Antinociceptive effect of Lonchocarpus araripensis lectin: activation of L-arginine/NO/cGMP/K+ATP signaling pathway.

OBJECTIVE AND DESIGN: The involvement of nitric oxide pathway in the antinociceptive activity of Lonchocarpus araripensis lectin (LAL) was investigated in the model of carragenan-induced hypernociception. METHODS: Swiss mice received LAL (0.01-10 mg/kg; i.v.) 30 min before s.c. injection of carragenan in the paws. For the involvement of nociceptive pathways, animals were previously treated with the blockers: NOS (L-NAME, aminoguanidine, 7-nitroindazole); soluble guanylyl cyclase (ODQ); channels of ATP-dependent K+ (glibenclamide); L-type Ca2+ (nifedipine), or Ca2+-dependent Cl- (niflumic acid). Participation of lectin domain was evaluated by injection of LAL associated with N-acetyl-glucosamine (GlcNAc). nNOS gene relative expression was evaluated in the paw tissues and nNOS immunostaining in dorsal root ganglia. RESULTS: LAL at all doses inhibited carrageenan-induced hypernociception (4.12 ± 0.58 g), being maximal at 10 mg/kg (3 h: 59%), and reversed by GlcNAc. At this time, LAL effect was reversed by nifedipine (39%), niflumic acid (59%), L-NAME (59%), 7-nitroindazole (44%), ODQ (45%), and glibenclamide (34%), but was unaltered by aminoguanidine. LAL increased (95%) nNOS gene expression in mice paw tissues, but not its immunoexpression in the dorsal root ganglia. CONCLUSION: The antinociceptive effect of Lonchocarpus araripensis lectin involves activation of the L-arginine/NO/GMPc/K+ATP pathway.

Inhibitory effect of Lonchocarpus araripensis lectin in rat acute models of inflammation.

Dalbergieae tribe lectins, possessing binding affinity for galactose and mannose, present inflammatory and nociceptive effects, while those for N-acetylglucosamine are anti-inflammatory. Since the anti-inflammatory effect of the seed lectin of L. araripensis (LAL) had been already demonstrated in mice, this effect was presently evaluated in rat models of acute inflammation. LAL (0.01-1 mg/kg) was administered by intravenous (i.v.) route in male Wistar rats 30 min before paw edema induction by dextran or carrageenan, and peritonitis by carrageenan. LAL (1 mg/kg) was incubated with N-acetylglucosamine for allowing lectin-sugar interactions before injection into animals. LAL toxicity was evaluated by the parameters: body mass, organs weight, stomach macroscopy, hematological and biochemical dosage. Statistical analysis was performed by ANOVA and Bonferroni's test (p<0.05). The paw edema induced by carrageenan (AUC: 0.96 ± 0.09) was inhibited by LAL about 39% (0-2 h) at all doses, and about 72% (3-5 h) at 0.1 and 1 mg/kg. The increase in the neutrophil migration stimulated by carrageenan was also inhibited by LAL (83%). In both models, LAL inhibitory effect was prevented by GlcNAc. The sub-chronic treatment with LAL was well tolerated by animals. LAL possesses anti-inflammatory effect via lectin domain, indicating potential modulator role in cellular inflammatory events.

The leguminous lectin of Lonchocarpus araripensis promotes antinociception via mechanisms that include neuronal inhibition of Na(+) currents.

OBJECTIVE AND DESIGN: Sodium channels are highly expressed in nociceptive sensory neurons during hypernociceptive conditions. Based on the presence of a glycosidic portion in the sodium channel ß subunit associated to the antinociceptive effect of leguminous lectins via lectin domain, this study investigated the antinociceptive activity of the lectin isolated from Lonchocarpus araripensis seeds (LAL) in mice behavioral models and in NaV current in the nociceptor of rat dorsal root ganglion (DRG). MATERIAL/METHODS: LAL antinociceptive activity and the participation of opioid system, lectin domain and sodium channels were evaluated in Swiss mice models of nociception (formalin, capsaicin, hot plate, tail flick, von Frey) and in primary cultures of Wistar rats neurons of DRG (patch clamp). RESULTS: LAL presented inhibitory effects in the nociception induced by chemical and mechanical, but not by thermal stimuli and reduced total Na(+) current. LAL activity was inhibited by the lectin association with its binding sugar N-acethyl-glucosamine. CONCLUSION: LAL inhibits peripheral hypernociception by mechanisms that involve the lectin domain, inflammatory mediators and Na(+) channels. The innovative inhibitory action of leguminous lectins on NaV current brings new insights for the investigation of sodium channels role in nociception.

A novel N-acetyl-glucosamine lectin of Lonchocarpus araripensis attenuates acute cellular inflammation in mice.

OBJECTIVE AND DESIGN: This study had investigated the anti-inflammatory activity of a seed lectin (LAL) isolated from Lonchocarpus araripensis. MATERIAL/METHODS: LAL was purified by affinity chromatography (chitin column) and ion exchange chromatography (DEAE-Sephacel). In vitro LAL was tested for hemagglutinating activity against rabbit erythrocytes. In vivo LAL was assessed for the anti-inflammatory activity via intravenous injection (i.v.) in Swiss mice (25-30 g; n = 6/group) in models of paw edema and peritonitis. STATISTICAL ANALYSIS: ANOVA (p < 0.05). RESULTS: LAL revealed two bands of 30 and 60 kDa (SDS-PAGE) and exhibited hemagglutinating activity. LAL (10 mg/kg) inhibited the paw edema (77%) and vascular permeability (26%) induced by carrageenan, and the paw edema induced by serotonin (80%), bradykinin (49%), sodium nitroprusside (83%), TNF-α (75%) and PGE2 (64%). LAL also inhibited the neutrophil migration induced by fMLP (70%) or carrageenan (69%). The intravital microscopy showed that LAL inhibited rolling (83%) and adhesion (70%) of leukocytes. LAL anti-inflammatory effect was reversed by its association with N-acetyl-glucosamine. The nine-daily treatment with LAL (10 mg/kg; i.v.) showed no toxicity. CONCLUSION: The novel N-acetyl-D-glucosamine-binding lectin isolated from L. araripensis seeds presents anti-inflammatory effect involving the lectin domain and the inhibition of 5-HT, BK, PGE2, NO, TNF-α and leukocyte rolling and adhesion.

Purification and primary structure of a mannose/glucose-binding lectin from Parkia biglobosa Jacq. seeds with antinociceptive and anti-inflammatory properties.

Parkia biglobosa (subfamily Mimosoideae), a typical tree from African savannas, possess a seed lectin that was purified by combination of ammonium sulfate precipitation and affinity chromatography on a Sephadex G-100 column. The P. biglobosa lectin (PBL) strongly agglutinated rabbit erythrocytes, an effect that was inhibited by d-mannose and d-glucose-derived sugars, especially α-methyl-d-mannopyranoside and N-acetyl-d-glucosamine. The hemagglutinating activity of PBL was maintained after incubation at a wide range of temperature and pH and also was independent of divalent cations. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis, PBL exhibited an electrophoretic profile consisting of a single band with apparent molecular mass of 45 kDa. An analysis using electrospray ionization-mass spectrometry indicated that purified lectin possesses a molecular average mass of 47 562 ± 4 Da, and the analysis by gel filtration showed that PBL is a dimer in solution. The complete amino acid sequence of PBL, as determined using tandem mass spectrometry, consists of 443 amino acid residues. PBL is composed of a single non-glycosylated polypeptide chain of three tandemly arranged jacalin-related domains. Sequence heterogeneity was found in six positions, indicating that the PBL preparations contain highly homologous isolectins. PBL showed important antinociceptive activity associated to the inhibition of inflammatory process.

Hydrogels dressings based on guar gum and chitosan: Inherent action against resistant bacteria and fast wound closure.

Hydrogels made with depolymerized guar gum, oxidized with theoretical oxidation degrees of 20, 35 and 50 %, were obtained via Schiff's base reaction with N-succinyl chitosan. The materials obtained were subjected to characterization by FT-IR, rheology, swelling, degradation, and morphology. Additionally, their gelation time categorized all three hydrogels as injectable. The materials' swelling degrees in Phosphate-Buffered Saline (PBS) were in the range of 26-35 g of fluid/g gel and their pore size distribution was heterogeneous, with pores varying from 67 to 93 µm. All hydrogels degraded in PBS solution, but maintained around 40 % of their initial mass after 28 days, which was more than enough time for wound healing. The biomaterials were also flexible, self-repairing, adhesive and cytocompatible and presented intrinsic actions, regardless of the presence of additives or antibiotics, against gram-positive (Staphylococcus aureus, Staphylococcus epidermidis) and gram-negative bacteria (Escherichia coli). However, the most pronounced bactericidal effect was against resistant Staphylococcus aureus - MRSA. In vivo assays, performed with 50 % oxidized gum gel, demonstrated that this material exerted anti-inflammatory effects, accelerating the healing process and restoring tissues by approximately 99 % within 14 days. In conclusion, these hydrogels have unique characteristics, making them excellent candidates for wound-healing dressings.

Purification and partial characterization of a novel lectin from Dioclea lasiocarpa Mart seeds with vasodilator effects.

A lectin from seeds of Dioclea lasiocarpa (DLL) was purified in a single step by affinity chromatography in a Sephadex G-50 column. DLL haemagglutinated rabbit erythrocytes showing stability even after 1 h of exposure to a different pH values (optimal between pH 6.0 and 8.0) but was inhibited after incubation with D-mannose and D-glucose. The pure protein possessed a molecular weight of 25 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis and 25,410Da by mass spectrometry. The results analyzed by the software SELCON 3 indicate that ß-sheet secondary structures are predominant in DLL (approximately 40.2% antiparallel ß-sheet, 4.6% parallel ß-sheet, 7.2% α-helices, 17.3% turns, and 28.7% unordered structures). Mechanical activity of isolated aorta from rat measured by cumulative concentration curves of DLL, performed at the contraction plateau induced by phenylephrine in either endothelium-intact or denuded aorta. DLL (IC(50) = 34.12 ± 3.46 µg/ml) relaxed precontracted endothelized aortic rings by 34.61 ± 9.06%, 55.19 ± 11.9%, and 81.33 ± 14.35%, respectively, at 10 µg/ml (initial concentration), 30 µg/ml, and 100 µg/ml (maximum effect). All effects occurred via interaction with lectin domains and participation of nitric oxide.

In vivo anti-inflammatory effect of a sulfated polysaccharide isolated from the marine brown algae Lobophora variegata.

CONTEXT: Lobophora variegata J.V. Lamouroux (Dictyotaceae) is a brown marine alga widely encountered in the Brazilian sea coast that presents high content of fucans. Anti-inflammatory effects of fucans are reported mostly in models in vitro, but little is known about its effects in vivo. OBJECTIVE: To investigate vascular and cellular effects of a sulfated polysaccharide from the brown marine algae L. variegata (SP-Lv) in acute inflammatory models. MATERIALS AND METHODS: SP-Lv was isolated by DEAE-cellulose and analyzed by agarose gel electrophoresis and evaluated for its inhibitory effect on paw edema, vascular permeability, leukocyte migration and peritoneal nitrite content induced by zymosan in Wistar rats. Anticoagulant activities and possible systemic toxicity were also evaluated. RESULTS: SP-Lv inhibited the paw edema (120 min: 1.42 ± 0.11 vs. 0.95 ± 0.05 mL), plasma exudation (21.53 ± 0.62 vs. 11.96 ± 0.68 µg/g), nitrite content (4.42 ± 0.33 vs. 2.86 ± 0.003 µM) and leukocyte migration (5.15 ± 1.21 vs. 1.99 ± 0.16 cells/10(3) mL) induced by zymosan. SP-Lv and L-NAME reduced the paw edema (60-120 min) elicited by L-arginine. However, at 180 min SP-Lv effect was more accentuated and sustained until 240 min, while that of L-NAME was abolished. Similarly to indomethacin, SP-Lv inhibited the entire edema time-course induced by phospholipase A(2), except for the time of 60 min. DISCUSSION AND CONCLUSION: The anti-edematogenic effect of SP-Lv seems to occur via inhibition of nitric oxide synthase and cyclooxygenase activities. These results suggest a potential applicability of polysaccharides from alga origin in acute inflammatory conditions.

Aminophylline (a theophylline-ethylenediamine complex) blocks ethanol behavioral effects in mice.

Aminophylline is a complex of theophylline-ethylenediamine, where theophylline is the main component. Theophylline is a methyxanthine and besides inhibiting phosphodiesterase enzymes, it is also a nonselective adenosine antagonist. Several reports suggested the involvement of the brain adenosinergic system in the ethanol-induced motor incoordination. Thus, the objective of this work was to study the effects of the interaction of ethanol with aminophylline as assessed by behavioral tests in mice. Eight groups of male Swiss mice were used. The animals were treated with either distilled water (control) or ethanol (E; 2, 4, and 6 g/kg, orally) for 5 days, or with distilled water for 4 days, and on the fifth day with aminophylline (A; 5 and 10 mg/kg, intraperitoneally). In the association groups (association protocols), the animals were treated with ethanol (E; 6 g/kg, orally) for 4 days, and on the fifth day received aminophylline (A; 10 mg/kg, intraperitoneally), 30 min after the last ethanol administration (first protocol, E/A). In the second association protocol (A/E), ethanol was administered for 4 days, and on the fifth day the animals received aminophylline (A; 10 mg/kg, intraperitoneally), followed again by ethanol (E; 6 g/kg, orally) administration, 30 min later. E (6 g/kg) evoked a central nervous system depressor effect, by decreasing both the locomotor activity and rearing in the open field test, and A (5 and 10 mg/kg) showed opposite effects. However, the E/A or A/E associations blocked the ethanol effect. In the rota rod test, ethanol presented a muscular relaxant effect, which was decreased in both association protocols. In the tail suspension test, while the E/A association decreased immobility, A/E association increased it, as compared with controls. In conclusion, the effects of ethanol were inhibited by its association with aminophylline, suggesting that ethanol acts on the adenosine neurotransmission.

Lectin purified from Lonchocarpus campestris seeds inhibits inflammatory nociception.

Lonchocarpus campestris (tribe Dalbergieae) possess a mannose biding lectin (LCaL) purified by ion exchange chromatography on DEAE-Sephacel, HiTrap DEAE FF and TSKgel engaged in AKTA-HPLC system. LCaL agglutinates trypsinized rabbit erythrocytes and its activity was maintained after incubation in a wide range of temperature (4-100 °C) and pH (4-9). The lectin had its apparent molecular weight evaluated by size-exclusion chromatography and SDS-PAGE and presented a profile of 10 kDa and 25 kDa in denaturing and native conditions, respectively. LCaL injected by intravenous route in mice showed antinociceptive activity in the behavioral tests of Formalin and Writhing. In the formalin test LCaL inhibited the licking time by 37% in the neurogenic phase and by 73% in the inflammatory phase. In the acetic acid-induced writhing test LCaL showed inhibitory effect at 0.1 mg/kg (72%), 1 mg/kg (74%) and 10 mg/kg (70%). The lectin also inhibited the increase in vascular permeability at 10 mg/kg and leukocyte migration at 0.1, 1 and 10 mg/kg concentrations. Additionally, LCaL inhibited paw edema (mainly from 1 to 3 h by 46%) and hyperalgesia (1 h: 82%; 3 h: 63%) induced by carrageenan. In conclusion, LCaL presents an antinociceptive action mainly via inhibition of inflammation.

An arabinogalactan-glycoconjugate from Genipa americana leaves present anticoagulant, antiplatelet and antithrombotic effects.

Glycoconjugates extracted from Genipa americana leaves (PE-Ga) were separated into two fractions, denominated as PFI and PFII (total carbohydrate: 23-36%/uronic acid: 9-30%; protein:4-5%; polyphenols:0.776-0.812 mg/g), mainly composed by arabinose, galactose and uronic acid and presenting high (PFI) and low (PFII) molecular weight (based on polyacrylamide electrophoresis gel and gel permeation chromatography). Uronic acid was also detected by FT-IR (wavenumbers: 1410 and 1333 cm-1) and NMR (α-GalpA). Deproteinization of glycoconjugates showed reduced protein and polyphenol levels with loss of its biological effects. PE-Ga and PFII prolonged clotting time-aPTT (3.6 and 1.8x), while PE-Ga and PFI inhibited by 48% (100 µg/µL) the ADP-induced platelet aggregation. In vivo, these glycoconjugates at 1 mg/kg inhibited (37-53%) venous thrombus formation (4.7 ± 0.1 mg) and increased bleeding time (PE-Ga and PFI:3.0x; PFII:1.7x vs. PBS:906 ± 16.7 s). In conclusion, the arabinogalactan-rich glycoconjugate of G. americana leaves, containing uronic acid, present antiplatelet, anticoagulant (intrinsic/common pathway) and antithrombotic effects, with low hemorrhagic risk.

Calycophyllum spruceanum BENTH ameliorates acute inflammation in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Calycophyllum spruceanum (Benth.) Hook. F. ex K. Schum. is widely distributed in the Amazonian region of Brazil, where it is popularly known as "mulateiro", "pau-mulato", "pau-mulato-de-várzea", "escorrega-macaco" or "pau-marfim". Preparations of C. spruceanum barks are used in the form of tea, poultice or skin patches to treat stomach diseases, skin inflammation and uterus tumors. PURPOSE OF THE STUDY: To investigate in vivo the antinociceptive and anti-inflammatory activities of the hydroalcoholic extract of Calycophyllum spruceanum barks (HECSb) in order to validate its popular usage in inflammatory conditions. MATERIALS AND METHODS: Chemical analysis of HECSb was performed using the UHPLC-MS system. Mice were treated per oral with HECSb (5-5000 mg/kg) and evaluated for acute toxicity (during 15 days); motor activity (Rota rod test); body weight (up to 72 h); antinociceptive activity: writhes induced by 0.8% acetic acid; paw licking induced by 2.5% formalin; paw withdrawal (von Frey test) induced by carrageenan (300 µg) or PGE2 (100 ng); anti-inflammatory (paw edema model). For histopathological analysis subplantar tissue fragments were collected 1 h after paw edema induction. RESULTS: HECSb chemical analysis revealed the presence of caffeoylquinic derivatives, small organic acids, and phenolic compounds. HECSb showed antinociceptive effect, reducing the number of acetic acid-induced writhes by 72% at 120 mg/kg, paw licking (phase 2- Formalin test) by 33% at 60 mg/kg and 49% at 120 mg/kg; and paw withdrawal elicited by carrageenan (53% at 120 mg/kg) and PGE2 (120 mg/kg) at 0.5 h (48%) and 1 h (45%). HECSb (120 mg/kg) also inhibited the paw edema elicited both by carrageenan (48%) and PGE2 (92%). Histopathological analysis (leukocyte infiltration, edema, focal areas of hemorrhage, vascular congestion) of HECSb treatment at 120 mg/kg demonstrated normal morphology [median 0 (0,1)] compared to PGE2, showing severe alterations [median 3 (2,3); p = 0,0035]. HECSb did not induce acute toxicity nor altered body mass or motor coordination. CONCLUSIONS: HECSb shows antinociceptive and anti-inflammatory effect in mice without inducing apparent acute toxicity.

Ximenia americana heteropolysaccharides ameliorate inflammation and visceral hypernociception in murine caerulein-induced acute pancreatitis: Involvement of CB2 receptors.

BACKGROUND: This study aimed to investigate and characterize the anti-inflammatory and anti-hypernociceptive effects of the total polysaccharides of X. americana (TPL-Xa) bark in a mouse model of acute pancreatitis-induced by caerulein and the potential involvement of cannabinoid receptors. METHODS: TPL-Xa was characterized by1H and 13C NMR spectroscopy. Animals received TPL-Xa (10 mg/kg, i.v.) 30 min before and after caerulein (50 µg/kg, 10×, i.p.) administration. To evaluate the involvement of cannabinoid receptors, AM281 (3 mg/kg, s.c.) and AM630 (1 mg/kg, s.c.) were administered 30 min before TPL-Xa. Plasma levels of amylase and lipase, pancreatic myeloperoxidase (MPO), histology, visceral hypernociception and motor coordination were evaluated 11 and 24 h after acute pancreatitis (AP) induction. RESULTS: TPL-Xa, containing a heteropolysaccharide composed of glucose, galactose, arabinose, rhamnose, fucose and galacturonic acid, reduced amylase and lipase levels, MPO activity, acinar cell necrosis, edema and neutrophil infiltration. TPL-Xa increased the threshold of visceral hypernociception, an effect reversed by AM630, an antagonist of cannabinoid receptor type 2 (CB2). In addition, TPL-Xa did not alter the animals' motor coordination. CONCLUSIONS: TPL-Xa contains heteropolysaccharides that inhibit inflammation and hypernociception in the experimental model of caerulein-induced AP, by a mechanism involving type CB2 receptors.

Effects of anethole and structural analogues on the contractility of rat isolated aorta: Involvement of voltage-dependent Ca2+-channels.

Anethole is a naturally occurring aromatic oxidant, present in a variety of medicinal plant extracts, which is commonly used by the food and beverage industry. Despite its widespread occurrence and commercial use, there is currently little information regarding effects of this compound on the vasculature. Therefore the actions of anethole on the contractility of rat isolated aorta were compared with those of eugenol, and their respective isomeric forms, estragole and isoeugenol. In aortic rings precontracted with phenylephrine (PE; 1 microM), anethole (10(-6) M-10(-4) M) induced contraction in preparations possessing an intact endothelium, but not in endothelium-denuded tissues. At higher concentrations (10(-3) M-10(-2) M), anethole-induced concentration-dependent and complete relaxation of all precontracted preparations, irrespective of whether the endothelium was intact or not, an action shared by eugenol, estragole and isoeugenol. The contractile and relaxant effects of anethole in PE-precontracted preparations were not altered by L-NAME (10 microM) or indomethacin (10 microM), indicating that neither nitric oxide nor prostaglandins were involved in these actions. The mixed profile of effects was not confined to PE-mediated contraction, since similar responses were obtained to anethole when tissues were precontracted with 25 mM KCl. Anethole and estragole (10(-6)-10(-4) M), but not eugenol or isoeugenol, increased the basal tonus of endothelium-denuded aortic rings, an action that was abolished by VDCC blockers nifedipine (1 microM) and diltiazem (1 microM), or by withdrawal of extracellular Ca(2+). Our data suggest complex effects of anethole on isolated blood vessels, inducing contraction at lower doses, mediated via opening of voltage-dependent Ca(2+)-channels, and relaxant effects at higher concentrations that are shared by structural analogues.

Lectin from Canavalia villosa seeds: A glucose/mannose-specific protein and a new tool for inflammation studies.

With important carbohydrate binding properties, lectins are proteins able to decipher the glycocode, and as such, they can be used in bioassays involving cell-cell communication, protein targeting, inflammation, and hypernociception, among others. In this study, a new glucose/mannose-specific lectin from Canavalia villosa seeds (Cvill) was isolated by a single affinity chromatography step in a Sephadex® G-50 column, with a purification yield of 19.35mg of lectin per gram of powdered seed. Analysis of intact protein by mass spectrometry showed the lectin is composed of three polypeptide chains, including a 25.6kDa α chain, 12.9KDa ß, and 12.6 KDa γ fragments, similar to the profile of ConA-like glucose/mannose-specific lectins. Partial sequence of the protein was obtained by MS-MALDI TOF/TOF covering 41.7% of its primary structure. Cvill presented sugar specificity to d-glucose, α-methyl-d-mannoside, d-mannose, and glycoproteins fetuin and ovoalbumin. The lectin characterization showed that Cvill presents high stability within a broad range of pH and temperature, also showing average toxicity against Artemia nauplii. The proinflammatory effect of Cvill was observed by induction of paw edema and hypernociception in mice, with the participation of the carbohydrate binding site, showing its potential to be used as tool in inflammation studies.

The acute inflammatory response induced in mice by the venom of the giant ant Dinoponera quadriceps involves macrophage and interleukin-1ß.

Dinoponera quadriceps (Hymenoptera, Formicidae, Ponerinae) is a primitive and endemic ant of Northeastern Brazil, that uses its sting and associated venom gland to capture preys and for defense. Venom of Dinoponera is of potential clinical importance, since it causes intense local pain, accompanied by erythema and edema, when injected by the sting. With other hymenopteran venoms, inflammatory effects are also reported. The aim of this study was to evaluate the inflammatory activity of D. quadriceps venom (DqV) in mice. Acrylamide electrophoresis of DqV revealed five main protein bands varying between 15 and 100 kDa, confirming the proteinous nature of DqV. DqV subplantar injection elicited edema at 5 µg/kg (3 fold), 50 µg/kg (4 fold) or 500 µg/kg (7 fold) from zero to 360 min compared to saline. DqV (50 µg/kg) increased vascular permeability (4 fold) in the first hour after induction. The paw tissue histology showed moderate inflammatory focus caused by DqV (50 µg/kg) in the first hour of paw edema, but severe tissue changes (edema, inflammatory infiltrate and focal areas of hemorrhage) in the third hour. Intraperitoneal injection of DqV (50 µg/kg) stimulated neutrophil (7 fold) and mononuclear (1.4 fold) migration vs saline. DqV edematogenic effect was inhibited by dexamethasone (92%), thalidomide (82%), cyproheptadine (62%), AA861 (58%), celecoxib (34%) or l-NAME (34%), but the neutrophil migration was only by dexamethasone (57%). DqV-elicited neutrophil migration at 50 µg/kg was potentiated 1.7 fold by the animals pre-treatment with 3% thioglycolate. DqV injection increased the levels of interleukin-1 beta (IL-1ß) in peritoneal cavities. DqV (50, 100 and 200 µg/mL) increased phospholipase activity (A425nm) from 10 min to 40 min. Raw 267 macrophages incubated with DqV (from 3.12 to 50 mg/mL) showed no significant decrease in cell viability or LDH measurements and at 35 µg/mL induced increase in IL-1ß (from 3 to 6 h). This study demonstrated, in mice, the inflammatory effect of D. quadriceps venom, characterized by edema, increase in vascular permeability and neutrophil migration, implying the participation of resident macrophages and IL-1ß, among other inflammatory mediators.

Antinociceptive activity of Calotropis procera latex in mice.

This work evaluated the antinociceptive effect of proteins from the Calotropis procera (Asclepiadaceae) latex using three different experimental models of nociception in mice. The latex protein fraction administered intraperitoneally in male mice at the doses of 12.5, 25 and 50 mg/kg showed the antinociceptive effect in a dose dependent manner compared to the respective controls in all assays. Inhibitions of the acetic acid-induced abdominal constrictions were observed at the doses of 12.5 (67.9%), 25 (85%) and 50 (99.5%) mg/kg compared to controls. Latex protein at the doses of 25 (39.8%; 42%) and 50 mg/kg (66.6%; 99.3%) reduced the nociception produced by formalin in the 1st and 2nd phases, respectively, and this effect was not reversed by pretreatment with naloxone (1 mg/kg). In the hot plate test, an increase of the reaction time was observed only at 60 min after the treatment with latex at the doses of 25 (79.5%) and 50 (76.9%) mg/kg, compared to controls and naloxone was ineffective to reverse the effect. It was concluded that the protein fraction derived from the whole latex of Calotropis procera possesses antinociceptive activity, which is independent of the opioid system.

Effects of chloride channel blockers on hypotonicity-induced contractions of the rat trachea.

1. We have investigated the inhibitory effects of blockers of volume-activated (Cl(vol)) and calcium-activated (Cl(Ca)) chloride channels on hypotonic solution (HS)-induced contractions of rat trachea, comparing their effects with those of the voltage-dependent calcium channel (VDCC) blocker nifedpine. 2. HS elicited large, stable contractions that were partially dependent on the cellular chloride gradient; a reduction to 41.45+/-7.71% of the control response was obtained when extracellular chloride was removed. In addition, HS-induced responses were reduced to 26.8+/-5.6% of the control by 1 microm nifedipine, and abolished under calcium-free conditions, indicating a substantial requirement for extracellular calcium entry, principally via VDCCs. 3. The established Cl(vol) blockers tamoxifen (

Seed lectin from pisum arvense: isolation, biochemical characterization and amino acid sequence.

A glucose/mannose lectin was purified by affinity chromatography from Pisum arvense seeds (PAL) and the 50 kDa molecular mass in solution determined by size exclusion chromatography. SDS-PAGE and electrospray ionization mass spectrometry showed two distinct polypeptide chains: alpha (Mr. 5591 Da) and beta (19986 Da). The lectin was extensively characterized in terms of its biochemical and biological aspects. The amino acid sequence was established by Edman degradation of overlapping peptides. PAL in solution behaves as a dimer and has its monomeric structure formed by two distinct polypeptide chains named alpha (Mr. 5591 Da) and beta (19986 Da) by Electrospray ionization (ESI) mass spectrometry. PAL possesses identical amino acid sequences to that of pea seed lectin but undoubtedly does not exhibit sequence heterogeneity. It is discussed that P. arvense should be considered as a synonym of P. sativum. Furthermore, like pea lectin, PAL discriminates biantennary fucosylated glycan, determined by surface plasmon resonance.

Red marine alga Bryothamnion triquetrum lectin induces endothelium-dependent relaxation of the rat aorta via release of nitric oxide.

We have investigated the vascular relaxant effects of the lectin from a red marine alga Bryothamnion triquetrum (BTL), in particular, the endothelial-dependency and the participation of a specific glycoprotein-binding site. BTL (1-100 microg mL(-1)) was applied to rat isolated aortic rings, with or without endothelium, tonically precontracted with phenylephrine (0.1 microM). Endothelium-dependent relaxation was assessed in the presence of indometacin (10 microM), L-nitro arginine methyl ester (L-NAME, 100 microM) and tetraethylammonium (TEA, 500 microM). For the involvement of the glycoprotein-binding site, BTL was assayed in presence of mucin (300 microg mL(-1)) or N-acetyl D-glucosamine (GlcNAc; 300 microg mL(-1)), a specific and non-specific lectin-binding sugar, respectively. BTL fully and concentration dependently relaxed preparations that possessed an intact endothelium (IC50 (concn producing 50% contraction) = 12.1 +/- 1.6 microg mL(-1)), whereas no significant relaxation was observed in endothelial-denuded tissue. L-NAME, but not indometacin or TEA, completely inhibited the lectin relaxation, suggesting the involvement of nitric oxide (NO). The lectin in association with mucin, but not with GlcNAc, inhibited BTL-induced relaxation, implicating the involvement of the lectin binding site. Our data suggest that the relaxant effect of the red marine alga Bryothamnion triquetrumlectin on isolated aorta occurs via interaction with a specific lectin-binding site on the endothelium, resulting in a release of NO.