This paper aims to investigate the influence of eucalyptol on the biological effects of spleen cold and spleen heat syndromes in rats and its regulation of transient receptor potential vanilloid 1(TRPV1), transient receptor potential melastatin 8(TRPM8), and uncoupling protein 1(UCP1), so as to explore the cold-heat properties of eucalyptol. Rats were randomly divided into groups as follows: blank group, spleen cold syndrome model group, spleen cold syndrome+Atractylodis Rhizoma group, spleen cold syndrome + low-dose eucalyptol group, and spleen cold syndrome+high-dose eucalyptol group, as well as blank group, spleen heat syndrome model group, spleen heat syndrome+Coptidis Rhizoma group, spleen heat syndrome + low-dose eucalyptol group, and spleen heat syndrome + high-dose eucalyptol group. Spleen cold and spleen heat syndromes were induced by disorders of hunger and satiety combined with bitter cold drugs, as well as a high-fat diet combined with liquor. Except for the blank and model groups, the other groups were administered once a day during the modeling process for 14 consecutive days. The general condition and body weight of rats in each group were observed, and the histopathological morphology of the gastric antrum and small intestine was observed by hematoxylin-eosin(HE) staining. The contents of cyclic adenosine monophosphate(cAMP), cyclic guanosine monophosphate(cGMP), triiodothyronine(T3), thyroxine(T4), Na~+-K~+-ATPase, total cholesterol(TC), triglyceride(TG), gastrin(GAS), motilin(MTL), D-xylose, and other related indices were detected in rats. The expression levels of TRPV1, TRPM8, and UCP1 in small intestine tissue of rats with spleen cold syndrome were detected. The results showed that eucalyptol had a certain degree of improvement in the overall state and body weight of rats with spleen cold syndrome. Compared with the spleen cold syndrome model group, high-dose eucalyptol significantly increased the levels of serum cAMP, cAMP/cGMP, TG, and TC in rats with spleen cold syndrome(P<0.05, P<0.01), decreased the content of cGMP, and significantly elevated the levels of gastrointestinal function-related indicators GAS, MTL, and D-xylose(P<0.05, P<0.01). Low-dose eucalyptol significantly increased the level of cAMP/cGMP in the serum and Na~+-K~+-ATPase levels in hepatic tissue(P<0.05, P<0.01), and significantly increased the levels of GAS and D-xylose(P<0.01). Eucalyptol showed similar effects to Atractylodis Rhizoma with a warm nature on rats with spleen cold syndrome. Compared with the spleen heat syndrome model group, the high-dose and low-dose eucalyptol groups showed a trend of increase in gastrointestinal indicators, with no significant changes in other indicators. In addition, high-dose eucalyptol increased the expression of TRPV1 and UCP1 and decreased the expression of TRPM8 in the small intestine tissue of rats with spleen cold syndrome. Eucalyptol could affect the cyclic nucleotide and material energy metabolism levels of rats with spleen cold syndrome and had a certain improvement effect on their gastrointestinal digestion and absorption function, thereby improving spleen cold syndrome. Eucalyptol had no significant improvement effect on rats with spleen heat syndrome, suggesting that eucalyptol may have a warm nature and regulate spleen meridians. It is speculated that eucalyptol may exhibit its medicinal properties by activating the TRPV1 pathway, promoting the expression of UCP1, and inhibiting the TRPM8 channel.
Animals ; Rats ; Spleen/metabolism* ; Male ; TRPV Cation Channels/genetics* ; Rats, Sprague-Dawley ; Eucalyptol/administration & dosage* ; TRPM Cation Channels/genetics* ; Uncoupling Protein 1/genetics* ; Humans ; Drugs, Chinese Herbal/administration & dosage* ; Cold Temperature ; Cyclic GMP/metabolism*

This paper aims to study the effect of p-cymene on mice with deficiency-cold syndrome induced by hydrocortisone and deficiency-heat syndrome induced by dexamethasone and explore the medicinal properties and mechanism of p-cymene with mild and warm nature based on the dominant characteristics of the two-way applicable conditions of mild drugs. A total of 80 KM mice were randomly divided into blank group, deficiency-cold syndrome model group, deficiency-cold syndrome + ginseng group, and deficiency-cold syndrome + low-dose and high-dose p-cymene groups, as well as blank group, deficiency-heat syndrome model group, deficiency-heat syndrome + American ginseng group, and deficiency-heat syndrome + low-dose and high-dose p-cymene groups. Hydrocortisone and dexamethasone solution were intragastrically administered for 14 consecutive days to prepare deficiency-cold syndrome and deficiency-heat syndrome models. Except for the blank group and the model group intragastrically administered with normal saline, the other groups were intragastrically administrated with drugs for 14 days. The levels of cyclic adenosine monophosphate(cAMP), cyclic guanosine monophosphate(cGMP), triiodothyronine(T3), thyroxine(T4), total cholesterol(TC), triglyceride(TG), immunoglobin G(IgG), and immunoglobin M(IgM) in serum, as well as the activity of Na~+-K~+-ATPase in liver tissue were detected. The expression of transient receptor potential melastatin 8(TRPM8), transient receptor potential vanilloid 1(TRPV1), and uncoupling protein 1(UCP1) in brown adipose tissue of deficiency-cold syndrome model after intervention with p-cymene was studied. The results showed that p-cymene could effectively improve the levels of cAMP, cAMP/cGMP, TC, IgM, and IgG in serum and the activity of Na~+-K~+-ATPase in liver tissue of mice with deficiency-cold syndrome and reduce the content of cGMP. The effects on T3, T4, and TG were not statistically significant. At the same time, p-cymene could reduce the levels of cAMP, cAMP/cGMP, and T4 in serum and the activity of Na~+-K~+-ATPase in liver tissue of mice with deficiency-cold syndrome and increase the levels of cGMP, IgM, and IgG, and it had no effect on T3, TC, and TG. In addition, p-cymene could up-regulate the expression of TRPV1 and UCP1 in brown fat of mice with deficiency-cold syndrome and down-regulate the expression of TRPM8. In summary, p-cymene could significantly regulate the syndrome indexes of mice with deficiency-cold syndrome, and some indexes of mice with deficiency-heat syndrome could be improved, but the effects on lipid metabolism and energy metabolism indexes were not obvious, indicating that the regulation effect of p-cymene on deficiency-cold syndrome model was more prominent and that the medicinal properties of p-cymene were mild and warm. The regulation of TRPV1/TRPM8/UCP1 channel expression may be the molecular biological mechanism of p-cymene with mild and warm nature affecting the energy metabolism of the body.
Animals ; Cymenes ; Mice ; Drugs, Chinese Herbal/administration & dosage* ; Male ; Disease Models, Animal ; Humans ; Cyclic AMP/metabolism* ; Monoterpenes/administration & dosage* ; Liver/metabolism* ; Cyclic GMP/metabolism* ; TRPV Cation Channels/genetics* ; Uncoupling Protein 1/genetics*

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.
Rats ; Male ; Animals ; Mice ; Interleukin-4/metabolism* ; Vascular Endothelial Growth Factor A/metabolism* ; Rats, Sprague-Dawley ; Asthma/genetics* ; Lung ; Bronchoalveolar Lavage Fluid ; RNA, Messenger/metabolism* ; Collagen/metabolism* ; Mucins/therapeutic use* ; Ovalbumin ; Disease Models, Animal ; Mice, Inbred BALB C ; TRPV Cation Channels/metabolism* ; Drugs, Chinese Herbal

This study aims to explore the pharmacodynamic effect of baicalin on rat brain edema induced by cerebral ischemia reperfusion injury and discuss the mechanism from the perspective of inhibiting astrocyte swelling, which is expected to serve as a refe-rence for the treatment of cerebral ischemia with Chinese medicine. To be specific, middle cerebral artery occlusion(suture method) was used to induce cerebral ischemia in rats. Rats were randomized into normal group, model group, high-dose baicalin(20 mg·kg~(-1)) group, and low-dose baicalin(10 mg·kg~(-1)) group. The neurobehavior, brain index, brain water content, and cerebral infarction area of rats were measured 6 h and 24 h after cerebral ischemia. Brain slices were stained with hematoxylin and eosin(HE) for the observation of pathological morphology of cerebral cortex after baicalin treatment. Enzyme-linked immunosorbent assay(ELISA) was employed to determine the content of total L-glutathione(GSH) and glutamic acid(Glu) in brain tissue, Western blot to measure the content of glial fibrillary acidic protein(GFAP), aquaporin-4(AQP4), and transient receptor potential vanilloid type 4(TRPV4), and immunohistochemical staining to observe the expression of GFAP. The low-dose baicalin was used for exploring the mechanism. The experimental results showed that the neurobehavioral scores(6 h and 24 h of cerebral ischemia), brain water content, and cerebral infarction area of the model group were increased, and both high-dose and low-dose baicalin can lower the above three indexes. The content of GSH dropped but the content of Glu raised in brain tissue of rats in the model group. Low-dose baicalin can elevate the content of GSH and lower the content of Glu. According to the immunohistochemical staining result, the model group demonstrated the increase in GFAP expression, and swelling and proliferation of astrocytes, and the low-dose baicalin can significantly improve this situation. The results of Western blot showed that the expression of GFAP, TRPV4, and AQP4 in the cerebral cortex of the model group increased, and the low-dose baicalin reduce their expression. The cerebral cortex of rats in the model group was severely damaged, and the low-dose baicalin can significantly alleviate the damage. The above results indicate that baicalin can effectively relieve the brain edema caused by cerebral ischemia reperfusion injury in rats, possibly by suppressing astrocyte swelling and TRPV4 and AQP4.
Animals ; Aquaporin 4/genetics* ; Astrocytes ; Brain Edema/drug therapy* ; Brain Ischemia/metabolism* ; Flavonoids ; Infarction, Middle Cerebral Artery/drug therapy* ; Rats ; Rats, Sprague-Dawley ; Reperfusion ; TRPV Cation Channels/therapeutic use*

To explore the role of vascular endothelial growth factor (VEGF) in diabetic peripheral neuropathic pain in rats.
 Methods: Twenty-four adult male Sprague-Dawley rats aged 8 weeks were randomly divided into 3 groups (n=8 per group). The control group (C group): rats were intraperitoneally injected with sodium citrate solution at 10 mL/kg; the model group (M group): rats were intraperitoneally injected with streptozotocin at 65 mg/kg; the treatment group (T group): rats received intraperitoneal injection of anti-VEGF antibody (10 mg/kg) at the 1st, 3rd, 7th, 10th day after STZ treatment. Meanwhile, rats of C and M group were received with the same volume of sodium citrate solution. Blood glucose was measured before 1 day or at the 1st, 3rd, 7th or 14th day after receiving STZ. Body weight, paw withdrawal mechanical threshold (PWMT) and paw withdrawal thermal latency (PWTL) were measured before 1 day or at the 1st, 3rd, 5th, 7th, 10th or 14th day after receiving STZ. All lumbar spinal cords were dissected to examine the p-protein kinase B (p-Akt) and transient receptor potential vanilloid 1 (TRPV1) expression by Western blot.
 Results: After injection with STZ, the body weight showed significant differences at some time point between the M, T or C group (P<0.01); body weight of rat in the C group were increased gradually. Compared with the C group, the fast blood glucose in the M or the T Group at the same time points were increased significantly (P<0.01). The PWMT and PWTL of the M, T or C group were significant difference among various time points (P<0.01). The PWMT and PWTL in the M or T group were obviously reduced compared with those in the C group (P<0.01). Compared with the M group, the PWMT and PWTL in the T group were increased at the 10th or 14th day (P<0.01 or P<0.05). Compared with the C group, the p-Akt and TRPV1 levels in the M and T group were increased (P<0.01). Compared with the M group, p-Akt and TRPV1 levels in T group were decreased (P<0.01).
 Conclusion: VEGF is able to regulate the expression of TRPV1 through PI3K/Akt pathway, which contributes to diabetic peripheral neuropathic pain in rats. Anti-VEGF treatment may be useful for alleviation of diabetic peripheral neuropathic pain.
Animals ; Antibodies ; pharmacology ; therapeutic use ; Diabetes Mellitus, Experimental ; chemically induced ; Diabetic Neuropathies ; chemically induced ; drug therapy ; Gene Expression Regulation ; drug effects ; Male ; Phosphatidylinositol 3-Kinases ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; TRPV Cation Channels ; genetics ; Vascular Endothelial Growth Factor A ; metabolism

Capsaicin in chili peppers bestows the sensation of spiciness. Since the discovery of its receptor, transient receptor potential vanilloid 1 (TRPV1) ion channel, how capsaicin activates this channel has been under extensive investigation using a variety of experimental techniques including mutagenesis, patch-clamp recording, crystallography, cryo-electron microscopy, computational docking and molecular dynamic simulation. A framework of how capsaicin binds and activates TRPV1 has started to merge: capsaicin binds to a pocket formed by the channel's transmembrane segments, where it takes a "tail-up, head-down" configuration. Binding is mediated by both hydrogen bonds and van der Waals interactions. Upon binding, capsaicin stabilizes the open state of TRPV1 by "pull-and-contact" with the S4-S5 linker. Understanding the ligand-host interaction will greatly facilitate pharmaceutical efforts to develop novel analgesics targeting TRPV1.
Binding Sites ; Capsaicin ; chemistry ; pharmacokinetics ; Humans ; Hydrogen Bonding ; Protein Binding ; TRPV Cation Channels ; chemistry ; genetics ; metabolism

OBJECTIVETo explore the analgesic effect and action mechanism of electroacupuncture (EA) on gastric ulcer rats with liver-depression syndrome.

METHODSThrough open-field experimental method, 45 qualified SPF-grade male SD rats were selected and divided into a blank group, a model group and an EA group according to random number table method, 15 rats in each group. The model of gastric ulcer rats with liver-depression syndrome was established in the model group and the EA group by using chronic unpredictable stimulation combined with acetic acid burning method. Rats in the blank group did not receive intervention. Rats in the model group were treated with fixation and immobilization for 13 days. Rats in the EA group were treated with EA at "Liangqiu" (ST 34) and "Ganshu" (BL 18); EA voltage was 2 V; disperse-dense wave was selected with 4 Hz of disperse wave and 15 Hz of dense wave, and the intensity of EA was according to the slight vibration of local skin and; muscles; the needles were retained for 20 min, once a day for consecutive 6 days; there was an interval of 1 day' and the treatment was given for 2 weeks. The general condition, open-field experimental result and gastric ulcer index were observed; the western blotting method was applied to measure the expression of vanilloid receptor subtype 1 (VR1) in hypothalamus and gastric antral mucosal, and ELISA method was applied to test the expression of 5-hydroxytryptamine (5-HT) and norepinephrine (NE) in hippocampus.

RESULTSAfter model establishment, the general behavior condition in the model group was inferior to that in the blank group, which was obviously improved after EA. The range of motion in the model group was less than that in the blank group (P<0.01) while that in the EA group was higher than that in the model group (P<0.01). The ulcer inhibition rate was. 54.95%, and the ulcer index in the EA group was lower than that in the model group (P<0.01). Compared with; the blank group, the expression of VR1 in hypothalamus and gastric antral mucosal in the model group was increased (P<0.05); compared with the model group, the expression of VR1 in the EA group was reduced (P<0.05). Compared with the blank group, the expression of 5-HT an NE in hippocampus in the model group was significantly reduced (both P<0.01); compared with the model group, the expression of 5-HT and NE in the EA group was increased (both P<0.01).

CONCLUSIONEA at "Liangqiu" (ST 34) and "Ganshu" (BL 18) has certain analgesic effect in gastric ulcer rats with liver-depression syndrome, which is likely to be related with lowering the contents of VR1 in hypothalamus and gastric antral mucosal and increasing the content of 5-HT and NE in hippocampus.

Acupuncture Analgesia ; Acupuncture Points ; Animals ; Electroacupuncture ; Humans ; Liver ; physiopathology ; Male ; Nociceptive Pain ; genetics ; metabolism ; physiopathology ; therapy ; Rats ; Rats, Sprague-Dawley ; Serotonin ; metabolism ; Stomach Ulcer ; genetics ; metabolism ; physiopathology ; therapy ; TRPV Cation Channels ; genetics ; metabolism

The study was aimed to investigate the changes in mechanical pain threshold in the condition of chronic inflammatory pain after transient receptor potential vanilloid 1 (TRPV1) gene was knockout. Hind-paw intraplantar injection of complete freund's adjuvant (CFA, 20 μL) produced peripheral inflammation in wild-type and TRPV1 knockout female mice. The mechanical pain thresholds were measured during the 8 days after injection and pre-injection by using Von-Frey hair. Nine days after injection, mice were killed and the differences of expression of c-Fos and P2X3 receptor in the dorsal root ganglia (DRG) and spinal cord dorsal horn were examined by Western blotting between the two groups. Compared with that in wild-type mice, the mechanical pain threshold was increased significantly in TRPV1 knockout mice (P < 0.05); 3 days after CFA injection, the baseline mechanical pain threshold in the TRPV1 knockout mice group was significantly higher than that in the wild-type mice group (P < 0.05); The result of Western blotting showed that the expression of c-Fos protein both in DRG and spinal cord dorsal horn of TRPV1 knockout mice group was decreased significantly compared with that in wild-type mice group (P < 0.01, P < 0.05), while the expression of P2X3 receptor in DRG of TRPV1 knockout mice group was increased significantly compared with that in wild-type mice group (P < 0.05). Our findings indicate that TRPV1 may influence the peripheral mechanical pain threshold by mediating the expression of c-Fos protein both in DRG and spinal cord dorsal horn and changing the expression of P2X3 receptor in DRG.
Animals ; Female ; Ganglia, Spinal ; metabolism ; Mice ; Mice, Knockout ; Pain ; metabolism ; Pain Threshold ; Proto-Oncogene Proteins c-fos ; metabolism ; Receptors, Purinergic P2X3 ; metabolism ; Spinal Cord ; metabolism ; TRPV Cation Channels ; genetics ; Up-Regulation

Transient receptor potential vanilloid 1 (TRPV1) is a non-selective positive ion channel that is mainly expressed in sensory neurons and a member of transient receptor potential (TRP) family. The receptor could be activated by mechanical irritation, chemical irritation or endogenous ligand to mediate pains and cause injury to body functions. Traditional Chinese medicine believes that the mechanism of pain is that "stagnation leads to pain". Specifically, both of the contracture and tautness caused by cold and the blood stasis could result in blood impassability and pain. Most of traditional Chinese medicines for clearing heat and removing toxicity have the anti-inflammatory effect, while those for warming interior, and promoting blood circulation to remove blood stasis have the effect in smoothening blood vessels. Therefore, either with the anti-inflammatory effect or the effect in smoothening blood vessels, traditional Chinese medicines for clearing heat and removing toxicity, warming interior, and promoting blood circulation have the analgesic effect In this paper, the authors summarize the analgesic effect of the above three traditional Chinese medicines, with TRPV1 as the target.
Analgesics ; administration & dosage ; Animals ; Drugs, Chinese Herbal ; administration & dosage ; Humans ; Pain ; drug therapy ; genetics ; metabolism ; TRPV Cation Channels ; antagonists & inhibitors ; genetics ; metabolism

The transient receptor potential vanilloid 4 (TRPV4) cation channel, a member of the TRP vanilloid subfamily, is expressed in a broad range of tissues where it participates in the generation of Ca2+ signals and/or depolarization of the membrane potential. Regulation of TRPV4 abundance at the cell surface is critical for osmo- and mechanotransduction. Defects in TRPV4 are the cause of several human diseases, including brachyolmia type 3 (MIM:113500) (also known as brachyrachia or spondylometaphyseal dysplasia Kozlowski type [MIM:118452]), and metatropic dysplasia (MIM:156530) (also called metatropic dwarfism or parastremmatic dwarfism [MIM:168400]). These bone dysplasia mutants are characterized by severe dwarfism, kyphoscoliosis, distortion and bowing of the extremities, and contractures of the large joints. These diseases are characterized by a combination of decreased bone density, bowing of the long bones, platyspondyly, and striking irregularities of endochondral ossification with areas of calcific stippling and streaking in radiolucent epiphyses, metaphyses, and apophyses. In this review, we discuss the potential effect of the mutation on the regulation of TRPV4 functions, which are related to human diseases through deviated function. In particular, we emphasize how the constitutive active TRPV4 mutant affects endochondral ossification with a reduced number of hypertrophic chondrocytes and the presence of cartilage islands within the zone of primary mineralization. In addition, we summarize current knowledge about the role of TRPV4 in the pathogenesis of several diseases.
Humans ; *Mutation ; Osteochondrodysplasias/*genetics ; Osteogenesis/genetics ; TRPV Cation Channels/chemistry/*genetics/metabolism