Vilma Lima

Effects of Tumor Necrosis Factor-α Inhibitors Pentoxifylline and Thalidomide on Alveolar Bone Loss in Short-Term Experimental Periodontal Disease in Rats

BACKGROUND Pentoxifylline (PTX) and thalidomide (TLD) have been shown to inhibit cytokine synthesis, mainly tumor necrosis factor (TNF)-α, in different inflammatory conditions. We studied the effects of these cytokine inhibitors in an experimental model of periodontitis. METHODS Wistar rats were subjected to a ligature placement around the second upper right molars. Alveolar bone loss was evaluated by the sum of the distances between the cusp tip and the alveolar bone along the axis of each molar root, subtracting from the contralateral side. Histopathological analysis was based on cell influx, amount of alveolar bone, and cementum integrity. Animals were weighed daily, and total and differential peripheral white blood cell counts were performed at 6 hours and 1, 7, and 11 days after induction of periodontitis. Groups were treated with saline (positive control), PTX, or TLD 1 hour before and daily up to 11 days after induction of periodontitis. RESULTS Alveolar bone loss was inhibited 42%, 54%, and 69% by PTX at 5, 15, and 45 mg/kg, and 25%, 25%, 42%, and 54% by TLD at 5, 15, 45, and 90 mg/kg, respectively, as compared to the control (P <0.05; analysis of variance). Histological analysis showed that PTX and TLD reduced cell influx and alveolar bone and cementum destruction. PTX and TLD also reversed peripheral lymphomonocytosis but not weight loss, as compared to controls. These data showed that both PTX and TLD reduced alveolar bone loss in periodontitis. CONCLUSION The data showed a protective effect of PTX and TLD on experimental periodontitis, suggesting a role for TNF-α in the pathophysiology of periodontitis. J Periodontol 2004;75:162-168.

Antinociceptive and anti-inflammatory activities of a sulfated polysaccharide isolated from the green seaweed Caulerpa cupressoides

BACKGROUND Red and brown algae sulfated polysaccharides (SPs) have been widely investigated as antinociceptive and/or anti-inflammatory agents; however, no description of these biological properties concerning green algae SPs have been reported. Caulerpa curpressoides (Chlorophyta) presents three SPs fractions (Cc-SP1, Cc-SP2, and Cc-SP3). Anticoagulant (in vitro) and anti- and pro-thrombotic (in vivo) effects of Cc-SP2 had been recently reported. We evaluated the effects of Cc-SP2 using models of nociception and acute inflammation in vivo. METHODS Male Swiss mice received Cc-SP2 (iv) 30 min prior to receiving 0.6% acetic acid (10 ml/kg, ip), 1% formalin (20 μl, sc) or were subjected to thermal stimuli (51 ± 1 °C). Cc-SP2 was injected sc to male Wistar rats in a peritonitis model or a paw edema model using carrageenan (ip or ipl, 500 μg). To analyze the systemic effects, Cc-SP2 (27 mg/kg, sc) was administrated to both genders mice before waiting for 14 days. RESULTS Cc-SP2 (3, 9 or 27 mg/kg) reduced (p < 0.05) the number of writhes induced by acetic acid by 57, 89.9 and 90.6%, respectively, the licking time in the first (9 or 27 mg/kg with 42.47 and 52.1%, respectively) and the second (3, 9 or 27 mg/kg with 68.95, 82.34 and 84.61%, respectively) phases. In the hot-plate test, the antinociceptive effect of Cc-SP2 (9 mg/kg) was primarily observed at 60 min (26.7 ± 1.2 s), with its effect reversed by naloxone (8.6 ± 1.3 s), suggesting the involvement of the opioid system. Cc-SP2 (3, 9 or 27 mg/kg, sc, p < 0.05) showed anti-inflammatory effects by decreasing neutrophils migration by 64, 69 and 73%, respectively, and potently reduced the paw edema, especially at the second (0.16 ± 0.02, 0.16 ± 0.03 and 0.12 ± 0.05 ml) and third (0.16 ± 0.03, 0.18 ± 0.02 and 0.14 ± 0.04 ml) hours, respectively. Cc-SP2 did not cause hepatic or renal alterations or affect body mass or the macroscopy of the organs examined (p > 0.05). Histopathological analyses of the liver and kidney showed that both organs were affected by Cc-SP2 treatment, but these effects were considered reversible. CONCLUSION The results indicate that the analgesic and anti-inflammatory effects of Cc-SP2 could be of biomedical applicability as a new, natural tool in pain and acute inflammatory conditions.

Antinociceptive and anti-inflammatory activities of lectin from the marine green alga Caulerpa cupressoides.

The search for new compounds for controlling pain and inflammation, with minimal side effects has focused on marine algae. The aim of this work was to investigate the effect of the purified lectin from the green marine alga Caulerpa cupressoides (CcL) in classical models of nociception and inflammation. Male Swiss mice received i.v. CcL 30 min prior to receiving 0.8% acetic acid (10 ml/kg; i.p); 1% formalin (20 microl; s.c.) or were subjected to thermal stimuli. We observed that CcL (3, 9 or 27 mg/kg) significantly reduced the number of writhes induced by acetic acid by 37.2%; 53.5% and 86.0%, respectively. CcL (27 mg/kg) also reduced the second phase of the formalin test. However, CcL (27 mg/kg) did not present significant antinociceptive effects in the hot plate test, when compared to morphine, suggesting that its antinociceptive action occurs predominantly through a peripheral mechanism. The antinociceptive effects were abolished when CcL was pre-incubated with mucin (20mg/kg; i.v.). When CcL (9 mg/kg) was administered i.v. in Wistar rats 30 min before carrageenan administration, neutrophil counts were reduced by 65.9%. CcL also inhibited paw edema in all time intervals, especially at the third hour. Finally, CcL (9 mg/kg) administered i.v. in mice did not cause hepatic or renal alterations and did not affect body mass or macroscopy of the organs examined. In conclusion, CcL appears to have important antinociceptive and anti-inflammatory activities and could represent an important agent for future studies.

Relationship between Periodontitis and Rheumatoid Arthritis: Review of the Literature

Periodontitis (PD) and rheumatoid arthritis (RA) are immunoinflammatory diseases where leukocyte infiltration and inflammatory mediators induce alveolar bone loss, synovitis, and joint destruction, respectively. Thus, we reviewed the relationship between both diseases considering epidemiological aspects, mechanical periodontal treatment, inflammatory mediators, oral microbiota, and antibodies, using the keywords “periodontitis” and “rheumatoid arthritis” in PubMed database between January 2012 and March 2015, resulting in 162 articles. After critical reading based on titles and abstracts and following the inclusion and exclusion criteria, 26 articles were included. In the articles, women over 40 years old, smokers and nonsmokers, mainly constituted the analyzed groups. Eight studies broached the epidemiological relationship with PD and RA. Four trials demonstrated that the periodontal treatment influenced the severity of RA and periodontal clinical parameters. Nine studies were related with bacteria influence in the pathogenesis of RA and the presence of citrullinated proteins, autoantibodies, or rheumatoid factor in patients with PD and RA. Five studies investigated the presence of mediators of inflammation in PD and RA. In summary, the majority of the articles have confirmed that there is a correlation between PD and RA, since both disorders have characteristics in common and result from an imbalance in the immunoinflammatory response.

Effect of Atorvastatin in radiographic density on alveolar bone loss in wistar rats

The purpose of this study was to evaluate the effect of Atorvastatin (ATV) on alveolar bone loss induced in rats. Periodontitis was induced by ligature placement around the upper second left molar in a total of 24 male Wistar rats (± 200 g). Groups of 6 animals received via oral gavage either saline or ATV (1, 3 and 9 mg/kg) during 11 days. After this time, the animals were sacrificed and their maxillae were removed, defleshed, radiographed by Digora System®, and latter stained to be photographed using a digital camera. Data were analyzed statistically by ANOVA and Bonferroni test at 5% significance level and presented as mean ± SEM. ATV (9 mg/kg) caused a significant increase on gray tone variation of over 48% (118.3 ± 12.0 gray tones) when compared to saline (79.8 ± 6.2 gray tones), indicating greater radiographic density. These data were corroborated by macroscopic findings, where ATV (9 mg/kg) reduced alveolar bone loss by over 47% (p<0.05), when compared to the group of untreated animals (saline). In summary, ATV was able to prevent alveolar bone loss seen on a ligature-induced periodontitis model.

Heme oxygenase/carbon monoxide-biliverdin pathway may be involved in the antinociceptive activity of etoricoxib, a selective COX-2 inhibitor

The aim of this study was to assess the interaction between the heme oxygenase-1/ biliverdin/carbon monoxide (HO-1/BVD/CO) and cyclooxygenase-2 (COX-2) pathways in the writhing test. Mice were pretreated with 0.1, 1 or 10 mg/kg, ip etoricoxib, a selective COX-2 inhibitor, or with one of the following HO-1/BVD/CO pathway modulators: 1, 3 or 9 mg/kg, sc ZnPP IX, a specific HO-1 inhibitor, 0.3, 1 or 3 mg/kg, sc hemin, a substrate of the HO-1/BVD/CO pathway; or 0.00025, 0.025 or 2.5 μmol/kg, sc DMDC, a CO donor. Mice pretreated with etoricoxib or one of the HO-1/BVD/CO pathway modulators received an injection of acetic acid (ip) after 30 and 60 min, respectively. Next, the number of writhes was quantified between 0 and 30 min after stimulus injection. In another series of experiments, ineffective doses of etoricoxib were co-administered with hemin or DMDC and an effective dose of etoricoxib with ZnPP IX, followed by an acetic acid injection. Four hours after the acetic acid injection, levels of bilirubin, which is a product of BVD conversion by the BVD reductase enzyme, in the peritoneal lavage were determined. Hemin or DMDC reduced (p<0.05) the number of writhes, but ZnPP IX potentiated (p<0.05) the effect of acetic acid by increasing (p < 0.05) the number of writhes. The co-administration of etoricoxib with hemin or DMDC reduced (p<0.05) the number of writhes. However, the analgesic effect of etoricoxib was not observed in the presence of ZnPP IX. Pretreatment with ZnPP IX reduced bilirubin levels, but etoricoxib pretreatment significantly increased the bilirubin concentration in peritoneal exudates. The data obtained from these experiments showed that the HO-1/BVD/CO pathway was activated in the acetic acid-induced abdominal writhing model. The analgesic effect of etoricoxib was at least partially dependent on the participation of the HO-1/BVD/CO pathway.

Anticoagulant activity of a sulfated polysaccharide isolated from the green seaweed Caulerpa cupressoides

The aim of this study was to evaluate certain molecular characteristics of a sulfated polysaccharide (SPs) with anticoagulant properties, isolated from Caulerpa cupressoides (Chlorophyta). Crude SPs were extracted by proteolytic digestion (papain), followed by ion-exchange chromatography on a DEAE-cellulose column. The fractions obtained were analyzed for molecular mass, 0.5% agarose gel electrophoresis and chemical composition. The activated partial thromboplastin time (APTT) test was applied using normal human plasma and standard heparin (HEP) (193 IU mg-1). The yield was ~ 3%, and the chromatography procedure separated the material into three different SP fractions (F I, F II and F III), eluted at the concentrations of 0.50, 0.75 and 1.00 M of NaCl, respectively. Only fraction F II was active (24.62 IU mg-1), with high sulfate content (23.79%) and number of molecular mass peaks. Therefore, the APTT of a fraction isolated from C. cupressoides was less potent than HEP.

Effect of alendronate on bone-specific alkaline phosphatase on periodontal bone loss in rats

OBJECTIVE The study aims to evaluate the effect of alendronate (ALD) on bone-specific alkaline phosphatase (BALP) serum levels on periodontal bone loss in Wistar rats. DESIGN Periodontitis was induced by ligature around the upper second molar in 36 male Wistar rats (± 200 g). Groups of six animals received 0.9% saline (SAL) or ALD (0.01; 0.05; 0.25 mgkg(-1), s.c.), over 11 days; then they were sacrificed and their maxillae were removed to be defleshed and stained for macroscopic or histopathological analysis. Blood samples were collected for BALP, transaminases and total alkaline phosphatase (TALP) serum dosage, and haematologic study. Rats were weighed daily. RESULTS Periodontitis induction caused reduction of BALP, intense alveolar bone loss (ABL), cementum and periodontal ligament destructions and intense leucocyte infiltration seen microscopically. Systemically, periodontitis induced leucocytosis, weight loss and TALP reduction. ALD (0.25 mgkg(-1)) prevented BALP reduction (19.17 ± 1.36 Ul(-1)) when compared to SAL (13.6 ± 1.5), as well as prevented ABL, by 57.2%, when compared to SAL (4.80+0.18 mm(2)), which was corroborated by histological findings (ALD 0.25 mgkg(-1)=1.5 (1-2) and SAL=3 (2-3)) (p<0.05). ALD did not alter transaminases but reduced TALP levels (p<0.05). ALD 0.25 mgkg(-1) reduced 6th-h neutrophilia (2.50 ± 0.22cell × 10(3)mm(-3)) and 7th- (12.29 ± 0.66) and 11th-day lymphomonocytosis (15.74 ± 0.52) when compared to SAL (5.20 ± 0.28; 18.24 ± 1.05; and 23.21 ± 1.48, respectively). ALD did not alter the weight loss. CONCLUSION ALD prevented BALP reduction and ABL and reduced inflammatory infiltrate, without causing systemic alterations.

Guided bone regeneration produced by new mineralized and reticulated collagen membranes in critical-sized rat calvarial defects.

The aim of this study was to evaluate the bone regenerative effect of glutaraldehyde (GA) cross-linking on mineralized polyanionic collagen membranes in critical-sized defects on rat calvarias. Bone calvarial defects were induced in Wistar rats, which were then divided into five groups: a sham group; a control group, which received a commercial membrane; and GA, 25GA, and 75GA groups, which received one of three different polyanionic collagen membranes mineralized by 0, 25, or 75 hydroxyapatite cycles and then cross-linked by GA. Bone formation was evaluated based on digital radiography and computerized tomography. Histological analyses were performed 4 and 12 weeks after the surgical procedure to observe bone formation, membrane resorption, and fibrous tissue surrounding the membranes. Measurement of myeloperoxidase activity, tumor necrosis factor alpha, and interleukin 1beta production was performed 24 h after surgery. The percentage of new bone formation in the GA, 25GA, and 75GA groups was higher compared with the control and sham groups. In the GA and 25 GA groups, the membranes were still in place and were contained in a thick fibrous capsule after 12 weeks. No significant difference was found among the groups regarding myeloperoxidase activity and interleukin 1beta levels, although the GA, 25GA, and 75GA groups presented decreased levels of tumor necrosis factor alpha compared with the control group. These new GA cross-linked membranes accelerated bone healing of the calvarium defects and did not induce inflammation. In addition, unlike the control membrane, the experimental membranes were not absorbed during the analyzed period, so they may offer advantages in large bone defects where prolonged membrane barrier functions are desirable.

Leukotoxicity of Aggregatibacter actinomycetemcomitans in generalized aggressive periodontitis in Brazilians and their family members

Objective The purpose of this study was to examine the leukotoxin promoter types of Aggregatibacter actinomycetemcomitans clones in subjects with generalized aggressive periodontitis (GAgP) and in their family members (FM). Material and Methods Thirty-five patients with GAgP (33.9±7.1 years), 33 of their FM (22.8±11.4 years), and 41 patients with chronic periodontitis (CP) (44.1±9.4 years) were clinically analyzed using the plaque index, gingival index, probing depth (PD), and clinical attachment level (CAL). Subgingival biofilm samples were collected from four interproximal periodontal sites (>PD and >CAL) of each patient. The presence of A. actinomycetemcomitans and its leukotoxic clone was confirmed by polymerase chain reaction (PCR). Results A. actinomycetemcomitans was observed in 23 (51.1%) GAgP patients and 16 (30.1%) CP patients. Thirty-seven (94.8%) patients showed minimally leukotoxic strains and 2 (5.1%) showed highly leukotoxic strains. In the FM group, 10 (30.3%) had aggressive periodontitis (AgP), 12 (36.3%) had CP, 11 (33.3%) were periodontally healthy or had gingivitis, and 12.2% were A. actinomycetemcomitans positive. Greater full mouth PD and CAL were observed in GAgP patients positive for the bacteria than those negative for it (p<;0.05), and the presence of A. actinomycetemcomitans positively correlated with GAgP (Odds ratio, 3.1; confidence interval, 1.4-7.0; p=0.009). Conclusions The presence of A. actinomycetemcomitans was associated with the clinical condition of GAgP, with most patients exhibiting a generalized form of the disease and minimally leukotoxic clones. Most of the relatives of GAgP patients presented either CP or AgP.