Bradykinin Receptors Play a Critical Role in the Chronic Post-ischaemia Pain Model.

Complex regional pain syndrome type-I (CRPS-I) is a chronic painful condition resulting from trauma. Bradykinin (BK) is an important inflammatory mediator required in acute and chronic pain response. The objective of this study was to evaluate the association between BK receptors (B1 and B2) and chronic post-ischaemia pain (CPIP) development in mice, a widely accepted CRPS-I model. We assessed mechanical and cold allodynia, and paw oedema in male and female Swiss mice exposed to the CPIP model. Upon induction, the animals were treated with BKR antagonists (HOE-140 and DALBK); BKR agonists (Tyr-BK and DABK); antisense oligonucleotides targeting B1 and B2 and captopril by different routes in the model (7, 14 and 21 days post-induction). Here, we demonstrated that treatment with BKR antagonists, by intraperitoneal (i.p.), intraplantar (i.pl.), and intrathecal (i.t.) routes, mitigated CPIP-induced mechanical allodynia and oedematogenic response, but not cold allodynia. On the other hand, i.pl. administration of BKR agonists exacerbated pain response. Moreover, a single treatment with captopril significantly reversed the anti-allodynic effect of BKR antagonists. In turn, the inhibition of BKRs gene expression in the spinal cord inhibited the nociceptive behaviour in the 14th post-induction. The results of the present study suggest the participation of BKRs in the development and maintenance of chronic pain associated with the CPIP model, possibly linking them to CRPS-I pathogenesis.

Topical hydrogel containing Achyrocline satureioides oily extract (free and nanocapsule) has anti-inflammatory effects and thereby minimizes irritant contact dermatitis.

Inflammatory dermatoses are prevalent worldwide, with impacts on the quality of life of patients and their families. The aim of this study was to determine the anti-inflammatory effects of Achyrocline satureioides oily extracts and nanocapsules on the skin using a mouse model of irritant contact dermatitis induced by croton oil, and a skin inflammation model induced by ultraviolet B (UVB) radiation. The mice were treated with 15 mg/ear oily extract (HG-OLAS) or nanocapsules (HG-NCAS) of A. satureioides incorporated into Carbopol® 940 hydrogels. We found that HG-OLAS and HG-NCAS formulations reduced ear edema in croton oil-induced lesions with maximum inhibitions of 54±7% and 74±3%, respectively. HG-OLAS and HG-NCAS formulations decreased ear edema induced by UVB radiation (0.5 J/cm2), with maximum inhibitions of 68±6% and 76±2% compared to the UVB radiation group, respectively. HG-OLAS and HG-NCAS modulated myeloperoxidase (MPO) activity after croton oil induction. Furthermore, croton oil and UVB radiation for 6 and 24 h, respectively, stimulated polymorphonuclear cells infiltration. The topical treatments reduced inflammatory processes, as shown by histological analysis. Together, the data suggest that topical application of A. satureioides oily extracts and nanocapsules produced antiedematogenic and anti-inflammatory effects. They constitute a compelling alternative for treatment of skin injuries.

Synthesis of novel trifluoromethyl-substituted spiro-[chromeno[4,3-d]pyrimidine-5,1'-cycloalkanes], and evaluation of their analgesic effects in a mouse pain model.

Herein we report the synthesis of twelve 2,5-substituted 4-(trifluoromethyl)-spirochromeno[4,3-d]pyrimidines (7-10), as well as an evaluation of their analgesic effect in a mouse pain model. The nine new chromeno[4,3-d]pyrimidines (7-9) were synthesized from the cyclocondensation reactions of three 2,2,2-trifluoro-1-(4-methoxyspiro[chromene-2,1'-cycloalkane]-3-yl)ethanones (3) containing 5-, 6- and 7-membered spirocycloalkanes, with some well-known amidine salts (4-6) [NH2CR(NH)]-in which R=Me, Ph, and NH2-at yields of 60-95%. Subsequently, three new 2-(pyrrol-1-yl)-4-(trifluoromethyl)-chromeno[4,3-d]pyrimidines (10) were obtained through a Clauson-Kaas reaction between the respective 2-(amino)-4-(trifluoromethyl)-chromeno[4,3-d]pyrimidines (9) and 2,5-dimethoxy-tetrahydrofuran. The analgesic evaluation showed that these 4-(trifluoromethyl)chromeno[4,3-d]pyrimidines (100mg/kg, p.o.) and Ketoprofen (100mg/kg, p.o.) significantly reduced capsaicin-induced spontaneous nociception. Moreover, the 2-pyrrolyl-spirocyclohexane derivative 10b (100 and 300mg/kg, p.o.) had an anti-allodynic effect comparable to Ketoprofen (100 and 300mg/kg, p.o.) in the arthritic pain model, without causing locomotor alterations in the mice. These results suggest that the compound 10b is a promising molecule for new analgesic drugs in the treatment of pathological pain, such as in arthritis.

Antinociceptive effect of a novel armed spider peptide Tx3-5 in pathological pain models in mice.

The venom of the Brazilian armed spider Phoneutria nigriventer is a rich source of biologically active peptides that have potential as analgesic drugs. In this study, we investigated the analgesic and adverse effects of peptide 3-5 (Tx3-5), purified from P. nigriventer venom, in several mouse models of pain. Tx3-5 was administered by intrathecal injection to mice selected as models of postoperative (plantar incision), neuropathic (partial sciatic nerve ligation) and cancer-related pain (inoculation with melanoma cells) in animals that were either sensitive or tolerant to morphine. Intrathecal administration of Tx3-5 (3-300 fmol/site) in mice could either prevent or reverse postoperative nociception, with a 50 % inhibitory dose (ID50) of 16.6 (3.2-87.2) fmol/site and a maximum inhibition of 87 ± 10 % at a dose of 30 fmol/site. Its effect was prevented by the selective activator of L-type calcium channel Bay-K8644 (10 µg/site). Tx3-5 (30 fmol/site) also produced a partial antinociceptive effect in a neuropathic pain model (inhibition of 67 ± 10 %). Additionally, treatment with Tx3-5 (30 fmol/site) nearly abolished cancer-related nociception with similar efficacy in both morphine-sensitive and morphine-tolerant mice (96 ± 7 and 100 % inhibition, respectively). Notably, Tx3-5 did not produce visible adverse effects at doses that produced antinociception and presented a TD50 of 1125 (893-1418) fmol/site. Finally, Tx3-5 did not alter the normal mechanical or thermal sensitivity of the animals or cause immunogenicity. Our results suggest that Tx3-5 is a strong drug candidate for the treatment of painful conditions.

The role of kinin B1 receptor and the effect of angiotensin I-converting enzyme inhibition on acute gout attacks in rodents.

OBJECTIVE: Verify the role of the kinin B1 receptors (B1R) and the effect of ACE inhibitors (ACEi) on acute gout induced by monosodium urate (MSU) crystals in rodents. METHODS: Painful (overt pain and allodynia) and inflammatory parameters (joint oedema, leukocyte trafficking, interleukin-1ß levels) of acute gout attacks were assessed several hours after an intra-articular injection of MSU (1.25 or 0.5 mg/articulation) into the ankle of rats or mice, respectively. The role of B1R was investigated using pharmacological antagonism or gene deletion. Additionally, B1R immunoreactivity in ankle tissue and sensory neurons, kininase I activity and des-Arg(9)-bradykinin synovial levels were also measured. Similar tools were used to investigate the effects of ACEi on a low dose of MSU (0.0125 mg/articulation)-induced inflammation. RESULTS: Kinin B1R antagonism or gene deletion largely reduced all painful and inflammatory signs of gout. Furthermore, MSU increased B1R expression in articular tissues, the content of the B1 agonist des-Arg(9)-bradykinin and the activity of the B1 agonist-forming enzyme kininase I. A low dose of MSU crystals, which did not induce inflammation in control animals, caused signs of acute gout attacks in ACEi-treated animals that were B1R-dependent. CONCLUSIONS: Kinin B1R contributes to acute gouty attacks, including the ones facilitated by ACEi. Therefore, B1R is a potential therapeutic target for the treatment and prophylaxis of gout, especially in patients taking ACEi.

Synthesis and antinociceptive activity of new 2-substituted 4-(trifluoromethyl)-5,6-dihydrobenzo[h]quinazolines.

A useful synthetic route for an initial new series of 2-substituted 4-(trifluoromethyl)-5,6-dihydrobenzo[h]quinazolines (3), as well as an evaluation of their analgesic effect in a mice pain model, is reported. Five new quinazolines were formed from the cyclocondensation reactions of 2,2,2-trifluoro-1-(1-methoxy-1,2,3,4-tetrahydronaphthalen-2-yl)ethanone (1) with some well-known amidine salts [NH2CR(=NH)] (2), in which R=H, Me, Ph, NH2 and SMe, at a 40-70% yield. Subsequently, due to the importance of the pyrrole nucleus, a 2-(pyrrol-1-yl)quinazoline (4) was obtained through a Clauson-Kaas reaction from the respective 2-(amino)quinazoline, in a reaction with 2,5-dimethoxy-tetrahydrofuran. The analgesic evaluation demonstrated that four 5,6-dihydrobenzo[h]quinazolines (compounds of 3c (R=Ph), 3d (R=NH2), 3e (R=SMe), and 4 (R=pyrrol-1-yl); 100mg/kg, p.o.) and ketoprofen (100mg/kg, p.o.) significantly reduced the spontaneous nociception in a capsaicin-induced test. Moreover, in comparison with ketoprofen (100 and 300mg/kg, p.o.), compound 3c (30-300mg/kg, p.o.) showed an anti-hyperalgesic action in an arthritic pain model without locomotor alterations in the mice, suggesting that quinazoline 3c is a promising prototype scaffold for new analgesic drugs in the treatment of pathological pain such as that in arthritis.

Transient receptor potential ankyrin 1 receptor stimulation by hydrogen peroxide is critical to trigger pain during monosodium urate-induced inflammation in rodents.

OBJECTIVE: Gout is a common cause of inflammatory arthritis and is provoked by the accumulation of monosodium urate (MSU) crystals. However, the underlying mechanisms of the pain associated with acute attacks of gout are poorly understood. The aim of this study was to evaluate the role of transient receptor potential ankyrin 1 (TRPA-1) and TRPA-1 stimulants, such as H2 O2 , in a rodent model of MSU-induced inflammation. METHODS: MSU or H2 O2 was injected into the hind paws of rodents or applied in cultured sensory neurons, and the intracellular calcium response was measured in vitro. Inflammatory or nociceptive responses in vivo were evaluated using pharmacologic, genetic, or biochemical tools and methods. RESULTS: TRPA-1 antagonism, TRPA-1 gene deletion, or pretreatment of peptidergic TRP-expressing primary sensory neurons with capsaicin markedly decreased MSU-induced nociception and edema. In addition to these neurogenic effects, MSU increased H2 O2 levels in the injected tissue, an effect that was abolished by the H2 O2 -detoxifying enzyme catalase. H2 O2 , but not MSU, directly stimulated sensory neurons through the activation of TRPA-1. The nociceptive responses evoked by MSU or H2 O2 injection were attenuated by the reducing agent dithiothreitol. In addition, MSU injection increased the expression of TRPA-1 and TRP vanilloid channel 1 (TRPV-1) and also enhanced cellular infiltration and interleukin-1ß levels, and these effects were blocked by TRPA-1 antagonism. CONCLUSION: Our results suggest that MSU injection increases tissue H2 O2 , thereby stimulating TRPA-1 on sensory nerve endings to produce inflammation and nociception. TRPV-1, by a previously unknown mechanism, also contributes to these responses.

Critical role of protease-activated receptor 2 activation by mast cell tryptase in the development of postoperative pain.

BACKGROUND: Studies have indicated that nearly half of all surgical patients still have inadequate pain relief. Thus, it is crucial to understand the mechanisms involved in postoperative pain in order to better treat it. Thus, the aim of this study was to investigate the involvement of mast cell degranulation, tryptase and its substrate, the protease-activated receptor 2, in a model of postoperative pain in mice. METHODS: We evaluated the effect of the compound 48/80 (to cause mast cell mediator depletion), cromoglycate or ketotifen (mast cell stabilizers), gabexate (tryptase inhibitor) or N3-methylbutyryl-N-6-aminohexanoyl-piperazine (protease-activated receptor 2 antagonist) in a postoperative pain model in mice (n = 5-10). Mast cell degranulation and tryptase activity were also evaluated in the operated tissue (n= 5-8). RESULTS: The pre-treatment with compound 48/80 or ketotifen was able to prevent nociception throughout the postoperative hyperalgesia course (until 5 days after surgery), whereas cromoglycate presented a shorter effect (until 1 day). Gabexate or N3-methylbutyryl-N-6-aminohexanoyl-piperazine also produced a short-lasting effect in preventing postoperative nociception. However, neither gabexate, N3-methylbutyryl-N-6-aminohexanoyl-piperazine nor cromoglycate was capable of reversing nociception when administered after incision. Surgery led to early mast cell degranulation on the incised tissue and increased tryptase activity in tissue perfusates. Cromoglycate fully prevented the tryptase release in the perfusate and the compound 48/80 substantially reduced tryptase activity in the incised tissue. CONCLUSION: Thus, the mast cell degranulation with the subsequent release of tryptase and protease-activated receptor 2 activation are potential targets for the development of novel therapies to prevent, but not reverse, postoperative pain.

Anti-nociceptive and anti-edematogenic effects of glibenclamide in a model of acute gouty attack in rats.

OBJECTIVE AND DESIGN: We investigated the effect of glibenclamide on inflammatory parameters in a model of acute gouty attack in rats. TREATMENT: Intra-articular injection of 50 µl of monosodium urate (MSU) crystals (1.25 mg/site) was used to induce gout-related inflammation. The effects of glibenclamide (1-10 mg/kg, s.c.) or dexamethasone (8 mg/kg, s.c., positive control) were assessed on several inflammation parameters. METHODS: Spontaneous nociception assessment, edema measurement, total and differential leucocyte counts, interleukin (IL)-1ß release, prostaglandin E2 production and determination of blood glucose levels were analyzed. Peritoneal macrophages were incubated with MSU and levels of IL-1ß were measured. Statistical significance was assessed by one- or two-way analysis of variance. RESULTS: Glibenclamide (3 mg/kg) or dexamethasone (8 mg/kg) prevented nociception and edema induced by MSU injection in rats. Glibenclamide did not affect leukocyte infiltration, IL-1ß release and PGE2 production, but only reduced IL-1ß production by MSU-stimulated macrophages at very high concentration (200 µM). Dexamethasone significantly reduced leukocyte infiltration, IL-1ß release and PGE2 production. Glibenclamide reduced whereas dexamethasone increased blood glucose levels of MSU-injected rats. CONCLUSIONS: Glibenclamide reduced nociception and edema, but not leukocyte infiltration, IL-1ß release and PGE2 production. However, its substantial effect on nociception and edema suggests that glibenclamide can be an interesting option as an adjuvant treatment for pain induced by acute attacks of gout.

Preemptive transcranial direct current stimulation induces analgesia, prevents chronic inflammation and fibrosis, and promotes tissue repair in a rat model of postoperative pain.

This study evaluated the effects of previous exposure to Transcranial Direct Current Stimulation (tDCS) on nociceptive, neuroinflammatory, and neurochemical parameters, in rats subjected to an incisional pain model. Forty adult male Wistar rats (60 days old; weighing âˆ¼ 250 g) were divided into five groups: 1. control (C); 2. drugs (D); 3. surgery (S); 4. surgery + sham-tDCS (SsT) and 5. surgery + tDCS (ST). Bimodal tDCS (0.5 mA) was applied for 20 min/day/8 days before the incisional model. Mechanical allodynia (von Frey) was evaluated at different time points after surgery. Cytokines and BDNF levels were evaluated in the cerebral cortex, hippocampus, brainstem, and spinal cord. Histology and activity of myeloperoxidase (MPO) and N-acetyl-ß-D-glucosaminidase (NAGase) were evaluated in the surgical lesion sites in the right hind paw. The results demonstrate that the surgery procedure increased BDNF and IL-6 levels in the spinal cord levels in the hippocampus, and decreased IL-1ß and IL-6 levels in the cerebral cortex, IL-6 levels in the hippocampus, and IL-10 levels in the brainstem and hippocampus. In addition, preemptive tDCS was effective in controlling postoperative pain, increasing BDNF, IL-6, and IL-10 levels in the spinal cord and brainstem, increasing IL-1ß in the spinal cord, and decreasing IL-6 levels in the cerebral cortex and hippocampus, IL-1ß and IL-10 levels in the hippocampus. Preemptive tDCS also contributes to tissue repair, preventing chronic inflammation, and consequent fibrosis. Thus, these findings imply that preemptive methods for postoperative pain management should be considered an interesting pain management strategy, and may contribute to the development of clinical applications for tDCS in surgical situations.

Transient receptor potential ankyrin 1 mediates headache-related cephalic allodynia in a mouse model of relapsing-remitting multiple sclerosis.

ABSTRACT: Primary headache conditions are frequently associated with multiple sclerosis (MS), but the mechanism that triggers or worsens headaches in patients with MS is poorly understood. We previously showed that the proalgesic transient receptor potential ankyrin 1 (TRPA1) mediates hind paw mechanical and cold allodynia in a relapsing-remitting experimental autoimmune encephalomyelitis (RR-EAE) model in mice. Here, we investigated the development of periorbital mechanical allodynia (PMA) in RR-EAE, a hallmark of headache, and if TRPA1 contributed to this response. RR-EAE induction by injection of the myelin oligodendrocyte peptide fragment35-55 (MOG35-55) and Quillaja A adjuvant (Quil A) in C57BL/6J female mice elicited a delayed and sustained PMA. The PMA at day 35 after induction was reduced by the calcitonin gene-related peptide receptor antagonist (olcegepant) and the serotonin 5-HT1B/D receptor agonist (sumatriptan), 2 known antimigraine agents. Genetic deletion or pharmacological blockade of TRPA1 attenuated PMA associated with RR-EAE. The levels of oxidative stress biomarkers (4-hydroxynonenal and hydrogen peroxide, known TRPA1 endogenous agonists) and superoxide dismutase and NADPH oxidase activities were increased in the trigeminal ganglion of RR-EAE mice. Besides, the treatment with antioxidants (apocynin or α-lipoic acid) attenuated PMA. Thus, the results of this study indicate that TRPA1, presumably activated by endogenous agonists, evokes PMA in a mouse model of relapsing-remitting MS.

Sensorial Perception of Astringency: Oral Mechanisms and Current Analysis Methods.

Understanding consumers' food choices and the psychological processes involved in their preferences is crucial to promote more mindful eating regulation and guide food design. Fortifying foods minimizing the oral dryness, rough, and puckering associated with many functional ingredients has been attracting interest in understanding oral astringency over the years. A variety of studies have explored the sensorial mechanisms and the food properties determining astringency perception. The present review provides a deeper understanding of astringency, a general view of the oral mechanisms involved, and the exciting variety of the latest methods used to direct and indirectly quantify and simulate the astringency perception and the specific mechanisms involved.

Physicochemical characterization, released profile, and antinociceptive activity of diphenhydraminium ibuprofenate supported on mesoporous silica.

The thermal, physical, and morphological properties of diphenhydraminium ibuprofenate ([DIP][IBU]) adsorbed onto mesoporous silica (SiO2-60 Šand SiO2-90 Å) from solution were determined. The thermal, physical, and morphological properties of [DIP][IBU] supported on silica were determined. The adsorption of [DIP][IBU] on the pores and surface of silica was proven by N2 adsorption/desorption isotherms. Additionally, release profiles were determined for all systems, and the antinociceptive activity of neat [DIP][IBU] and [DIP][IBU] supported on silica were determined. The interaction of [DIP][IBU] and silica was dependent on pore size, with the formation of a [DIP][IBU] monolayer on SiO2-60 and a multilayer on SiO2-90. The release profile was sustained and slow and dependent on the pore size of the silica, in which the smaller the pore size, the faster the release. The nociceptive evaluation showed that [DIP][IBU] presents a greater (99.21 ±â€¯0.85%) antinociceptive effect than the ibuprofen (46 ±â€¯4.3%). Additionally, [DIP][IBU] on SiO2-60 (90 ±â€¯5.8%) had a greater antinociceptive effect than on SiO2-90 (73 ±â€¯13.2%), which indicates that in vivo tests are in accordance with the in vitro experiments.

Impacts of dose and length of exposure to boldenone and stanazolol on enzymatic antioxidant systems, myeloperoxidase and NAGase activities, and glycogen and lactate levels in rat liver.

We investigated the adverse effects of the anabolic androgenic steroids (AAS) boldenone (BOL) and stanazolol (ST) on the enzymatic antioxidant systems of the rat liver. Male Wistar rats were divided in three protocols (P): PI, 5 mg/kg BOL or ST once a week for 4 weeks; PII, 2.5 mg/kg BOL or ST once a week for 8 weeks; PIII, 1.25 mg/kg BOL or ST once a week for 12 weeks. AAS were administered intramuscularly (0.2 ml, olive oil vehicle) once a week in all protocols. Activities of the enzymes glutathione peroxidase (GPx), glutathione S-transferase (GST), and glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT), were investigated. We assessed the content of hydrogen peroxide (H2O2), glycogen and lactate; and enzyme markers of neutrophils (myeloperoxidase, MPO) and macrophages (NAGase). PI and PII altered the SOD and CAT activities and increased the H2O2 content. PI led to increases in the MPO and NAGase activities. In contrast, changes in GPx, GST and, GR were observed under PII and, to a greater extend, under PIII. Following PIII, GPx, GR, and GST exhibited reduced activities. All protocols altered the glycogen and lactate content. The use of high doses of AAS for a short duration first alters SOD/CAT activity. In contrast, at lower doses of AAS for long periods is associated with changes in the glutathione system. Protocols with high doses of AAS for a short duration exert the most deleterious effects on redox status, markers of cellular infiltration, and the metabolic functioning of hepatic tissues.

Antinociceptive effect of novel trihalomethyl-substituted pyrazoline methyl esters in formalin and hot-plate tests in mice.

The aim of the present study was to evaluate the antinociceptive potential of four novel pyrazoline methyl ester compounds on chemical and thermal models of pain in mice. The following 5-trihalomethylated-4,5-dihydro-1H-pyrazole methyl ester compounds were tested: 3-methyl-5-trifluoromethyl-(MPF3), 4-methyl-5-trifluoromethyl-(MPF4), 3-methyl-5-trichloromethyl-(MPCl3) and 4-methyl-5-trichloromethyl-(MPCl4). MPF3, MPF4, MPCl3 and MPCl4 (0.03-1.0 mmol/kg) given intraperitoneally decreased neurogenic and inflammatory phases of nociception in the formalin test. Moreover, MPF3, MPF4, MPCl3, MPCl4 (0.1-1.0 mmol/kg) and dipyrone (1.5 mmol/kg) also produced a dose-dependent antinociceptive effect in the hot-plate test. However, MPF3, MPF4, MPCl3 and MPCl4 did not impair motor coordination in the rotarod test or spontaneous locomotion in the open field test. The antinociceptive effect of MPF4 (1.0 mmol/kg, i.p.) was reversed by the opioid receptor antagonist naloxone (2 mg/kg, i.p.), but not by the alpha(2)-adrenergic receptor antagonist yohimbine (0.15 mg/kg, i.p.) or by p-chlorophenylalanine ethyl ester (PCPA, 300 mg/kg, i.p.) treatment. In contrast to morphine (5 mg/kg, i.p.), MPF4 given daily for up to 8 days did not generate a tolerance to its antinociceptive effect. However, similar to morphine (11 mg/kg, i.p.), MPF4 reduced gastrointestinal transit in mice. Taken together these results demonstrate that these novel pyrazoline methyl esters tested may be promising prototypes of additional mild analgesics.

Antinociceptive action of 4-methyl-5-trifluoromethyl-5-hydroxy-4, 5-dihydro-1H-pyrazole methyl ester in models of inflammatory pain in mice.

AIMS: The aim of the present study was to evaluate the antinociceptive effect of the novel pyrazoline methyl ester: 4-methyl-5-trifluoromethyl-5-hydroxy-4,5-dihydro-1H-pyrazole methyl ester (MPF4). MAIN METHODS: The effect of MPF4 was assessed in two models of pain: arthritic pain caused by Complete Freund's Adjuvant (CFA) and postoperative pain caused by surgical incision in mice. KEY FINDINGS: MPF4 given intraperitoneally (1.0 mmol/kg, i.p.) produced marked antinociception in inflammatory allodynia caused by CFA. The antinociceptive effect produced by MPF4 was reversed with the pre-treatment of animals with naloxone or naltrindole. Oral administration of MPF4 (1.0 mmol/kg, p.o), dipyrone (1.0 mmol/kg, p.o.) and morphine (0.026 mmol/kg, p.o.) also produced an anti-allodynic effect. However, none of the compounds evaluated reversed the paw edema produced by CFA. Moreover, MPF4, dipyrone and morphine also produced an anti-allodynic effect in the surgical incisional pain model. The maximal inhibitions obtained with preemptive drug treatment were 66+/-7%, 73+/-9% and 88+/-8% for MPF4 (1.0 mmol/kg, p.o.), dipyrone (1.0 mmol/kg, p.o.) and morphine (0.026 mmol/kg, p.o.), respectively. The maximal inhibitions obtained with curative drug treatment were 53+/-9%, 83+/-7% and 84+/-7%, for MPF4, dipyrone and morphine, respectively. Unlike indomethacin, MPF4 did not induce gastric lesions at the dose that caused the highest antinociception (1.0 mmol/kg, p.o). The anti-allodynic action of MPF4, dipyrone and morphine was not associated with impairment of motor activity. SIGNIFICANCE: The results of the present study suggest that MPF4 represents a potential target for the development of new drugs to treat persistent inflammatory pain.

Structural monitoring and modeling of the mechanical deformation of three-dimensional printed poly(ε-caprolactone) scaffolds.

Three-dimensional (3D) printed poly(ε-caprolactone) (PCL) based scaffolds have being proposed for different tissue engineering applications. This study addresses the design and fabrication of 3D PCL constructs with different struts alignments at 90°, 45° and 90° with offset. The morphology and the mechanical behavior under uniaxial compressive load were assessed at different strain percentages. The combination of a new compressionCT device and micro computed tomography (micro-CT) allowed understanding the influence of pore geometry under controlled compressive strain in the mechanical and structural behavior of PCL constructs. Finite element analysis (FEA) was applied using the micro-CT data to modulate the mechanical response and compare with the conventional uniaxial compression tests. Scanning electron microscopic analysis showed a very high level of reproducibility and a low error comparing with the theoretical values, confirming that the alignment and the dimensional features of the printed struts are reliable. The mechanical tests showed that the 90° architecture presented the highest stiffness. With the compressionCT device was observed that the 90° and 90° with offset architectures presented similar values of porosity at same strain and similar pore size, contrary to the 45° architecture. Thus, pore geometric configurations affected significantly the deformability of the all PCL scaffolds under compression. The prediction of the FEA showed a good agreement to the conventional mechanical tests revealing the areas more affected under compression load. The methodology proposed in this study using 3D printed scaffolds with compressionCT device and FEA is a framework that offers great potential in understanding the mechanical and structural behavior of soft systems for different applications, including for the biomedical engineering field.

Nanoencapsulation of coenzyme Q10 and vitamin E acetate protects against UVB radiation-induced skin injury in mice.

This study aimed to investigate the feasibility of producing semisolid formulations based on nanocapsule suspensions containing the association of the coenzyme Q10 and vitamin E acetate by adding gellan gum (2%) to the suspensions. Furthermore, we studied their application as an alternative for the treatment of inflammation induced by ultraviolet B (UVB) radiation. For this, an animal model of injury induced by UVB-radiation was employed. All semisolids presented pH close to 5.5, drug content above 95% and mean diameter on the nanometric range, after redispersion in water. Besides, the semisolids presented non-Newtonian flow with pseudoplastic behavior and suitable spreadability factor values. The results also showed that the semisolid containing coenzyme Q10-loaded nanocapsules with higher vitamin E acetate concentration reduced in 73±8% the UVB radiation-induced ear edema. Moreover, all formulations tested were able to reduce inflammation parameters evaluated through MPO activity and histological procedure on injured tissue and the semisolids containing the nanoencapsulated coenzyme Q10 reduced oxidative parameters assessment through the non-protein thiols levels and lipid peroxidation. This way, the semisolids based on nanocapsules may be considered a promising approach for the treatment and prevention of skin inflammation diseases.

Impacts of dose and time of boldenone and stanazolol exposure in inflammatory markers, oxidative and nitrosative stress and histopathological changes in the rat testes.

The present study was conducted to analyze the adverse effects of the anabolic steroids boldenone (BOL) and stanazolol (ST) in the reproductive function of male rats. These molecules were administered using three different protocols. In Protocol I, BOL and ST were administered in a higher dose than what is recommended but for a short period. In Protocol II, a moderate dose of these compounds was applied for an intermediate period, whereas in Protocol III a reduced dose was administered but for an extended period. Notably, Protocol I and III resulted in increased levels of reactive oxygen specimens (ROS [I, p < 0.01] [III, p < 0.001)]) and nitrite plus nitrate (NOx [I, p < 0.01] [II, p < 0.01] [III,p < 0.05]), respectively, whereas non-protein thiols (NPSH) levels were decreased only after Protocol III (p < 0.01). Myeloperoxidase activity was significantly increased after treatment with BOL in protocol II (p < 0.01) and III (p < 0.05) than with ST in protocol III (p < 0.05). Boldenone and ST also caused a significant up-regulation in the levels of serum testosterone when protocols I (p < 0.01) and II (p < 0.05) were performed. There were also visible histopathological alterations in the testes induced by treatment with BOL, namely degenerative changes primarily characterized by a decrease in the germinal epithelium. Together, these results suggest that the administration of BOL or ST exerts a significantly harmful effect in the testes of male rats. Moreover, all the treatment protocols used in this study induced deleterious effects on the testes, as indicated by the different biochemical parameters investigated. However, only the protocols of longer exposure time (II and III) induced morphological changes compatible with infertility.

Extraction and characterization of collagen from Antarctic and Sub-Antarctic squid and its potential application in hybrid scaffolds for tissue engineering.

Collagen is the most abundant protein found in mammals and it exhibits a low immunogenicity, high biocompatibility and biodegradability when compared with others natural polymers. For this reason, it has been explored for the development of biologically instructive biomaterials with applications for tissue substitution and regeneration. Marine origin collagen has been pursued as an alternative to the more common bovine and porcine origins. This study focused on squid (Teuthoidea: Cephalopoda), particularly the Antarctic squid Kondakovia longimana and the Sub-Antarctic squid Illex argentinus as potential collagen sources. In this study, collagen has been isolated from the skins of the squids using acid-based and pepsin-based protocols, with the higher yield being obtained from I. argentinus in the presence of pepsin. The produced collagen has been characterized in terms of physicochemical properties, evidencing an amino acid profile similar to the one of calf collagen, but exhibiting a less preserved structure, with hydrolyzed portions and a lower melting temperature. Pepsin-soluble collagen isolated from I. argentinus was selected for further evaluation of biomedical potential, exploring its incorporation on poly-ε-caprolactone (PCL) 3D printed scaffolds for the development of hybrid scaffolds for tissue engineering, exhibiting hierarchical features.