Comparison of the analgesic effects between electro-acupuncture and moxibustion with visceral hypersensitivity rats in irritable bowel syndrome

Acupuncture reduces sedative and anaesthetic consumption and improves pain tolerance in patients undergoing colonoscopy: a Meta-analysis

OBJECTIVE

To evaluate the effects of acupuncture anesthesia on the consumption of sedatives and anesthetics, pain, and time consumption in patients undergoing colonoscopy, thus providing evidence that acupuncture anesthesia should be extended to endoscopists and anesthetists.

METHODS

Four English and four Chinese databases were searched for randomised controlled trials of acupuncture anaesthesia in patients undergoing colonoscopy, published from database inception to 1 March 2023. Outcomes were consumption of sedatives and anaesthetics, pain tolerance, visual analog scale (VAS) score, the meantime consumption of examination, satisfaction, and adverse reactions.

RESULTS

Thirty-one randomized controlled trials with a total of 4790 participants were included. Results showed that acupuncture anaesthesia significantly reduced consumption of sedatives and anaesthetics [9 studies, n = 944, standardized mean difference (SMD) = －0.82, 95% CI (－1.31, －0.33), P = 0.001], VAS score [9 studies, n = 1790, mean difference (MD) = －1.13, 95% CI (－1.70, －0.57), P < 0.001], meantime consumption [21 studies, n = 3799, MD = －2.09, 95% CI (－3.15, －1.03), P<0.001] and adverse reactions of colonoscopy [7 studies, n = 738, odds ratio (OR) = 0.17, 95% CI (0.10, 0.28), P<0.001]. Acupuncture also significantly improved pain tolerance [14 studies, n = 1661, OR = 7.05, 95% CI (3.79, 13.12), P<0.001], while no beneficial effects were found for satisfaction [7 studies, n = 843, SMD = 0.02, 95% CI (－0.38, 0.43), P = 0.91].

CONCLUSION

Acupuncture has beneficial effects on patients undergoing colonoscopy, particularly in reducing consumption of sedatives and anaesthetics, alleviating pain, shortening the time consumption of examination and preventing adverse events. As an alternative, effective, inexpensive, and accessible approach, acupuncture anaesthesia should be extended to endoscopists and anaesthesiologists.

Effectiveness of acupuncture for postoperative gastrointestinal recovery in patients undergoing thoracoscopic surgery: a prospective randomized controlled study

BACKGROUND

Postoperative gastrointestinal dysfunction (PGD) is one of the most common complications among patients who have undergone thoracic surgery. Acupuncture has long been used in traditional Chinese medicine to treat gastrointestinal diseases and has shown benefit as an alternative therapy for the management of digestive ailments. This study aimed to explore the therapeutic effectiveness of acupuncture as a means to aid postoperative recovery of gastrointestinal function in patients undergoing thoracoscopic surgery.

METHODS

In total, 112 patients aged 18-70 years undergoing thoracoscopic surgery between 15 June 2022 and 30 August 2022 were randomized into two groups. Patients in the acupuncture group (AG) first received acupuncture treatment 4 h after surgery, and treatment was repeated at 24 and 48 h. Patients in the control group (CG) did not receive any acupuncture treatment. Both groups received the same anesthetic protocol. Ultrasound-guided thoracic paravertebral block (TPVB) was performed in the paravertebral spaces between T4 and T5 with administration of 20 mL of 0.33% ropivacaine. All patients received patient-controlled intravenous analgesia (PCIA) after surgery.

RESULTS

Median time to first flatus [interquartile range] in the AG was significantly less than in the CG (23.25 [18.13, 29.75] vs 30.75 [24.13, 45.38] h, p < 0.001). Time to first fluid intake after surgery was significantly less in the AG, as compared with the CG (4 [3, 7] vs 6.5 [4.13, 10.75] h, p = 0.003). Static pain, measured by visual analog scale (VAS) score, was significantly different on the third day after surgery (p = 0.018). Dynamic pain VAS scores were lower in the AG versus CG on the first three postoperative days (p = 0.014, 0.003 and 0.041, respectively).

CONCLUSION

Addition of acupuncture appeared to improve recovery of postoperative gastrointestinal function and alleviate posteoperative pain in patients undergoing thoracoscopic surgery. Acupuncture may represent a feasible strategy for the prevention of PGD occurrence.

TRIAL REGISTRATION NUMBER

ChiCTR2200060888 (Chinese Clinical Trial Registry).

The efficacy and neural mechanism of acupuncture therapy in the treatment of visceral hypersensitivity in irritable bowel syndrome

Irritable Bowel Syndrome (IBS) is a complex functional gastrointestinal disorder primarily characterized by chronic abdominal pain, bloating, and altered bowel habits. Chronic abdominal pain caused by visceral Hypersensitivity (VH) is the main reason why patients with IBS seek medication. Significant research effort has been devoted to the efficacy of acupuncture as a non-drug alternative therapy for visceral-hyperalgesia-induced IBS. Herein, we examined the central and peripheral analgesic mechanisms of acupuncture in IBS treatment. Acupuncture can improve inflammation and relieve pain by reducing 5-hydroxytryptamine and 5-HT3A receptor expression and increasing 5-HT4 receptor expression in peripheral intestinal sensory endings. Moreover, acupuncture can also activate the transient receptor potential vanillin 1 channel, block the activity of intestinal glial cells, and reduce the secretion of local pain-related neurotransmitters, thereby weakening peripheral sensitization. Moreover, by inhibiting the activation of N-methyl-D-aspartate receptor ion channels in the dorsal horn of the spinal cord and anterior cingulate cortex or releasing opioids, acupuncture can block excessive stimulation of abnormal pain signals in the brain and spinal cord. It can also stimulate glial cells (through the P2X7 and prokinetic protein pathways) to block VH pain perception and cognition. Furthermore, acupuncture can regulate the emotional components of IBS by targeting hypothalamic-pituitary-adrenal axis-related hormones and neurotransmitters via relevant brain nuclei, hence improving the IBS-induced VH response. These findings provide a scientific basis for acupuncture as an effective clinical adjuvant therapy for IBS pain.

Electroacupuncture Alleviates 46-Trinitrobenzene Sulfonic Acid-Induced Visceral Pain via the Glutamatergic Pathway in the Prefrontal Cortex

Visceral pain caused by inflammatory bowel disease (IBD) greatly diminishes the quality of life in affected patients. Yet, the mechanism of how IBD causes visceral pain is currently not fully understood. Previous studies have suggested that the central nervous system (CNS) and gut-brain axis (GBA) play an important role in IBD-inducing visceral pain. As one of the treatments for IBD, electroacupuncture (EA) has been used to treat various types of pain and gastrointestinal diseases in clinical practice. However, whether EA relieves the visceral pain of IBD through the gut-brain axis has not been confirmed. To verify the relationship between visceral pain and CNS, the following experiments were conducted. ¹H-NMR analysis was performed on the prefrontal cortex (PFC) tissue obtained from IBD rat models to determine the link between the metabolites and their role in EA treatment against visceral pain. Western blot assay was employed for detecting the contents of glutamate transporter excitatory amino acid transporters 2 (EAAT2) and the glutamate receptor N-methyl-D-aspartate (NMDA) to verify whether EA treatment can alleviate neurotoxic symptoms induced by abnormal increases of glutamate. Study results showed that the glutamate content was significantly increased in the PFC of TNBS-induced IBD rats. This change was reversed after EA treatment. This process was associated with increased EAAT2 expression and decreased expression of NMDA receptors in the PFC. In addition, an increase in intestinal glutamic-metabolizing bacteria was observed. In conclusion, this study suggests that EA treatment can relieve visceral pain by reducing glutamine toxicity in the PFC, and serves an alternative clinical utility.

Modulation of colonic function in irritable bowel syndrome rats by electroacupuncture at ST25 and the neurobiological links between ST25 and the colon

Irritable bowel syndrome (IBS) is a chronic functional gastrointestinal disease characterized by abdominal pain and defecation disorders. Acupuncture therapy positively affects IBS, with ST25 being the main point. However, ST25 has mostly been used in conjunction with other acupoints. This study aimed to observe the therapeutic effect of electroacupuncture at ST25 alone in IBS and the neurobiological mechanism of ST25 associated with the colon. First, we observed the effect of electroacupuncture at ST25 on the visceral pain threshold and slow-wave discharge of the colon in IBS model rats. Second, we explored the neurobiological mechanism of ST25 associated with the colon using a neural tracer technique. The results showed that (1) electroacupuncture at ST25 alone can alleviate visceral hypersensitivity and restore normal slow-wave frequency and rhythm of the colon in IBS rats; (2) there is a close neuroanatomical connection between ST25 and the colon, i.e., in the dorsal root ganglion (DRG), ST25 is similar in innervation to the colon, mainly in the T8-L1 segment, while the presence of double-labeled positive neurons is present in a part of the DRG; retrogradely labeled motor neurons associated with ST25 were observed in the anterior horn of the spinal cord, and retrogradely labeled sympathetic postganglionic neurons associated with ST25 were observed in the sympathetic nerve chain. These findings suggested that the DRGs and the dorsal horn of the spinal cord are important targets for electroacupuncture at ST25 to reduce visceral hypersensitivity in IBS rats. The sympathetic ganglia may be an important site for ST25 to regulate intestinal motility. The neurobiological mechanism of ST25 action in IBS rats should be further investigated in the future by combining related techniques, such as pseudorabies virus, optogenetics, calcium imaging, and electrophysiology.

Effects of acupuncture treatment on postoperative gastrointestinal dysfunction in colorectal cancer: study protocol for randomized controlled trials

Background

Postoperative gastrointestinal dysfunction (PGID) is a common complication arising from colorectal cancer surgery. Attributing factors, such as anesthesia, surgical retraction, and early intake of water, can inhibit gastrointestinal motility, causing constipation, reduction or absence of bowel sounds, nausea, vomiting, and other symptoms. Delayed recovery in gastrointestinal function can lead to intestinal obstructions or paralysis, anastomotic leaks, and other complications, affecting the patient’s recovery and quality of life negatively. Due to its complex pathophysiology, treatment for PGID in colorectal patients has remained a challenge. Acupuncture is an alternative therapy commonly used for postoperative recovery. This study aims to evaluate the therapeutic efficacy and safety of acupuncture on PGID. Through the complementation of acupuncture and enhanced recovery after surgery (ERAS) protocols, the advantages of acupuncture treatments could be demonstrated to promote its application in future clinical practice.

Methods

The study design is a prospective randomized controlled trial (RCT). One hundred sixty postoperative colorectal cancer patients will be recruited from Cancer Hospital Chinese Academy of Medical Sciences (CICAMS). Subjects who fulfill inclusion criteria will be randomly assigned into the acupuncture group (AG) (n = 80) or control group (CG) (n = 80). AG will receive acupuncture treatment and perioperative care guided by ERAS protocols, and CG will only receive perioperative care guided by ERAS protocols. The intervention will begin on the first day post-surgery, continuing for 4 days, with a follow-up assessment in a month. Time of first postoperative flatus would be the primary outcome measure. Secondary outcome measures include the time of first postoperative defecation, time of first fluid intake, time of first ambulation, postoperative hospital stay, gastrointestinal reaction score, acupuncture sensation evaluation scale, laboratory tests, postoperative quality of life, readmission rate, and postoperative complications. All results are evaluated from baseline, post-treatment, and upon follow-up.

Discussion

The results of the study would help elucidate evidence of the therapeutic effects of acupuncture on the recovery of postoperative gastrointestinal function. The objective of the study aims for the eventual inclusion of acupuncture in the ERAS protocol, allowing for wider application in clinical practice.

Trial registration

ClinicalTrials.gov ChiCTR2000036351. Registered on August 22, 2020

Therapeutic mechanism of steaming umbilical cord therapy with Chinese herbal medicine on a rat model of IBS-D via the PAR-2/TRVP1 pathway

OBJECTIVE

This study aimed to investigate the PAR-2/TRVP1-based mechanism of steaming umbilical cord therapy with Chinese Herbal Medicine (SUCT-CHM) in IBS-D rat models.

METHODS

Sixty-two IBS-D modeled rats were established, and were randomly assigned to the control group (n = 31) and the experimental group (n = 31). The model group did not receive intervention measures, and the experimental group was treated with SUCT-CHM. After 14 days of intervention, the two groups of rats were compared in terms of body weight, gastrointestinal function, Bristol stool score, wet/dry weight ratio of rat stool, and abdominal withdrawal reflex scores. The transient receptor potential vanilloid receptor 1 (TRPV1), protease-activated receptors-2 (PAR-2), calcitonin gene related peptide (CGRP) and Substance P (SP) protein expression were detected using ELISA.

RESULTS

After 14 d of intervention, compared to the control group, the rats in the experimental group showed a significant increase in body mass indexes (P < 0.05); decreased Bristol stool scores (P < 0.05); less stagnation of the intestinal contents and greater intestine propulsion rate (P < 0.05), lower wet/dry weight ratio of rat stool (P < 0.05), abdominal withdrawal reflex scores (P < 0.05) as well as PAR-2, TRVP1, CGRP and SP expression levels (P < 0.05).

CONCLUSION

SUCT-CHM was effective in treating IBS-D in rats. It improved gastrointestinal function and reduced visceral hypersensitivity in rats possibly via the PAR-2/TRVP1 pathway.

Moxibustion for the side effects of surgical therapy and chemotherapy in patients with gastric cancer: A protocol for systematic review and meta-analysis

BACKGROUND

Side effects after surgical therapy and chemotherapy of gastric cancer substantially reduce patients' quality of life. This systematic review aims to investigate whether moxibustion, as a complementary treatment, is effective in alleviating side effects in patients with gastric cancer who underwent surgical therapy or chemotherapy.

METHODS

We will systematically search nine English and Chinese electronic databases to find relevant randomized controlled trials (RCTs) that compare basic treatment with and without moxibustion for treating the side effects induced by surgical therapy or chemotherapy in patients with gastric cancer. The time frame of the search will be from inception to July 1, 2020, and the publication language will not be limited. The literature screening and data extraction will be completed independently by 2 reviewers. The Cochrane risk of bias tool will be used to assess the risk of bias. For the analyses of the side effects of both surgical therapy and chemotherapy, the primary outcomes are defined as the incidence of any side effect, response rate, and quality of life. For the analyses of the side effects of surgical therapy, the secondary outcomes include the incidence of each individual side effect, time to first flatus/defecation/bowel sounds, and length of in-hospital stay. For the analysis of the side effects of chemotherapy, the secondary outcomes include incidence of each individual side effect, white blood cell/red blood cell/platelets counts, and hemoglobin level. R v3.6.2 software will be used to perform the meta-analyses. The quality of evidence will be classified using the Grading of Recommendations Assessment, Development and Evaluation system.

RESULTS

This study will provide the first systematic review evidence on the efficacy of moxibustion as adjuvant management for gastric cancer by rigorous quality assessment and appropriate data synthesis. The results will be submitted to a peer-reviewed journal for publication.

CONCLUSION

The findings of this study will provide currently best evidence on moxibustion for patients with gastric cancer who underwent surgical therapy or chemotherapy and may impact clinical practice.PROSPERO registration number: CRD42020169511.

Electroacupuncture Improves IBS Visceral Hypersensitivity by Inhibiting the Activation of Astrocytes in the Medial Thalamus and Anterior Cingulate Cortex

Objective

To explore whether the effect of electroacupuncture (EA) on visceral hypersensitivity (VH) in rats with irritable bowel syndrome (IBS) is related to the changes of astrocyte activation in the medial thalamus (MT) and anterior cingulate cortex (ACC).

Method

Male Sprague-Dawley rats were randomly divided into the normal control (NC) group, model control (MC) group, electroacupuncture (EA) group, and fluorocitrate (FCA) group. A model of visceral hypersensitivity was established by neonatal colorectal irritation. In the EA group, needles were inserted into the skin at the Tianshu (ST25) and Shangjuxu (ST37) acupoints, once a day for 7 days. The FCA group received intrathecal injection of FCA on the 1st, 4th, and 7th days. Visceral hypersensitivity was evaluated by the abdominal withdrawal reflex (AWR), and glial fibrillary acidic protein (GFAP) mRNA and protein levels in the MT and ACC were detected by real-time PCR, immunohistochemistry, and western blots.

Results

The AWR score in the MC group was significantly higher than in the NC group, and EA and FCA reduced the AWR score of VH rats. GFAP mRNA and protein levels in the MT and ACC of rats in the MC group were significantly increased compared with the NC group. After either electroacupuncture or fluorocitrate, GFAP mRNA and protein levels in the MT and ACC were both clearly reduced.

Conclusion

Electroacupuncture alleviates IBS visceral hypersensitivity by inhibiting the activation of astrocytes in the MT and ACC.

Effects of sacral nerve electrical stimulation on 5‑HT and 5‑HT3AR/5‑HT4R levels in the colon and sacral cord of acute spinal cord injury rat models

Spinal cord injury (SCI) often leads to defecation dysfunction. Sacral nerve electrical stimulation (SNS) therapy could improve defecation function. The present study aimed to assess SNS therapy, with regard to the levels of serotonin (5-HT) and its receptors (5-HT3AR and 5-HT4R) in the colon and sacral cord, a rat model of acute severe SCI was used. This rat model was made using the New York University Impactor device. Model rats were randomized to the SCI and SNS (electrical stimulation on the S3 nerve) groups. After 14 days of treatment, enteric transmission function was assessed. 5-HT and 5-HT3AR/5-HT4R were measured by ELISA, quantitative PCR, immunohistochemistry and western blotting. In SCI rats, SNS significantly increased the quantity of feces, shortened the time to the first fecal passage, and improved fecal texture and colon histology. SNS elevated 5-HT contents in the colon and spinal cord, and enhanced 5-HT3AR/5-HT4R protein expression and distribution in the colonic myenteric plexus and mucosa, sacral intermediolateral nucleus and dorsal horn. SNS upregulated the relative expression levels of 5-HT3AR/5-HT4R mRNA and protein in the colon and spinal cord. SNS can improve defecation and accelerate the recovery of colonic transmission functions in rat models of acute SCI. These effects involved upregulation of the 5-HT/5-HT3AR/5-HT4R axes.

Electroacupuncture Inhibits the Activity of Astrocytes in Spinal Cord in Rats with Visceral Hypersensitivity by Inhibiting P2Y1 Receptor-Mediated MAPK/ERK Signaling Pathway

Background

Irritable bowel syndrome (IBS) is a chronic functional bowel disease characterized by abdominal pain and changes in bowel habits in the absence of organic disease. Electroacupuncture (EA) has been shown to alleviate visceral hypersensitivity (VH) in IBS rat models by inhibiting the activation of astrocytes in the spinal cord. However, the underlying molecular mechanisms mediated by P2Y₁ receptor of this effect of electroacupuncture remain unclear.

Aim

To explore whether EA inhibits the activity of astrocytes in the spinal cord dorsal horn of rat with visceral hypersensitivity by inhibiting P2Y₁ receptor and its downstream mitogen activated protein kinase/extracellular regulated kinase 1 (MAPK/ERK) pathway.

Methods

Ten-day-old Sprague-Dawley (SD) male rats were given an intracolonic injection of 0.2 ml of 0.5% acetic acid (AA) to establish a visceral hypersensitivity model. EA was performed at Zusanli (ST 36) and Shangjuxu (ST 37) at 100 Hz for 1.05 s and 2 Hz for 2.85 s alternately, pulse width for 0.1 ms, 1 mA, 30 min/d, once a day, for 1 week. Cytokines IL-6, IL-1β, and TNF-α were analyzed by ELISA. The expressions of the P2Y₁ receptor and pERK1/2 were analyzed by Western Blot and real-time PCR in the model and EA treated animals to explore the molecular mechanism of EA in inhibiting the activity of spinal cord dorsal horn (L₆-S₂ segment) astrocytes in rats with IBS visceral hypersensitivity.

Results

EA significantly reduced the behavioral abdominal withdrawal reflex score (AWRs) of IBS rats with visceral hypersensitivity induced by AA. For comparison, intrathecal injection of astrocytes activity inhibitor fluorocitrate (FCA) also reduced visceral hypersensitivity in IBS rats. EA at Zusanli and Shangjuxu inhibited the mRNA and protein expression of the glial fibrillary acidic protein (GFAP) and in rat spinal cord and reduced the release of inflammatory cytokines IL-6, IL-1, and TNF-α were analyzed by ELISA. The expressions of the P2Y₁ receptor and pERK1/2 were analyzed by Western Blot and real-time PCR in the model and EA treated animals to explore the molecular mechanism of EA in inhibiting the activity of spinal cord dorsal horn (L₆-S₂ segment) astrocytes in rats with IBS visceral hypersensitivity. β, and TNF-μg, 10 μg, 10 

Conclusion

EA inhibited astrocyte activity in the spinal cord dorsal horn of rat with IBS visceral hypersensitivity by inhibiting the P2Y₁ receptor and its downstream, PKC, and MAPK/ERK1/2 pathways.

PDTC Alleviates Depressive Symptoms and Colon Tissue Injury via Inhibiting NO Overproduction in CUMS Rats

Background

The accumulated evidence demonstrates that stress plays an important role in the pathogenesis of depression that is associated with intestinal dysfunctions. However, the mechanisms remain unresolved.

Methods

A total of 40 male Wistar rats were obtained and randomly divided into four equal-sized group: control, PDTC + chronic and unpredictable mild stress (CUMS), FLX + CUMS, and CUMS. Western blotting and qRT-PCR were used to examine the levels of nitric oxide (NO), nuclear factor kappa beta (NF-κB), inducible nitric oxide synthase (iNOS), and iNOS mRNA in spinal cord L1-2 and colon.

Key Results

Chronic and unpredictable mild stress increased the serum CORT level, decreased body weight and sucrose preference, and altered OFT performance, while increased levels of NO, iNOS mRNA, iNOS and NF-κB protein in colon and spinal cord were accompanied by histopathological changes in colon. Pretreatment with an NF-κB inhibitor, pyrrolidine dithiocarbamate (PDTC), reversed these effects. Fluoxetine failed to prevent NO increase in both spinal cord and colon, while the iNOS protein level, although not statistically significantly increased compared to control, was not decreased compared to CUMS. Also, fluoxetine failed to prevent histological changes.

Conclusion

In conclusion, the NF-κB/iNOS pathway may be involved in the mechanism of CUMS-induced depressive-like behavior and colon tissue injury.

Moxibustion Eases Chronic Inflammatory Visceral Pain In Rats Via MAPK Signaling Pathway In The Spinal Cord

Purpose

The purpose of this study was to explore the central analgesia mechanism of moxibustion for chronic inflammatory visceral pain (CIVP).

Methods

A CIVP rat model was established by 2,4,6-trinitrobenzene sulfonic acid (TNBS) plus 50% ethanol via enema. The analgesic effect of moxibustion was evaluated using the abdominal withdrawal reflex (AWR), mechanical withdrawal threshold (MWT), and thermal withdrawal latency (TWL). The expression profile of phosphorylated proteins of the mitogen-activated protein kinase (MAPK) signaling pathway in the spinal cord was assayed by protein microarray. The differentially expressed proteins were examined by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) for functional clusters and corresponding signaling pathways.

Results

Moxibustion exerted a significant analgesic effect for CIVP rats, mainly presenting as a decrease in the AWR score (all P<0.01) under different levels of distending pressure and an increase in MWT and TWL thresholds (all P<0.05). Compared with the normal group, 76 proteins were upregulated while 15 were downregulated, and MAPK signaling pathway was activated in the model group. Compared with the model group, there were 53 downregulated and 38 upregulated proteins in the moxibustion group, and MAPK signaling pathway was inhibited. Fold change (FC)>1.3 or <0.77 was taken as the screening standard to define the differentially expressed proteins. Fifteen differentially expressed proteins upregulated in the model group were downregulated in the moxibustion group. GO analysis showed that the differentially expressed proteins mainly controlled cellular metabolism regulation, transportation, and stress reactions. KEGG analysis revealed that these differentially expressed proteins were mostly involved in the ERK, JNK, and p38 pathways, and the ERK pathway was predominant.

Conclusion

Moxibustion mitigates CIVP in rats and inhibits the phosphorylation of proteins in the spinal MAPK signaling pathway. The analgesic effect of moxibustion may be associated with the regulation of the spinal MAPK signaling pathway.

Studies on the Neuroprotection of Osthole on Glutamate-Induced Apoptotic Cells and an Alzheimer's Disease Mouse Model via Modulation Oxidative Stress

In the present study, the neuroprotection of osthole (OST) was confirmed. In L-glutamic acid (L-Glu)-damaged HT22 cells, a 3-h pre-incubation with OST-enhanced cell viability suppressed the apoptosis rate; inhibited the activities of caspase-3, caspase-8, and caspase-9; reduced the over-accumulation of intracellular reactive oxygen species; restored the dissipated mitochondrial membrane potential; and regulated the expression levels of B cell lymphoma-2 (Bcl-2), Bax, cleaved poly (ADP-ribose) polymerase (PARP), NF-E2p45-related factor 2 (Nrf2), and its downstream proteins. In amyloid precursor protein/presenilin 1 (APP/PS1) transgenic mice, an 8-week OST administration improved the pathological behaviors related to memory and cognition, and reduced the expression levels of 4-hydroxynonenal, the deposition of β-amyloid peptides and neuronal fiber tangles formed by the high phosphor-Tau in the brain. OST enhanced the expression levels of Nrf2 and its downstream proteins including superoxide dismutase-1 (SOD-1) and heme oxygenase-1 (HO-1). The present data confirmed the protection of OST against AD-like symptoms via modulating oxidative stress, especially Nrf2 signaling.

Inonotus obliquus polysaccharides protect against Alzheimer's disease by regulating Nrf2 signaling and exerting antioxidative and antiapoptotic effects

Inonotus obliquus polysaccharide (IOPS) was initially separated and purified via precipitation from an aqueous extract with 80% alcohol, a DEAE-52 cellulose anion exchange column, and a Sephadex G-100 gel permeation chromatography system. IOPS was found to have a molecular weight of 111.9 kDa. In L-glutamic acid (L-Glu)-damaged HT22 cells, a 3-h pre-incubation with IOPS enhanced cell viability, inhibited apoptosis and caspase-3 activity, reduced the release of lactate dehydrogenase, restored the dissipated mitochondrial membrane potential, and suppressed the excess accumulation of intracellular reactive oxygen species. Compared with L-Glu-exposed cells, IOPS pre-treated cells exhibited reduced levels of Bcl-2 associated X protein (Bax) and Kelch-like ECH-associated protein 1 (Keap1) and enhanced levels of B-cell lymphoma-2 (Bcl-2), NF-E2p45-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), superoxide dismutase-1 (SOD-1), and cysteine ligase catalytic subunit. In amyloid precursor protein/presenilin 1 (APP/PS1) transgenic mice, an 8-week course of IOPS improved the pathological behaviors related to memory and cognition, reduced the deposition of β-amyloid peptides and neuronal fiber tangles induced by enhanced phosphor-Tau in the brain, and modulated the levels of anti- and pro-oxidative stress enzymes. Additionally, IOPS enhanced the expression levels of Nrf2 and its downstream proteins, including HO-1 and SOD-1, in the brains of APP/PS1 mice. The present study successfully demonstrated the protective effect of IOPS against AD and revealed the possible mechanism underlying the ability of IOPS to modulate oxidative stress, especially Nrf2 signaling, and mediate mitochondrial apoptosis.

Protective roles of isoastilbin against Alzheimer's disease via Nrf2‑mediated antioxidation and anti‑apoptosis

By analyzing the L‑glutamic acid (L‑Glu)‑induced apoptosis of PC12 cells and an AlCl3 combined with D‑galactose (D‑gal)‑developed Alzheimer's disease (AD) mouse model, the protective effects of isoastilbin (IAB) against AD were systematically investigated in the present study. Pre‑incubation with IAB for 3 h prior to treatment with 25 mM L‑Glu decreased cell viability and inhibited apoptosis, suppressed the accumulation of intracellular reactive oxygen species, and restored mitochondrial membrane potential in PC12 cells induced by L‑Glu. In mice with AD, the reduced escape latency time in the water maze test, suppressed chronic movement in the center area of an open field test and enhanced ability to seek hidden food in a Y maze test indicated that abnormal behaviors had improved after 28 days of treatment with IAB. Furthermore, IAB reduced the deposition of amyloid β (Aβ) and the expression of phosphorylated‑Tau in the mouse brain and enhanced the serum levels of Aβ. IAB ameliorated the oxidative stress via modulating the levels of associated enzymes and improved the functioning of the central cholinergic system, as indicated by an increase in acetylcholine and choline acetyltransferase concentrations. The expression levels of acetylcholine esterase were reduced in the mouse brain in response to IAB pre‑treatment. In cells and brain tissue, IAB regulated the expression levels of pro‑ and anti‑apoptotic proteins and enhanced the nuclear levels of NF‑E2p45‑related factor 2 (Nrf2); subsequently, IAB further enhanced the expression of superoxide dismutase 1, catalase, and heme oxygenase‑1 and ‑2. The findings of the present study indicated that the protection of IAB against AD is at least partially associated with its antioxidation and anti‑apoptotic properties.

Pharmacological basis for application of scutellarin in Alzheimer's disease: Antioxidation and antiapoptosis

Scutellarin (SC), mainly extracted from the Chinese herb Erigeron breviscapus (vant.), has been reported to possess various pharmacological activities; however, its effects on Alzheimer's disease (AD) have not been systemically reported. The protective effects of SC on AD were investigated using an L‑glutamic acid (L‑Glu)‑damaged HT22 cell apoptosis model and an aluminum chloride plus D‑galactose‑induced AD mouse model. In L‑Glu‑damaged HT22 cells, SC significantly increased cell viability, inhibited lactate dehydrogenase release, reduced caspase‑3 activity and suppressed apoptosis, which were determined via an MTT assay, an in vitro Toxicology Assay kit, a Caspase‑3 activity assay kit, and propidium iodide and Annexin V staining. Furthermore, SC suppressed the accumulation of intracellular reactive oxygen species (ROS), restored the dissipation of mitochondrial membrane potential, enhanced the expression of antiapoptotic proteins and reduced the expression of pro‑apoptotic proteins, as determined by immunofluorescence assays and western blotting. In AD mice, SC enhanced vertical and horizontal movements in an autonomic activity test, and reduced the escape latency time in the water maze test. SC reduced the deposition of amyloid β1‑42 (Aβ1‑42) and the expression of phosphorylated‑Tau in the hippocampus as determined by immunohistochemistry analysis, but enhanced the serum levels of Aβ1‑42 of AD mice as determined by ELISA. ELISA analyses also revealed that SC enhanced the levels of acetylcholine, and superoxide dismutase in serum and brain lysate, whereas reduced the levels of ROS in brain lysate of AD mice. The present study confirmed that the protective effects of SC in AD in vitro and in vivo are associated with its antioxidant and antiapoptotic properties.