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A β-D-glucan was obtained from the edible mushroom Pholiota nameko by hot aqueous extraction and purification. NMR and methylation analyses of the purified fraction (GHW-PN, 1.46% yield) indicated the presence of a (1 → 3)-linked β-D-glucan, highly substituted (~27%) at O-6 by single units of β-D-Glcp or by (1 → 6)-β-D-Glcp fragments. The β-glucan (at 0.5, 1, and 2%) showed shear thinning behavior and when the concentration of the solution increased, there was an increase in apparent viscosity. The β-D-glucan presented gel-like behavior and thermal stability under a simulated pasteurization process, suggesting its potential as a thickening and gelling agent in products submitted to temperature variations. The β-D-glucan at 0.3, 1.0 and 3.0 mg kg−1 significantly inhibited the inflammatory pain in 24.8, 56.9 and 82.3%, respectively, in the formalin-induced nociception in mice. The results pointed out that the β-D-glucan (GHW-PN) isolated from P. nameko presents potential application for the food industry or for medical purposes.

Inflammatory bowel disease (IBD) includes two distinct diseases: Crohn's disease (CD) and ulcerative colitis (UC). IBD is a chronic systemic disease of the gastrointestinal tract, characterized by an inflammatory process. The mechanisms by which diseases develop are still unknown, but it is known that it results from a complex interaction between genetic variability, the host's immune system, and environmental factors. One of the main complaints of patients is abdominal pain, which may be associated with the release of inflammatory mediators, changes in the normal motility of the digestive tract, and increased intestinal permeability. Currently available drugs for abdominal pain are not satisfactory, therefore, it is extremely necessary to seek new therapeutic options for the treatment of abdominal pain. Polysaccharides extracted from fruits have attracted interest, as these molecules protect the intestinal mucosa and promote wound healing, attenuating inflammation, pain, and altered intestinal motility. In this study, we investigated the ability of pectic polysaccharides obtained from guavira pomace, named CPW to reduce visceral hypersensitivity, regulate intestinal motility, and control diarrhea in mice. Acetic acid, capsaicin, or mustard oil were used to assess visceral pain in normal mice. CPW reduced abdominal writhing, cell migration, and capsaicin-induced visceral nociception. Furthermore, it regulated intestinal motility and all measured parameters of castor oil-induced diarrhea. CPW treatment reversed the increase in mucosal permeability, TEER, and tissue weight caused by acetic acid. In addition, molecular docking analysis showed that specific the CPW units binds to the 3N8V, 5COX, 2J67 and 6RBF proteins. Thus, the results suggest that CPW has attractive therapeutic characteristics for the treatment of abdominal pain and ulcerative colitis.

Acmella oleracea (jambu), is used as ingredient for food and in folk medicine to relief toothache. Jambu edible flowers are rich in alkylamides, mainly spilanthol, which are responsible to evoke chemesthetic sensations. This study aimed to investigate the local effects promoted by the intraplantar injection of the hexanic fraction (HF) rich in alkylamides from jambu flowers and compare to synthetic isobutylalkyl amide (IBA). Swiss male mice were intraplantarly administrated with HF and IBA (0.1–30 μg/20 μL), and the underlying mechanisms associated to the antinociceptive (0.1 μg) and pronociceptive (30 μg) effects were evaluated in chemical and sensorial tests. HF and IBA at 0.1 μg promoted analgesia in neurogenic and inflammatory phases of formalin test, against glutamate-induced nociception and independent of the activation of endogenous opioidergic system and dependent of TRPV1 modulation, whereas only HF reduced both nociception and mast cell degranulation in hindpaw induced by compound 48/80. However, both potentiated the TRPA1-mediated nociception. In contrast, HF and IBA (30 μg)-evoked nociceptive behaviors were reduced by the activation of opioidergic system, by TRPA1 antagonist and TRP nociceptive fibers desensitization. In addition, 30 μg IBA-evoked nociception by activation of TRPV1, and 30 μg HF by mast cell degranulation. Furthermore, on the contrary of IBA, HF elevated both mechanical and thermal paw threshold. Altogether, these results indicate that alkylamides could elicited dual effects, adding new evidences and mechanisms for these opposite actions in different doses. Although further research is needed, we confirmed that alkylamides displays local analgesic and/or anesthetic effects.

Croton cajucara Benth. is a medicinal plant popularly used in the Brazilian Amazonia, where it is known as sacaca, being consumed as tea, decoction or infusion of the leaves and stem bark. From a decoction of the leaves, a comprehensive phytochemical analysis was developed by liquid chromatography-mass spectrometry. Many compounds were identified for the first time in C. cajucara, such as O-glycosides of kaempferol and quercetin, flavonoid-C-glycosides, tannins and cinnamic acid derivatives. These compounds were fractionated by polarity and assayed for their anti-inflammatory activity, using a model of mice edema, induced by an intraplantar injection of carrageenan. All fractions exhibited anti-inflammatory properties.

Croton cajucara Benth. is a tree from the Amazon Forest, where it is known as sacaca. Its leaves and barks are used in medicinal preparations to treat different diseases, including gastric ulcers. The crude polysaccharide fraction (CCP), obtained from the hot aqueous extract of C. cajucara leaves, was able to promote gastroprotection on an ethanol induced gastric ulcer model. Therefore, a bioguided fractionation was performed to isolate the active polysaccharide fraction. After freezing-thawing, ultrafiltration and dialyses at 100, 50, and 25kDa cut-off membranes, fraction 25R was obtained. It contained glucose, galactose, rhamnose, arabinose, galacturonic acid and mannose in a 7:5:5:3:1:1 molar ratio approximately, and had a Mw of 42,840g/mol. Methylation analysis and NMR spectroscopy indicated that 25R is a very complex polysaccharide fraction containing type I rhamnogalacturonan, arabinan, type I arabinogalactan, type II arabinogalactan, rhamnan, starch and mannan. It was able to reduce ethanol-induced gastric ulcers in rats, through preservation of mucus and GSH levels.

Tomato is a known functional food due to its content of bioactive compounds. Herein, polysaccharides were extracted from mucilage of tomatoes, and a purified fraction (PTOK) was analyzed by sugar composition, methylation, and NMR spectroscopy analysis. The results showed the presence of an arabinoxylan, having (1→4)-linked β-d-Xylp units in the main chain, which carried a low proportion of branching (∼5.6%), at O-2 and O-3 position, with side chains constituted by single Araf or Xylp units. Intraperitoneal administration of the arabinoxylan in mice significantly reduced the number of abdominal constrictions induced by 0.6% acetic acid and the inflammatory phase of nociception induced by 2.5% formalin, indicating that it had an antinociceptive effect on inflammatory pain models, amplifying the biological role displayed by arabinoxylans in the diet. Furthermore, this study reports the presence of an arabinoxylan in a dicotyledon plant, and also it is the first study of polysaccharides from mucilage of tomatoes.

Leaves of Arctium lappa contain several mono- and dicaffeoylquinic acids, as evaluated by liquid chromatography-mass spectrometry. In order to investigate the protection on gastric mucosa against ulcers, rats were treated with fractions from leaf extract prior to ethanol-induced ulcers. The original fraction obtained as ethanol soluble fraction from hot aqueous extract was able to protect de gastric mucosa, and this effect was retained in the ethyl acetate fraction, obtained from liquid/liquid fractionation. The main compound in this fraction was isolated and chemically characterized by nuclear magnetic resonance and mass spectrometry, assisted by isopropylidene derivatization which gave rise a mass increment of 40 units. Therefore, the underivatized compound that had m/z 515.119 [M-H](-) was shifted to m/z 555.151, being confirmed as 1,3-O-dicaffeoylquinic acid, which presented an ED50 of 57 µg kg(-1) on gastric protection, lesser than the therapeutic concentration of omeprazole (40 mg kg(-1)).

Parkinson's disease (PD) is a chronic neurodegenerative disorder characterized by progressive loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc). The etiology and pathogenesis of PD are still unknown, however, many evidences suggest a prominent role of oxidative stress, inflammation, apoptosis, mitochondrial dysfunction and proteosomal dysfunction. The peroxisome proliferator-activated receptor (PPAR) ligands, a member of the nuclear receptor family, have anti-inflammatory activity over a variety of rodent's models for acute and chronic inflammation. PPAR-α agonists, a subtype of the PPAR receptors, such as fenofibrate, have been shown a major role in the regulation of inflammatory processes. Animal models of PD have shown that neuroinflammation is one of the most important mechanisms involved in dopaminergic cell death. In addition, anti-inflammatory drugs are able to attenuate toxin-induced parkinsonism. In this study we evaluated the effects of oral administration of fenofibrate 100mg/kg 1h after infusion of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in the SNpc. First, we assessed the motor behavior in the open field for 24h, 7, 14 and 21 days after MPTP. Twenty-two days after surgery, the animals were tested for two-way active avoidance and forced swimming for evaluation regarding cognitive and depressive parameters, respectively. Twenty-three days after infusion of the toxin, we quantified DA and turnover and evaluated oxidative stress through the measurement of GSH (glutathione peroxidase), SOD (superoxide dismutase) and LOOH (hydroperoxide lipid). The data show that fenofibrate was able to decrease hypolocomotion caused by MPTP 24h after injury, depressive-like behavior 22 days after the toxin infusion, and also protected against decreased level of DA and excessive production of reactive oxygen species (ROS) 23 days after surgery. Thus, fenofibrate has shown a neuroprotective effect in the MPTP model of Parkinson's disease.

Ethnopharmacological relevance In Brazil, Acmella oleracea (L.) R.K. Jansen, popularly known as “jambu”, has been used by some communities from Amazon region to treat toothache. In this study we examined the antinociceptive effect of the ethanolic extract obtained from the flowers of Acmella oleracea (EEAO) in animal models of nociceptive (chemical and thermal) and neuropathic (partial sciatic nerve ligation) pain. Materials and methods Adult male mice were treated by intraperitoneal route (i.p.) with EEAO before the induction of nociceptive response by formalin, capsaicin and cinnamaldehyde, thermal heat hyperalgesia (hot plate test) and mechanical allodynia (traumatic sciatic nerve injury). Acute toxicity and non-specific sedative effects were evaluated. Results EEAO (10, 30 and 100 mg/kg) reduced both neurogenic and inflammatory phases of the formalin- and also capsaicin- and cinnamaldehyde-induced orofacial nociception. Interestingly, EEAO at 100 mg/kg (i.p.) also reversed capsaicin-induced heat hyperalgesia assessed as the latency to paw withdrawal in the hot plate test. Also in the hot plate test, paw withdrawal latency was increased by EEAO (100 mg/kg) and this response was only partially reversed by naloxone. Furthermore, EEAO (100 mg/kg) also reduced mechanical allodynia caused by partial sciatic nerve ligation for 3 h. The estimated LD50 value was 889.14 mg/kg and EEAO did not alter the locomotion of animals in the open-field test. Conclusion Taken together, our data show that EEAO produces prevalent antinociceptive effects and does not cause adverse effects. The presence of N-alkylamides, including spilanthol, suggests that the therapeutic effect of EEAO is related to its highest anesthetic activity.

Ethnopharmacological relevance Piper tuberculatum Jacq. (Piperaceae) is medicinally used as an analgesic and as a treatment for gastric complaints. Thus, the current study aimed to investigate the gastroprotective and antisecretory properties of the dichloromethane fraction of the fruit of Piper tuberculatum (DFPT) and piplartine, a compound isolated from the DFPT, in rats. Materials and methods Gastric ulcers were induced in fasted rats by oral administration of absolute ethanol and then mucus content and glutathione (GSH) levels were measured. Mechanisms underlying the antisecretory action were studied through gastric H + ,K + -ATPase activity of highly purified rabbit gastric microsomes and pylorus ligature method in rats. Results In the acute toxicity test the values of estimated LD 50 for oral and intraperitoneal administration of DFPT were 1.6266 and 0.2684 g/kg, respectively. The DFPT (ED 50 =29 mg/kg, p.o.) and piplartine (4.5 mg/kg, p.o.) promoted gastroprotection against acute lesions induced by ethanol, effect that could be related with the maintenance of GSH levels in the gastric mucosa. However, only DFPT stimulated gastric mucus secretion. In vitro , the DFPT and piplartine inhibited the H + ,K + -ATPase activity and, in vivo DFPT and piplartine also reduced basal gastric acid secretion, as well as that stimulated by pentagastrin. Conclusions These results demonstrate that DFPT and piplatine cause marked gastroprotective effects accompanied by the increase and maintenance of gastric mucus and GSH levels, as well as a reduction in gastric acid secretion through the gastrinergic pathway.

We evaluate the curative efficacy of the ethanolic extract (EET) of roots from Arctium lappa (bardana) in healing of chronic gastric ulcers induced by 80% acetic acid in rats and additionally studies the possible mechanisms underlying this action. Oral administration of EET (1, 3, 10 and 30mg/kg) reduced the gastric lesion area in 29.2%, 41.4%, 59.3% and 38.5%, respectively, and at 10mg/kg promoted significant regeneration of the gastric mucosa, which was confirmed by proliferating cell nuclear antigen immunohistochemistry. EET (10mg/kg) treatment did not increase the gastric mucus content but restored the superoxide dismutase activity, prevented the reduction of glutathione levels, reduced lipid hydroperoxides levels, inhibited the myeloperoxidase activity and reduced the microvascular permeability. In addition, EET reduced the free radical generation and increased scavenging of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals in vitro. Furthermore, intraduodenal EET (10 and 30mg/kg) decreased volume and acidity of gastric secretion. Total phenolic compounds were high in EET (Folin-Ciocalteau assay) and the analysis by liquid chromatography-mass spectrometry revealed that the main compounds present in EET were a serie of hydroxycinnamoylquinic acid isomers. In conclusion, these data reveal that EET promotes regeneration of damaged gastric mucosa, probably through its antisecretory and antioxidative mechanisms.

Ethnopharmacological relevance Piper aleyreanum is a small tree that is widely distributed in tropical and subtropical regions, mostly in North and South America, and is used as an immunomodulator, analgesic and antidepressant in folk medicine. Aim of the study This study was designed to investigate the antinociceptive, anti-inflammatory and gastric antiulcer activities of the essential oils from the aerial parts of Piper aleyreanum (EOPa) in rodents. Materials and methods The antinociceptive and anti-inflammatory effects of orally administered EOPa were evaluated in mice subjected to the formalin and pleurisy models, respectively. We also pretreated the rats with EOPa before acute ethanol-induced gastric lesions and measured gastric lesion extension and mucus and glutathione (GSH) levels in the gastric mucosa. Finally, we performed a phytochemical analysis of EOPa. Results The chemical composition of EOPa was analyzed by gas chromatography and mass spectrometry (GC/MS), which identified 35 compounds, representing 81.7% of total oil compounds. Caryophyllene oxide (11.5%), β-pinene (9%), spathulenol (6.7%), camphene (5.2%), β-elemene (4.7%), myrtenal (4.2%), verbenone (3.3%) and pinocarvone (3.1%) were the major oil constituents. The oral administration of EOPa (10–1000 mg/kg) significantly inhibited the neurogenic and inflammatory phases of formalin-induced licking, with ID50 values of 281.2 and 70.5 mg/kg, respectively. The antinociception caused by EOPa (100 mg/kg, p.o.) was not reversed by naloxone (1 or 5 mg/kg, i.p.) in the formalin test. EOPa (100–300 mg/kg, p.o.) did not affect animal motor coordination in an open-field model. In carrageenan-induced pleurisy, EOPa (1–100 mg/kg, p.o.) significantly decreased the total cell count, neutrophils and mononuclear cells with mean ID50 values of 53.6, 21.7 and 43.5 mg/kg, respectively. In addition, EOPa (1–30 mg/kg, p.o.) protected the rats against ethanol-induced gastric lesions with an ID50 value of 1.7 mg/kg and increased the mucus and GSH levels of the gastric mucosa to levels similar to those of the non-lesioned group. Conclusions These data show for the first time that EOPa has significant antinociceptive and anti-inflammatory actions, which do not appear to be related to the opioid system. EOPa also has interesting gastroprotective effects related to the maintenance of protective factors, such as mucus production and GSH. These results support the widespread use of Piper aleyreanum in popular medicine and demonstrate that this plant has therapeutic potential for the development of phytomedicines with antinociceptive, anti-inflammatory and gastroprotective properties.

β-d-Glucan, a polysaccharide isolated from an edible mushroom Pleurotus pulmonarius (Fr.) Quel., presented antinociceptive activity in mice. This study evaluated the involvement of transient receptor potential (TRP) channels and protein kinase C (PKC) on antinociceptive effect of a (1→3),(1→6)-linked β-d-glucan (GL) in mice. Intraperitoneal administration of GL potently inhibited nociceptive responses induced by intraplantar injections of capsaicin, cinnamaldehyde, menthol, acidified saline and phorbol myristate acetate (PMA). Moreover, Western blot analysis revealed that GL treatment also prevented PMA-induced PKCɛ activation. Collectively, present results demonstrate that GL could constitute an attractive molecule of interest for the development of new analgesic drugs.

Ethnopharmacological relevance Salvia officinalis L. has been used as a traditional herbal medicine for gastric disturbances and inflammatory processes. This study investigated the toxicological, antinociceptive and anti-inflammatory effects of the hydroalcoholic extract (HE) from leaves of Salvia officinalis and its isolated compounds in mice. Materials and methods Mice were treated with HE before the induction of nociceptive response by chemical agents (acetic-acid, formalin, glutamate, capsaicin and cinnamaldehyde). Total leukocytes and plasma extravasation induced by acetic acid and paw oedema induced by glutamate, capsaicin and cinnamaldehyde were also measured. The antinociceptive effect of carnosol and ursolic acid/oleanolic acid were evaluated on formalin and cinnamaldehyde models. Results In the acute toxicity test the value of estimated LD50 for HE was 44.7579 g/kg. Oral administration of HE (10, 30 and 100 mg/kg) inhibited the number of writhings, total leukocytes and plasma extravasation induced by acetic acid. In the formalin test, HE reduced both neurogenic and inflammatory phases, effect that was affected by naloxone. The glutamate-, capsaicin- and cinnamaldehyde-induced nociception and paw oedema were reduced by HE at doses that did not affect the locomotor activity of mice in the open field test. Carnosol (10 mg/kg) and ursolic acid/oleanolic acid (30 mg/kg) inhibited the inflammatory phase of formalin and the nociception and mechanical allodynia induced by cinnamaldehyde. Conclusions These results demonstrate that HE presents significant anti-inflammatory and also antinociceptive effects on chemical behavioral models of nociception that involves an opioid mechanism. In addition, carnosol and ursolic acid/oleanolic acid contained in this plant appears to contribute for the antinociceptive property of the extract, possibly through a modulatory influence on TRPA1-receptors. However, further studies regarding the precise site and the mechanism of action of HE and carnosol and ursolic acid/oleanolic acid merited exploring further.

The present work explored the antinociceptive effects of the flavonoid myricitrin in models of overt nociception triggered by intraplantar injection of chemical algogens into the hind paw of mice. The nociception induced by bradykinin (3 nmol/paw i.pl.) was abolished by prior treatment with myricitrin (10-100mg/kg, i.p.) with ID(50) of 12.4 (8.5-18.1)mg/kg. In sharp contrast, myricitrin failed to affect the nociception elicited by prostaglandin E(2) (3 nmol/paw i.pl.). Cinnamaldehyde (10 nmol/paw i.pl.)-induced nociception was reduced by myricitrin (100mg/kg, i.p.) and camphor (7.6 mg/kg,s.c.) in 43±10% and 57±8%, respectively. Myricitrin (30-100mg/kg, i.p.) and amiloride (100mg/kg, i.p.) inhibited nociceptive responses induced by acidified saline (pH 5/paw i.pl.), with ID(50) of 22.0 (16.1-30.0)mg/kg and inhibition of 71±6% and 64±5%, respectively. Moreover, myricitrin (10-30 mg/kg, i.p.) and ruthenium red (3mg/kg, i.p.) significantly reduced the nociception induced by menthol (1.2 μmol/paw i.pl.) with the mean ID(50) of 2.4 (1.5-3.7)mg/kg and inhibition of 95±3% and 51±7%, respectively. In addition, myricitrin administration (30 and 100mg/kg, i.p.) markedly reduced menthol-induced mechanical allodynia. However, myricitrin (100mg/kg, i.p.) prevented (only in time of 60 min) cold allodynia induced by menthol. Collectively, the present results extend prior data and show that myricitrin promotes potent antinociception, an action that is likely mediated by an inhibition of the activation of nociceptors by bradykinin and TRPs agonist (i.e. cinnamaldehyde, acidified saline and menthol), probably via inhibition of PKC pathways. Thus, myricitrin could constitute an attractive molecule of interest for the development of new analgesic drugs.

We used multiple pain models to investigate the effects of (-)-linalool, a monoterpene alcohol present in the essential oil of plants, on chronic inflammatory and neuropathic hypersensitivity in adult Swiss mice. Inflammatory or neuropathic hypersensitivity was induced by intraplantar (i.pl.) injection of complete Freund's adjuvant (CFA) or partial sciatic nerve ligation (PSNL), respectively. Twenty-four hours after CFA injection, we used Von Frey filaments and acetone-evoked cooling to evaluate tactile and thermal hypersensitivity, respectively. A single i.p. injection of (-)-linalool (50 or 200 mg/kg) administered 30 minutes before testing reduced CFA-induced mechanical hypersensitivity. Similarly, (-)-linalool reduced acetone-evoked hypersensitivity up to 4 hours after treatment. Compared with vehicle, (-)-linalool produced a marked reduction in CFA-induced paw edema. (-)-Linalool also reduced mechanical hypersensitivity induced by PSNL 7 days after injury. Multiple (-)-linalool treatments given chronically (twice a day for 10 days; 50 mg/kg, i.p.) significantly reduced mechanical hypersensitivity induced by CFA and PSNL. This multidose strategy did not cause tolerance. We also reasoned that (-)-linalool might reduce nociceptive behavior in response to direct administration of inflammatory mediators. Therefore, we injected the cytokines IL-1β (.1 pg/site) and TNF-α (1 pg/site) intrathecally. (-)-Linalool inhibited the biting response induced by IL-1β and TNF-α. Perspective The article adds information about antinociceptive properties of (-)-linalool in chronic inflammatory and neuropathic hypersensitivity. It also indicates that (-)-linalool might be potentially interesting in the development of new clinically relevant drugs for the management of persistent pain.

A type I arabinogalactan (CPP) was isolated from the viscous gum exuded by Cereus peruvinus (Cactaceae). It contained arabinose, galactose, galacturonic acid, and rhamnose in a 15:66:6:13 molar ratio and had Mw 9 × 105 g mol−1. Methylation analysis and 13C NMR spectroscopy indicated that CPP is composed of a (1 → 4)-linked β- d -Galp main-chain with substituents of α- l -Araf at O-2, O-3 and O-6, which are in turn substituted at O-2, O-3, and O-2,3. These are probably linked to O-4 of some rhamnosyl units of a type I rhamnogalacturonan (RG1). The main chain is formed by repeating (1 → 4)-α- d -GalpA-(1 → 2)-α- l -Rhap groups. The methylation analysis suggested the presence of (1 → 3)-linked β-Galp structures, perhaps linked to the (1 → 4)-linked β- d -Galp backbone. CPP significantly inhibited ethanol-induced gastric lesions in rats at an ED50 of 49 mg kg−1, indicating that it has a gastroprotective effect. The gastric lesion inhibition by CPP suggests a potential use of this polysaccharide, or the crude plant extract, in phytotherapy.

Previous studies from our group investigated the antinociceptive property of amyrin octanoate, a synthetic compound derivative from natural precursor alpha, beta-amyrin, against nociceptive response induced by acetic acid and formalin. Here, we investigated some of the mechanisms of action underlying the antinociceptive effects of amyrin octanoate. Amyrin octanoate given intraperitoneally (0.001-1 mg /kg) or intrathecally (10-1000 ng /site) caused dose-dependent and long-lasting inhibition of acetic acid-induced visceral nociception, with mean ID(50) values of 0.003 (0.001-0.005) mg/kg and 122.4 (60.8-246.6) ng/site, respectively. In the capsaicin- and glutamate-induced paw licking, amyrin octanoate caused significant and dose-dependent inhibition of both nociceptive responses, with ID(50) values of 1.36 and 0.04 mg/kg, respectively. Furthermore, amyrin octanoate also reduced significantly the nociception caused by intrathecal injection of glutamate, substance P and capsaicin, with inhibitions of 36+/-11%, 67+/-10% and 78+/-5%, respectively. The antinociception caused by amyrin octanoate in the acetic acid test was significantly attenuated by neonatal pretreatment of mice with capsaicin, but seems to involve mechanisms independent of G(i/o) protein, opioidergic, serotonergic, noradrenergic and cholinergic system, since it was not affected by pertussis toxin, naloxone, yohimbine, mecamylamine or atropine. In addition, amyrin octanoate reduced thermal and mechanical hyperalgesia induced by bradykinin and phorbol myristate acetate in rats, without affecting similar responses caused by prostaglandin E(2). Taken together, the present results shown that octanoate amyrin produces antinociceptive and antihyperalgesic effects, through an interaction with capsaicin-sensitive fibers and the inhibition of the PKC signaling pathway.

A glucuronoarabinoxylan (CNAL) was extracted with 1% aq. KOH (25°C) from Cocos nucifera gum exudate. It had a homogeneous profile on HPSEC-MALLS-RI (Mw 4.6 × 10(4)g/mol) and was composed of Fuc, Ara, Xyl, GlcpA (and 4-O-GlcpA) in a 7:28:62:3 molar ratio. Methylation data showed a branched structure with 39% of non-reducing end units, 3-O-substituted Araf (8%), 3,4-di-O- (15%), 2,4-di-O- (5%) and 2,3,4-tri-O-substituted Xylp units (17%). The anomeric region of CNAL (13)C NMR spectrum contained 9 signals, indicating a complex structure. The main chain of CNAL was characterized by analysis of a Smith-degraded polysaccharide. Its (13)C NMR spectrum showed 5 main signals at δ 101.6, δ 75.5, δ 73.9, δ 72.5, and δ 63.1 that were attributed to C-1, C-4, C-3, C-2 and C-5 of (1→4)-linked β-Xylp-main chain units, respectively. CNAL exhibited gastroprotective effect, by reducing gastric hemorrhagic lesions, when orally administered (1 and 3mg/kg) to rats prior to ethanol administration.

Tamarillo ( Solanum betaceum ) is a tropical exotic fruit whose polysaccharides were extracted from the ripe pulp. After various purification steps, homogeneous fractions (designated PTW, STK-1000R and PF) were analyzed by sugar composition, HPSEC, methylation and NMR spectroscopy analysis. The results showed that the fraction PTW consisted of a linear arabinan with (1 → 5)-linked α- l -arabinofuranosyl units. Fractions designated as STK-1000R and PF contained galactoarabinoglucuronoxylans, with (1 → 4)-linked β- d -Xyl p residues in the backbone, carrying branches exclusively at O -2. The polysaccharide in STK-1000R is less branched than that in the PF fraction (∼20.0% and 36.5%, respectively), with side-chains formed by (1 → 5)-linked α- l -Ara f residues and (1 → 4)-linked α- d -Glc p A residues and with non-reducing end units formed by α- l -Ara f , β-Ara p , β- d -Gal p , α- d -GlcpA and 4- O -Me-α- d -Glc p A. Intraperitoneal administration of the STK-1000R fraction in mice significantly reduced the number of abdominal constrictions induced by 0.6% acetic acid and the inflammatory phase of nociception induced by 2.5% formalin, indicating that that fraction has an antinociceptive effect on inflammatory pain models.

After removal of starch, cell wall polysaccharides of seeds of quinoa were studied. They were extracted successively with water and with aq. 10% KOH. The extracted polysaccharides were fractionated and purified by freeze–thaw treatment and by sequential ultrafiltration through membranes. The purified fractions (PQW, K2-30EM, K1-10RM and K1-30RM) were analyzed by sugar composition, HPSEC, methylation and 13 C NMR spectroscopy analysis. The results showed that PQW consisted of a linear arabinan with (1 → 5)-linked α- l -arabinofuranosyl units. Fractions K2-30EM, K1-10RM and K1-30RM were related to rhamnogalacturonan type I with a branched arabinan and galactan side-chains. This arabinan has (1 → 5)-linked α- l -arabinofuranosyl units substituted exclusively in O-3. The main differences between these fractions were their molecular mass and content of Rha and GalA, which probably arise from an increase in their rhamnogalacturonan backbone. A pool of these polysaccharides (arabinan and arabinan-rich pectic polysaccharides) showed gastroprotective activity on ethanol-induced acute gastric lesions in rats.