Chemical Composition and Pharmacological Activity of a Propolis Extract from Ecuador

Aims: Propolis is a resinous substance accumulated by bees from resinous plants material, produced by different botanical processes. It has been used since ancient times for its therapeutic benefits. The chemical composition of propolis is mostly influenced by the geographic zone and also by botanic sources that the honey bee has used. In this sense, the aim of this study was to analyse the phytochemical profile and pharmacological activity of a sample of propolis from Ecuador. Methodology: Chemical composition was analyzed by using gas chromatography coupled to mass spectrometry (GC/MS). The anti-inflammatory activity was determined by ear edema induced by 12-O-tetradecanoylphorbol-13 acetate and antinociceptive activity was analyzed by using writhing test induced by acetic acid. Results: The chemical composition showed the presence of sugars, fatty acids, flavonoids and triterpenes in the sample. The analysis of the relative abundance of the detected signals suggested that triterpenes represent 25.38% of the total components of the mixture and 9,19-cyclo-9-beta-lanostane-24-on-3-beta-iloxyl (cycloartenol), the majority compound. Propolis induced a maximun inhibition (77.2 %) in TPA model at a dose of 3 mg/ear, reducing dermal edema, cellular infiltration and ear thickness induced by TPA. Also, it produced a dose-related inhibition of acetic acid-induced writhing response with a maximal antinociceptive effect (49.5%) at dose of 500 mg/kg po. Conclusion: The chemical analysis showed a predominant triterpene profile, being cycloartenol the majority compound in the sample and its anti-inflammatory and antinociceptive activities were confirmed by in vivo models.

Quantitative Electrophysiological Evaluation of the Analgesic Efficacy of Two Lappaconitine Derivatives: A Window into Antinociceptive Drug Mechanisms / 神经科学通报·英文版

Quantitative evaluation of analgesic efficacy improves understanding of the antinociceptive mechanisms of new analgesics and provides important guidance for their development. Lappaconitine (LA), a potent analgesic drug extracted from the root of natural Aconitum species, has been clinically used for years because of its effective analgesic and non-addictive properties. However, being limited to ethological experiments, previous studies have mainly investigated the analgesic effect of LA at the behavioral level, and the associated antinociceptive mechanisms are still unclear. In this study, electrocorticogram (ECoG) technology was used to investigate the analgesic effects of two homologous derivatives of LA, Lappaconitine hydrobromide (LAH) and Lappaconitine trifluoroacetate (LAF), on Sprague-Dawley rats subjected to nociceptive laser stimuli, and to further explore their antinociceptive mechanisms. We found that both LAH and LAF were effective in reducing pain, as manifested in the remarkable reduction of nocifensive behaviors and laser-evoked potentials (LEPs) amplitudes (N2 and P2 waves, and gamma-band oscillations), and significantly prolonged latencies of the LEP-N2/P2. These changes in LEPs reflect the similar antinociceptive mechanism of LAF and LAH, i.e., inhibition of the fast signaling pathways. In addition, there were no changes in the auditory-evoked potential (AEP-N1 component) before and after LAF or LAH treatment, suggesting that neither drug had a central anesthetic effect. Importantly, compared with LAH, LAF was superior in its effects on the magnitudes of gamma-band oscillations and the resting-state spectra, which may be associated with their differences in the octanol/water partition coefficient, degree of dissociation, toxicity, and glycine receptor regulation. Altogether, jointly applying nociceptive laser stimuli and ECoG recordings in rats, we provide solid neural evidence for the analgesic efficacy and antinociceptive mechanisms of derivatives of LA.

Quantitative Electrophysiological Evaluation of the Analgesic Efficacy of Two Lappaconitine Derivatives: A Window into Antinociceptive Drug Mechanisms / 神经科学通报·英文版

Quantitative evaluation of analgesic efficacy improves understanding of the antinociceptive mechanisms of new analgesics and provides important guidance for their development. Lappaconitine (LA), a potent analgesic drug extracted from the root of natural Aconitum species, has been clinically used for years because of its effective analgesic and non-addictive properties. However, being limited to ethological experiments, previous studies have mainly investigated the analgesic effect of LA at the behavioral level, and the associated antinociceptive mechanisms are still unclear. In this study, electrocorticogram (ECoG) technology was used to investigate the analgesic effects of two homologous derivatives of LA, Lappaconitine hydrobromide (LAH) and Lappaconitine trifluoroacetate (LAF), on Sprague-Dawley rats subjected to nociceptive laser stimuli, and to further explore their antinociceptive mechanisms. We found that both LAH and LAF were effective in reducing pain, as manifested in the remarkable reduction of nocifensive behaviors and laser-evoked potentials (LEPs) amplitudes (N2 and P2 waves, and gamma-band oscillations), and significantly prolonged latencies of the LEP-N2/P2. These changes in LEPs reflect the similar antinociceptive mechanism of LAF and LAH, i.e., inhibition of the fast signaling pathways. In addition, there were no changes in the auditory-evoked potential (AEP-N1 component) before and after LAF or LAH treatment, suggesting that neither drug had a central anesthetic effect. Importantly, compared with LAH, LAF was superior in its effects on the magnitudes of gamma-band oscillations and the resting-state spectra, which may be associated with their differences in the octanol/water partition coefficient, degree of dissociation, toxicity, and glycine receptor regulation. Altogether, jointly applying nociceptive laser stimuli and ECoG recordings in rats, we provide solid neural evidence for the analgesic efficacy and antinociceptive mechanisms of derivatives of LA.

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.

Microwave-assisted synthesis and pharmacological screening of some triazolothiadiazole derivatives

In this study, twenty-two new [1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles (5a-n, 6a-h) were synthesized under microwave irradiation (MWI). The chemical structures of the compounds were elucidated by their IR, 1H-NMR, LC-MS, and elemental analysis. The compounds were tested for antinociceptive activity by using the tail clip, tail flick, hot plate, and writhing methods in mice. The varying levels of antinociceptive activity of the compounds were compared with those of aspirin. Among these compounds, compound 5g and 5j were found to be significantly more active than the other compounds and the standard in the tests. Also, inhibitory effects of the test compounds on COX-1 and COX-2 activities were investigated. DuP-697 for COX-2 and SC-560 for COX-1 were used as reference standards.

Research progress on chemical constituents of Rhododendron molle and its pharmacological activities / 中草药

Rhododendron molle is a plant of the Ericaceae family. It is commonly used in the treatment of rheumatoid arthritis. Modern pharmacological studies have confirmed that its diterpenoids are main medicinal ingredients with anti-inflammatory, analgesic and other pharmacological effects. Through reviewing domestic and foreign literatures, this review aims to provide a comprehensive overview of the research progress in the chemical constituents and pharmacological effects of R. molle, and briefly prospects research of the titled plant.

Antinociceptive grayanane-derived diterpenoids from flowers of

Twelve new grayanoids (-) along with five known compounds were isolated from flowers of . Their structures were fully characterized using a combination of spectroscopic analyses, computational calculations, and single crystal X-ray diffraction. Rhomollone A () possesses an unprecedented 5/6/6/5 tetra-cyclic ring system (B- grayanane) incorporating a cyclopentene-1,3-dione scaffold. Rhodomollein XLIII () is a dimeric grayanoid, containing a novel 14-membered heterocyclic ring with a symmetry axis. The antinociceptive activities of compounds , , , , and - were evaluated by an acetic acid-induced writhing test. Among them, compounds , , , and displayed significant antinociceptive activities at a dose of 20 mg/kg with inhibition rates ranging from 41.9% to 91.6%. Compounds and inhibited 46.0% and 39.4% of the acetic acid-induced writhes at a dose of 2 mg/kg, while compound inhibited 34.3% of the writhes at a dose of 0.4 mg/kg.

Anti-inflammatory and anti-nociceptive activities of essential oil of Waltheria indica / Actividades antiinflamatorias y nociceptivas del aceite esencial de Waltheria indica

This paper reports for the first time volatile compounds, anti-nociceptive and anti-inflammatory activities of essential oils from the leaves of Waltheria indica L. (Stericullaceae) growing in Nigeria. The essential oil was hydro-distilled and characterized by gas chromatography-flame ionization detection (GC-FID) and gas chromatography coupled with mass spectrometry (GC-MS) analyses. The anti-inflammatory activity was evaluated on carrageenan induced rat paw edema while the anti-nociceptive test was based on hot plate model. The hydro-distillation afforded 0.41% (dry weight basis) of light green oil. Forty compounds representing 99.8% were identified in the oil. The main constituents of the oil were limonene (34.7%), sabinene (21.2%) and citronellal (9.7%). The anti-nociceptive property of the essential oils statically inhibited edema development (p<0.001) at a dose of 200 and 400 mg/kg independent of time of exposure. However, the 100 mg/kg Waltheria indica essential oils (WIEO) displayed a relatively low inhibition (p<0.01-p>0.5) which declines as exposure time increases. The anti-inflammatory activities shows a steady rate and non-dose dependent activity (p<0.001) up to the 3rd h of inflammation study. Conversely, a sharp reduction at the rate of p<0.5, 0.1 and 0.01 for the 100, 200 and 400 mg/kg WIEO doses respectively. Overall, the results presented sustain and establish the anti-nociceptive and anti-inflammatory properties and justifies the need for further evaluation and development of the essential oils from this plant.

Este artículo informa por primera vez de compuestos volátiles, actividades anti-nociceptivas y antiinflamatorias de aceites esenciales de las hojas de Waltheria indica L. (Stericullaceae) que crecen en Nigeria. El aceite esencial fue hidro-destilado y se caracterizó por cromatografía de gases-detección de ionización de llama (GC-FID) y cromatografía de gases junto con análisis de espectrometría de masas (GC-MS). La actividad antiinflamatoria se evaluó en el edema de pata de rata inducido por carragenano, mientras que la prueba antinociceptiva se basó en el modelo de placa caliente. La destilación hidráulica proporcionó 0,41% (en peso seco) de aceite verde claro. Cuarenta compuestos que representan el 99.8% fueron identificados en el aceite. Los principales componentes del aceite fueron el limoneno (34,7%), el sabineno (21,2%) y el citronelal (9,7%). La propiedad anti-nociceptiva de los aceites esenciales inhibió estáticamente el desarrollo del edema (p<0.001) a una dosis de 200 y 400 mg/kg independientemente del tiempo de exposición. Sin embargo, los aceites esenciales de Waltheria indica de 100 mg/kg (WIEO) mostraron una inhibición relativamente baja (p<0.01-p>0.5) que disminuye a medida que aumenta el tiempo de exposición. Las actividades antiinflamatorias muestran una tasa constante y una actividad no dependiente de la dosis (p<0.001) hasta la tercera hora del estudio de inflamación. Por el contrario, una fuerte reducción a una tasa de p<0.5, 0.1 y 0.01 para las dosis de 100, 200 y 400 mg/kg de WIEO respectivamente. En general, los resultados presentados sostienen y establecen las propiedades anti-nociceptivas y antiinflamatorias y justifican la necesidad de una mayor evaluación y desarrollo de los aceites esenciales de esta planta.

Anti-inflammatory, antinociceptive and antioxidant activities of the hydromethanolic fraction from Annona nutans leaves / Atividade anti-inflamatória, antinociceptiva e antioxidante da fração hidrometanólica das folhas de annona nutans

Annona nutans (Annonaceae) is a plant species found in Bolivia, Paraguay, Argentina, and the Brazilian Cerrado, specifically in the states of Mato Grosso and Mato Grosso do Sul (Brazil). Its common names are Araticû-Mi and Araticû-Ñu. The research contributions regarding the chemical composition and biological activities of extracts from A. nutans are rare, with only four articles being found in the literature. Therefore, the present study evaluated the anti-inflammatory and antinociceptive activities of the hydromethanolic fraction (FHMeOH) using carrageenan-induced paw edema and hot-plate tests. In addition, the antioxidant activity was evaluated by DPPH radical scavenging, total phenolic, flavonoid and tannin content assays and quantification of the major metabolites by LC-MS were performed. Oral treatment with the FHMeOH (at a dose of 300 mg.kg-1) significantly reduced paw edema 2 h and 4 h after the inflammatory stimulus. The intraperitoneal (i.p.) treatment with the FHMeOH (50 and 100 mg.kg-1) proved to be most effective, and the inhibition of acute inflammation was still visible 6 h after carrageenan injection. At doses of 50 and 100 mg.kg-1 (i.p.), FHMeOH exhibits central antinociceptive effects by increasing the latency of the reaction in the hot-plate model. The FHMeOH showed antioxidant potential, and the metabolites quercetin-3-O-galactoside, quercetin-3-O-glucoside, isorhamnetin-3-O-galactoside, quercetin-3-O-ß-D-apiofuranosyl-(1→2)-galactopyranoside, and chlorogenic acid were identified and quantified by LC-MS. Our results indicate, for the first time, that FHMeOH has anti-inflammatory, antinociceptive and antioxidant potential, and it is a promising source of studies for new herbal medicines

Annona nutans (Annonaceae) é uma espécie de planta encontrada na Bolívia, Paraguai, Argentina e no Cerrado brasileiro, especificamente nos estados de Mato Grosso e Mato Grosso do Sul (Brasil). Seus nomes mais comuns são aratico e Araticû-Mi e Araticû-Ñu. As contribuições da pesquisa em relação à composição química e atividades biológicas dos extratos de A. nutans são raras, com apenas quatro artigos encontrados na literatura. Portanto, o presente estudo avaliou as atividades anti-inflamatória e antinociceptiva da fração hidrometanólica (FHMeOH) utilizando edema de pata induzido por carragenina e testes de placaquente. Além disso, a atividade antioxidante foi avaliada por meio de sequestro de radical DPPH, e foram realizados ensaios de quantificação de fenóis, flavonoides e taninos totais e quantificação dos principais metabólitos por CL-EM. O tratamento oral com a FHMeOH (na dose de 300 mg.kg-1) reduziu significativamente o edema da pata 2 e 4 h após o estímulo inflamatório. Por outro lado, o tratamento intraperitoneal (i.p.) com FHMeOH (50 e 100 mg.kg-1) provou ser mais eficaz e a inibição da inflamação aguda foi ainda visível 6 horas após a injeção de carragenina. Nas doses de 50 e 100 mg.kg-1 (i.p.), FHMeOH exibiu efeitos antinociceptivos centrais aumentando a latência da reação no modelo de placa quente. FHMeOH apresentou potencial antioxidante e os metabólitos quercetina-3-O-galactosídeo, quercetina-3-O-glicosídeo, isoramnetina-3-O-galactosídeo, quercetina- 3-O-ß-D-apiofuranosil-(1 → 2)-galactopiranosídeo e ácido clorogênico foram identificados e quantificados por CL-EM. Nossos resultados indicam, pela primeira vez, que o FHMeOH possui efeitos anti-inflamatórios, antinociceptivos e antioxidantes, sendo uma fonte promissora de estudos para novos medicamentos fitoterápicos.

Effectiveness of low dose physostigmine for dose reduction of morphine in pain management

Background: This is an interventional study, undertaken in the experimental animal models for the evaluation of the antinociceptive potential of Physostigmine and its combination with Morphine at their sub-analgesic doses. The objective of the study was to evaluate the antinociceptive potential of Physostigmine alone and in combination with morphine.Methods: Antinociceptive effect of Physostigmine in three graded doses (50, 100 and 200 ?g/kg) and combination of Physostigmine at low dose (50 ?g/kg) with sub-analgesic dose of Morphine (0.1 mg/kg) and Morphine in analgesic dose (1 mg/kg) was evaluated by using Hot Water Bath method in albino rats.Results: Comparison of maximal possible effect in percentage (MPE in %) between groups at 90 minutes in control, Morphine, Physostigmine in 50, 100, 200 ?g/ kg doses and combination group respectively, demonstrated significant difference (p <0.001) when compared by one way ANOVA test. There was no much increase in maximal possible effect in the tail withdrawal latency in Physostigmine 50 ?g/kg (SC) treatment at 90 min (5.50±0.88) in comparison to control (NS) treatment group. Combination treatment of low doses of both Physostigmine 50 ?g/kg + Morphine 0.1 mg/kg increased in maximal possible effect the tail withdrawal latency 90 min (53.87±1.38) in-comparison to control (NS) treatment group (6.17±0.92).Conclusions: Physostigmine is more potent antinociceptive than Morphine and Physostigmine potentiated the antinociceptive activity of low dose of standard drug Morphine.

Antinociceptive and anti-inflammatory effects of N-acetylcysteine and verapamil in Wistar rats / 대한통증학회지

BACKGROUND: Antinociceptive anti-inflammatory drugs have many adverse effects. The goal of this investigation is to study the probable anti-inflammatory and analgesic effects of verapamil and N-acetylcysteine (NAC) in experimental rats. METHODS: Adult male Wistar rats were randomly divided into 4 groups in the antinociceptive study, each containing 6 rats; the normal control group, which received saline (1 mL/kg); the diclofenac group, which received diclofenac sodium (5 mg/kg); the NAC group, which received NAC (125 mg/kg); and the verapamil group, which received verapamil (8 mg/kg). In the anti-inflammatory study, 5 groups were used, the 4 previous groups with the addition of an edema control group, received saline and were subjected to formalin test. Hot plate latency time was recorded for antinociceptive evaluation. Paw edema thickness and biochemical parameters were recorded for anti-inflammatory evaluation. RESULTS: Administration of NAC showed significant prolongation of hot plate latency time at 1 hour when compared to the control group while verapamil showed a significant prolongation of hot plate latency time at 1 and 2 hours when compared to the control group and NAC group values. Administration of NAC and verapamil significantly decreased paw edema thickness at 2, 4, and 8 hours when compared to edema control values. Regarding biochemical markers, NAC and verapamil significantly decreased serum nitric oxide synthase, C-reactive protein, and cyclooxygenase-2 levels compared to the edema control value. In accordance, a marked improvement of histopathological findings was observed with both drugs. CONCLUSIONS: NAC and verapamil have antinociceptive and anti-inflammatory effects comparable to diclofenac sodium.

Anti-nociceptive effect of seed extract of Acacia tortilis in rodents

Background: Management of pain is a primary clinical concern for any pathology in medical field. Addiction liability of opioids and troublesome gastrointestinal side effects of NSAIDs leads to intensive research for compound with lesser side effects.The aim of the study to evaluate the anti-nociceptive activity of Acacia Tortilis Seed Extract (ATE) in experimental animals.Methods: First of all, animals were randomly allocated into four groups of six animals each. In acetic acid induced writhing test model, Group I (NC) served as vehicle control received saline/Tween 80 0.1%, 10ml/kg BW orally, group II (ATE-100) and III (ATE-200) received ATE in dose of 100 and 200mg/kg BW orally respectively and group IV received the standard drug diclofenac sodium in dose of 50 mg/kg BW orally. Group I to IV were same in rest of three experimental models. One additional group of standard drugs (group V) morphine sulfate in dose of 5 mg/kg BW subcutaneously (SC) was allocated for screening method hot plate and tail flick tests. In Formalin induced paw licking test, three additional groups (group V) morphine sulfate in dose of 5mg/kg BW SC, group VI- morphine+naloxone (5mg/kg SC +2mg/kg intra-peritoneally (IP) and group VII - ATE+ naloxone (200mg/kg BW orally +2mg/kg BW IP) were also made.Results: The ATE when administered orally in dose of 100 and 200mg/ kg body weight (BW), produced significant analgesic activity (P <0.01) in acetic acid induced writhing syndrome and late phase of formalin test. In the hot plate test in mice and tail flick test in rats, ATE in same doses also showed significant analgesic activity (P <0.05) which is almost equally efficacious to standard drug diclofenac sodium (50mg/kg BW orally) but far less efficacious than morphine sulfate (5mg/kg BW subcutaneous).ATE (200mg/Kg BW orally) activity did not blocked by naloxone (2mg/kg intra-peritoneal).Conclusions: ATE possesss significant anti-nociceptive activity as evidenced in all the animal models of nociception. It might exert its effect through the peripheral mechanism of analgesic action possibly by interference in biosynthesis, release and/or action of prostaglandins and leukotrienes.

Anti-inflammatory and antinociceptive activities of Rhipicephalus microplus saliva

Objective: To evaluate the antinociceptive and anti-inflammatory activities and the toxic effects of Rhipicephalus microplus saliva for elucidating the modulation mechanism between arthropod saliva and host. Methods: For saliva collection, engorged ticks were obtained from a controlled bovine infestation and collected by natural fall. The ticks were fixed and injected pilocarpine 0.2% for induction of salivation. Saliva was collected, lyophilized and stored at - 80 °C. Cytotoxic activity was assessed by the hemolysis method (25, 50, 100, 200 and 300 μ g/mL) and MTT cell viability assay (2.5, 5, 10, 20 and 40 μ g/mL) for 24, 48 and 72 h. Anti-inflammatory activity was evaluated using the method of neutrophil migration to the peritoneal cavity of mice at doses of 10, 15 and 20 mg/kg; antinociceptive activity was assessed using the acetic acid-induced writhing test, and formalin-induced paw-licking in mice at dose of 15 mg/kg. Results: Saliva did not cause erythrocytes hemolysis at any concentration tested, as well as did not decrease cell viability in the MTT assay. Saliva inhibited neutrophil migration by 87% and 73% at doses of 15 and 20 mg/kg, respectively. In the nociceptive tests, saliva presented analgesic activity of 69.96% in the abdominal writhing test, and of 84.41% in the formalin test. Conclusions: The study proves that Rhipicephalus microplus saliva has significant in vivo anti-inflammatory and antinociceptive activities. The data presented herein support the development of further studies to elucidate the active principles of Rhipicephalus microplus saliva and its mechanism of action and, in future, to develop novel anti-inflammatory and analgesic drugs.

Sedative and antinociceptive activities of two new sesquiterpenes isolated from Ricinus communis / 中国天然药物

Two new sesquiterpenes, trivially named ricinusoids A (1) and ricinusoids B (2), were isolated from ethyl acetate fraction of Ricinus communis. The structures of new compounds were elucidated by detailed spectroscopic techniques, including 1D- and 2D-NMR, UV, IR spectroscopy, and mass spectrometry. The compounds (1-2) were also assessed for in-vivo sedative and analgesic like effects in open field and acetic acid induced writhing tests respectively at 5, 10, and 20 mg·kg i.p. Pretreatment of both test compounds caused significant (P ≤ 0.05) reduction in locomotive activity like sedative agents and abdominal constrictions like analgesics. Both compounds (1-2) possessed marked sedative and antinociceptive effects in animal models.

Anti-inflammatory and antinociceptive activities of Rhipicephalus microplus saliva

Objective: To evaluate the antinociceptive and anti-inflammatory activities and the toxic effects of Rhipicephalus microplus saliva for elucidating the modulation mechanism between arthropod saliva and host. Methods: For saliva collection, engorged ticks were obtained from a controlled bovine infestation and collected by natural fall. The ticks were fixed and injected pilocarpine 0.2％for induction of salivation. Saliva was collected, lyophilized and stored at - 80 ℃. Cytotoxic activity was assessed by the hemolysis method (25, 50, 100, 200 and 300 μg/mL) and MTT cell viability assay (2.5, 5, 10, 20 and 40 μg/mL) for 24, 48 and 72 h. Anti-inflammatory activity was evaluated using the method of neutrophil migration to the peritoneal cavity of mice at doses of 10, 15 and 20 mg/kg; antinociceptive activity was assessed using the acetic acid-inducedwrithing test, and formalin-induced paw-licking in mice at dose of 15 mg/kg. Results: Saliva did not cause erythrocytes hemolysis at any concentration tested, as well as did not decrease cell viability in the MTT assay. Saliva inhibited neutrophil migration by 87％ and 73％ at doses of 15 and 20 mg/kg, respectively. In the nociceptive tests, saliva presented analgesic activity of 69.96％ in the abdominal writhing test, and of 84.41％ in the formalin test. Conclusions: The study proves that Rhipicephalus microplus saliva has significant in vivo anti-inflammatory and antinociceptive activities. The data presented herein support the development of further studies to elucidate the active principles of Rhipicephalus microplus saliva and its mechanism of action and,in future, to develop novel anti-inflammatory and analgesic drugs.

Sedative and antinociceptive activities of two new sesquiterpenes isolated from Ricinus communis / 中国天然药物

Two new sesquiterpenes, trivially named ricinusoids A (1) and ricinusoids B (2), were isolated from ethyl acetate fraction of Ricinus communis. The structures of new compounds were elucidated by detailed spectroscopic techniques, including 1D- and 2D-NMR, UV, IR spectroscopy, and mass spectrometry. The compounds (1-2) were also assessed for in-vivo sedative and analgesic like effects in open field and acetic acid induced writhing tests respectively at 5, 10, and 20 mg·kg i.p. Pretreatment of both test compounds caused significant (P ≤ 0.05) reduction in locomotive activity like sedative agents and abdominal constrictions like analgesics. Both compounds (1-2) possessed marked sedative and antinociceptive effects in animal models.

Isovitexin as marker and bioactive compound in the antinociceptive activity of the Brazilian crude drug extracts of Echinodorus scaber and E. grandiflorus

Abstract Echinodorus scaber Rataj and Echinodorus grandiflorus (Cham. & Schltdl.) Micheli, Alismataceae, are popularly used to relieve inflammatory complaints and as diuretic. A study on the antinociceptive effect and selected marker compounds in eleven extracts from different locations was undertaken and their antinociceptive effect was assessed. The fingerprints were compared by HPLC-DAD and the content of vitexin, isovitexin, isoorientin and vitexin-2-O-rhamnoside were determined. All samples presented antinociceptive activity reducing the writhes by 36.4-62.5% and 47.4-79.8% at 10 and 50 mg/kg, respectively; indomethacin (5 mg/kg) reduced writhes by 82.6-90.1%. The content of the flavonoids C-glycosides, however, presented a strong variation. Isovitexin and isoorientin were found in all the samples, with content ranging from traces to 14.70 µg/mg and 2.12-84.27 µg/mg extract, respectively, while vitexin-2-O-rhamnoside occurred in quantifiable amounts only in 3 out of 11 samples ranging from 5.43 to 33.13 µg/mg extract; vitexin was not detected at all or detected in trace amounts. According to the fingerprints, the samples could be arranged in four main groups. All eleven extracts showed antinociceptive activity. Isovitexin was the only flavonoid present in all samples and can be regarded, acting in synergy with the other compounds or not, as the responsible for the antinociceptive activity. Therefore, isovitexin is a good choice as chemical marker when the antinociceptive activity of E. scaber and E. grandiflorus is investigated.

Polysaccharide rich fractions from barks of Ximenia americana inhibit peripheral inflammatory nociception in mice Antinociceptive effect of Ximenia americana polysaccharide rich fractions

Abstract Ximenia americana L., Olacaceae, barks are utilized in folk medicine as analgesic and anti-inflammatory. The objective was to evaluate the toxicity and antinociceptive effect of polysaccharides rich fractions from X. americana barks. The fractions were obtained by extraction with NaOH, followed by precipitation with ethanol and fractionation by ion exchange chromatography. They were administered i.v. or p.o. before nociception tests (writhing, formalin, carragenan-induced hypernociception, hot plate), or during 14 days for toxicity assay. The total polysaccharides fraction (TPL-Xa: 8.1% yield) presented 43% carbohydrate (21% uronic acid) and resulted in two main fractions after chromatography (FI: 12%, FII: 22% yield). FII showed better homogeneity/purity, content of 44% carbohydrate, including 39% uronic acid, arabinose and galactose as major monosaccharides, and infrared spectra with peaks in carbohydrate range for COO- groups of uronic acid. TPL-Xa (10 mg/kg) and FII (0.1 and 1 mg/kg) presented inhibitory effect in behavior tests that evaluate nociception induced by chemical and mechanical, but not thermal stimuli. TPL-Xa did not alter parameters of systemic toxicity. In conclusion, polysaccharides rich fractions of X. americana barks inhibit peripheral inflammatory nociception, being well tolerated by animals.

Antioxidant effect of quinoline derivatives containing or not selenium: Relationship with antinociceptive action quinolines are antioxidant and antinociceptive

ABSTRACT The present study investigated the antioxidant effect of a new class of quinoline derivatives (a-d) on assays in vitro. Lipid peroxidation, thiol peroxidase-like and free radical scavenging activities were determined to evaluate antioxidant activity of compounds. Thiol oxidase-like and δ-aminolevulinate dehydratase activities were performed as a toxicological parameter. A second objective of this study was to evaluate the in vivo antinociceptive effect of the compound with better antioxidant effect and without toxic effects in a model of nociception induced by formalin in mice. In liver, at 100 µM, compound a reduced the lipid peroxidation to the control levels, while compounds c and d partially reduced it. In brain, only compound d partially reduced the lipid peroxidation at 50 and 100 µM. Compound b did not have an effect on the lipid peroxidation. Thiol peroxidase-like and free radical scavenging activities are not involved in the antioxidant mechanisms of these compounds. Compounds did not present thiol oxidase-like activity and effect on the δ-aminolevulinate dehydratase. In vivo experiments showed that compound a caused an inhibition of licking time in the first and second phases, and edema formation induced by formalin. In conclusion, quinoline derivative without selenium presented better in vitro antioxidant effect and in vivo antinociceptive activity.

Curcumin attenuates morphine antinociceptive tolerance through suppressing up-regulation of spinal Toll-like receptor 4 in rats / 解放军医学杂志

Objective To investigate the effects of curcumin (Cur) on activation of spinal Toll-like receptor 4 (TLR4) and on the chronic antinociceptive tolerance of morphine.Methods Sixty male Sprague-Dawley rats with successful intrathecal catheterization were randomly divided into four groups (n=15):saline (NS) group;morphine (MOR) group;curcumin (Cur) group and morphine plus curcumin (MOR+Cur) group.A morphine tolerance model of rats was induced by intrathecal ifjection of morphine 15μg,once a day for 7 consecutive days in MOR and MOR+Cur group;100μg curcumin was administered intrathecally once a day for 7 consecutive days in Cur and MOR+Cur group,10μl saline was administered intrathecally once a day for 7 consecutive days in NS group.The effect of curcumin intrathecal catheterization on morphine antinociceptive tolerance was explored by the tail flick latency (TFL) method and mechanical withdrawal threshold (MWT),and then the maximum possible potential effect (MPE) was calculated.The immunofluorescence staining method was applied to detect the effect of curcumin on the activation of lumbar spinal microglia.Real-time PCR and Western blotting were used to evaluate the effect of curcumin on the expression of mRNA and protein of spinal TLR4.Results The ％MPE TFL and ％MPE MWT increased significantly in MOR+Cur group than in MOR group (P＜0.05) after 7 days of intrathecal injection of morphine,intrathecal injection of curcumin and saline failed to induce analgesic effect.There was no significant difference in MPE between Cur group and NS group (P＞0.05).The lumbar spinal microglia increased markedly and the expressions of polyclonal antibody IBA-1 and TLR4 were significantly up-regulated in MOR group than in NS group (P＜0.05).The lumbar spinal microglia decreased obviously and the expressions of IBA-1 and TLR4 were significantly down-regulated in MOR+Cur group as compared with that in MOR group (P＜0.0S),but there was no significant difference in the expressions of IBA-1 and TLR4 between Cur group and NS group (P＞0.05).Conclusion Curcumin may attenuate chronic morphine antinociceptive tolerance through inhibiting spinal TLR4 up-regulation.