spleen had no statistical significance among groups (P>0.05). CONCLUSION: TaVNS is effective on neuroprotection in MCAO rats, which may be related to its function of inhibition of GFAP expression and promotion of MAP2 expression in the ischemic penumbra.

Auricular Vagus Nerve Stimulation Ameliorates Functional Dyspepsia with Depressive-Like Behavior and Inhibits the Hypothalamus-Pituitary-Adrenal Axis in a Rat Model.

BACKGROUND: The hypothalamus-pituitary-adrenal axis is the most important endocrine system to control irritability response. Functional dyspepsia (FD) is closely related to irritability. This study aimed to preliminarily explore the corticotropin-releasing factor (CRF) mechanism of auricular vagus nerve stimulation (aVNS) for FD model rats. METHODS: Sprague-Dawley adult male rats were randomly divided into normal group, model group, aVNS group, and sham-aVNS group. Except for the normal rats, all other rats were induced into the FD model through tail-clamping stimulation for 3 weeks. Once the rat model was developed successfully, rats in the aVNS group and sham-aVNS group were intervened with aVNS or sham-aVNS for 2 weeks. No intervention was given to rats in the normal and model groups. The effect of aVNS was assessed. The expressions of hippocampal corticotropin-releasing hormone receptor 1 (CRHR1), hypothalamus CRF, adrenocorticotropic hormone (ACTH), and corticosterone in serum were assessed. RESULTS: 1. Compared with normal rats, model-developing rats showed FD-like behavior. 2. Compared with model rats, rats in the aVNS group showed an improved general condition score and gastric motility, and increased horizontal and vertical motion scores. 3. The release of corticosterone, ACTH in serum, and CRF in the hypothalamus all increased in model rats but decreased with aVNS instead of sham-aVNS. 4. The expression of hippocampus CRHR1 was lower in model rats but higher in the aVNS group. CONCLUSION: aVNS ameliorates gastric motility and improves the mental state in the FD-like rat, probably via inhibiting the CRF pathway.

Transcutaneous auricular vagus nerve stimulators: a review of past, present, and future devices.

INTRODUCTION: As an emerging neuromodulation therapy, transcutaneous auricular vagus nerve stimulation (taVNS) has been proven to be safe and effective for epilepsy, major depressive disorders, insomnia, glucose metabolic disorders, pain, stroke, post stroke rehabilitation, anxiety, fear, cognitive impairment, cardiovascular disorders, tinnitus, Prader-Willi Syndrome, and COVID-19. AREAS COVERED: Although the history of taVNS is only two decades, the devices carrying taVNS technique have been constantly updated. Especially in recent years, the development of taVNS devices has presented a new trend. To conclude, the development of taVNS devices has entered a new era, thus the update speed and quality of taVNS devices will be considerably improved in the future. This article reviewed the history and classification of taVNS devices. EXPERT OPINION: The correlation between the effectiveness and stimulation parameters from taVNS devices still remains unclear. There is a lack of standard or harmonization among different taVNS devices. Strategies, including further comparative research and establishment of standard, have been recommended in this article to promote the future development of taVNS devices.

[Systematic review and Meta-analysis on the auriculotherapy in treatment of insomnia].

OBJECTIVE: To review the effectiveness and safety of auriculotherapy in treatment of insomnia. METHODS: The articles were collated by computer retrieval from 8 databases from the initiation to April 30, 2021, i.e. PubMed, EMbase, the Cochrane Library, the Web of Science, CNKI, Wanfang database, VIP and Chinese biomedical literature database (SinoMed). Meta-analysis was conducted with RevMan5.3 software. RESULTS: A total of 38 articles were included, with 3 707 cases involved. The results showed: ①The effective rate of auriculotherapy was better than that of single application of western medication with sleeping pills (RR=1.26, 95%CI:1.15 to 1.39, Z=4.77, P<0.000 01), conventional acupuncture (RR=1.10, 95%CI: 1.05 to 1.16, Z=3.83, P=0.000 1) and Chinese herbal medicine (RR=1.41, 95%CI: 1.23 to 1.63, Z=4.80, P<0.000 01), respectively. ② The total score of PSQI was reduced remarkably under the auriculotherapy when compared with the single application of western medication (MD=-1.61, 95%CI: -2.61 to -0.60, Z=3.14, P=0.002) and Chinese herbal medicine (MD=-3.76, 95%CI: -4.84 to -2.68, Z=6.84, P<0.000 01). But the difference was not significant when compared with conventional acupuncture (MD=-1.02, 95%CI: -2.11 to 0.08, Z=1.82, P=0.07). ③Auricular point selection: the auricular points distributed in the areas of vagus nerve were more advantageous in reducing PSQI score (MD=-3.21, 95%CI: -4.45 to -1.96, Z=5.03, P<0.000 01) compared with the points in other areas. ④Stimulant selection: the difference in the effective rate was not significant among different stimulants (magnetic beads, the seeds of Vaccaria segetalis, micro-needles) (MD=1.62, 95%CI: 0.71 to 3.73, Z=1.14, P=0.25). ⑤Stimulation frequency: there was no significant difference between high-frequency stimulation and low-frequency stimulation of auricular point sticking in improving the effective rate and reducing PSQI score (P>0.05). But the result should be considered cautiously in terms of the sensitivity analysis. ⑥Adverse reactions: the case numbers of adverse reactions of auriculotherapy (auricular point sticking) were less than those of western medication (MD=0.15, 95%CI: 0.06 to 0.35, Z=4.38, P<0.000 1). CONCLUSION: Auriculotherapy has certain curative advantages in treatment of insomnia compared with western and Chinese medications as well as conventional acupuncture. This therapy may relieve the symptoms of insomnia and has less adverse effects. But those outcomes need to be further verified with more high-quality randomized controlled trials.

Electroacupuncture Alleviates Hyperalgesia by Regulating CB1 Receptor of Spinal Cord in Incisional Neck Pain Rats.

Acupuncture therapy is effective in relieving postoperative pain of neck surgery, but its underlying mechanisms remain largely unknown. This study, in the incisional neck pain rat model, was designed to explore whether the endocannabinoid receptor 1 (CB1) in the cervical spinal cord is involved in the analgesic effect of electroacupuncture (EA) or not.The incisional neck pain model was established by making a longitudinal incision and applied EA treatment of Futu (LI18), Hegu-Neiguan (LI4-PC6), or Zusanli-Yanglingquan (ST36-GB34) for pain relief. The results showed that EA LI18 and EA LI4-PC6 effectively relieve allodynia caused by neck incision, which was obviously better than EA ST34-GB34 (P < 0.05). After EA, the expression levels of CB1 mRNA at 4h in the EALI18 group, and 24 and 48h in both EALI18 and EALI4-PC6 groups, and those of CB1 protein at 4, 24, and 48h in the EALI18 group, and the immunoactivity of CB1 in both EALI18 and EALI4-PC6 groups at 4h were significantly upregulated in contrast to those of the model group (P < 0.05). EA of either acupoint group had no effect on the expression of CB2 protein (P > 0.05). Moreover, the antinociceptive effect of EA was reversed by AM251 (CB1 antagonist). Immunofluorescence dual staining showed that CB1 expressed in astrocytes in the superficial layer (laminae I and II) of dorsal horns of the cervical spinal cord. Therefore, the findings of this study revealed that upregulation of CB1 expression in the cervical spinal cord contributes to the analgesic effect of EA in incisional neck pain rats. The CB1 receptor expresses on astrocytes.

Integrated Strategy of UHPLC-Q-TOF-MS and Molecular Networking for Identification of Diterpenoids from Euphorbia fischeriana Steud. and Prediction of the Anti-Breast-Cancer Mechanism by the Network Pharmacological Method.

Breast cancer is one of the most common malignancies in women worldwide. Traditional Chinese medicine has been used as adjunctive or complementary therapy for breast cancer. Diterpenoids from Euphorbia fischeriana Steud. have been demonstrated to possess anti-breast-cancer activity. This research was aimed to systematically explore the diterpenoids from E. fischeriana and study the multiple mechanisms on breast cancer. The structures of diterpenoids were identified by the integrated strategy of UHPLC-Q-TOF-MS and molecular networking. A total of 177 diterpenoids belonging to 13 types were collected. In silico ADME analysis was performed on these compounds. It indicated that 130 of 177 diterpenoids completely adjusted to Lipinski's rule. The targets of compounds were obtained from PharmMapper. The targets of breast cancer were collected from GeneCards. Then, 197 compounds-related targets and 544 breast cancer-related targets were identified. After the intersection process, 58 overlapping targets between compounds-related targets and breast cancer-related targets were acquired. The STRING database was applied to predict the protein-protein interactions. The GO and KEGG pathway enrichment analysis were performed by using the KOBAS database. It indicated that these predicted pathways were closely related to breast cancer. The treatment effect of E. fischeriana on breast cancer might be performed through signaling pathways, such as IL-17 signaling pathway, MAPK signaling pathway, and PI3K-Akt signaling pathway. The predicted top genes such as EGFR, ESR, MAPK, SRC, CASP3, CDK2, and KDR were involved in cell proliferation, gene transcription, apoptosis, signal transduction, DNA damage and repair, tumor differentiation, metastasis, and cell cycle, which indicated that E. fischeriana might treat breast cancer comprehensively. A compounds-KEGG pathways-related targets network was built by using cytoHubba to analyze the hub compounds and targets. It concluded that E. fischeriana treated breast cancer not only by the main components but also by the microconstituents, which reflected the overall regulatory role of multicomponents treating breast cancer. To estimate the binding affinities, binding sites, and binding postures, molecular docking simulations between 177 diterpenoids and top 19 targets were carried out. The results are basically in line with expectations. In conclusion, these results can serve as references for researchers studying potential targets of diterpenoids from E. fischeriana on breast cancer in the future.

[Effects of transcutaneous auricular vagus nerve stimulation on autonomic nervous function in rats with functional dyspepsia].

OBJECTIVE: To observe the effect of transcutaneous auricular vagus nerve stimulation (taVNS) on the autonomic nerve function in a rat model of functional dyspepsia (FD), so as to explore the mechanism of taVNS underlying regulation of FD. METHODS: SD rats were randomly divided into normal control group(n=8) and FD model group(n=26).The FD model was replicated with iodoacetamide gavage. The FD model rats were randomly divided into model, taVNS, sham-taVNS and Zusanli(ST36) groups, with 6 rats in each group. Rats in the taVNS group received electrical stimulation of auricular concha,while the sham-taVNS group received no electrical stimulation and rats in the ST36 group received stimulation at ST36 for 30 min once daily for 14 consecutive days. Cervical trapezius electromyography score and abdominal withdrawal reflex (AWR) score were used to evaluate gastric sensitivity. Histopathological changes of the gastric antrum tissue were observed under microscope after H.E. staining. Autonomic nerve function in rats was recorded and assessed by heart rate variability(HRV). The content of acetylcholine (Ach) and the expression of Ach receptor M3R in gastric antrum was detect by ELISA and Western blot, separately. RESULTS: Compared with the normal control group, the cervical trapezius electromyography and AWR scores of the model group increased (P<0.01, P<0.001), and there was no erosion in the gastric antral mucosa and muscle layer. The high-frequency power (HF) in HRV decreased (P<0.05), the ratio of low-frequency power/high-frequency power (LF/HF) increased (P<0.001), and the Ach content and its receptor M3R expression in gastric antrum tissue decreased (P<0.05). Following interventions, the cervical trapezius electromyography and AWR scores decreased (P<0.01,P<0.001, P<0.05), HF in HRV increased and LF/HF decreased(P<0.01，P<0.05,P<0.001), and the content of Ach in gastric antrum tissue and the expression of its receptor M3R increased (P<0.01, P<0.05) in both taVNS and ST36 groups relevant to the model group. CONCLUSION: taVNS can increase the activity of the vagus nerve and regulate the balance of the autonomic nerve function, which may be one of the mechanisms of taVNS in reducing the gastric sensitivity of rats with FD. In regulating the vagus nerve function, taVNS and acupuncture at ST36 acupoint have the similar effects.

[Effect of transcutaneous auricular vagus nerve stimulation on the expression of TLR4、MyD88、IL-18 protein in the prefrontal cortex of depression rats].

OBJECTIVE: To observe the effect of transcutaneous auricular vagus nerve stimulation (taVNS) on the depressive behavior in depression rats, so as to explore its mechanism underlying improvement of depression. METHODS: A total of 24 male Sprague Dawley rats were randomly divided into normal, depression model, taVNS, tnVNS (transcutaneous auricular none-vagus nerve stimulaton) groups (n=6 in each group). The depression model was established by chronic unpredictable mild stimulation combined with solitary raising for 35 consecutive days. After 14 days modeling, transcutaneous electrostimulation (2 mA, 2 Hz/15 Hz) was applied to auricular concha or auricular margin, respectively. Each intervention was conducted for 30 minutes, once daily for 21 days. The depression-like behavior was evaluated by forced swimming immobility time and body weight. The expression levels of Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88) and interleukin-18 (IL-18) protein in the prefrontal cortex were detected by Western blot. RESULTS: Following modeling, the increase amount of body weight was decreased, the forced swimming immobility time and expression TLR4, MyD88 and IL-18 protein in the prefrontal cortex were increased in the model group than those in the normal group (P<0.01). Following the treatment and compared with the model group, the increase amount of body weight in the taVNS group was obviously increased (P<0.05), the swimming immobility time and the expression of TLR4, MyD88, IL-18 protein in the taVNS and tnVNS groups were significantly decreased (P<0.01). CONCLUSION: TaVNS is able to improve depression in depression rats, which is probably related to its effect in inhibiting inflammatory response of TLR4/MyD88 signaling pathway in prefrontal cortex.