Danielle Rocha do Val

Effects of Atorvastatin on Periodontitis of Rats Subjected to Glucocorticoid-Induced Osteoporosis

BACKGROUNDnAtorvastatin (ATV) has shown pleiotropic effects on bone tissue, and osteoporosis can aggravate periodontitis. Thus, the effects of ATV on experimental periodontitis (EP) in rats subjected to glucocorticoid-induced osteoporosis (GIOP) was assessed.nnnMETHODSnMale Wistar rats were divided into the following groups: 1) naive; 2) EP; 3) GIOP + EP; and 4) ATV. Groups GIOP + EP and ATV received 7 mg/kg dexamethasone intramuscularly once per week for 5 weeks, and the others received saline (SAL). Groups EP, GIOP + EP, and ATV were submitted to EP by ligature around the maxillary left second molars for 11 days. Group ATV received 27 mg/kg ATV orally, and the others received SAL 30 minutes before EP. Periodontium was analyzed by macroscopy, microtomography, and histopathology; by immunohistochemical examination of receptor activator of nuclear factor-κB ligand (RANKL), osteoprotegerin (OPG), wingless (WNT) 10b, dickkopf-related protein 1 (DKK-1), and β-catenin; and by enzyme-linked immunosorbent assay analysis of myeloperoxidase (MPO), tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-8, IL10, reduced glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT). Leukogram, liver and kidney enzymes, and bone-specific alkaline phosphatase (BALP) serum levels were evaluated.nnnRESULTSnATV decreased bone loss, reduced MPO, TNF-α, IL-1β, IL-6, and IL-8, and increased IL-10, GSH, SOD, and CAT levels. ATV reduced RANKL and DKK-1 and increased OPG, WNT10b, and β-catenin expressions and BALP activity.nnnCONCLUSIONnATV reduced inflammation, oxidative stress, and bone loss in rats with EP and GIOP, with participation of the WNT signaling pathway.

Effects of glucocorticoid-induced osteoporosis on bone tissue of rats with experimental periodontitis

OBJECTIVEnTo evaluate the effects of osteoporosis induced by glucocorticoid (GIOP) on bone tissue of rats with experimental periodontitis (EP).nnnDESIGNn48 male Wistar rats divided into groups: Naïve, EP, GIOP and GIOP+EP. Rats of GIOP and GIOP+EP groups received 7mg/kg of dexamethasone intramuscularly once a week for 5 weeks. Following, EP and GIOP+EP groups were subjected to ligature-induced periodontitis. Naïve group experienced no manipulation. After 11 days, the animals were euthanized and left maxillae collected for macroscopic, radiographic, micro-tomographic and microscopic analysis of alveolar bone loss (ABL). Blood samples were collected for determination of bone-specific alkaline phosphatase (BALP) levels and the right femurs were removed for radiographic and biomechanical analysis.nnnRESULTSnEP caused ABL and reduced BALP levels (p<0,05), but it did not change the architecture or biomechanics of femur, compared to Naïve. GIOP did not cause ABL, but it significantly decreased alveolar bone mineral density (ABMD), bone percentage and trabecular thickness (Tb.Th) and increased alveolar bone porosity (p<0.05) and significantly reduced BALP serum levels, as well as radiographic density and Youngs module of femur, compared to Naïve. There was a greater ABL in group GIOP+EP when compared to EP (p<0.05). GIOP+EP caused a greater decrease on ABMD, Tb.Th, bone percentage and increased bone porosity (p<0.05) and also presented a significant reduction in BALP levels (p<0.05), in radiographic density and in Youngs module of femur compared to EP (p<0.05).nnnCONCLUSIONSnGIOP can potentiate the destructive effects of EP on alveolar bone and alter the systemic bone loss, by promoting bone resorption and reducing osteoblast activity.

Lectin from Abelmoschus esculentus reduces zymosan-induced temporomandibular joint inflammatory hypernociception in rats via heme oxygenase-1 pathway integrity and tnf-α and il-1β suppression.

Temporomandibular joint (TMJ) disorders show inflammatory components, heavily impacting on quality of life. Abelmoschus esculentus is largely cultivated in Northeastern Brazil for medicinal purposes, having it shown anti-inflammatory activity. We evaluated A. esculentus lectin (AEL) efficacy in reducing zymosan-induced temporomandibular joint inflammatory hypernociception in rats along with the mechanism of action through which it exerts anti-inflammatory activity. Animals were pre-treated with AEL (0.01, 0.1 or 1mg/kg) before zymosan (Zy) injection in the TMJ to determine anti-inflammatory activity. To analyse the possible effect of the hemeoxygenase-1 (HO-1) and the nitric oxide (NO) pathways on AEL efficacy, animals were pre-treated with ZnPP-IX (3mg/kg), a specific HO-1 inhibitor, or aminoguanidine (30mg/kg), a selective iNOS inhibitor, before AEL administration. Von Frey test evaluated inflammatory hypernociception, synovial fluid collection was performed to determine leukocyte counting and myeloperoxidase (MPO) activity 6h after Zy injection, and Evans Blue extravasation determined vascular permeability. TMJ tissue was collected for histopathological analysis (H&E) and immunohistochemistry (TNF-α, IL-1β, HO-1). In addition, TMJ tissue and trigeminal ganglion collection was performed for TNF-α and IL-1β dosage (ELISA). AEL increased inflammatory nociceptive threshold, reduced leukocyte influx along with MPO activity, leukocyte influx into the synovial membrane, and Evans Blue extravasation. It promoted HO-1 overexpression whilst decreased TNF-α and IL-1β expression in the TMJ tissue. AEL reduced TNF-α and IL-1β levels in TMJ tissue and trigeminal ganglion. AEL effects, however, were not observed in the presence of ZnPP-IX. These findings suggest that AEL efficacy depends on TNF-α/IL-1β inhibition and HO-1 pathway integrity.

Anti-inflammatory and anti-nociceptive effects of strontium ranelate on the zymosan-induced temporomandibular joint inflammatory hypernociception in rats depend on TNF-α inhibition

BACKGROUNDnTemporomandibular joint (TMJ) disorders show inflammatory components, heavily impacting on quality of life. Strontium ranelate has previously shown anti-inflammatory and antinociceptive effects on other experimental inflammatory pain models. Thus, we aim to investigate the strontium ranelate efficacy in reducing the zymosan-induced inflammatory hypernociception in the TMJ of rats by evaluating the TNF-α, IL-1β, and hemeoxygenase-1 (HO-1) involvement.nnnMETHODSnWistar rats were treated with strontium ranelate (0.5, 5 or 50u2009mg/kg, per os) 1u2009h before zymosan injection (iart). Mechanical threshold was assessed by Von Frey test and synovial lavage was collected for leukocyte counting and myeloperoxidase measurement, joint tissue and trigeminal ganglion were excised for histopathological analysis (H&E) and TNF-α/IL-1β levels dosage (ELISA). Moreover, rats were pre-treated with ZnPP-IX (3u2009mg/kg, sc), a specific HO-1 inhibitor, before strontium ranelate administration (0.5u2009mg/kg, per os), and Evans Blue (5u2009mg/kg, iv) was administered to assess plasma extravasation. Pre-treatment with indomethacin (5u2009mg/kg, sc) was used as positive control while the sham group received 0.9% sterile saline (per os and iart).nnnRESULTSnStrontium ranelate did not reduce leukocyte counting, myeloperoxidase activity, Evans Blue extravasation, IL-1β levels, and TNF-α/IL-1β immunolabeling; but it increased the nociceptive threshold and reduced TNF-α levels. Additionally, HO-1 inhibition did not change the strontium ranelate effects.nnnCONCLUSIONnStrontium ranelate may achieve its antinociceptive effects through the reduction of TNF-α levels in the trigeminal ganglion, but not suppressing IL-1β expression nor inducing the HO-1 pathway.

Mechanisms involved in antinociception induced by a polysulfated fraction from seaweed Gracilaria cornea in the temporomandibular joint of rats

Temporomandibular disorder is a common clinical condition involving pain in the temporomandibular joint (TMJ) region. This study assessed the antinociceptive effects of a polysulfated fraction from the red seaweed Gracilaria cornea (Gc-FI) on the formalin-induced TMJ hypernociception in rats and investigated the involvement of different mechanisms. Male Wistar rats were pretreated with injection (sc) of saline or Gc-FI 1h before intra- TMJ injection of formalin to evaluate the nociception. The results showed that pretreatment with Gc-FI significantly reduced formalin-induced nociceptive behavior. Moreover, the antinociceptive effect of the Gc-FI was blocked by naloxone (a non-selective opioid antagonist), suggesting the involvement of opioids selective receptors. Thus, the pretreatment with selective opioids receptors antagonists, reversed the antinociceptive effect of the Gc-FI in the TMJ. The Gc-FI antinociceptive effect depends on the nitric oxide/cyclic GMP/protein kinase G/ATP-sensitive potassium channel (NO/cGMP/PKG/K+ATP) pathway because it was prevented by pretreatment with inhibitors of nitric oxide synthase, guanylate cyclase enzyme, PKG and a K+ATP blocker. In addition, after inhibition with a specific heme oxygenase-1 (HO-1) inhibitor, the antinociceptive effect of the Gc-FI was not observed. Collectively, these data suggest that the antinociceptive effect induced by Gc-FI is mediated by μ/δ/κ-opioid receptors and by activation NO/cGMP/PKG/K+ATP channel pathway, besides of HO-1.

Role of central opioid on the antinociceptive effect of sulfated polysaccharide from the red seaweed Solieria filiformis in induced temporomandibular joint pain

&NA; This study aimed to investigate the effect of sulfated polysaccharide from red seaweed Solieria filiformis (Fraction F II) in the inflammatory hypernociception in the temporomandibular joint (TMJ) of rats. Male Wistar rats were pretreated (30 min) with a subcutaneous injection (s.c.) of vehicle or FII (0.03, 0.3 or 3.0 mg/kg) followed by intra‐TMJ injection of 1.5% Formalin or 5‐hydroxytryptamine (5‐HT, 225 &mgr;g/TMJ). In other set of experiments rats were pretreated (15 min) with an intrathecal injection of the non‐selective opioid receptors Naloxone, or &mgr;‐opioid receptor antagonist CTOP, or &dgr;‐opioid receptor Naltridole hydrochloride, or &kgr;‐opioid receptor antagonist Nor‐Binaltorphimine (Nor‐BNI) followed by injection of FII (s.c.). After 30 min, the animals were treated with an intra‐TMJ injection of 1.5% formalin. After TMJ treatment, behavioral nociception response was evaluated for a 45‐min observation period, animals were terminally anesthetized and periarticular tissue, trigeminal ganglion and subnucleus caudalis (SC) were collected plasma extravasation and ELISA analysis. Pretreatment with F II significantly reduced formalin‐ and serotonin‐induced TMJ nociception, inhibit the plasma extravasation and inflammatory cytokines release induced by 1.5% formalin in the TMJ. Pretreatment with intrathecal injection of Naloxone, CTOP, Naltridole or Nor‐BNI blocked the antinociceptive effect of F II in the 1.5% formalin‐induced TMJ nociception. In addition, F II was able to significantly increase the &bgr;‐endorphin release in the subnucleus caudalis. The results suggest that F II has a potential antinociceptive and anti‐inflammatory effect in the TMJ mediated by activation of opioid receptors in the subnucleus caudalis and inhibition of the release of inflammatory mediators in the periarticular tissue. HighlightsF II has antinociceptive and anti‐inflammatory effect in the TMJ.F II inhibits the release of inflammatory cytokines IL‐1&bgr; and TNF‐&agr;.F II increases the &bgr;‐endorphin release in the subnucleus caudalis.The antinociceptive effect of F II depends on the opioid receptors mu, delta e kappa.

A lectin fraction from green seaweed Caulerpa cupressoides inhibits inflammatory nociception in the temporomandibular joint of rats dependent from peripheral mechanisms

Temporomandibular disorders are the second most common cause of orofacial pain mediated by inflammatory compounds, which in many cases leads to chronic orofacial pain. This study assessed the antinociceptive and anti-inflammatory effects of a lectin from the green seaweed Caulerpa cupressoides (CcL) on hypernociception inflammatory in TMJ of rats and investigated the involvement of different mechanisms. Rats received i.v. CcL 30u202fmin prior to injection of flogistic agentes or 0.9% saline into the left TMJ. Pretreatment with CcL (0. 1; 1 or 10u202fmg/kg) promoted a reduction (pu202f<u202f0.05) of inflammatory hypernociception induced by 1.5% Formalin along with inhibition of inflammatory plasma extravasation, cytokines levels, ciclooxigenase-2, and intercellular adhesion molecule (ICAM-1). CcL was able to inhibit the nociceptive response induced by 1.5% Capsaicin, suggesting that CcL has an antinociceptive effect, acting directly on the primary nociceptive neurons. CcL also inhibited the nociceptive response induced by Carrageenan (100u202fμg/TMJ) or Serotonin (5-HT) (225u202fμg/TMJ). In conclusion, the results demonstrate that administration of CcL has a potential antinociceptive and anti-inflammatory effect, with a mechanism that is partially dependent on TNF-α, IL-1β, COX-2 and ICAM-1 inhibition and independently from the cannabinoide and opioid system and NO/cGMP/PKG/K+ATP channel pathway.

Heme oxygenase-1/biliverdin/carbon monoxide pathway downregulates hypernociception in rats by a mechanism dependent on cGMP/ATP-sensitive K+ channels

Objective and designTo investigate the role of heme oxygenase-1 (HO-1), carbon monoxide (CO), and biliverdin (BVD) in the zymosan-induced TMJ arthritis in rats.Materials and MethodsMechanical threshold was assessed before and 4xa0h after TMJ arthritis induction in rats. Cell influx, myeloperoxidase activity, and histological changes were measured in the TMJ lavages and tissues. Trigeminal ganglion and periarticular tissues were used for HO-1, TNF-α, and IL-1β mRNA time course expression and immunohistochemical analyses. Hemin (0.1, 0.3, or 1xa0mg kg−1), DMDC (0.025, 0.25, or 2.5xa0µmol kg−1), biliverdin (1, 3, or 10xa0mg kg−1), or ZnPP-IX (1, 3 or 9xa0mg kg−1) were injected (s.c.) 60xa0min before zymosan. ODQ (12.5xa0µmol kg−1; s.c.) or glibenclamide (10xa0mg kg−1; i.p.) was administered 1xa0h and 30xa0min prior to DMDC (2.5xa0µmol kg−1; s.c), respectively.ResultsHemin (1xa0mg kg−1), DMDC (2.5xa0µmol kg−1), and BVD (10xa0mg kg−1) reduced hypernociception and leukocyte migration, which ZnPP (3xa0mg kg−1) enhanced. The effects of DMDC were counteracted by ODQ and glibenclamide. The HO-1, TNF-α, and IL-1β mRNA expression and immunolabelling increased.ConclusionsHO-1/BVD/CO pathway activation provides anti-nociceptive and anti-inflammatory effects on the zymosan-induced TMJ hypernociception in rats.

Anti-inflammatory and antiresorptive effects of Calendula officinalis on inflammatory bone loss in rats

ObjectiveThe aim of this work was to evaluate the anti-inflammatory and antiresorptive effects of Calendula officinalis (CLO) on alveolar bone loss (ABL) in rats.Material and methodsMale Wistar rats were subjected to ABL by ligature with nylon thread around the second upper left molar. The contralateral hemimaxillae were used as control. Rats received saline solution (SAL) or CLO (10, 30, or 90xa0mg/kg) 30xa0min before ligature and daily until the 11th day. The maxillae were removed and prepared for macroscopic, radiographic, micro-tomographic, histopathologic, histometric analysis, and immunohistochemical localization of receptor activator of nuclear factor kappa-B ligand (RANKL) and osteoprotegerin (OPG). The gingival tissues were used to quantify the myeloperoxidase (MPO) activity, tumor necrosis factor-alpha (TNF-α), and interleukin-1β (IL-1β) concentrations by ELISA. Blood samples were collected for leukogram and to evaluate the bone-specific alkaline phosphatase (BALP) activity and serum levels of aspartate and alanine transaminases (AST/ALT).ResultsThe bone loss induced by 11 days of ligature induced bone loss, reduced levels of BALP, leukocyte infiltration, increased MPO activity, gingival concentrations of TNF-α and IL-1β, and RANKL while reduced OPG immunoexpressions in the periodontal tissue and leukocytosis. Of the CLO, 90xa0mg/kg reduced bone loss, neutrophilia, the levels of pro-inflammatory mediators, and RANKL expression, while it increased OPG immunopositive cells and BALP serum levels, when compared to SAL. CLO did not affect either kidney or liver function, indicated by serum AST/ALT levels.ConclusionThe present data suggests that CLO reduced inflammatory bone resorption in experimental periodontitis, which may be mediated by its anti-inflammatory properties and its effects on bone metabolism.Clinical relevanceCLO can be a potential therapeutical adjuvant in the treatment of periodontitis.

Antinociceptive, anti-inflammatory and toxicological evaluation of semi-synthetic molecules obtained from a benzyl-isothiocyanate isolated from Moringa oleifera Lam. in a temporomandibular joint inflammatory hypernociception model in rats

Inflammation is a key component of many clinical conditions that affect the temporomandibular joint (TMJ) and Moringa oleifera Lam. has been used to treat inflammatory diseases. Here, we evaluated the toxicological effects on mice of a naturally-occurring isothiocyanate from M. oleifera and its seven analogue molecules. Further, the anti-nociceptive and anti-inflammatory effects on a rat model of TMJ inflammatory hypernociception were assessed. The systemic toxicological profile was determined in mice over a 14-day period: MC-1 1u202fμg/kg; MC-D1 1u202fμg/kg, MC-D3 100u202fμg/kg, MC-D6 1u202fμg/kg, MC-D7 1u202fμg/kg, MC-D8 1u202fμg/kg, MC-D9 10u202fμg/kg, and MC-H 1u202fμg/kg. The safest molecules were assayed for anti-nociceptive efficacy in the formalin (1.5%, 50u202fμL) and serotonin (255u202fmg) induced TMJ inflammatory hypernociception tests. The anti-inflammatory effect was evaluated through the vascular permeability assay using Evans blue. Further, the rota-rod test evaluated any motor impairment. Among the tested molecules, MC-D7, MC-D9, and MC-H were not toxic at the survival rate test, biochemical, and hystological analysis. They reduced the formalin-induced TMJ inflammatory hypernociception, but only MC-H decreased the serotonin-induced TMJ inflammation, suggesting an adrenergic receptor-dependent effect. They diminished the plasmatic extravasation, showing anti-inflammatory activity. At the rota-rod test, no difference was observed in comparison with control groups, reinforcing the hypothesis of anti-nociceptive effetc without motor impairment in animals. The analogues MC-D7, MC-D9, and MC-H were safe at the tested doses and efficient in reducing the formalin-induced TMJ hypernociception in rats. Our next steps include determining their mechanisms of anti-nociceptive action.