Research on the mechanisms of ethanol extract of Scutellaria baicalensis Georgi in improving CFA-induced inflammatory pain rats based on 1H NMR metabolomics / 药学学报

The purpose of this study was to investigate the effects of ethanol extract of Scutellaria baicalensis Georgi (SGE) on endogenous metabolites in toes of rats with inflammatory pain induced by complete Freund's adjuvant (CFA) based on 1H NMR metabolomics, which would provide foundation for revealing the effects and mechanisms of SGE in improving inflammatory pain. This animal experiment was approved by the Committee on the Ethics of Animal Experiments of Shanxi University (SXULL2022062). The rats model of inflammatory pain was induced by subcutaneous injection of CFA (0.1 mL), and the effect of low, medium and high doses of SGE (1.5, 3, 6 g·kg-1) on inflammatory pain were explored. The effects of SGE on relieving inflammatory pain was evaluated by mechanical nociceptive thresholds (MNTs) test. Western blot was used to detect the effects of SGE on protein expression of cyclooxygenase-2 (COX-2), nuclear factor kappa-B (NF-κB) and phospho-NF-κB (p-NF-κB). 1H NMR metabolomics was used to analyze the regulatory effects of SGE on endogenous metabolites in the toes of rats with inflammatory pain. The results showed that SGE (6 g·kg-1) could significantly relieve CFA-induced inflammatory pain, and also notably inhibit the protein expression of COX-2, NF-κB and p-NF-κB. SGE could markedly reverse the changes of 8 differential metabolites, such as glycine, glutamine, succinate, phosphorylcholine, etc. The metabolites were involved in eight metabolic pathways, such as glycine, serine and threonine metabolism, alanine, aspartate and glutamate metabolism, glyoxylate and dicarboxylate metabolism, glutathione metabolism, glycerophospholipid metabolism. These results suggest that SGE may relieve inflammatory pain by regulating NF-κB signaling pathway and metabolic abnormality.

Anti-arthritic effect of Distemonanthus benthamianus extracts against rheumatoid arthritis in rats

Objective: To evaluate the anti-arthritic effect of aqueous and methanolic extracts of Distemonanthus benthamianus. Methods: Monoarthritis was induced by an injection of 0.3 mL zymosan A (0.9% NaCl, v/v) in the right posterior knee joints of rats. Then, joint diameter and pain threshold were determined. Polyarthritis was induced by an intracaudal injection of complete Freund’s adjuvant and rats were treated from day 14 post 1st complete Freund’s adjuvant injection until 28 day. The clinical, hematological, biochemical and oxidative stress parameters were evaluated. In addition, histological analysis of the knee joint was perfomed in both tests. Results: The aqueous and methanolic extracts of Distemonanthus benthamianus at a dose of 500 mg/kg ameliorated zymosan A-induced monoarthritis, as evidenced by reduced joint diameter, increased pain threshold, as well as improved joint architecture. In addition, both extracts of Distemonanthus benthamianus markedly increased body weight and pain threshold, while reducing paw edema in polyarthritic rats. They also led to a marked decrease in platelets and white blood cells (P<0.05), as well as a significant increase in red blood cells, hemoglobin and hematocrit (P<0.05). The aqueous and methanolic extracts of Distemonanthus benthamianus significantly reduced alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase activities, while increasing serum protein levels (P<0.05) with no significant variation in creatinine level. Moreover, both extracts increased catalase and glutathione activities (P<0.05), and inhibited malondialdehyde and nitric oxide production (P<0.01 and P<0.001) in the liver and kidneys. Histological analysis of the joints showed that both extracts triggered tissue reparation. Conclusions: Distemonanthus benthamianus could be used as a potential candidate in the treatment of rheumatoid arthritis.

Evolution of mirror-image pain in temporomandibular joint osteoarthritis mouse model

Abstract Mirror-image pain is a kind of pain that occurs on the contralateral side, but its pathogenesis remains unclear. Objective To develop an osteoarthritis mouse model for investigating mirror-image pain through observing nocifensive behaviors, histological changes, and nociceptive activity at days 3, 7, 14, 21, and 28 after the chemical induction of unilateral temporomandibular joint (TMJ) osteoarthritis. Methodology We randomly divided 6-week-old mice into sham and complete Freund adjuvant groups. To induce nocifensive behaviors, we applied 0.04 g of von Frey filament, 10 psi of air puff, and cold acetone on both sides of whisker pads at different days. The histology of TMJ on both sides was observed by hematoxylin/eosin staining and microcomputed tomography scanning. Furthermore, the nociceptive activity was evaluated using the phosphorylated cyclic AMP response element binding protein (pCREB) and a microglia marker at different days in the trigeminal subnucleus caudalis. Results Nocifensive behaviors against mechanical and temperature stimuli on the contralateral side became stronger than the baseline on day 28, in agreement with the elevation of the pCREB and the microglia marker in the trigeminal subnucleus caudalis. Thus, hypernociception on the contralateral side occurred at day 28. Conclusions Clearly, the TMJ model with unilateral osteoarthritis exhibited mirror-image pain. Therefore, this model is useful in investigating the pathogenesis of pain and in developing treatments.

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.

Evaluation of antiarthritic activity of ginkgolic acid against Freund's adjuvant induced arthritic rat model

This study aimed to analyze the antiarthritic activity of ginkgolic acid against the Complete Freund's Adjuvant (CFA)-induced arthritis in rats. Arthritis was induced through an intradermal injection of CFA (0.1 mL) at the right hind footpad of adult Wistar Albino rats. Ginkgolic acid was administered orally at doses of 25 mg/kg and 50 mg/kg, respectively, once daily via gavage for 25 days upon inducing arthritis. Indomethacin was administered orally at a dose of 3 mg/kg twice in a week which served as positive control group. The animals were sacrificed and subjected to biochemical and histopathological analysis upon completion of treatment. Ginkgolic acid was able to reverse the arthritic effect (p < 0.01) induced by CFA in a dose dependent manner. Swelling of paw, thymus and spleen index, serum biomarker levels, and pro-inflammatory cytokines were significantly reduced (p < 0.01) by the acid whereas the antioxidant enzyme activities were remarkably restored. The histopathological findings were in agreement with the biochemical results. The results indicate that the antioxidant and anti-inflammatory properties of ginkgolic acid can be credited to the antiarthritic effects, and it can be promoted as a potential agent for therapeutic use against osteoarthritis

Analgesic Effect of Panlongqi Tablet on Rats with Chronic Inflammatory Pain / 中国实验方剂学杂志

Objective:To observe the analgesic effect of Panlongqi tablet（PLQT） on rats with chronic inflammatory pain， and to explore mechanism of the action preliminarily from the perspective of the nuclear factor kappa-light-chain-enhancer of activated B cells （NF-κB）and mitogen-activated protein kinase（MAPKs） signaling pathways. Method:Rats were induced to establish model of chronic inflammatory pain by complete Freund adjuvant（CFA）， which was divided into normal group， model group， the PLQT 0.16，0.32，0.64 g·kg-1 group， and the ibuprofen 0.05 g·kg-1 group（also positive group）， give the medicine once a day by gavage. Standard Von Frey fiber was used to evaluated the mechanical pain threshold， acetone was used to stimulated rats inflammatory foot to get the cold-induced response score， with the mechanical pain threshold and cold-induced response score to be observed at 1， 2， 3， 4 and 6 h before and after administration on day 1， and at 4 h after administration on day 3-7. The content of PGE2， IL-1， TNF-α in serum， inflammatory foot and 4-5 lumbar spinal cord was detected by enzyme-linked immunosorbent assay（ELISA）. The protein level of MAPKs （p-p38， p-ERK， p-JNK） in lumbar spinal cord 4-5 was detected by Western blot. The expression of NF-κB p65 in the lumbar spinal cord was detected by IFA. Result:Model group had lower mechanical pain threshold and higher cold-induced response score than these in normal group（P<0.01）， while the mechanical pain threshold and cold-induce response score of the model rats were dose-dependent better regulated after administration of PLQT 0.16， 0.32， 0.64 g·kg-1·d-1（P<0.05，P<0.01）， these effect lasted 6 h， of which PLQT groups get the most significant effect on 4 h， however the effect of IBP was similar to that of PLQT medium dose group. In addition， PLQT reduced the abnormal increase of PGE2， IL-1 and TNF-α contents in serum， inflammatory foot and spinal cord of rats in model group， decreased the protein phosphorylation levels of ERK and JNK in spinal cord， and decreased the protein expression of NF-κB p65， that was significant in the PLQT high-dose group（P<0.01）. Conclusion:PLQT had significant analgesic effect on chronic inflammatory pain model rats， which may be related to the inhibition of NF-κB and MAPKs signaling pathways in spinal cord.

Effect of Xiao Chaihutang on NF-κB Signaling Pathway in Synovial Tissue of CFA Rats / 中国实验方剂学杂志

Objective:To observe the expression of tumor necrosis factor receptor-associated death domain (TARDD), nuclear transcription factor-κB inhibiting protein α(IκBα)IκB kinase-α (IKKα) and nuclear transcription factor (NF)-κB p65 protein in the NF-κB signaling pathway of synovial tissues of complete Freund's adjuvant (CFA) rats after treatment with Xiao Chaihutang (XCHT). Method:In animal experiments, SPF health adult female Wistar rats were used to prepare the CFA animal model of rats with rheumatoid arthritis with Freund's complete adjuvant and cattle Ⅱ collagen type. According to the random number table, the rats were randomly divided into the normal group, the model group, the low-dose XCHT group, the medium-dose XCHT group, the high-dose XCHT group, and the Tripterygium glucosides group. The drugs were given at 7 d after the model was built. Both normal group and model group were given water for injection,and low-dose XCHT group(5.94 g·kg-1),medium-dose XCHT group(11.88 g·kg-1),high-dose XCHT group(23.76 g·kg-1),Tripterygium glucosides group(0.006 3 g·kg-1) were given corresponding drugs by gavage for three times a day, 2 mL/time. The histopathology of rat ankle joint was observed, and the protein expressions of TARDD,IKKα,IκBα,NF-κB p65 in the NF-κB signaling pathway in synovial tissue of CFA rats were detected by Western blot. Result:With the increase of the dosage of XCHT, the histopathological score of the right posterior ankle joint of the experimental rats was increased. And in the protein expressions of TARDD,IKKα,IκBα,NF-κB p65 in NF-κB signaling pathway in Synovial Tissue of CFA rats, compared with the model group, the statistical results of the low-dose XCHT group showed decreased protein expressions (PPPα, IκB α, NF-κB p65 in the NF-κB signaling pathway were significantly increased (PPα, IκBα, NF-κB p65 key protein expressions in the NF-κB signaling pathway and protein expressions in low-dose XCHT group were obviously lower (PPConclusion:This study shows that as the dose of Xiao Chaihutang increases, it could effectively improve synovitis, and suppress the expressions of key proteins in the inflammatory signaling pathway of NF-κB, thereby preventing inflammation and suppressing bone erosion.

Immunosuppressant effect of Boswellia serrata extract on CFA induced arthritis in rats

Background: Rheumatoid arthritis (RA) is an immune-mediated arthropathy, so for the treatment disease modifying antirheumatoid drugs are required. In this study we are evaluating the immunomodulatory property of Boswellia serrata extract (BSE) as an alternative medicine.Methods: Complete Freund’s adjuvant (CFA), 0.1ml was injected intradermally in the footpad of left hind paw in 36 Wistar rats to induce RA. Animals were divided into 6 groups. BSE in the doses of 45mg/kg, 90mg/kg and 180mg/kg was administered and cyclophosphamide as standard drug. Various parameters as body weight, paw thickness, ankle diameter, paw volume, arthritis index, TNF- ? and histopathological changes were analyzed.Results: Marked reduction in paw thickness, ankle diameter, paw volume, arthritis index and an improved body weight was found in high dose BSE (180mg/kg) group but the effect was lesser than standard drug Cyclophosphamide.Conclusions: BSE has significant potential as an alternative medicine for treatment of autoimmune diseases like rheumatoid arthritis.

Paeoniflorin-6′-O-benzene sulfonate influences expression of CXCL12/CXCR4 in spleen of adjuvant-induced arthritis / 中国药理学通报

Aim To observe the expression of CXCL12 and its receptor CXCR4 in spleen of rats with adjuvant-induced arthritis (AA) and the effects of paeoniflorin-6′-O-benzene sulfonate (CP-25). Methods AA rats were induced using complete Freund's adjuvant and were randomly divided into normal group,AA group, CP-25 group (50 mg·kg-1) and methotrexate group (MTX,0.5 mg·kg-1),which were treated from d 14 to d 28. HE staining was used to assess the pathologi-cal changes of spleen. The expression of CXCL12 and CXCR4 in spleen was detected by ELISA,immunohis-tochemitry and Western blot. Results CP-25 (50 mg ·kg-1)alleviated the pathological changes of spleen and decreased the expression of CXCL12 and CXCR4 in spleen of AA rats. The pathological changes of spleen and the expression of CXCL12/CXCR4 in spleen revealed a positive correlation. Conclusions Increased expression of CXCL12 and its receptor CX-CR4 may be associated with the pathological changes of spleen in AA rats,which plays an important role in the pathogenesis of RA. CP-25 has obvious therapeutic effect on AA rats and its mechanism may be related to the inhibition of the expression of CXCL12 and CXCR4 in the spleen.

Role and mechanism of Epac protein in regulation of inflammatory pain in paraventricular nucleus of hypothalamus / 中国药理学通报

Aim To investigate the role and mecha-nism of exchange protein directly activated by cAMP (Epac) protein in the paraventricular nucleus(PVN) of the hypothalamus in the development of inflammatory pain in rats. Methods Adult SD male rats were cho-sen to establish the model of inflammatory pain through subcutaneous injection of complete Freund's adjuvant(CFA) on the center of left hind foot. Western blot was used to detect the changes of the expression of Ep-ac protein. Thermal withdrawal latency(TWL) was ob-served after the PVN injecting 8p-CPT-2′-O-Me-cAMP (8p-CPT),the agonist of Epac. Then activated down-stream MEK1/2 protein of Epac in PVN was detected using Western blot when the potency was the strongest.Results ① Compared with normal saline(control group),TWL decreased significantly on d 1, d 3, d 5, d 7,d 9 on the ipsilateral foot of CFA group rats(P<0.01),whereas it returned to normal level in d 13;the paw mechanical withdrawal threshold(PMWT) de-creased significantly on d 6,d 8,d 10,d 12 and d 14 (P<0.05);②Compared with the control,the Epac1 protein in CFA group rats began to decrease from d 3, and significantly decreased on d 3 and d 9(P<0.05), however the expression of Epac2 had no significant change, meanwhile p-MEK1/2 protein decreased sig-nificantly on d 3(P<0.05);③Compared with micro-injection of saline into the PVN(Saline group), the heat hyperalgesia of 20 min and 1h decreased signifi-cantly and TWL increased significantly after PVN ad-ministration of 8p-CPT(8p-CPT group)(P <0.05);paraventricular nucleus p-MEK1/2 protein expression increased significantly in 30 min(P <0.05) and re-covered to normal level 2 h after administration. Con-clusion The Epac1-MEK1/2 signaling pathway in the paraventricular nucleus of the hypothalamus may be in-volved in the development of chronic inflammatory pain induced by CFA.

Heliopsis longipes: anti-arthritic activity evaluated in a Freund's adjuvant-induced model in rodents

ABSTRACT This study assesses the anti-arthritic effect of the affinin-enriched (spilanthol, main alkamide) hexane extract from the roots of Heliopsis longipes (A. Gray) S.F. Blake, Asteraceae, on a Freund adjuvant-induced arthritis model in rodents. The extract was orally administered at a dose of 2, 6.6, or 20 mg/kg; a significant edema-inhibitory activity in the acute and chronic phases was observed with a dose of 2 and 20 mg/kg, respectively. The extract showed higher anti-inflammatory and anti-arthritic effects than the reference drug phenylbutazone (80 mg/kg). Moreover, the extract prevented the occurrence of secondary lesions associated to this pharmacological model.

Effects of Different Concentrations of Capsaicine on the Chronic Knee Arthritis Pain Model in Mice / 现代生物医学进展

Objective:To observe the therapeutic effect ofcapsaicin at different concentrations on chronic knee arthritis pain model in mice.Methods:Choosing 50 healthy adult male Kunming mice builded chronic knee arthritis pain model by injecting 0.01 mL CFA (Complete Freund's Adjuvant,CFA) into left joint cavity.The model would be succeed in building after 3 weeks.The successful model mice were divided into five groups randomly (n=10):The first experimental group (saline group),the second experimental group (capsaicin excipient group),the third experimental group (0.5 ％ of capsaicin),the fourth experimental group (3 ％ of capsaicin) and the fifth experimental group (8 ％ of capsaicin).All of the mice would be observed the time of withdrawal latencies from the thermal heated surface after administration of one,four and seven hours,and thermal withdrawal time within 60 days after the injection.Results:①The physiological saline group compared with excipient group,the thermal withdrawal time had no statistically significant difference (P＞0.05)after administration of one,four and seven hours,and thermal withdrawal time within 60 days.②The acute pain duration of the third group would disappear after capsaicin injection 7 hours,four hours for the fourth group,and one hour for the fifth group.③The duration of analgesia of the third group,lasted for 18.9± 1.1 days;The analgesia time of the fourth group lasted for 33.7± 1.0 days;The analgesia time of the fifth group lasted for 58.2± 1.2 days.Conclusions:Capsaicin has analgesic effects on chronic knee pain model in mice induced by CFA,and the days of analgesia increases with the concentration of capsaicin.

Evaluación de la actividad de Baccharis latifolia en modelos de artritis experimental / Evaluation of Baccharis latifolia activity in experimental arthritis models

La artritis reumatoide (AR) es una enfermedad crónica de naturaleza autoinmune e inflamatoria que conduce a la formación de pannus seguido de la destrucción de las articulaciones, se caracteriza por hiperplasia sinovial, inflamación y angiogénesis. La especie vegetal Baccharis latifolia es utilizada tradicionalmente en muchas regiones de nuestro país para tratar el dolor, la inflamación y la artritis. En el presente estudio se evaluó la actividad antiartrítica del extracto etanólico de B. latifolia en modelos murinos de artritis reumatoide inducida por adyuvante, la estimación del edema/espesor de la pata inflamada, parámetros hematológicos (hemoglobina, velocidad de sedimentación globular, recuento de eritrocitos, recuento total de leucocitos) y observación radiológica fueron evaluados. La administración oral del extracto etanólico de B. latifolia (600 mg/kg de p.c.) inhibió significativamente (p<0.001) el incremento del edema/espesor de la pata en el modelo de artritis subcrónica. Del mismo modo, B. latifolia (500 mg/kg de p.c.) inhibió significativamente el incremento del edema/espesor de la pata en el modelo de artritis crónica (p<0.05, p<0.01), los pesos de los animales se mantuvieron sin variación durante el tratamiento. Por otro lado, los parámetros hematológicos señalan que los niveles de hemoglobina disminuyen en ratones artríticos y que esta disminución es revertida tras la administración de los extractos de B. latifolia, este mismo perfil de recuperación es observado tras el recuento de glóbulos rojos. Adicionalmente, la velocidad de sedimentación globular (VSG) incrementada en ratones artríticos, es revertida tras la administración de B. latifolia. El análisis radiológico evidenció el efecto del extracto etanólico de B. latifolia en el retraso de la destrucción ósea. Los resultados sugieren que el extracto etanólico de B. latifolia tiene una potencial actividad antiartrítica.

Rheumatoid arthritis (RA) is a chronic autoimmune and inflammatory disease leading to pannus formation followed by the destruction of the joints; it is characterized by synovial hyperplasia, inflammation and angiogenesis. The plant species Baccharis latifolia is traditionally used in many regions of our country to treat pain, inflammation and arthritis. In the present study the anti-arthritic activity of ethanol extract of B. latifolia was evaluated in murine experimental model of rheumatoid arthritis induced by adjuvant, edema estimation / thickness of the inflamed foot, hematological parameters (hemoglobin, erythrocyte sedimentation rate, erythrocyte count was assessed, total white blood cell) and radiological observation were evaluated. The oral administration of the ethanolic extract of B. latifolia (600 mg / kg p.c.) significantly inhibited (p<0,001) increased edema / paw thickness in the subchronic model of arthritis. Similarly, B. latifolia (500 mg / kg bw) significantly inhibited the increase of edema / paw thickness in the model of chronic arthritis (p <0.05, p <0.01), the weights of the animals were kept without variation during treatment. Moreover hematological parameters indicate that hemoglobin levels decrease in arthritic mice and that this decline is reversed after administration of the extracts of B. latifolia, this same profile is observed recovery after red blood cell count. Additionally, erythrocyte sedimentation rate (ESR) increased in arthritic mice is reversed after administration of B. latifolia. The radiological analysis showed the effect of ethanol extract of B. latifolia in delaying bone destruction. The results suggest that the ethanolic extract of B. latifolia has potential antiarthritic activity.

Potential of Vigna radiata (L.) sprouts in the management of inflammation and arthritis in rats: Possible biochemical alterations.

Vigna radiata (Fabaceae) is an important pulse crop widespread throughout the tropics and warm temperature regions. In this study, we evaluated the in vitro anti-inflammatory and in vivo antiarthritic activity of Vigna radiata sprouts in rats. The in vitro anti-inflammatory activity was determined by membrane stabilization and protein denaturation method. Whereas, the antiarthritic activity of the ethanolic extract of the sprouts was evaluated by complete Freund’s adjuvant model with diclofenac sodium as the standard drug. Body weights, paw volume, biochemical parameters such as lipid peroxidation, total reduced glutathione, myeloperoxidase and lysosomal enzymes like cathepsin-D, N-acetyl β-D-glucosamindase and β-D-glucuronidase were estimated. Treatment with ethanolic extract of V. radiata exhibited significant membrane stabilization activity and protein denaturation activity, and significantly attenuated the biochemical changes induced by administration of complete Freund’s adjuvant. The findings of the present study suggest the possible role of Vigna radiata in the therapeutics of arthritis.

Effects of dehydrocorydaline on complete Freund's adjuvant-induced mechanical hyperalgesia in mice / 中华行为医学与脑科学杂志

Objective To investigate the effects of dehydrocorydaline(DHC) on complete Freund's adjuvant (CFA)-induced mechanical hyperalgesia in mice.Methods 40 mice were divided randomly into 4 groups (CFA test:experiment group =8,control group =8;locomotor activity and organ coefficient test:experiment group=12,control group =12).Subcutaneously injected CFA in the plantar of mice to establish pain model.The experimental group mice were injected with 10 mg/kg DHC while the control group mice received 10％ DMSO.The paw withdrawal mechanical threshold(PWMT) of mice was tested before and after administration of DHC.The effects of DHC on spontaneous activity and organ coefficient were observed in mice.Results The basic values of PWMT showed there were no statistically significant differences between experimental group and control group ((10.27± 1.34)g vs (10.28 ±0.35)g,P＞0.05).Compared with the control group,the values of PWMT in experimental group at 0.5 h,1 h,2 h,3 h after administration of DHC were significantly increased(0.5 h:(8.18±0.87) g vs (4.85±0.65) g;1 h:(7.85±0.59) g vs (4.84±0.54) g;2 h:(7.36±0.49) g vs (4.90±0.59) g;3 h:(6.66±0.45) g vs (5.00±0.36) g;all P＜0.01).Compared with the control group,no significant effect was observed on the number mice crossed grids and lifted forelimb and stood in 2 min in the experimental group (P＞ 0.05).And no significant effect was observed on the liver,kidney,spleen,heart,lung and brain organ coefficient in the experiment group (P＞0.05).Conclusion DHC can alleviate CFA-induced mechanical hyperalgesia in mice.

Anti-inflammatory effects of botulinum toxin type A in a rat model of arthritis / 中华物理医学与康复杂志

Objective To verify the anti-inflammatory effects of intra-articular injection of botulinum toxin type A (BoNT/A) on adjuvant-induced arthritis using a rat model.Methods A murine model of chronic ankle arthritis was established in 90 Wistar rats by injection of 0.1 ml of complete Freund adjuvant (CFA) into the pads of their left paws.They were then randomly divided into a BoNT group (n =30) which received an intra-articular injection of 0.1 ml (20 IU) of BoNT/A,an NS group (n=30) which received intra-articular injection of0.1 ml of normal saline solution and a sham group (n =30) which were punctured without any injection.In addition,30 normal rats formed a control group.Infrared thermal imaging was performed and an index of arthritis was evaluated every three days.The infrared thermal imaging revealed the expression of interleukin-1β (IL-1β) through hematoxy-eosin (HE) staining.Results The arthritis index began to increase 3 days after the injection of CFA and it had increased significantly after 10 days,reaching a peak value of 18,24 days after the injection.The infrared thermal imaging showed that the temperature in the right paw increased greatly after the injection.Following the development of arthritis,the temperature declined gradually,arriving at a steady temperature of between 37.5 and 38.0 ℃ in both ankles 20 days after the injection.The average temperature in both paws of the BoNT group had decreased significantly more by 7 and 14 days after the injection than in the NS and sham groups.The expression of IL-1β in the synovium of the ankle joint also had decreased significantly more in the BoNT group after 7 and 14 days.HE scoring showed an obvious histopathologic change in the hypertrophic synovium,inflamnatory cell infiltration,cartilage destruction and exposure of subchondral bone after 7 and 14 days compared with right after the injection in all groups except the control group.Moreover,the average HE scores of the BoNT group rats after 7 and 14 days were significantly lower than those seen in the NS and sham groups at the same time points.Conclusion Intra-articular injection of botulinum toxin type A has an anti-inflammatory effect on arthritis induced by complete Freund adjuvant,at least in rats.

Periphery analgesic effect of myricetin on a rat model of inflammatory pain / 中国药理学通报

Aim To investigate the periphery analge-sic effect of myricetin on a rat model of inflammatory pain and the mechanism. Methods Rat models of in-flammatory pain were induced by complete Freund ’ s adjuvant ( CFA) injection in left hindlimb plantar cen-ter. The thermal withdrawal latency ( TWL) was meas-ured before and after CFA or myricetin treatment. Elec-trophysiological method was used to identify the effect of myricetin on the action potential frequency and the voltage dependent potassium channel currents in small DRG neurons. Results Rats with CFA injected showed thermal hyperalgesia ( P <0. 05 ) and TWL in-creased significantly after myricetin intraperitoneally in-jected ( P <0. 05 ) . Current clamp recording showed the action potential frequency of small DRG neurons in rats was inhibited by myricetin ( P<0. 01 ) and voltage calmap recording showed the inhibitory effect of myr-icetin was enhanced by calcium depended potassium channel currents ( P<0. 05 ) . Conclusion Myricetin exerts periphery analgesic effect by enhancing calcium depended potassium channel currents and inhibiting excitability of small neurons of dorsal root ganglion.

Contributions of K ATP within the paraventricular nucleus in the modulation of inflammatory pain in rats / 中国药理学通报

Aim To explore the role of KATP in the pa-raventricular nucleus in inflammatory pain. MethodsMale Sprague-Dawley rats,250~280 g, were randomly assigned into 5 groups ( each, n =6 ): Normal group, Saline group ( for control, subcutaneous injection of 100 μl of saline into the plantar surface of the left hindpaw) , CFA group ( subcutaneous injection of 100μl of complete freund's adjuvant into the plantar sur-face of the left hindpaw) , Vehicle group ( treated with dimethylsulfoxide), KATP selective agonist group(trea-ted with diaoxide) . Rats in each group were tested for TWL with radiant heat apparatus. Immunofluorescent technique was used to label KATP in PVN and c-Fos in lumber spinal cord. Three days after injected with CFA, a selective KATP agonist, diaoxide, was injected into one side of PVN to test its effect on inflammatory pain and c-Fos expression in lumber spinal cord. Re-sults ① Compared with pre-operation and saline group, rats showed significantly lower TWL on day 1, 3, 7 after injection of CFA;the numbers of KATP posi-tive cells were significantly lower; the numbers of c-Fos positive cells were significantly higher. ② Com-pared with those of vehicle group, TWL and the num-ber of c-Fos in lumber spinal cord were both signifi-cantly lower after injection of diaoxide into one side of PVN. Conclusion KATP in PVN is related to inflam-matory pain.

Effect of Radix Rehmanniae Praeparata on footpad inflammation induced by complete Freund's adjuvant in Wistar rats / 中国生化药物杂志

Purpose To investigate the anti-inflammatory effect of Radix Rehmanniae Praeparata(RRP)on the footpad inflammation induced by complete Freund's adjuvant(CFA)in rats.Methods CFA 100 μL were injected subcutaneously to the Wistar rats at the pad of right hindfoots.19 days later,the rats were daily siven RRP water extract(0.625,1.250,2.500 g/kg·bw)or dexamethasone(0.5mg/ks·bw)intragastrically.The changes of body weight and foot volume were measured.The indexes of organ and blood were determined at the 29th day,the foot pad was removed,and routine paraffin section was performed.Results The model rats kept foot swelling and lymphocyte infiltrating,and the platelet number decreased.The other indexes were statistically insignificant when compared to the controls.RRP did not display any anti-inflammatory effect on the swollon foots,but thoracic gland and spleen indexes were rescued,and platelet number and creatinine content were increased by RRP administration in a dose-dependent manner.The anti-inflammation of dexamethasone was conspicuous,but the side effects were also significant.Conclusion RRP may be plays an adjunctive action in herbal recipes to treat rheumatoid arthritis.

A Blockade of the Central MAPK Pathway Attenuates Referred Pain in Rats with Complete Freund's Adjuvant-Induced Inflammation of the Temporomandibular Joint

We investigated the role of the central MAPK pathways in extra-territorial (referred) pain resulting from inflammation of the temporomandibular joint (TMJ). Experiments were carried out on male Sprague-Dawley rats weighing 220-280 g. Under anesthesia, these animals were injected with 50 microL of complete Freund's adjuvant (CFA) into the TMJ using a Hamilton syringe. In the control group, saline was injected into the TMJ. To identify the extent of inflammation of the TMJ, Evans blue dye (0.1%, 5 mg/kg) was injected intravenously at 1, 3, 6, 9, 12 and 15 days after CFA injection. The concentration of Evans blue dye in the extracted TMJ tissue was found to be significantly higher in the CFA-treated animals than in the saline-treated group. Air-puff thresholds in the vibrissa pad area were evaluated 3 days before and at 3, 6, 9, 12, 15 and 18 days after CFA injection into the TMJ. Referred mechanical allodynia was established at 3 days, remained until 12 days, and recovered to preoperative levels at 18 days after CFA injection. This referred mechanical allodynia was observed in contralateral side area. To investigate the role of central MAPK pathways, MAPK inhibitors (10 microg) were administrated intracisternally 9 days after CFA injection. SB203580, a p38 MAPK inhibitor, significantly attenuated referred mechanical allodynia, as compared with the vehicle group. PD98059, a MEK inhibitor, also reduced CFA-induced referred mechanical allodynia. These results suggest that TMJ inflammation produces extra-territorial mechanical allodynia, and that this is mediated by central MAPK pathways.