The bronchoconstrictive action of evodiamine, an indoloquinazoline alkaloid isolated from the fruits of Evodia rutaecarpa, on guinea-pig isolated bronchus: possible involvement on vanilloid receptors

Evodiamine, a constituent of Evodiae Fructus (Evodia rutaecarpa Benth., Rutaceae), produced a bronchial contraction that is resistant to atropine and abolished by pretreatment with a mixture of the NK1 and NK2 receptor antagonists. Contractile responses to evodiamine were examined in guinea-pig isolated bronchus and compared with those to capsaicin. Both compounds evoked bronchial contraction in a concentration-dependent manner. Maximal contractions for evodiamine and capsaicin were observed at concentrations of 3 microM and 1 microM, respectively. Capsazepine (10 microM), an established antagonist of vanilloid receptor (capsaicin receptor), competitively inhibited the bronchial contraction evoked by evodiamine, suggesting that evodiamine activated vanilloid receptors. Evodiamine (3 microM) and capsaicin (1 microM) produced complete crossed tachyphylaxis. Both compounds desensitized tissues to subsequent additions of either evodiamine or capsaicin. These results suggest that the evodiamine-induced contractile response of the bronchus could be attributed to the resultant tachykinin release from sensory neurons by binding of evodiamine to vanilloid receptors. Rutaecarpine, which belongs to the same indoloquinazoline-type alkaloid as evodiamine, showed neither bronchoconstrictive, desensitizing effects nor vanilloid antagonistic effects at all the concentrations examined (up to 200 microM).     

The positive inotropic and chronotropic effects of evodiamine and rutaecarpine, indoloquinazoline alkaloids isolated from the fruits of Evodia rutaecarpa, on the guinea-pig isolated right atria: possible involvement of vanilloid receptors

Cardiotonic effects of evodiamine and rutaecarpine, constituents of the fruits of Evodia rutaecarpa Bentham Rutaceae, were evaluated on guinea pig isolated atria. Comparison with capsaicin, a vanilloid receptor agonist, revealed similar positive inotropic and chronotropic activity, as judged from antagonistic effects of the competitive vanilloid receptor (capsaicin receptor) antagonist capsazepine, the non-competitive vanilloid receptor antagonist ruthenium red, the calcitonin gene related peptide antagonist CGRP(8-37), the P2X purinoceptor antagonist PPADS, and various desensitization studies. Evodiamine and rutaecarpine produced transient positive inotropic and chronotropic effects on the guinea-pig isolated atria, followed by a desensitizing effect to additional administration. Dose-response relationships for evodiamine, rutaecarpine and capsaicin were obtained. All the compounds evoked positive inotropic and chronotropic effects in a concentration-dependent manner. Maximal contractions for evodiamine, rutaecarpine and capsaicin were observed at concentrations of 1 microM, 3 microM and 0.3 microM, respectively. The cardiotonic responses evoked by both evodiamine and rutaecarpine were shifted to the right by capsazepine, an established antagonist of vanilloid receptor (capsaicin-receptor). The effects of both evodiamine (1 microM) and rutaecarpine (3 microM) were abolished by pretreatment with a desensitizing dosage of capsaicin (1 microM), developing cross-tachyphylaxis between these compounds. The effects of evodiamine (1 microM), rutaecarpine (3 microM) and capsaicin (0.3 microM) were also significantly reduced by pretreatment with ruthenium red (10 microM) and CGRP (8-37) (10 microM). The effects of evodiamine, rutaecarpine and capsaicin were not affected by pretreatment with PPADS (100 microM), a highly selective P2X purinoceptor antagonist, and the possibility of the involvement of the P2X purinoceptor was excluded. These results suggest that the positive inotropic and chronotropic effects on the guinea-pig isolated right atria induced by both evodiamine and rutaecarpine could be attributed to their interaction with vanilloid receptors and the resultant release of CGRP, a cardiotonic neurotransmitter, from capsaicin-sensitive nerves as with capsaicin.     

Capsaicin-like anti-obese activities of evodiamine from fruits of Evodia rutaecarpa, a vanilloid receptor agonist

Evodiamine, a major alkaloidal principle of Evodia fruits (Evodia rutaecarpa, Rutaceae), showed vanilloid receptor agonistic activities comparable to capsaicin. The Chinese literature refers to Evodia fruits as a "hot nature" herb. In spite of the similarities in the actions of evodiamine and capsaicin in vitro, evodiamine has no perceptible taste, including a peppery hot taste. Therefore, the effectiveness of evodiamine and the extract of Evodia fruits in preventing obesity on male C3H mice, or male SD rats were examined. When evodiamine was supplemented at 0.03% of the diet and fed to mice for 12 days, the perirenal fat weight became significantly lower than in the control group. The epididymal fat mass was also decreased in the evodiamine diet group. When evodiamine was supplemented at 0.02% in the form of ethanol extract of Evodia fruits to the high-fat diet and fed to rats for 21 days, the body weight, the perirenal fat weight, epididymal fat weight, the levels of serum free fatty acid, total lipids in the liver, triglyceride in the liver, and cholesterol level in the liver were significantly reduced as compared with the control diet group. Furthermore, both lipolytic activity in the perirenal fat tissue and specific GDP binding in brown adipose tissue mitochondria, as the biological index of enhanced heat production, were significantly increased in the evodiamine fed rats. Fasting mice subcutaneously administered 1-3 mg/kg evodiamine showed decreased core body temperature by 1-2 degrees C. This hypothermic effect was prevented by the pretreatment of intraperitoneally administered 10 mg/kg capsazepine, a vanilloid receptor antagonist. On the other hand, food-sated mice subcutaneously administered 1-3 mg/kg evodiamine showed unchanged core body temperature and increased tail skin temperature by more than 5 degrees C, suggesting the increased energy expenditure by enhanced heat dissipation. In conclusion, we have demonstrated that a novel non-pungent vanilloid receptor agonist, evodiamine, mimics the characteristic anti-obese effects induced by capsaicin. Evodiamine would induce heat loss and heat production at the same time and dissipate food energy, preventing the accumulation of perivisceral fat and the body weight increase.     

Antinociceptive Activity of Aqueous and Alcohol Extract of Evodia Rutaecarpa

Water, methanol and ethanol extracts of Evodia rutaecarpa were tested for antinociceptive activity, which were correlated with the contents of evodiamine, rutaecarpine and evodine. Determination of contents was achieved by chromatographic techniques. Extracts were evaluated for antinociceptive activities using hot-plate test; acetic acid-induced writhing test and formalin test. All three extracts of Evodia rutaecarpa showed antinociceptive activities but the ethanol extract exhibited better effect. The better antinociceptive activity appeared to be related to higher contents of evodiamine, rutaecarpine and evodine in ethanol extract of Evodia rutaecarpa.     

The validation of Calophyllum brasiliense (“guanandi”) uses in Brazilian traditional medicine as analgesic by in vivo antinociceptive evaluation and its chemical analysis

Calophyllum brasiliense is used as anti-inflammatory and analgesic in Brazilian traditional medicine. Thus, the main purpose of this study is to evaluate the antinociceptive effect of the chloroform fraction of C. brasiliense (CFCB) roots and to investigate its main mechanism of action. The antinociceptive effect of CFCB was evaluated in mice using acetic acid-induced writhing, formalin-induced paw licking, and hot-plate tests and capsaicin- and glutamate-induced nociception. Brasiliensic acid and 1,2-dimethoxyxanthone were isolated and evaluated in writhing test. The amount of 1,2-dimethoxyxanthone was determined in the fraction by UPLC-DAD. CFCB inhibited abdominal constrictions induced by acetic acid up to 97%, with an ID₅₀ of 9.4 mg/kg (i.p.) and 131.8 mg/kg (p.o.). In the formalin test, CFCB impaired paw licking with an ID₅₀ of 26.3 mg/kg for the first phase and 27.5 mg/kg for the second phase (i.p.). The painful response evoked by capsaicin and glutamate was significantly reduced (ID₅₀ 26.7 and 47.9 mg/kg, i.p.). The latency time was increased up to 76% at 60 mg/kg (i.p.) in the hot-plate test. 1,2-Dimethoxyxanthone was almost three times more potent (ID₅₀ 27.6 μmol/kg, i.p.) than brasiliensic acid (72.0 μmol/kg) in acetic acid-induced writhing test. The amount of the xanthone was estimated as 92.5 mg/g in the extract. CFCB inhibited the nociceptive response associated to several agents. TRPV1 channels play an important role in the mechanism of action of the fraction. In addition, 1,2-dimethoxyxanthone largely contributes to the antinociceptive effect of CFCB.

     

The anti-inflammatory and anti-nociceptive effects of ethyl acetate fraction of cynanchi paniculati radix

The anti-inflammatory and anti-nociceptive effects and sedative activities of the ethyl acetate fraction of Cynanchum paniculatum (EACP) were evaluated in mice and rats by acetic acid-induced vascular permeability, arachidonic acid-induced paw edema, cotton pellet-induced granuloma formation, formalin-induced licking time, acetic acid-induced writhing response, and pentobarbital-induced sleeping time. EACP at a dose of 40 mg/kg significantly exhibited anti-inflammatory activities on acetic acid-induced vascular permeability, arachidonic acid-induced paw edema, and the late phase of formalin-induced licking time. Moreover, it showed anti-nociceptive effects on acetic acid-induced writhing responses and significant sedative effects on pentobarbital-induced sleeping time. The results demonstrated that the anti-nociceptive effects are apparently related to the sedative effects of EACP. These results support the use of Cynanchum paniculatum in relieving inflammatory pain.     

Intrathecal GABA, glycine, taurine or beta-alanine elicits dyskinetic movements in mice

Dyskinetic, writhing-like movements, similar to those produced in mice after an intraperitoneal (IP) injection of acetic acid, were elicited by intrathecal (IT) injection of GABA, glycine, taurine or beta-alanine. Baclofen and muscimol failed to produce this behavior. While acetic acid-induced writhing is inhibited by narcotic and nonnarcotic compounds, GABA-induced writhing was found to be insensitive to pretreatment with either morphine or capsaicin. Moreover, acetic acid-induced writhing does not appear to involve GABAergic transmission as IT injections of nipecotic acid did not alter the intensity of response to IP acetic acid while it enhanced the response to IT GABA. Writhing induced by glycine was not inhibited by strychnine at subconvulsive doses, suggesting that it involves an action at strychnine-insensitive receptors. Together these data suggest that while the dyskinetic movements produced by inhibitory amino acids do not appear to reflect an alteration in nociception, they may mimic either the motor response to abdominal pain or spasticity.     

Anti-inflammatory and antinociceptive properties of dantrolene sodium in rats and mice

Our study aimed at examining the possible anti-inflammatory and antinociceptive effects of dantrolene sodium in rats and mice. The anti-inflammatory effect of dantrolene sodium (2.5, 5 and 10 mg kg (-1)) was investigated and compared with diclofenac sodium (5 mg kg (-1)) using the formalin-, histamine-, and carrageenan-induced paw oedema and cotton pellet granuloma tests. Analgesic effects of dantrolene sodium were evaluated and compared with metamizol (200 mg kg (-1)) in acetic acid-induced writhing and formalin-induced paw licking tests. It was found that dantrolene sodium significantly diminished the nociceptive response in mice, showing at the same time considerable anti-inflammatory properties in rats.     

Differential effect of zileuton, a 5-lipoxygenase inhibitor, against nociceptive paradigms in mice and rats

Pain is commonly associated with inflammation. Several mediators including prostaglandins have been implicated in pain and inflammation. However, the recent reports indicated the role of leukotrienes as signaling molecules in pain. The present study was aimed to evaluate the effect of 5-LOX inhibitor, zileuton in nociceptive paradigms including inflammatory pain. Acetic acid-induced writhing, tail flick and hot plate tests to assess pain response were used. The effect on carrageenan-induced mechanical hyperalgesia, and acetic acid-induced vascular permeability was also determined. Zileuton (ED50=31.81 mg/kg p.o.), zafirlukast (ED50=6.19 mg/kg p.o.), montelukast (ED50=7.17 mg/kg p.o.) inhibited acetic acid-induced writhing in mice. Further, zileuton and ZK 158252, leukotriene B4 receptor antagonist did not alter basal response against tail flick and hot plate assays. Acetic acid-induced vascular permeability was significantly inhibited by zileuton. Oral administration of zileuton showed efficacy against carrageenan-induced mechanical hyperalgesia and also reversed histological changes in paw biopsies. These data suggest that zileuton, a 5-LOX inhibitor, exhibited antinociceptive effect in paradigms of inflammatory pain.     

Ruthenium red antagonism of the effect of capsaicin on the motility of the isolated guinea-pig ileum

Ruthenium red (1 microM), an inorganic dye which blocks transmembrane calcium (Ca) fluxes in neural tissues, selectively reduced the capsaicin (1 microM)-induced contraction of the guinea-pig ileum and protected the sensory fibers from capsaicin-induced desensitization. The ruthenium red (0.5-1 microM) antagonism of capsaicin-induced inhibition of responses to mesenteric nerve stimulation or field stimulation in the isolated guinea-pig ileum was an example of a similar antagonism of the effect of capsaicin. In view of the known action of ruthenium red on the depolarization-coupled entry of Ca into synaptosomes and the release of transmitter, our results support the proposal that ruthenium red could antagonize the action of capsaicin on the peripheral terminals of sensory nerves by a similar mechanism, thereby suppressing transmitter release and preventing the establishment of desensitization.     

乳洁安胶囊的镇痛作用

目的观察乳洁安胶囊的镇痛作用。方法采用小鼠扭体法、热板法、蛋清致大鼠肿胀足组织中前列腺素E2(PGE2)含量的测定、观察乳洁安胶囊的镇痛作用。结果乳洁安胶囊中、高剂量组能明显减少醋酸致小鼠扭体反应次数,提高小鼠的痛阈值;随着剂量的增加其镇痛作用有增强的趋势,同时具有明显抑制大鼠足肿组织中PGE2产生的作用。结论乳洁安胶囊具有较好的镇痛作用。     

Antinociceptive profile of (-)-spectaline: a piperidine alkaloid from Cassia leptophylla

The antinociceptive activity of (-)-spectaline (1), a piperidine alkaloid isolated from Cassia leptophylla Vog. (Leguminosae), was investigated. We have also studied the acute oral toxicity of 1 in mice and it did not show any signals of toxicity in doses lower than 400 micromol/kg. The antinociceptive effect of 1 was evaluated on chemical (acetic acid, formalin and capsaicin) and thermal (hot plate and tail flick) pain models in mice, using classical standard drugs. Dipyrone ID (50) = 14.68 micromol/kg (4.8 mg/kg), indomethacin ID (50) = 0.78 micromol/kg (0.28 mg/kg) and (-)-spectaline ID (50) = 48.49 micromol/kg (15.75 mg/kg), all produced a significant inhibition of acetic acid-induced abdominal writhing in mice. (-)-Spectaline was inactive in the hyperalgesic model of formalin and did not show any central analgesic activity (hot plate and tail flick models). In the capsaicin-induced neurogenic pain model, (-)-spectaline presented an important inhibitory effect with an ID (50) = 20.81 microg/paw and dipyrone ID (50) = 19.89 microg/paw. The ensemble of results permitted us to identify 1 as an antinociceptive compound. The mechanism underlying this antinociceptive effect of 1 remains unknown, but the results suggest that such an effect could be related to pathways associated to vanilloid receptor systems.     

偏痛胶囊流浸膏镇痛抗炎作用实验研究

目的:研究偏痛胶囊流浸膏镇痛、抗炎药效学作用.方法:热板法、醋酸扭体法观察偏痛胶囊流浸膏对小鼠的镇痛作用,二甲苯致小鼠耳肿胀、蛋清致大鼠足肿胀的方法研究偏痛胶囊流浸膏的抗炎作用.结果:偏痛胶囊流浸膏能明显减少醋酸致小鼠扭体次数,显著提高小鼠痛阈值(P＜0.01或P＜0.05);明显抑制小鼠耳肿胀,减少耳重差,对大鼠足跖肿胀有显著抑制作用(P＜0.01或P＜0.05).结论:偏痛胶囊流浸膏具有较好的镇痛、抗炎作用.     

月矾栓抗炎镇痛作用研究

目的研究月矾栓的抗炎镇痛作用。方法采用二甲苯致小鼠耳廓肿胀、角叉菜胶致小鼠足跖肿胀模型,观察月矾栓的抗炎作用;采用小鼠醋酸扭体法和热板法,观察月矾栓的镇痛作用。结果月矾栓对醋酸引起的小鼠扭体反应有明显的抑制作用,能明显提高小鼠热板痛阈值;月矾栓能抑制二甲苯引起的小鼠耳廓肿胀和角叉菜胶引起的小鼠足跖肿胀度,其中对小鼠耳肿胀和醋酸扭体的抑制作用呈明显量效关系。结论月矾栓有明显的抗炎、镇痛作用。     

Differential effects of intraplantar capsazepine and ruthenium red on capsaicin-induced desensitization in mice

Intraplantar injection of capsaicin (1.6 microg/paw) into the mouse hindpaw produced an acute paw-licking/biting response. This study was designed (1) to investigate the antinociceptive effects of intraplantar administration of capsazepine, a competitive vanilloid receptor antagonist, and ruthenium red, a noncompetitive antagonist, in the nociceptive licking/biting response induced by intraplantar injection of capsaicin, and (2) to determine whether these compounds were able to prevent capsaicin-induced desensitization in mice. Both capsazepine and ruthenium red produced a dose-dependent reduction in the capsaicin-induced nociceptive response. In licking/biting response to intraplantar capsaicin, ruthenium red was more potent than capsazepine in producing antinociceptive activity as assayed by the capsaicin test. The first injection of capsaicin induced a profound desensitization to the second and third injections of capsaicin at the interval of 15 or 30 min. The capsaicin-induced desensitization was prevented dose-dependently by antinociceptive doses of capsazepine, whereas ruthenium red in doses exhibiting antinociceptive activity was without effect on capsaicin-induced desensitization. The present results suggest that both capsazepine and ruthenium red can produce a local peripheral antinociceptive action, which may be mediated by inhibiting the membrane ion channel activated by capsaicin. In addition, these data suggest that capsazepine may act in the mechanism clearly different from ruthenium red in the capsaicin-induced nociceptive desensitization.     

POSSIBLE MEDIATORS OF THE WRITHING RESPONSE INDUCED BY ACETIC ACID OR PHENYLBENZOQUINONE IN MICE

1. Despite widespread use of the writhing response to phenylbenzoquinone or acetic acid injection in mice as a screen for analgesic activity, possible mediators of this response remain unidentified. 2. In the present experiments both in vivo and in vitro techniques have been used in an attempt to identify these mediators. 3. Acetic acid-induced writhing was unaffected by pretreatment with mepyramine, methysergide, disodium cromoglycate or cimetidine. 4. Phenylbenzoquinone-induced writhing was partially blocked by pretreatment with mepyramine or other antihistamines. 5. Using guinea-pig isolated ileum and rat fundus preparations as in vitro assay systems, no significant differences were detected in histamine, serotonin, or prostaglandin content of peritoneal fluid from writhing and control mice. 6. Acetylcholine levels were at the limit of detection in these samples, and there was no evidence of kinin release. 7. Thus the mediators involved in the writhing response remain undefined.     

前列清颗粒的抗炎、镇痛作用

目的:评价前列清颗粒的抗炎、镇痛作用。方法:设前列清颗粒高、中、低3个剂量组以及吲哚美辛对照组和空白对照组,采用大鼠角叉菜胶足跖肿胀实验和小鼠二甲苯耳郭肿胀试验,观察前列清颗粒的抗炎作用;采用小鼠热板镇痛试验和扭体镇痛试验,观察前列清颗粒的镇痛作用。结果:与空白对照组比较,前列清颗粒3个剂量组能明显减轻大鼠足跖肿胀率(P<0.01);前列清颗粒中、高剂量组对小鼠耳郭肿胀具有显著的抑制作用(P<0.05,P<0.01);3组均能明显延长小鼠痛阈值(P<0.05,P<0.01);显著延长小鼠扭体的潜伏时间,减少扭体次数(P<0.05,P<0.01)。结论:前列清颗粒具有一定的抗炎、镇痛作用。     

Contribution of vanilloid receptors to the overt nociception induced by B2 kinin receptor activation in mice

1. The vanilloid receptor (TRPV1) is viewed as a molecular integrator of several nociceptive stimuli. In the present study, we have investigated the role played by TRPV1 in the nociceptive response induced by the peripheral activation of kinin B(2) receptor in mice. 2. The intraplantar (i.pl.) administration of bradykinin (BK) and the selective B(2) agonist Tyr(8)-BK, or the vanilloid agonists resiniferatoxin and capsaicin, into the mouse paw induced a dose-related overt nociception of short duration. The B(2) receptor antagonist Hoe 140 inhibited BK-induced, but not capsaicin-induced, nociceptive response. On the other hand, the TRPV1 antagonist capsazepine inhibited both capsaicin- and BK-mediated nociception. 3. Repeated injections of BK or capsaicin produced desensitization to their nociceptive response. Capsaicin desensitization greatly reduced BK-induced nociception, but in contrast, the desensitization to BK increased the capsaicin response. 4. Administration of low doses of capsaicin or acidified saline did not produce nociception when administered alone, but caused a pronounced effect when administered in association with a subthreshold dose of BK. Moreover, the degeneration of the subset of primary afferent fibers, sensitive to capsaicin, abolished both capsaicin- and BK-induced nociception. 5. The inhibition of phospholipase C (PLC), protein kinase C or phospholipase A(2) markedly decreased the nociception caused by BK, but not that of capsaicin. BK administration increased leukotriene B(4) levels in the injected paw. Likewise, BK-induced overt nociception was decreased by lipoxygenase (LOX) inhibition. 6. These results demonstrate that BK produces overt nociception mediated by TRPV1 receptor stimulation, via PLC pathway activation and LOX product formation.     

颈舒胶囊抗炎镇痛作用的实验研究

目的:对颈舒胶囊进行抗炎、镇痛等有关药效学方面的实验研究.方法:采用角叉菜胶致炎法、二甲苯致耳廓肿胀法、热板法、扭体法等多种动物模型和方法.结果:颈舒胶囊对二甲苯引起的小鼠耳廓肿胀及角叉菜胶引起的大鼠足跖肿胀有较好的抑制作用,可抑制冰醋酸所致小鼠腹腔毛细血管通透性亢进,对大鼠棉球肉芽肿有较好的抑制作用;对小鼠热板致痛及醋酸诱发的小鼠腹痛有较好的镇痛作用;对大鼠佐剂性关节炎的足跖肿胀有较好的治疗作用.结论:颈舒胶囊有抗炎、镇痛、消肿等作用.     

Antinociceptive profiles of crude extract from roots of Angelica gigas NAKAI in various pain models

To characterize the antinociceptive profiles of Angelica gigas NAKAI (ANG; Korean angelica), methanol extract from the dried roots of ANG was made and mice were administered orally at the various doses (from 0.25 to 3 g/kg). ANG produced the increased latencies of the tail-flick and hot-plate paw-licking responses in a dose-dependent manner. In acetic acid-induced writhing test, ANG dose-dependently decreased writhing numbers. Moreover, the cumulative response time of nociceptive behaviors induced by intraplantar formalin injection was reduced during both the 1st and the 2nd phases in a dose-dependent manner in ANG-treated mice. Furthermore, oral administration of ANG did not cause licking, scratching and biting responses induced by TNF-alpha (100 pg), IFN-gamma (100 pg) or IL-1beta (100 pg) injected intrathecally (i.t.), especially at higher dose (3 g/kg). Additionally, in ANG treated mice, the cumulative nociceptive response time for i.t. administration of substance P or capsaicin was dose-dependently diminished. Finally, nociceptive responses elicited by i.t. injection of glutamate (20 microg), N-methyl-D-aspartic acid (60 ng), alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (13 ng) or kainic acid (12 ng) were decreased by oral administration of ANG. Our results suggest that ANG produces antinociception via acting on the central nervous system and shows antinociceptive profiles in various pain models, especially inflammatory pain.