The alga Bryothamnion seaforthii contains carbohydrates with antinociceptive activity

Bryothamnion seaforthii, a red alga common to the Northeastern coast of Brazil, was used to prepare the protein fraction F0/60 by ammonium sulfate precipitation. The chromatography of F0/60 on DEAE-Sephadel column resulted in two lectin fractions, PI and PII, which have antinociceptive properties in rodents. We determined the antinociceptive activity of the PII fraction and of a carbohydrate-containing fraction (CF) in mice. The CF was prepared from the dried algae, after digestion with 100 mM sodium acetate, pH 6.0, containing 5 mM cysteine, EDTA and 0.4% papain, at 60ºC. A 10% cetylpyridinium chloride was added to the filtrate, and the precipitate was dissolved with 2 M NaCl:ethanol (100:15, v/v) followed by the carbohydrate precipitation with ethanol. The final precipitate, in acetone, was dried at 25ºC. The PII fraction markedly inhibited acetic acid-induced abdominal writhing after ip administration (control: 27.1 ± 2.20; PII 0.1 mg/kg: 5.5 ± 1.85; 1 mg/kg: 1.6 ± 0.72 writhes/20 min) and after oral administration (control: 32.0 ± 3.32; PII 0.1 mg/kg: 13.1 ± 2.50; 1 mg/kg: 9.4 ± 3.96 writhes/20 min). PII was also effective against both phases of pain induced by 1% formalin (control, ip: 48.2 ± 2.40 and 27.7 ± 2.56 s; PII: 1 mg/kg, ip: 34.3 ± 5.13 and 5.6 ± 2.14 s; control, po: 44.5 ± 3.52 and 25.6 ± 2.39 s; PII 5 mg/kg, po: 26.5 ± 4.67 and 15.3 ± 3.54 s for the 1st and 2nd phases, respectively) and in the hot-plate test. The CF (ip) also displayed significant antinociceptive properties in all tests but at higher doses (1 and 5 mg/kg, ip and po). Thus, CF at the dose of 5 mg/kg significantly inhibited writhes (ip: 7.1 ± 2.47 and po: 14.5 ± 2.40 writhes/20 min) as well as the 1st (po: 19.6 ± 1.74 s) and 2nd (po: 7.1 ± 2.24 s) phases of the formalin test compared to controls ip and po. The antinociceptive effects of both the PII and CF in the formalin and hot-plate tests were prevented at least partially by pretreatment with the opioid receptor antagonist naloxone (2 mg/kg, sc). Moreover, both fractions retained antinociceptive activity in the acetic acid-induced writhing test following heating, a procedure which abolished the hemagglutinating activity of the fraction, presumably due to lectins also present. Finally, both fractions also prolonged the barbiturate-induced sleeping time. These results indicate that carbohydrate molecules present in the PII (26.8% carbohydrate) and CF (21% of the alga dried weight) obtained from B. seaforthii display pronounced antinociceptive activity which is resistant to heat denaturation and is mediated by an opioid mechanism, as indicated by naloxone inhibition.

Effect of Sapindus trifoliatus on hyperalgesic in vivo migraine models

Phytotherapies have offered alternative sources of therapy for migraine and gained much importance in prophylactic treatment. Sapindus trifoliatus is a medium-sized deciduous tree growing wild in south India that belongs to the family Sapindaceae. The pericarp is reported for various medicinal properties. A thick aqueous solution of the pericarp is used for the treatment of hemicrania, hysteria or epilepsy in folklore medicine. We have investigated the antihyperalgesic effects of the lyophilized aqueous extract of S. trifoliatus in animal models predictive of experimental migraine models using morphine withdrawal-induced hyperalgesia on the hot-plate test and on 0.3% acetic acid-induced abdominal constrictions in adult male Swiss albino mice. The extract significantly (N = 10, P < 0.05) increased the licking latency in the hot-plate test when administered ip at 10 mg/kg (6.70 ± 0.39 s in saline control vs 18.76 ± 0.96 s in S. trifoliatus-treated animals) and significantly (N = 10, P < 0.001) reduced the abdominal constrictions when administered ip at 2 and 10 mg/kg (40.20 ± 1.36 in saline control vs 30.20 ± 1.33 and 23.00 ± 0.98 for 2 and 10 mg/kg, ip, respectively, in S. trifoliatus-treated animals). Furthermore, when administered ip at 20 and 100 mg/kg, the extract significantly (N = 10, P < 0.05) inhibited the apomorphine-induced climbing behavior in mice (climbing duration 15.75 ± 5.0 min for saline control vs 11.4 ± 1.28 and 3.9 ± 1.71 min for 20 and 100 mg/kg, respectively, in S. trifoliatus-treated animals). In receptor radioligand-binding studies, the extract exhibited affinity towards D2 receptors. The findings suggest that dopamine D2 antagonism could be the mechanism involved in the antihyperalgesic activity of the aqueous extract of S. trifoliatus.

Antinociceptive properties in mice of a lectin isolated from the marine alga Amansia multifida Lamouroux

The antinociceptive effects of a lectin (LEC) isolated from the marine alga Amansia multifida were determined in Swiss mice. The LEC (1, 5, and 10 mg/kg) inhibited acetic acid-induced abdominal writhings in a dose-dependent manner after intraperitoneal or oral administration. A partial but significant inhibition of writhings was observed after the combination of LEC (10 mg/kg) with avidin (1 mg/kg), a potent inhibitor of the hemmaglutinant activity of the lectin. However, total writhing inhibition was demonstrable in the group of mice treated with LEC plus mannose (1 mg/kg), as compared to LEC alone or to control groups. Furthermore, avidin and mainly mannose also play a role in antinociception, somehow facilitating the interaction of LEC with its active cell sites. In the formalin test, although both phases of the response were significantly inhibited, the effect of LEC was predominant during phase 2, causing inhibition of licking time that ranged from 48 to 88% after oral (5 and 10 mg/kg) and intraperitoneal (1 to 5 mg/kg) administration. As is the case with morphine, the effect of LEC (2 mg/kg) was reversed by naloxone (2 mg/kg), indicating the involvement of the opioid system. LEC was also effective in the hot-plate test, producing inhibitory responses to the thermal stimulus, and its effects were blocked by naloxone. In the pentobarbital-induced sleeping time, although LEC did not alter the onset of sleep significantly, it increased the time of sleep within the same dose range compared to control. These results show that LEC presents antinociceptive effects of both central and peripheral origin, possibly involving the participation of the opioid system.

Exercise training attenuates acute hyperalgesia in streptozotocin-induced diabetic female rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Qualea parviflora Mart.: An integrative study to validate the gastroprotective, antidiarrheal, antihemorragic and mutagenic action

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of the analgesic and antiedematogenic activities of Quassia amara bark extract

We evaluated the possible antiedematogenic, antinociceptive and/or sedative effects of four different extracts obtained from the bark of Quassia amara namely, 70% ethanol (70EtOH), 100% ethanol (100EtOH), dichloromethane (DCM) and hexane extracts (HEX). The oral administration (100, 250 and 500 mg/kg) of these extracts did not show significant effects in any experiment. However, when administered intraperitoneally, the HEX extract decreased the paw edema induced by carrageenan, showed antinociceptive effects on the hot-plate test and on acetic acid-induced writhing, and showed sedative effects on pentobarbital-induced sleep. Naloxone did not reverse the antinociceptive effect of this extract. In conclusion, although the mechanisms are uncertain, the results demonstrated that these effects are apparently related to sedative and muscle relaxant or psychomimetic activities of the HEX extract of the plant. (C) 2002 Elsevier B.V. Ireland Ltd. All rights reserved.

Antinociceptive and anti-inflammatory activities of ethanolic extracts of Lychnophora species

Extracts from Lychnophora species are traditionally used in Brazil as anti-inflammatory, and to treat bruise, pain and rheumatism. The ethanolic extract of aerial parts of five species of Lychnophoras and one specie of Lychnophoriopsis were examined for the antinociceptive (hot-plate and writhing tests) and anti-inflammatory (carrageenan-induced paw oedema test) activity in mice, by oral and topical routes, respectively. In the hot-plate test, the Lychnophora pinaster (0.75 g/kg) and Lychnophora ericoides (1.50 g/kg) extracts significantly increased the time for licking of the paws. The species Lychnophora passerina, Lychnophoriopsis candelabrum and Lychnophora pinaster, using the dose of 0.75 g/kg, and Lychnophora ericoides and Lychnophora trichocarpha in both doses evaluated (0.75 and 1.50 g/kg) significantly reduced the number of writhes induced by acetic acid. The administration of Lychnophora pinaster and Lychnophora trichocarpha ointments, in both concentrations evaluated (5 and 10%, w/w), and Lychnophora passerina and Lychnophoriopsis candelabrum, in the concentration of 10%, significantly reduced the paw oedema measured 3 h after carrageenan administration, suggesting, for the first time, an anti-inflammatory activity upon topical administration of these species. The present work comparatively demonstrated the antinociceptive and anti-inflammatory activities of some Brazilian Lychnophoras. (C) 2007 Elsevier B.V. All rights reserved.

Antinociceptive profile of 2,3,6-trisubstituted piperidine alkaloids: 3-O-acetyl-spectaline and semi-synthetic derivatives of (-)-spectaline

In early studies, we have reported the antinociceptive profile of (-)-spectaline, a piperidine alkaloid from Cassia spectabilis. The present study describes the synthesis, the antinociceptive and anti-inflammatory activities of a series of 2,3,6-trialkyl-piperidine alkaloids: the natural (-)-3-O-acetyl-spectaline (LASSBio-755) and ten semi-synthetic spectaline derivatives. Structure-activity relationship (SARs) studies were performed. The structures of all synthesized derivatives were confirmed by means of nuclear magnetic resonance. Compounds were evaluated for their analgesic (acetic acid-induced mouse abdominal constrictions, hot-plate test, formalin-induced pain test) and some of them for the anti-inflammatory activities (carrageenan-induced rat paw edema test). The pharmacological results showed that several of the new compounds given orally at a dose of 100 mu mol/kg significantly inhibited the acetic acid-induced abdominal constrictions, but they were less active than (-)-spectaline. LASSBio-755 and LASSBio-776 were the most actives with 37% and 31.7% of inhibition. In the formalin-induced pain only LASSBio-776 was able to inhibit by 34.4% the paw licking response of the inflammatory phase, (-)-spectaline and LASSBio-755 did show any activity. In the carrageenan-induced rat paw edema, only (-)-spectaline exhibited an anti-inflammatory profile, showing an ED(50) value of 56.6 mu mol/kg. Our results suggest different mechanisms of action for the analgesic activity observed for LASSBio-776 (3-O-Bocspectaline), LASSBio-755 (3-O-acetyl-spectaline) and (-)-spectaline (LASSBio-754). The antinociceptive profile of some of the semi-synthetic spectaline derivatives extends our research concerning the chemical and pharmacological optimization of isolated natural products in the search of new drug candidates from brazilian biodiversity.

Applications of the hexanic fraction of Agave sisalana Perrine ex Engelm (Asparagaceae): control of inflammation and pain screening

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fertility of male adult rats submitted to forced swimming stress

We investigated whether stress interferes with fertility during adulthood. Male Wistar rats (weighing 220 g in the beginning of the experiment) were forced to swim for 3 min in water at 32ºC daily for 15 days. Stress was assessed by the hot-plate test after the last stressing session. To assess fertility, control and stressed males (N = 15 per group) were mated with sexually mature normal females. Males were sacrificed after copulation. Stress caused by forced swimming was demonstrated by a significant increase in the latency of the pain response in the hot-plate test (14.6 ± 1.25 s for control males vs 26.0 ± 1.53 s for stressed males, P = 0.0004). No changes were observed in body weight, testicular weight, seminal vesicle weight, ventral prostate weight or gross histological features of the testes of stressed males. Similarly, no changes were observed in fertility rate, measured by counting live fetuses in the uterus of normal females mated with control and stressed males; no dead or incompletely developed fetuses were observed in the uterus of either group. In contrast, there was a statistically significant decrease in spermatid production demonstrated by histometric evaluation (154.96 ± 5.41 vs 127.02 ± 3.95 spermatids per tubular section for control and stressed rats, respectively, P = 0.001). These data demonstrate that 15 days of forced swimming stress applied to adult male rats did not impair fertility, but significantly decreased spermatid production. This suggests that the effect of stress on fertility should not be assessed before at least the time required for one cycle of spermatogenesis.

Investigation of anti-inflammatory and antinociceptive activities of trans-dehydrocrotonin, a 19-nor-clerodane diterpene from Croton cajucara .1.

The anti-inflammatory and antinociceptive effects of trans-dehydrocrotonin, isolated from the bark of Croton cajucara (Euphorbiaceae), were investigated using several animal models. The trans-dehydrocrotonin produced a significant inhibition of carrageenin-induced paw edema and cotton pellet granuloma in rats. It also inhibited the writhings in mice induced by acetic acid, but did not show a significant effect in the hot-plate test in mice. The LD(50) of t-DCTN was 555.0 mg/kg (p.o.) for mice.

Anti-nociceptive effects of Carpolobia lutea G. Don (Polygalaceae) leaf fractions in animal models

Leaves from Carpolobia lutea (Polygalaceae) were screened to establish the antiulcer ethnomedicinal claim and to quantitatively isolate, elucidate the active compounds by semi-preparative HPLC. The anti-nociceptive effects of Carpolobia lutea (CL) G. Don (Polygalaceae) organic leaf extracts were tested in experimental models in mice. The anti-nociceptive mechanism was determined using tail-flick test, acetic acid-induced abdominal constrictions, formalin-induced hind paw licking and the hot plate test. The fractions (ethanol, ethyl acetate, chloroform, n-hexane) and crude ethyl acetate extract of CL (770 mg/kg, i.p.) produced significant inhibitions of both phases of the formalin-induced pain in mice, a reduction in acetic acid-induced writhing as well as and an elevation of the pain threshold in the hot plate test in mice. The inhibitions were greater to those produced by indomethacin (5 mg/kg, i.p.). Ethyl acetate fraction revealed cinnamic and coumaric acids derivatives, which are described for the first time in literature. These cinnamalglucosides polyphenols characterised from CL may in part account for the pharmacological activities. These findings confirm its ethnomedical use in anti-inflammatory pain and in pains from gastric ulcer-associated symptoms. © 2011 Springer Basel AG.

Estudo da ação antinociceptiva e antiinflamátoria do 1-Nitro-2-Feniletano, principal constituinte da Aniba Canelilla

A Aniba canelilla (H.B.K) Mez, conhecida popularmente como casca-preciosa é uma espécie da família Lauraceae que apresenta ampla distribuição na região amazônica. O chá das folhas e das cascas são utilizados na medicina popular como digestivo, carminativo e antiinflamatório. Neste estudo decidiu-se avaliar se esta atividade é devida a um de seus principais constituintes, o 1-nitro-2-feniletano. A amostra obtida por purificação do óleo essencial de Aniba canelilla possui 97,5% de 1-nitro-2-feniletano foi fornecida pelo Laboratório de Engenharia Química da UFPA. Nos modelos de nocicepção foram realizados os testes da contorção abdominal, placa quente e formalina. Enquanto que nos modelos de inflamação foram realizados a dermatite induzido pelo óleo de croton, edema de pata induzido por dextrana e carragenina e peritonite induzido pela carragenina. No teste de contorção abdominal induzido por ácido acético, o 1-nitro-2-feniletano nas doses de 15, 25 e 50 mg/kg reduziu de maneira significativa o número de contorções abdominais. No teste de placa quente (55 0,5 C), o 1-nitro-2-feniletano nas doses de 50, 100 e 200 mg/kg não induziu alterações no tempo de latência quando comparado ao grupo controle. No teste de formalina, o 1-nitro-2-feniletano nas doses de 25 e 50 mg/kg reduziu de maneira significativa o estímulo álgico na 2 fase do teste. Além disso, a antinocicepção foi revertida pela naloxona na segunda fase. Na dermatite induzida pelo óleo de croton, o 1-nitro-2-feniletano nas doses de 25 e 50 mg/kg reduziu de maneira significativa o eritema em relação ao grupo controle (inibição de 73% e 79%, respectivamente). Nos edemas de pata induzido por carragenina e dextrana, o 1-nitro-2-feniletano foi capaz de impedir o desenvolvimento do edema, nas doses de 25 e 50 mg/kg, em comparação com o grupo controle. Na peritonite induzida por carragenina, o 1-nitro-2-feniletano na dose de 25 mg/kg reduziu o número de células globais e o número de neutrófilos quando comparado ao grupo controle (inibição de 22,55% e 38,13%, respectivamente). Nossos resultados sugerem que o 1-nitro-2-feniletano tem atividade antinociceptiva e antiinflamatória, provavelmente, de origem periférica, além disso, os resultados sugerem que os receptores opióides estão envolvidos no efeito antinociceptivo do 1-nitro-2-feniletano.

Avaliação da atividade antinociceptiva e antiinflamatória do óleo essencial de Hyptis crenata (Pohl) ex Benth

Hyptis crenata (Pohl) ex Benth. é uma planta herbácea, medicinal e aromática, pertencente à família lamiaceae, conhecida popularmente como salva-do-marajó, malva-do-marajó e hortelã-bravo. Distribui-se no estuário do Rio Amazonas, Pantanal e no estado de Minas-Gerais. Seu óleo essencial é caracterizado pela presença de monoterpenos e sesquiterpenos. É utilizada popularmente como sudorífico, tônico, estimulante, bem como para tratar inflamação de olhos e garganta, constipação e artrite. Baseado nessas informações, decidiu-se avaliar a atividade antinociceptiva e antiinflamatória do óleo essencial desta espécie (OEHc) através dos seguintes testes: teste das contorções abdominais induzidas por ácido acético, placa quente, formalina, dermatite induzida pelo óleo de croton, edemas induzidos por dextrana e carragenina e peritonite induzida por carragenina. Para a análise estatística utilizou-se ANOVA seguida de um método de múltiplas comparações (Teste de Student-Newman-Keuls ou teste "t" de Student). O óleo foi extraído por hidrodestilação, obtendo um rendimento de 0,6%. É composto predominantemente por monoterpenos (94,5%). A dose letal media DL50 foi de 5000 mg/kg. Nas contorções abdominais induzidas por ácido acético o óleo (250, 350 e 500 mg/kg) reduziu de forma significante de maneira dose-dependente estas contorções em 22,56%, 60,76% e 75,53%, respectivamente, cujo coeficiente de correlação linear foi de r = 0,9341 e DE50 = 364,22 mg/kg. No teste da placa quente, o óleo não foi capaz de aumentar o tempo de latência de maneira significante. No teste da formalina, o OEHc produziu uma inibição da 1 fase em 26,49% e da 2 fase em 43,39%. Além disso, a naloxona reverteu o efeito do OEHc neste teste. Na dermatite induzida pelo óleo de croton, o OEHc reduziu o edema de maneira significante em 44,26%. No edema induzido por dextrana, o óleo foi capaz de impedir o desenvolvimento do edema na dose de 364,22 mg/kg de maneira significante em relação ao grupo controle. Porém, no edema induzido por carragenina esta inibição não foi observada. Na peritonite induzida por carragenina, o OEHc reduziu o número de leucócitos e o de neutrófilos em 47,55% e 66,47%, respectivamente. A partir dos resultados obtidos, sugere-se que o OEHc apresenta atividade antinociceptiva provavelmente através da ação direta sobre as fibras nociceptivas, além de sugerir que os receptores opióides possam estar envolvidos neste processo; e atividade antiinflamatória provavelmente de origem periférica. Pode-se sugerir, também, que os possíveis componentes responsáveis por essas ações sejam os compostos monoterpênicos presentes no OEHc.

Anti-inflammatory and opioid-like activities in methanol extract of Mikania lindleyana, sucuriju

ABSTRACT: Mikania lindleyana DC., Asteraceae (sucuriju), grows in the Amazon region, where is frequently used to treat pain, inflammatory diseases and scarring. This study was carried out to investigate phytochemical profile accompanied by in vivo antinociceptive and anti-inflammatory screening of n-hexane (HE), dichloromethane (DME) and methanol (ME) extracts obtained from the aerial parts of the plant. The oral administration of ME (0.1, 0.3, 1 g/kg) caused a dose-related reduction (16.2, 42.1 e 70.2%) of acetic acid-induced abdominal writhing while HE and DME (1 g/kg, p.o.) were ineffective. In the hot plate test, ME (300 mg/kg, p.o.) increased the latency of heat stimulus between 30 and 120 min and inhibited the first (45%) and second (60%) phases of nociception in the formalin test. The antinociception induced by ME or positive control fentanyl (150 µg/kg, s.c.) in hot plate and formalin tests was prevented by naloxone (3 mg/kg, s.c.). When submitted to the carrageenan-induced peritonitis test, ME (0.5, 1.0, 2.0 g/kg, p.o.) impaired leukocyte migration into the peritoneal cavity by 46.8, 59.4 and 64.8% respectively, while positive control dexamethasone (2 mg/kg, s.c.), inhibited leukocyte migration by 71.1%. These results indicate that the antinociception obtained after oral administration of methanol extract of M. lindleyana involves anti-inflammatory mechanisms accompanied with opioid-like activity which could explain the use of the specie for pain and inflammatory diseases.