Mechanism of Renshentang in Treatment of Atherosclerosis Based on Autophagic Effect of TRPV1 on Arterial Smooth Muscle / 中国实验方剂学杂志

ObjectiveTo investigate the mechanism of Renshentang， recorded in Synopsis of Golden Chamber， in the treatment of atherosclerosis （AS） based on the autophagic effect of transient receptor potential vanilloid subtype 1 （TRPV1） on arterial smooth muscle. MethodFourteen SPF-grade 8-week-old male C57BL/6J mice were assigned to the normal group and 70 8-week-old apolipoprotein E knockout （ApoE-/-） mice were assigned to the experimental group. The AS model was induced by a high-fat diet in the mice in the experimental group for eight weeks. The model mice were then randomly divided into model group， low-， medium-， and high-dose Renshentang groups （2.715， 5.43， and 10.68 g·kg-1·d-1）， and simvastatin group （0.02 g·kg-1·d-1）. Drug treatment lasted eight weeks. Serum was taken and serum total cholesterol （CHO）， triglyceride （TG）， low-density lipoprotein cholesterol （LDL-C）， and high-density lipoprotein cholesterol （HDL-C） levels were measured by assay kits to observe the changes in lipid levels in mice. The aorta was stained with hematoxylin-eosin （HE） to observe the overall pathology of the aortic root and oil red O staining was used to detect the lipid deposition in the aortic plaque and calculate the percentage of the aortic root area to the lumen area. The protein expression of TRPV1， adenylate-activated protein kinase （AMPK）， phosphorylated AMPK （p-AMPK）， autophagy effector-1 （Beclin-1）， and microtubule-associated protein 1 light chain 3 （LC3Ⅱ） in mouse aortic tissues was determined by Western blot. ResultCompared with the normal group， the model group showed increased serum CHO， TG， and LDL-C levels， decreased HDL-C， and increased aortic root plaque area （P<0.01）. Compared with the model group， the Renshentang groups showed decreased levels of CHO， TG， and LDL-C in serum （P<0.05， P<0.01）， especially in the low- and medium-dose Renshentang groups （P<0.01）. Compared with the normal group， the simvastatin group and the Renshentang groups showed reduced aortic root plaque area （P<0.05）， especially in the high-dose Renshentang group （P<0.01）. Compared with the normal group， the model group showed decreased relative expression levels of TRPV1， p-AMPK/AMPK， Beclin-1， and LC3Ⅱ/LC3Ⅰ（P<0.05， P<0.01）. Compared with the model group， the medium- and high-dose Renshentang groups showed increased relative expression levels of TRPV1， p-AMPK/AMPK， Beclin-1， and LC3Ⅱ/LC3Ⅰ（P<0.05，P<0.01）. ConclusionThe anti-AS effect of Renshentang recorded in Synopsis of Golden Chamber may be achieved by up-regulating TRPV1 expression to restore the level of autophagy mediated by AMPK.

Intervention effect of Qufeng Gutong Cataplasm on myofascial pain syndrome in rats and its mechanism / 中国中药杂志

This paper aims to investigate the intervention effect of Qufeng Gutong Cataplasm(QFGT) on myofascial pain syndrome(MPS) in rats and to preliminarily explain its mechanism from the perspective of improving muscle inflammation and pain. Male SD rats were divided into 6 groups, namely normal group, model group, positive control drug(Huoxue Zhitong Ointment, HXZT) group, and low, medium, and high-dose QFGT groups(75, 150, and 300 mg·d~(-1)). The rat model of MPS was established by striking combined with centrifugation for 8 weeks, during which QFGT and HXZT were used for corresponding intervention. Standard VonFrey fiber was used to evaluate the mechanical pain threshold, and acetone was used to detect the cold pain threshold. The electrophysiological activity of muscle at trigger point was detected, and the electromuscular analysis of trigger point was performed. CatWalk gait analyzer was used to detect pain-induced gait adaptation changes. The hematoxylin-eosin(HE) staining was used to observe the pathological changes in muscle and skin tissues at the trigger point of rats. Immunohistochemistry was used to detect the expression of capsaicin receptor transient receptor potential vanilloid 1(TRPV1) in muscle tissues and interleukin(IL)-33 in skin tissues at the trigger point. The protein expression levels of TRPV1, protein kinase B(Akt), phosphorylated protein kinase B(p-Akt), IL-1β, and tumor necrosis factor-α(TNF-α) in muscle tissues at the trigger point were detected by Western blot. The results showed that as compared with the model group, the mechanical pain threshold and cold pain threshold of rats in other groups were increased after treatment with QFGT. The spontaneous electromyography(EMG) activity was observed in the model group, but QFGT alleviated the EMG activity in a dose-dependent manner. Gait analysis showed that standing duration, average intensity, swing speed, maximum contact point, maximum contact area, paw print length, paw print width, and paw print area were significantly improved in all QFGT groups. Pathological results showed that the disorder of muscle arrangement at the trigger point was decreased, muscle fiber adhesion and atrophy were reduced, and inflammatory cell infiltration was alleviated after treatment with QFGT. In addition, QFGT and HXZT both inhibited the protein expression of TRPV1, PI3K, Akt, p-Akt, IL-1β, and TNF-α in the muscle tissues of rats with MPS. However, there was no significant difference in the pathological structure and expression of IL-33 in the treated skin as compared with the normal group. The related results have proved that QFGT can inhibit the release of inflammatory factors by inhibiting the TRPV1/PI3K/Akt signaling pathway in the muscle trigger point of rats with MPS and finally attenuate the atrophy and adhesion of local muscles and inflammatory infiltration, thereby relieving the muscle pain of rats with MPS, and local administration has no skin irritation.

Propofol relieves the subcutaneous chloroquine-induced pruritus in rats via TRPV1 and CB1 receptors of spinal cord / 中国临床药理学与治疗学

AIM: To explore the possible mechanism of propofol in alleviating pruritus induced by subcutaneous injection of chloroquine in rats. METHODS: The pruritus model of chloroquine in SD rats was established and the administration time was determined. 18 rats with successful pruritus model induced by subcutaneous injection of chloroquine were randomly divided into NS group, I group and P group. Normal saline 80 μL/kg, fat emulsion 80 μL/kg and propofol 0.8 mg/kg were injected through internal jugular vein catheter 5 minutes after subcutaneous injection of chloroquine. Another 6 rats were randomly selected as group C, and the same volume of normal saline as the other 3 groups was injected subcutaneously in the back of the neck and through the internal jugular vein catheter. The rats were killed 16 minutes after the corresponding drugs were injected into the internal jugular vein. The expressions of TRPV1 and CB1 receptors in the spinal cord were detected by Western blot. RESULTS: Compared with NS group and I group, the expression level of TRPV1 receptor in the spinal cord of P group rats was significantly increased (P<0.01), while there was no statistically significant difference between C group, NS group, and I group; The expression level of CB1 receptor was significantly higher than that of group C, NS, and I (P<0.05), while there was no statistically significant difference between group C, NS, and I. CONCLUSION: Propofol can significantly alleviate pruritus caused by subcutaneous injection of chloroquine in rats, which may exert an antipruritic effect by increasing the expression of TRPV1 and CB1 receptors in the spinal cord of rats.

Improvement effect of Shegan Mahuang Decoction on rats with cold-induced asthma based on TRPV1/NRF-1/mtTFA pathway / 中国中药杂志

This study investigated the therapeutic effect of Shegan Mahuang Decoction(SGMHD) on cold-induced asthma in rats and explored its underlying mechanism. Seventy-two healthy male SD rats of specific pathogen free(SPF) grade were randomly divided into a blank group, a model group, a positive control group(dexamethasone, 0.4 mg·kg~(-1)), and low-, medium-, and high-dose SGMHD groups(3.2, 6.4, and 12.8 g·kg~(-1)). The blank group received saline, while the other groups were sensitized by intraperitoneal injection of ovalbumin(OVA) solution. Subsequently, the rats were placed in a cold chamber adjustable to 0-2 ℃, and OVA solution was ultrasonically nebulized to induce cold-induced asthma in rats. After three weeks of treatment, the general behaviors of rats were observed. Hematoxylin-eosin(HE) staining was used to evaluate pathological changes in lung tissues, periodic acid-Schiff(PAS) staining assessed mucin changes, and Masson staining was performed to examine collagen deposition. Enzyme-linked immunosorbent assay(ELISA) was used to measure the levels of the inflammatory factors interleukin-4(IL-4) and vascular endothelial growth factor(VEGF) in serum and bronchoalveolar lavage fluid(BALF). Real-time quantitative polymerase chain reaction(RT-PCR) was employed to assess the mRNA expression levels of transient receptor potential vanilloid subfamily member 1(TRPV1), nuclear respiratory factor 1(NRF-1), and mitochondrial transcription factor A(mtTFA) in lung tissues. Western blot was used to measure the protein expression levels of TRPV1, NRF-1, and mtTFA in lung tissues. Compared with the blank group, the model group exhibited signs of rapid respiration, increased frequency of defecation with looser stools, and disheveled and dull fur. Pathological results showed significant infiltration of inflammatory cells in lung tissues, narrowing of bronchial lumens, increased mucin secretion, and enhanced collagen deposition in the model group. Additionally, the levels of IL-4 and VEGF in serum and BALF were significantly elevated, and the mRNA and protein expression levels of TRPV1, NRF-1, and mtTFA in lung tissues were significantly increased. Compared with the model group, SGMHD improved the behaviors of rats, alleviated pathological changes in lung tissues, mucin production, and collagen deposition, significantly decreased the levels of IL-4 and VEGF in serum and BALF, and reduced the mRNA expression levels of TRPV1, NRF-1, and mtTFA in lung tissues, with the medium-dose SGMHD group showing the most significant effect. Moreover, the protein expression levels of TRPV1, NRF-1, and mtTFA in lung tissues were also reduced, with the medium-dose SGMHD group exhibiting the most significant effect. In conclusion, this study demonstrates that SGMHD can alleviate airway inflammation and inhibit airway remodeling in cold-induced asthma rats. These effects may be associated with the modulation of the TRPV1/NRF-1/mtTFA signaling pathway.

A-80426 suppresses CFA-induced inflammatory pain by suppressing TRPV1 activity via NFκB and PI3K pathways in mice

Abstract Objectives Pain is associated with many circumstances, including inflammatory reactions, which arise from modification of the features of signaling pathways. α2-adrenergic receptor antagonists are widely utilized in narcosis. Here, the authors focused on the narcotic effect of A-80426 (A8) on Complete Freund's Adjuvant (CFA) injections-triggered chronic inflammation pain in WT and TRPV1-/- mice and explored whether its antinociceptive impact was modulated via Transient Receptor Potential Vanilloid 1 (TRPV1). Method CFA with or without A8 was co-administered to the mice, which were categorized randomly into four groups: CFA, A8, control, and vehicle. Pain behaviors underwent evaluation through mechanical withdrawal threshold, abdominal withdrawal reflex, and thermal withdrawal latency of WT animals. Results Quantitative polymerase chain reaction revealed that inflammation-promoting cytokines (IL-1β, IL-6, and TNF-α) were upregulated in Dorsal Root Ganglion (DRG) and Spinal Cord Dorsal Horn (SCDH) tissues of WT animals. A8 administration reduced the pain behaviors and production of pro-inflammatory cytokines; however, this effect was significantly reduced in TRPV1-/- mice. Further analysis showed that CFA treatment reduced the TRPV1 expression in WT mice and A8 administration increased its expression and activity. The co-administration of SB-705498, a TRPV1 blocker, did not influence the pain behaviors and inflammation cytokines in CFA WT mice; however, SB-705498 the effect of A8 in WT mice. In addition, the TRPV1 block decreased the NFκB and PI3K activation in the Dorsal Root Ganglia (DRG) and Spinal Cord Dorsal Horn (SCDH) tissues of WT mice. Conclusions Together, A8 exerted a narcotic impact on CFA-supplemented mice via the TRPV1-modulated NFκB and PI3K pathway.

Relationship Between TRPV1 and TRPM8 in Reflux Esophagitis Models / 胃肠病学

Background: Studies have shown that transient receptor potential (TRP) channels play important roles in gastroesophageal reflux disease (GERD), however, the relationship between TRPV1 and TRPM8 in reflux esophagitis (RE) remains unclear. Aims: To investigate the expressions of TRPV1, TRPM8 and their correlation in guinea pigs with RE. Methods: Thirty male guinea pigs aged 3⁃4 weeks were randomly divided into 3 groups: blank control group, negative control group and model group, with 10 animals in each group. Guinea pigs in model group and negative control group were given esophageal perfusion with 0.1 mol/L HCl containing 0.5% pepsin and normal saline, respectively, once a day for 14 days; guinea pigs in blank control group were free to drink sterile water for 14 days. On day 15, the esophagus was dissected for macroscopic and histopathological examination, and Western blotting and/or real⁃time PCR were used to detect the expression levels of TRPV1, TRPM8, GNAQ (an isoform of G protein), and the tight junction proteins and proinflammatory cytokines in esophageal tissue. The co⁃localization of TRPV1 and TRPM8 was assessed by immunofluorescence. Results: Esophageal mucosal congestion, hyperplasia of esophageal epithelial cells, infiltration of inflammatory cells, as well as up⁃regulation of proinflammatory cytokines and down⁃regulation of tight junction proteins were observed in esophageal tissue of guinea pigs in model group, which indicated the successful RE model construction. As compared with the negative control group, expression levels of TRPV1 and GNAQ mRNA and protein were significantly increased, while expression levels of TRPM8 mRNA and protein were significantly reduced in esophageal tissue of guinea pigs in model group (all P<0.05). TRPV1 and TRPM8 channels were co ⁃ localized in the lamina propria of esophageal mucosa. Conclusions: There is a certain equilibrium mechanism between TRPV1 and TRPM8 channels in RE models. G protein⁃coupled receptor signaling pathway and the downstream TRPV1/TRPM8 might be involved in the occurrence and development of GERD.

Rutaecarpine prevents Ang II -induced vascular smooth muscle cell senescence through TRPV1/ SIRT1 pathway / 中国药理学通报

Aim To evaluate the effects of Rutaecarpine(Rut)on the expression of SIRT1 and the senescence of vascular smooth muscle cells(VSMCs)induced by angiotensin Ⅱ.Methods VSMC senescencewas induced by exposure to AngⅡ(1 μmol·L-1)for 72 h.VSMCs were treated with different concentrations of Rut(0.3, 1, 3 μmol·L-1).TRPV1 competitive antagonist CAPZ(10 μmol·L-1)and AMPK inhibitor Compound C(1 μmol·L-1)were used to explore whether TRPV1/AMPK mediated the protective effect of Rut.The quantity of senescent cells were determined by senescence-associated SA-β-Gal staining, and the intracellular ROS level was measured by(DCFH-DA)fluorescent probe.The migration ability of VSMCs was evaluated by Wound-healing assay combined with Transwell assay.The protein level of longevity protein SIRT1 and senescence-related proteins p53, p21 and AMPK phosphorylation level were detected by Western blot.Results Rut significantly inhibited Ang Ⅱ-induced VSMC senescence and ROS production and prevented VSMCs migration.Preprocessing of TRPV1 antagonist CAPZ could abolish the protective effect of Rut.Ang Ⅱ inhibited the expression of longevity protein SIRT1.Rut recovered SIRT1 expression in a dose-dependent manner, while prevented the up-regulation of senescence-related proteins p53 and p21.Ang Ⅱ inhibited AMPK phosphorylation, pre-treatment with Rut restored AMPK phosphorylation level.CAPZ and Compound C eliminated the up-regulating function of Rut on SIRT1 expression.Conclusions Rut up-regulates the expression of SIRT1 and prevents the senescence and migration of VSMCs induced by Angiotensin Ⅱ, which is related to activation of the TRPV1/AMPK signaling pathway.

Mechanism of Aconiti Kusnezoffii Radix Processed with Chebulae Fructus Against H9c2 Cardiomyocyte Toxicity Based on TRPV1 Channel / 中国实验方剂学杂志

ObjectiveTo explore the role of transient receptor potential vanilloid 1 （TRPV1） channel in reducing cardiomyocyte toxicity of Aconiti Kusnezoffii Radix processed with Chebulae Fructus. MethodH9c2 cardiomyocytes cultured in vitro were used as a model to assess cell viability by methyl thiazolyl tetrazolium （MTT） assay， the expression of TRPV1 mRNA was detected by real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）， and the leakage rate of lactate dehydrogenase （LDH）， the changes of nucleus， reactive oxygen species （ROS）， mitochondrial membrane potential and Ca2+ contents were detected by enzyme linked immunosorbent assay （ELISA）. ResultCompared with the blank group， when the concentration was ≥0.5 g·L-1， the cell viability was significantly decreased （P<0.01）， the leakage rate of LDH， the release of ROS and Ca2+ were increased， the mitochondrial membrane potential was decreased， and the nucleus was pyknosis or even broken in raw Aconiti Kusnezoffii Radix and Aconiti Kusnezoffii Radix processed with Chebulae Fructus groups. When the concentration was ≥0.5 g·L-1， compared with the same mass concentration of raw Aconiti Kusnezoffii Radix group， the cell viability increased significantly （P<0.01）， the leakage rate of LDH， the release of ROS and Ca2+ decreased， the mitochondrial membrane potential increased， and the nuclear morphology improved in Aconiti Kusnezoffii Radix processed with Chebulae Fructus group. Application of the same mass concentration of raw Aconiti Kusnezoffii Radix to H9c2 cardiomyocytes pretreated with the TRPV1 inhibitor BCTC significantly increased cell viability， decreased leakage rate of LDH， ROS and Ca2+ release， increased mitochondrial membrane potential and improved nuclear pyknosis compared with untreated H9c2 cardiomyocytes. Application of the same mass concentration of Aconiti Kusnezoffii Radix processed with Chebulae Fructus to H9c2 cardiomyocytes pretreated with BCTC decreased cell viability， increased LDH leakage rate， ROS and Ca2+ release， reduced mitochondrial membrane potential compared with untreated H9c2 cardiomyocytes. Real-time PCR results showed that both raw Aconiti Kusnezoffii Radix and Chebulae Fructus decoction could increase the expression of TRPV1 mRNA in cardiomyocytes in a concentration dependent manner. ConclusionRaw Aconiti Kusnezoffii Radix can induce cardiomyocyte apoptosis and cardiotoxicity by activating TRPV1 channel， while Aconiti Kusnezoffii Radix processed with Chebulae Fructus can attenuate the toxicity through TRPV1 channel， which may be related to the synergistic effect of acid components in Chebulae Fructus and alkaloids in Aconiti Kusnezoffii Radix on TRPV1 channel.

Muscle pain induced by static contraction is modulated by transient receptor potential vanilloid 1 and ankyrin 1 receptors

Abstract Molecular mechanisms involved in the development of muscle pain induced by static contraction are not completely elucidated. This study aimed to evaluate the involvement of the transient receptor potential vanilloid 1 (TRPV1) and the transient receptor potential ankyrin 1 (TRPA1) receptors expressed in peripheral and central terminals of primary afferents projected to gastrocnemius muscle and spinal cord in muscle pain induced by static contraction. An electrical stimulator provided the contraction of rat gastrocnemius muscle and mechanical muscle hyperalgesia was quantified through the pressure analgesimeter Randall-Selitto. AMG9810 and HC030031 were used. When administered in ipsilateral, but not contralateral gastrocnemius muscle, drugs prevented mechanical muscle hyperalgesia induced by static contraction. Similar results were obtained by intrathecal administrations. We propose that, in an inflammatory muscle pain, peripheral and central TRPV1 and TRPA1 work together to sensitize nociceptive afferent fibers, and that TRPV1 and TRPA1 receptors are potential target to control inflammatory muscle pain.

Implications of Transient Receptor Potential Cation Channels in Migraine Pathophysiology / 神经科学通报·英文版

Migraine is a common and debilitating headache disorder. Although its pathogenesis remains elusive, abnormal trigeminal and central nervous system activity is likely to play an important role. Transient receptor potential (TRP) channels, which transduce noxious stimuli into pain signals, are expressed in trigeminal ganglion neurons and brain regions closely associated with the pathophysiology of migraine. In the trigeminal ganglion, TRP channels co-localize with calcitonin gene-related peptide, a neuropeptide crucially implicated in migraine pathophysiology. Many preclinical and clinical data support the roles of TRP channels in migraine. In particular, activation of TRP cation channel V1 has been shown to regulate calcitonin gene-related peptide release from trigeminal nerves. Intriguingly, several effective anti-migraine therapies, including botulinum neurotoxin type A, affect the functions of TRP cation channels. Here, we discuss currently available data regarding the roles of major TRP cation channels in the pathophysiology of migraine and the therapeutic applicability thereof.

Complement C3 Aggravates Post-epileptic Neuronal Injury Via Activation of TRPV1 / 神经科学通报·英文版

Epilepsy is a brain condition characterized by the recurrence of unprovoked seizures. Recent studies have shown that complement component 3 (C3) aggravate the neuronal injury in epilepsy. And our previous studies revealed that TRPV1 (transient receptor potential vanilloid type 1) is involved in epilepsy. Whether complement C3 regulation of neuronal injury is related to the activation of TRPV1 during epilepsy is not fully understood. We found that in a mouse model of status epilepticus (SE), complement C3 derived from astrocytes was increased and aggravated neuronal injury, and that TRPV1-knockout rescued neurons from the injury induced by complement C3. Circular RNAs are abundant in the brain, and the reduction of circRad52 caused by complement C3 promoted the expression of TRPV1 and exacerbated neuronal injury. Mechanistically, disorders of neuron–glia interaction mediated by the C3–TRPV1 signaling pathway may be important for the induction of neuronal injury. This study provides support for the hypothesis that the C3–TRPV1 pathway is involved in the prevention and treatment of neuronal injury and cognitive disorders.

Regulation of capsaicin receptor TRPV1 on depressive behavior and neuronal autophagy in cerebral ischemia-reperfusion mice / 中华行为医学与脑科学杂志

Objective:To explore the effect and molecular mechanism of capsaicin receptor(TRPV1) on neuronal autophagy and depression-like behavior in mice.Methods:Using the method of random number table, 87 C57 male mice were divided into Sham operation group (Sham group), cerebral ischemia/reperfusion group (I/R group) and capsazepine(CPZ) preconditioning cerebral ischemia/reperfusion group (I/R+ CPZ group), with 28 mice in each group due to 3 incompatible.Mice in the I/R group were subjected to right middle cerebral artery occlusion (MCAO) to establish a cerebral ischemia-reperfusion model.Mice in the I/R+ CPZ group were injected with CPZ in the lateral ventricle prior to moulding.Mice in the Sham group had only wire plugs inserted and no arterial embolization was performed.The mNSS score was used to evaluate the degree of neurological deficits.The depression-like behaviour of mice was detected by the tail suspension test and forced swimming test.The infarct volume was observed by TTC staining.The pathological changes in the amygdala were observed by HE staining, and the expression of Beclin-1, LC3, p62 and p-PI3K, p-AKT and p-mTOR proteins were detected by Western blot.Statistical analysis was performed using SPSS 23.0 software.The t-test was used for comparison between two groups and one-way ANOVA was used for comparison of multiple group. Results:The neurological deficit score in I/R+ CPZ group (9.77±2.32) was significantly lower than that in I/R group (12.85±2.73) ( t=3.10, P<0.01). Compared with I/R group, the tail suspension immobility time of I/R+ CPZ Group ((93.28±50.69)s, (143.80±35.61) s; t=2.94, P<0.01) and the forced swimming immobility time ((139.50±13.33)s, (175.30±19.78)s; t=2.94, P<0.01) were significantly reduced.The results of TTC staining showed that the cerebral infarct volume in I/R+ CPZ group was significantly lower than that in I/R group ((19.30±5.19)%, (33.60±3.90)%; t=5.40, P<0.01). HE staining showed that the number of cells in the amygdala region of mice in the I/R+ CPZ group increased compared with that in the I/R group, with tighter arrangement and reduced deep staining of nuclear fixation.Western blot showed that compared with I/R group, the expression levels of autophagy related proteins Beclin-1( t=2.94, P<0.05) and LC3 ( t=3.16, P<0.05) in amygdala of I/R+ CPZ group were down-regulated, while the expression levels of p62( t=3.60, P<0.05), p-PI3K ( t=7.79, P<0.01), p-AKT ( t=4.15, P<0.01) and p-mTOR ( t=6.15, P<0.01) were up-regulated. Conclusion:Cerebral ischemia/reperfusion activates neuronal autophagy, and CPZ may regulate the PI3K-AKT-mTOR pathway, thus inhibits excessive activation of autophagy, thereby acting as a neuroprotective agent and improving post-stroke depression-like behaviour.

Capsaicin Induces Apoptosis of Colon Cancer SW480 Cells Through TRPV1 / 中国实验方剂学杂志

Objective:To investigate the effects of capsaicin on colon cancer SW480 cells and the underlying molecular mechanism through the transient receptor potential vanilloid 1（TRPV1）. Method:Capsaicin groups with different concentrations and a blank group were set up. The cell viability was detected by cell counting kit-8 （CCK-8） after SW480 cells were treated with capsaicin（50，100，200，300，400，500，600，800，1 000 μmol·L^-1） for 12，24，and 48 h to select the concentration of capsaicin which can effectively inhibit proliferation. The cell cycle and apoptosis were detected by flow cytometry after SW480 cells were treated with capsaicin （200，400，800 μmol·L^-1） for 24 h. The protein expression levels of TRPV1，p53，p-p53，B-cell lymphoma-2（Bcl-2），Bcl-2-associated X protein（Bax），cleaved cysteinyl aspartate-specific protease-3（cleaved Caspase-3），cleaved Caspase-8，and cleaved poly adenosine diphosphate ribose polymerase （PARP） were detected by Western blot after SW480 cells were treated with capsaicin （200，400 μmol·L^-1） for 24 h．In addition，the apoptosis was detected after SW480 cells were treated with TRPV1 microRNA（mRNA） and capsaicin（200 μmol·L^-1）. Western blot analysis was used to detect the protein expression levels of the above proteins. Result:As compared with the blank group，capsaicin（≥200 μmol·L^-1）significantly inhibited the cell viability of SW480 cells（<italic>P</italic><0.01） in dose- and time-dependent manners. The cell cycle was arrested in G₂/M phase by 200 and 400 μmol·L^-1 capsaicin treatment，and arrested in G₁ phase by 800 μmol·L^-1 capsaicin treatment （<italic>P</italic><0.05）. Flow cytometry showed that capsaicin （200， 400， 800 μmol·L^-1） significantly promoted apoptosis of SW480 cells simultaneously（<italic>P</italic><0.05，<italic>P</italic><0.01）. Western blot showed that capsaicin （200，400 μmol·L^-1） significantly up-regulated the protein levels of apoptosis-related proteins（p53，p-p53，Bax，cleaved Caspase-3，cleaved Caspase-8，and cleaved PARP） （<italic>P</italic><0.05，<italic>P</italic><0.01），and significantly down-regulated Bcl-2（<italic>P</italic><0.01）. In addition，siRNA-mediated knockdown of TRPV1 significantly attenuated capsaicin-induced apoptosis and the protein levels of apoptosis-related proteins in SW480 cells（<italic>P</italic><0.05，<italic>P</italic><0.01）. Conclusion:Capsaicin can inhibit cell proliferation，arrest cell cycle，and induce apoptosis of SW480 cells，and the possible mechanism may be related to TRPV1 activation.

Complement C3 Aggravates Post-epileptic Neuronal Injury Via Activation of TRPV1 / 神经科学通报·英文版

Epilepsy is a brain condition characterized by the recurrence of unprovoked seizures. Recent studies have shown that complement component 3 (C3) aggravate the neuronal injury in epilepsy. And our previous studies revealed that TRPV1 (transient receptor potential vanilloid type 1) is involved in epilepsy. Whether complement C3 regulation of neuronal injury is related to the activation of TRPV1 during epilepsy is not fully understood. We found that in a mouse model of status epilepticus (SE), complement C3 derived from astrocytes was increased and aggravated neuronal injury, and that TRPV1-knockout rescued neurons from the injury induced by complement C3. Circular RNAs are abundant in the brain, and the reduction of circRad52 caused by complement C3 promoted the expression of TRPV1 and exacerbated neuronal injury. Mechanistically, disorders of neuron-glia interaction mediated by the C3-TRPV1 signaling pathway may be important for the induction of neuronal injury. This study provides support for the hypothesis that the C3-TRPV1 pathway is involved in the prevention and treatment of neuronal injury and cognitive disorders.

A standardized extract of Centella asiatica (ECa 233) prevents temporomandibular joint osteoarthritis by modulating the expression of local inflammatory mediators in mice

Abstract Objectives To investigate the effect of a standardized extract of Centella asiatica (ECa 233), which has anti-inflammatory properties, on the local expression of the transient receptor potential vanilloid 1 (TRPV1), the acid-sensing ion channel subunit 3 (ASIC3), and the calcitonin gene-related peptide (CGRP) in the temporomandibular joint (TMJ) structure 21 days after injecting the TMJ with complete Freund's adjuvant (CFA). Methodology A mouse model was induced by analyzing the CFA-injected TMJ on days 7, 14, and 21. We assessed TMJ histology by the osteoarthritis cartilage grade score. Then, we observed the effect of different ECa 233 concentrations (30, 100, and 300 mg/kg) and of 140 mg/kg ibuprofen doses on TRPV1, ASIC3, and CGRP local expression on day 21. Results Osteoarthritis cartilage scores were 1.17±0.37 and 3.83±0.68 on days 14 and 21, respectively, in the CFA group (n=5). On day 21, TRPV1, ASIC3, and CGRP expression significantly increased in the CFA group. In the ibuprofen-treated group, TRPV1 expression significantly decreased, but ASIC3 and CGRP showed no significant difference. All ECa 233 doses reduced TRPV1 expression, but the 100 mg/kg ECa 233 dose significantly decreased ASIC3 expression. Conclusions TRPV1, ASIC3, and CGRP expression increased in mice with TMJ-OA on day 21. All ECa 233 and ibuprofen doses inhibited pathogenesis by modulating the local expression of TRPV1 and ASIC3. Therefore, ECa 233 was more effective than ibuprofen.

Mechanistic Investigation On Anti-Nociceptive Potential Of Bartogenic Acid Containing Barringtonia Racemosa Fraction In Experimental Models Of Pain

Barringtonia racemosa (B. racemosa) is a tropical medicinal plant possessing interesting biological activities. B. racemosa fruits are traditionally used in India for the treatment of pain, inflammation, and rheumatic conditions. Earlier, we have reported anti-inflammatory activity of ethyl acetate fraction (BREAF) obtained from B. racemosa fruits in animal models of inflammation and delayed-type hypersensitivity. The present study aimed to assess the anti-nociceptive activity of BREAF. Acetic acid-induced writhing test, and hot plate and tail immersion tests were employed to study the effect of BREAF on peripheral and central pain mechanisms, respectively. The involvement of opioid system was confirmed through naloxone antagonism. Formalin induced pain test was performed to assess the effect of BREAF on neurogenic and inflammatory pain components. Capsaicin induced pain models were used to investigate the involvement of transient receptor potential vanilloid 1 receptor. The BREAF reduced writhing episodes and delayed the onset of acetic acid-induced writhings. The raised percentage maximum protective effects by BREAF in hot plate and tail immersion tests suggest the efficacy of BREAF in pain alleviation. A reversal of the analgesic effect of BREAF following naloxone treatment indicates the involvement of opioid receptors. The BREAF also inhibited inflammatory and neurogenic components of formalin-induced pain. The inhibition of capasaicin induced pain to some extent by the BREAF indicates the possibility of involvement of TRPV1 receptors. This study reinforces the traditional use of B. racemosa in the treatment of painful conditions. However, further studies are reasonable to explore the detailed mechanism(s) of the anti-nociceptive action of BREAF.

Effect of Houpu Mahuangtang on Airway Inflammation and Expression of TRPA1, TRPV1 mRNA and Protein in Asthmatic Mice / 中国实验方剂学杂志

<b>Objective::To investigate the effect of Houpu Mahuangtang on airway inflammation and expressions of gene and proteins of Transient receptor potential ankyrin 1, vanilloid 1 (TRPA1, TRPV1) in asthmatic mice. <b>Method::Sixty female Balb/c mice were randomly divided into six groups: control group, model group, low, medium and high-dose Houpu Mahuangtang groups (7, 14, 28 g·kg^-1) and dexamethasone group (0.002 4 g·kg^-1), with 10 mice in each group. A mouse model of asthma was replicated by sensitizing and challenging with ovalbumin. The changes of enhanced pause (Penh) following acetylcholine chloride (ACh) inhalation were detected. The pathological changes of the lung tissues were observed. The number of eosinophils (EOS) in peripheral blood and the percentage of EOS in bronchoalveolar lavage fluid (BALF) were detected. Interleukin (IL)-4, IL-13, prostaglandin D₂ (PGD₂) and substance P (SP) were detected by enzyme-linked immuno sorbent assay (ELISA). The expressions of TRPA1 and TRPV1 gene and protein in lung tissues were detected by Quantitative Real-time polymerase chain reaction (Real-time PCR) and Western blot. <b>Result::Compared with control group, mice of model group showed significantly increased in Penh following ACh inhalation (<italic>P</italic><0.05, <italic>P</italic><0.01), EOS in blood and the percentage of EOS in BALF (<italic>P</italic><0.01). Histopathological changes in lungs showed inflammatory cell infiltration and bronchial mucosa damage. The levels of IL-4, IL-13, PGD₂ and SP in BALF and the expressions of TRPA1, TRPV1 mRNA and protein in lung tissues significantly increased (<italic>P</italic><0.05, <italic>P</italic><0.01). Compared with model group, treatment groups had significant effects in decreasing Penh, relieving lung injury, reducing EOS count in blood and the percentage of EOS in BALF (<italic>P</italic><0.05, <italic>P</italic><0.01), reducing IL-4, IL-13, PGD₂ and SP levels in BALF (<italic>P</italic><0.05, <italic>P</italic><0.01), as well as down-regulating TRPA1 and TRPV1 mRNA and protein expressions in lung tissues (<italic>P</italic><0.05, <italic>P</italic><0.01). <b>Conclusion::Houpu Mahuangtang could reduce airway inflammation, airway responsiveness. In addition to the reduction of levels of Th2 related cytokines, the mechanism of Houpu Mahuangtang might be related to the regulation of TRPA1, TRPV1 mRNA and protein expressions, and the decrease of associated neurofactor levels.

Effects of transient receptor potential vanillic acid subtype 1 receptor and its modulators on neuropathic pain: research advances / 国际药学研究杂志

Neuropathic pain(NPP)has always been a problem that puzzles the medical community because of its unclear pathogenesis and poor drug treatment. With the development of molecular biology and electrophysiological techniques, studies have shown that the complex pathological mechanism of NPP may be related to the activation of transient receptor potential vanillic acid sub-type 1(TRPV1). TRPV1 receptors are mainly expressed in peripheral sensory neurons, which can detect harmful stimuli in the external and internal environment and transmit information to the central nervous system, thereby playing an important role in peripheral neuropathic pain. TRPV1 modulators exert analgesic effects by blocking the pain transmission function of TRPV1 and have become a potential therapeutic agent in the treatment of NPP. This article reviews TRPV1 receptor-mediated NPP models and the role of TRPV1 modulators in NPP treatment.

Exploration on effect mechanism of Miao medicinal acupuncture therapy in treatment of knee osteoarthritis based on TRPV ion channel / 中国针灸

OBJECTIVE@#To observe the effect of Miao medicinal acupuncture therapy on transient receptor potential vanilloid (TRPV) channel in knee joint synovial tissue of the rabbits with knee osteoarthritis (KOA) model and to explore the mechanism of Miao medicinal acupuncture therapy in treatment of KOA.@*METHODS@#Of 34 New Zealand male rabbits, 6 rabbits were selected randomly as the normal group. KOA model was established in the rest rabbits by injecting a mixture of papain and L-cysteine in right knee joints. The 24 successfully modeled rabbits were randomized into a model group, a Miao medicinal acupuncture therapy group, a dermal needle group and a smearing group, 6 rabbits in each one. In the Miao medicinal acupuncture therapy group, Miao medicinal acupuncture therapy was adopted, in which, the roller type of dermal needle was used on the surface of right knee joint [a rectangle shape formed by "Xuehai" (SP 10), "Liangqiu" (ST 34), "Yanglingquan" (GB 34) and "Yinlingquan" (SP 9)], rolling in a " shape, on which, Miao medicinal solution was smeared in advance. In the dermal needle group, the rolling stimulation was exerted on the right the right knee joint surface with the roller type of dermal needle. In the smearing group, Miao medicinal solution was smeared on the right knee joint surface. The intervention was given once every two days, 3 times weekly and the intervention was exerted consecutively for 4 weeks. Successively, on day 1, 21, 28, 35, 42 and 49 of experiment, paw withdrawal threshold (von Frey threshold) after mechanical stimulation was detected in the rabbits. HE staining was adopted to observe the histomorphological changes of the right knee joint cartilage in the rabbits. ELISA was used to determine the contents of interleukin-1 (IL-1β) and tumor necrosis factor-α (TNF-α) in the right knee synovial fluid. Western blot method and real-time PCR were used to determine the relative expressions of protein and mRNA of TRPV1 and TRPV4 in knee synovial tissue of the rabbits.@*RESULTS@#Compared with the normal group, on day 49 of experiment, von Frey threshold was reduced significantly in the rabbits of the model group (@*CONCLUSION@#Miao medicinal acupuncture therapy plays a role in treatment of KOA probably through inhibiting the expressions of IL-1β and TNF-α of knee synovial fluid and down-regulating the expressions of protein and mRNA of TRPV1 and TRPV4 in knee synovial tissue.

Effect of Rifaximin on Visceral Sensitivity via TRPV1-VGLUT2/3 Pathway in Rats / 胃肠病学

Background: Rifaximin has obvious effect on relieving abdominal pain in patients with irritable bowel syndrome, but the mechanism is not clear. Aims: To investigate the effect and mechanism of rifaximin on visceral sensitivity in rats. Methods: Chronic water avoidance stress (WAS) model was established in rats, and rats were divided into control group, WAS group and rifaximin group. Electromyogram was used to evaluate the visceral sensitivity. Immunological activities of TRPV1 and VGLUT2/3 in L6S1 DRG were determined by immunofluorescence, protein expressions of TRPV1 and VGLUT2/3 in L6S1 spinal cord were determined by Western blotting. Bacterial 16S rDNA sequencing analysis for intestinal flora was performed. Results: WAS could induce visceral hyperalgesia in rats, immunological activities of TRPV1 and VGLUT2/3 in L6S1 DRG were significantly increased, protein expressions of TRPV1 and VGLUT2/3 in L6S1 spinal cord were significantly increased, and imbalance of intestinal flora was induced. Rifaximin could ameliorate visceral hyperalgesia; immunological activities of TRPV1 and VGLUT2/3 in L6S1 DRG and protein expressions of TRPV1 and VGLUT2/3 in L6S1 spinal cord were significantly decreased; imbalance of intestinal flora was ameliorated. TRPV1 antagonist could significantly decrease the immunological activities of VGLUT2/3. Conclusions: Rifaximin can ameliorate the visceral hyperalgesia induced by WAS via intestinal flora and TRPV1-VGLUT2/3 pathway.