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

Macrophage-derived exosomes rescue the TNF-ɑ-suppressed osteo-/cementogenic differentiation of hPDLCs

OBJECTIVE

Inflammatory stimuli compromise the differentiation potency of human periodontal ligament cells (hPDLCs). Macrophage-derived exosomes (M-Exo) play a role in several aspects of cellular activity. This study investigated how M-Exo contributes to the osteo-/cementogenic differentiation of hPDLCs under inflammation and the mechanism involved.

METHODS

M-Exo was identified by transmission electron microscopy, western blotting (WB), and dynamic light scattering. The internalization of M-Exo by hPDLCs was observed. After M-Exo treatment, the osteo-/cementogenic markers were detected by RT-qPCR and WB, and alkaline phosphatase (ALP) activity by ALP staining. Tumor necrosis factor alpha (TNF-ɑ) was applied to simulate inflammation. The rescue effect of M-Exo on TNF-ɑ-suppressed differentiation was validated. The p38 MAPK pathway activity was tested and a specific inhibitor was applied to explore the mechanism.

RESULTS

M-Exo was successfully isolated, identified and internalized by hPDLCs. M-Exo enhanced the osteo-/cementogenic differentiation of hPDLCs, as indicated by upregulated osteo-/cementogenic markers and elevated ALP activity. Moreover, TNF-ɑ inhibited the differentiation capabilities of hPDLCs, on which M-Exo showed a rescue effect. M-Exo activated the p38 MAPK pathway and SB203580 attenuated its promotion effect.

CONCLUSION

This study showed that M-Exo ameliorated the TNF-ɑ-suppressed osteo-/cementogenic differentiation of hPDLCs partly through the p38 MAPK pathway.

The Effect of Two Different Doses of Astaxanthin on Alveolar Bone Loss in an Experimental Model of Periodontitis in Diabetic Rats

This study evaluated the effects of astaxanthin (ASX) on alveolar bone loss, receptor activator of nuclear factor-κB ligand (RANKL), and osteoprotegerin (OPG) activity in ligature-induced periodontitis in diabetic rats. Diabetes mellitus (DM) was induced with 50 mg/kg intraperitoneal streptozotocin in 40 male Wistar rats. The Wistar rats were divided into six experimental groups: non-ligated (NL; n = 6); ligature only (L; n = 6); DM only (D; n = 6); DM + ligature (DP; n = 6); DM + ligature + 1 mg/kg/day ASX (ASX 1 group; n = 8); and DM + ligature + astaxanthin 5 mg/kg/day ASX (ASX 5 group; n = 8). Silk ligatures were placed along the gingival margin of the left mandibular first molar tooth. The study duration was 11 days, after which the animals were euthanised. Changes in alveolar bone levels were clinically measured, and RANKL and OPG activities were immunohistochemically examined. Alveolar bone loss was the most significant in the DP group (p < 0.05). Decreased alveolar bone loss was observed in the ASX 5 group (p < 0.05). Although RANKL activity was highest in the DP group, it was observed at lower levels in the groups to which ASX was administered. OPG activity did not differ between groups (p > 0.05). The results of this study suggested that 1 and 5 mg/kg ASX administration reduced RANKL activity and alveolar bone loss in rats with experimentally induced periodontitis.

Effects of curcumin gel on osteoclastogenic bone markers in experimental periodontitis and alveolar bone loss in wistar rats

BACKGROUND/PURPOSE

Curcumin has anti-inflammatory impacts and was suggested as an inflammatory disease therapy. This study aimed to investigate the implications of curcumin gel on experimental periodontitis (EPD) and alveolar bone loss in rats.

MATERIALS AND METHODS

In this study, twenty-four male Wistar rats were divided equally into four groups: negative control (with no EPD); positive control (EPD induced around lower centrals without treatment); control-treated group: EPD treated with chlorhexidine; and test EPD group treated with curcumin. After 30 days, the serum concentrations of RANKL and IL-1β were measured via ELISA. All animals were sacrificed, and mandibular central incisors with the periodontium were removed. The lingual probing depth and radiographical alveolar bone loss were measured, then samples processed for routine preparation of H&E stained sections and histologically assessed for counting inflammatory cells, osteoclasts, and PDL width.

RESULTS

A significant decrease in the inflammatory cells infiltration, probing depth, and osteoclast numbers with the improvement of PDL associated with a reduction in RANKL and IL-1β serum concentration were seen in both EPD treated groups.

CONCLUSION

Curcumin is as effective as chlorhexidine in treating experimental periodontitis in rats. It was demonstrated to stop bone destruction related to periodontitis by regulating the RANKL and IL-1β markers level in the blood.

Induced oral mucositis in Wistar rats treated with different drugs: Preventive potential in cytokine production

The aim of the present study was to investigate the preventive potential of pentoxifylline, atorvastatin and trans-caryophyllene in oral mucositis through histopathological analysis of wounds in the oral mucosa of Wistar rats treated with 5-FU, and to evaluate the immunomodulatory effect of these drugs on serum nitrite production, in situ IFN-γ, TNF-α and TGF-β, and TNF-α in tissues. A total of 32 male Wistar rats with an average age of 9 weeks and an average body weight of 250 g were divided into four treatment groups: Saline, trans-caryophyllene, pentoxifylline and atorvastatin. Oral mucositis was then induced. On days 3 and 4, the mucosa of the mouth of eight pre-treated animals in each group was bilaterally scarified twice with the tip of a sterile needle, with an anesthetic solution. Mucosal samples from animals treated with trans-caryophyllene preserved a thin epithelial lining associated with focal perivascular inflammatory infiltrates. Pentoxifylline-treated animals exhibited total epithelial loss in oral wounds with severe inflammatory infiltrates and mild re-epithelialization associated with mild and diffuse inflammatory infiltrates. Samples from atorvastatin-treated animals exhibited no epithelial dissolution, with preserved thin lining and mild diffuse inflammatory infiltrates. The analysis of TNF-α expression revealed improved results in trans-caryophyllene animals. The analysis of TGF-β expression revealed positive mononuclear cells. Preventive treatment with atorvastatin was demonstrated to modulate the serum expression levels of TNF-α during all stages of the experiment. Treatment with trans-caryophyllene modulated serum IFN-γ levels negatively, whereas treatment with atorvastatin and trans-caryophyllene maintained lower levels of IFN-γ compared with the control group.

Uncaria tomentosa reduces osteoclastic bone loss in vivo

BACKGROUND

The genus Uncaria (Rubiaceae) has several biological properties significant to human health. However, the mechanisms underlying the protective effect of this plant on bone diseases are uncertain.

PURPOSE

The present study investigated the role of Uncaria tomentosa extract (UTE) on alveolar bone loss in rats and on osteoclastogenesis in vitro.

MATERIALS

UTE was characterized by an Acquity UPLC (Waters) system, coupled to an Electrospray Ionization (ESI) interface and Quadrupole/Flight Time (QTOF, Waters) Mass Spectrometry system (MS). The effect of UTE treatment for 11 days on the ligature-induced bone loss was assessed focusing on several aspects: macroscopic and histological analysis of bone loss, neutrophil and osteoclast infiltration, and anabolic effect. The effect of UTE on bone marrow cell differentiation to osteoclasts was assessed in vitro.

RESULTS

The analysis of UTE by UPLC-ESI-QTOF-MS/MS identified 24 compounds, among pentacyclic or tetracyclic oxindole alkaloids and phenols. The administration of UTE for 11 days on ligature-induced rat attenuated the periodontal attachment loss and alveolar bone resorption. It also diminished neutrophil migration to the gingiva tissue, demonstrated by a lower level of MPO. UTE treatment also decreased the level of RANKL/OPG ratio, the main osteoclast differentiation-related genes, followed by reduced TRAP-positive cell number lining the alveolar bone. Additionally, the level of bone-specific alkaline phosphatase, an anabolic bone marker, was elevated in the plasma of UTE treated rats. Next, we determined a possible direct effect of UTE on osteoclast differentiation in vitro. The incubation of primary osteoclast with UTE decreased RANKL-induced osteoclast differentiation without affecting cell viability. This effect was supported by downregulation of the nuclear factor activated T-cells, cytoplasmic 1 expression, a master regulator of osteoclast differentiation, and other osteoclast-specific activity markers, such as cathepsin K and TRAP.

CONCLUSION

UTE exhibited an effective anti-resorptive and anabolic effects, which highlight it as a potential natural product for the treatment of certain osteolytic diseases, such as periodontitis.

Stimuli Responsive In Situ Gelling Systems Loaded with PLGA Nanoparticles of Moxifloxacin Hydrochloride for Effective Treatment of Periodontitis

The objectives of the present research work were systematic development of novel in situ gel formulation containing nanoparticles for localised delivery of moxifloxacin against bacterial periodontitis. PLGA nanoparticles were prepared and optimised in a systematic manner. Factor screening was performed with the help of half-factorial design to identify the influential factors, while response surface optimisation of the nanoparticles was conducted using central composite design. The optimum nanoparticle formulation was chosen on the basis of lower particle size, higher drug entrapment and controlled drug release characteristics up to 1 week time period, while the optimum in situ gel was selected on the basis of faster gelling and higher viscosity and gel strength properties for improved retention in the periodontium. In vivo histopathological studies and in vivo gamma scintigraphy studies revealed the extended release, superior efficacy and enhanced retention of nanoparticle-loaded in situ gelling system. Results obtained from in vivo histopathological studies after 1 week treatment with in situ gel formulation containing nanoparticles of moxifloxacin were found to be better than with 3 weeks treatment of marketed gel formulation. Overall, the studies ratify successful development of an effective site-specific drug delivery system with enhanced biopharmaceutical attributes for the periodontitis treatment.

Electroacupuncture increases immunoexpression of CB1 and CB2 receptors in experimental model of inflammatory bone loss

This study evaluated the participation of CB1 and CB2 receptors in the antiresorptive effect of electroacupuncture (EA) on an experimental model of inflammatory bone loss in rats. 30 rats were divided into five groups: C (control); EP (experimental periodontitis); EA (C+ EA); EP-EA (EP+ EA in the acupoints LI4, LG11, ST36, ST44); EP - EA-sham (EP+ EA in sham acupoints). For the EP groups, a ligature was placed around the right mandibular first molars at day 1. Sessions of EA or EA-sham were assigned every other day. Animals were euthanized at day 11. Histometric analysis was performed to evaluate the percentage of bone area in the furcation area. Immunolabeling patterns in the periodontal tissues and immunofluorescent staining in the trigeminal ganglia and in the trigeminal spinal tract for CB1 and CB2 receptors were performed. It was observed increased bone loss in the furcation in the EP and EP-EA-sham groups, in comparison to the other groups (p < 0.05). Enhanced CB2 immunolabeling was observed in the periodontal tissues in the EP-EA group, when compared to the EP and EP-EA-sham groups (p < 0.05). Increased CB1 immunofluorescent staining was observed in the neural tissues in the EA treated group in comparison with the other groups (p < 0.05), while no expression of CB2 was observed in those regions. Our study showed that in the presence of inflammatory bone disease, EA treatment reduced bone erosion and increased the immunoexpression of CB1 in the neural tissues and CB2 in the periodontal tissues.

A novel Nanoformulation Development of Eugenol and their treatment in inflammation and periodontitis

OBJECTIVE

To prepare a novel nanoemulsion- Carbopol® 934 gel for Eugenol, in order to prevent the periodontitis.

MATERIAL AND METHODS

Spontaneous emulsification method was used for the preparation of nanoemulsion in which it contain Eugenol (oil phase), Tween-80 (surfactant), and PEG (co-surfactant). To the development of best nanoemulsion, three-factor three-level central composite design was used in which %oil; %Smix and % water were optimized as independent variables. An optimized-nanoemulsion were converted to nanoemulsion-Carbopol® 934 gel.

RESULTS

5.5% oil, 35.5% Smix and 59.0% water were optimized as independent and dependent variables. Finally dependent variables optimized as a particle size (nm), PDI and %transmittance were observed 79.92 ± 6.33 nm, 0.229 ± 0.019, and 98.88 ± 1.31% respectively. The values of final results for dependent variables like particle size (nm), PDI and % transmittance were evaluated as 79.92 ± 6.33 nm, 0.229 ± 0.019, and 98.88 ± 1.31%, respectively. TEM and SEM showed a spherical shape of developed nanoemulsion with refractive index (1.63 ± 0.038), zeta potential (-19.16 ± 0.11), pH (7.4 ± 0.06), viscosity (34.28 ± 6 cp), and drug content of 98.8 ± 0.09%. After that a final optimized EUG-NE-Gel was assessed on the basis of their pH measurement, drug content, syringeability, and mucoadhesion on the goat buccal mucosa. Optimized EUG-NE-Gel (Tween-80 and Carbopol® 934 used) showed the results, to improve the periodontal drug delivery of EUG in future.

CONCLUSION

EUG-NE-Gel showed a significant role in anti-inflammatory activity, analgesic, and anesthetic, antibacterial, and treatment of periodontal disease.

The anti-inflammatory effect of 10-oxo-trans-11-octadecenoic acid (KetoC) on RAW 264.7 cells stimulated with Porphyromonas gingivalis lipopolysaccharide

BACKGROUND

There is rapidly developing interest into the role of several anti-inflammatory agents to resolve inflammation in periodontal disease. A bioactive polyunsaturated fatty acid, 10-oxo-trans-11-octadecenoic acid (KetoC), is known to have various beneficial physiological effects; however, the effect of KetoC on inflammation remains unclear. Here, we investigated the effect of KetoC on RAW 264.7 cells stimulated with Porphyromonas gingivalis lipopolysaccharide, and explored the intracellular mechanism responsible for its anti-inflammatory effects.

METHODS

RAW 264.7 cells were pre-treated with or without KetoC, and then stimulated with or without P. gingivalis lipopolysaccharide. Levels of tumor necrosis factor α (TNFα), interleukin (IL)-6 and IL-1β were determined by real-time polymerase chain reaction and enzyme-linked immunosorbent assay. Specific antagonists for G protein-coupled receptor (GPR)40 and GPR120 were used to clarify the receptor for KetoC. The intracellular mechanism was investigated using western blotting analysis to separate nuclear and cytosolic NF-κB p65 protein.

RESULT

KetoC (5 μmol/L) was not toxic to RAW 264.7 cells, and significantly reduced the expression of TNFα and IL-6 mRNA and protein, and IL-1β mRNA. No protein production of IL-1β was observed. Additionally, when bound to GPR120, KetoC trended to downregulate nuclear NF-κB p65 protein levels. However, the antagonist for GPR40 failed to diminish the action of KetoC.

CONCLUSION

KetoC suppressed the proinflammatory cytokines TNFα, IL-6 and IL-1β via NF-κB p65, by binding to its receptor GPR120. KetoC is a promising candidate in future studies as a bioactive anti-inflammatory agent in treating periodontal disease.

Tocoyena sellowiana extract decreases bone loss in an experimental model of periodontitis in rats: Putative role for cyclooxygenase-2 and IL-1? inhibition

Tocoyena sellowiana (Cham. & Schltdl.) K.Schum is one of the most important families of Brazilian medicinal plants. This study aimed to evaluate the effect of Tocoyena sellowiana (Cham. & Schltdl.) K.Schum ethanolic extract in a pre-clinical trial of periodontitis and to investigate possible mechanisms underlying such effects. Periodontitis was induced in Wistar rats by placing a nylon thread ligature around second upper left molars for 11 days. Rats received (per os) Tocoyena sellowiana (0.1, 1 or 10?mg?kg) or vehicle 1?h before ligature and daily until day 11. Macroscopic, histopathological, and COX-2 immunohistochemical analyses were performed to evaluate the periodontium. The gingival tissue was used to quantify the myeloperoxidase (MPO) activity and interleukin (IL)-1? levels by ELISA. Blood samples were collected to evaluate bone-specific alkaline phosphatase (BALP), the dosage of creatinine, aspartate and alanine transaminases. The liver, kidneys, spleen, and body mass variations were also evaluated. Tocoyena sellowiana decreased bone loss, reduced MPO, IL-1? levels as well as COX-2 immunostaining, and increased BALP activity. Moreover, Tocoyena sellowiana did not alter organs nor body weight. Tocoyena sellowiana reduced bone loss in rats and its efficacy was at least partially dependent upon both IL-1? and cyclooxygenase-2 inhibition.

Use of antidepressive agents as a possibility in the management of periodontal diseases: A systematic review of experimental studies

Antidepressant agents have anti-inflammatory functions that could be interesting as adjuvants in periodontal therapy. The aim of the present study was to analyze the effect of antidepressive drugs in the management of periodontal disease. The MEDLINE, Scopus, Embase, LILACS, and SciELO databases were searched. To be included, the studies had to be experimental studies; randomized, controlled; double-blinded; or blinded studies. A total of 565 articles were initially searched, of which five were selected for the systematic review. All studies used rats, and three different drugs were evaluated: tianeptine, venlafaxine, and fluoxetine. Two of these studies evaluated the effect of antidepressive agents in rats submitted to both ligature-induced periodontitis and depression models, showing that depressive rats had greater alveolar bone loss (ABL). Only the venlafaxine study was not able to find any significant ABL reduction in the group that used this antidepressive drug. The other four studies showed statistically-significant differences, favoring the group with the antidepressant agent. Treatments that are able to modulate the brain-neuroendocrine-immune system could be used as an adjuvant to periodontal disease management. However, studies on humans and animals are scarce, limiting the conclusion of a positive effect in the present systematic review.

Preventive Effect of Phosphodiesterase Inhibitor Pentoxifylline Against Medication-Related Osteonecrosis of the Jaw: An Animal Study

PURPOSE

The aim of this experimental study was to investigate the prophylactic effect of pentoxifylline (PTX) on medication-related osteonecrosis of the jaw (MRONJ).

MATERIALS AND METHODS

Female Sprague-Dawley rats (n = 33) received zoledronic acid (ZA) for 8 weeks to create an osteonecrosis model. The left mandibular second molars were extracted and the recovery period lasted 8 weeks before sacrifice. PTX was intraperitoneally administered to prevent MRONJ. The specimens were histopathologically and histomorphometrically evaluated.

RESULTS

Histomorphometrically, between the control and ZA groups, there was no statistically significant difference in total bone volume (P = .999), but there was a statistically significant difference in bone ratio in the extraction sockets (P < .001). A comparison of the bone ratio of the ZA group with the ZA/PTX group (PTX administered after extraction) showed no statistically significant difference (P = .69), but there was a statistically significant difference with the ZA/PTX/PTX group (PTX administered before and after extraction; P = .008). Histopathologically, between the control and ZA groups, there were statistically significant differences for inflammation (P = .013), vascularization (P = .022), hemorrhage (P = .025), and regeneration (P = .008). Between the ZA and ZA/PTX groups, there were no statistically significant differences for inflammation (P = .536), vascularization (P = .642), hemorrhage (P = .765), and regeneration (P = .127). Between the ZA and ZA/PTX/PTX groups, there were statistically significant differences for inflammation (P = .017), vascularization (P = .04), hemorrhage (P = .044), and regeneration (P = .04).

CONCLUSION

In this experimental model of MRONJ, it might be concluded that although PTX, given after tooth extraction, improves new bone formation that positively affects bone healing, it is not prophylactic. However, PTX given before tooth extraction is prophylactic. Therefore, PTX might affect healing in a positive way by optimizing the inflammatory response.

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

OBJECTIVE

To evaluate the effects of osteoporosis induced by glucocorticoid (GIOP) on bone tissue of rats with experimental periodontitis (EP).

DESIGN

48 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.

RESULTS

EP 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 Young's 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 Young's module of femur compared to EP (p<0.05).

CONCLUSIONS

GIOP can potentiate the destructive effects of EP on alveolar bone and alter the systemic bone loss, by promoting bone resorption and reducing osteoblast activity.

Anti-inflammatory Activity of a High-molecular-weight Cranberry Fraction on Macrophages Stimulated by Lipopolysaccharides from Periodontopathogens

Periodontitis is a chronic inflammatory disease affecting oral tissues. The continuous, high production of cytokines by host cells triggered by periodontopathogens is thought to be responsible for the destruction of tooth-supporting tissues. Macrophages play a critical role in this host inflammatory response to periodontopathogens. The aim of this study was to investigate the effect of non-dialyzable material prepared from cranberry juice concentrate on the pro-inflammatory cytokine response of macrophages induced by lipopolysaccharides (LPS) from Actinobacillus actinomycetemcomitans, Fusobacterium nucleatum subsp. nucleatum, Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, and Escherichia coli. Interleukin-1 beta (IL-1β), IL-6, IL-8, tumor necrosis factor alpha (TNF-α), and Regulated on Activation Normal T-cell Expressed and Secreted (RANTES) production by macrophages treated with the cranberry fraction prior to stimulation by LPS was evaluated by ELISA. Our results clearly indicate that the cranberry fraction was a potent inhibitor of the pro-inflammatory cytokine and chemokine responses induced by LPS. This suggests that cranberry constituents may offer perspectives for the development of a new therapeutic approach to the prevention and treatment of periodontitis.

Inhibitory effects of Persicariae Rhizoma aqueous extracts on experimental periodontitis and alveolar bone loss in Sprague-Dawley rats

Persicariae Rhizoma (PR) is the dried stem parts of Persicaria tinctoria H. Gross (Polygonaceae), and has been traditionally used as anti-inflammatory and detoxifying agent. In the present study, the effects of PR aqueous extracts on ligation-induced experimental periodontitis (EPD) and associated alveolar bone loss in rats were examined. Following the induction of EPD in rats, PR extracts were orally administered once a day for 10 days, and the changes and gains in body weight, alveolar bone loss and total aerobic bacterial counts of buccal gingiva were observed with histopathological analysis. In addition, anti-inflammatory effects were evaluated by monitoring myeloperoxidase (MPO) activities, and interleukin (IL)-1β and tumor necrosis factor (TNF)-α contents, and anti-oxidant effects were investigated by measuring inducible nitric oxide synthase (iNOS) activities and malondialdehyde (MDA) levels. Bacterial proliferation, periodontitis and associated alveolar bone loss induced by ligature placement were significantly and dose-dependently inhibited by the treatment with PR extracts. The inhibitory effects of 200 mg/kg PR were similar to those of 5 mg/kg indomethacin on ligation-induced periodontitis and associated alveolar bone losses in this study. The results suggest that PR effectively inhibits ligature placement-induced periodontitis and alveolar bone loss in rats via antibacterial, antioxidative and anti-inflammatory activities.

Dry Extract of Matricaria recutita L. (Chamomile) Prevents Ligature-Induced Alveolar Bone Resorption in Rats via Inhibition of Tumor Necrosis Factor-α and Interleukin-1β

BACKGROUND

Matricaria recutita L. (chamomile) has demonstrated anti-inflammatory activity. Accordingly, the ability of the Matricaria recutita extract (MRE) to inhibit proinflammatory cytokines and its influence on alveolar bone resorption (ABR) in rats.

METHODS

Wistar rats were subjected to ABR by ligature with nylon thread in the second upper-left molar, with contralateral hemiarcade as control. Rats received polysorbate TW80 (vehicle) or MRE (10, 30, and 90 mg/kg) 1 hour before ligature and daily until day 11. The periodontium was analyzed by macroscopy, histometry, histopathology, and immunohistochemistry for the receptor activator of nuclear factor-kappa B ligand (RANKL), osteoprotegerin (OPG), and tartrate-resistant acid phosphatase (TRAP). The gingival tissue was used to quantify the myeloperoxidase (MPO) activity and tumor necrosis factor (TNF)-α and interleukin (IL)-1β levels by enzyme-linked immunosorbent assay. Blood samples were collected to evaluate bone-specific alkaline phosphatase (BALP), leukogram, and dosages of aspartate and alanine transaminases, urea, and creatinine. Aspects of liver, kidneys, spleen, and body mass variations were also evaluated.

RESULTS

The 11 days of ligature induced bone resorption, low levels of BALP, leukocyte infiltration; increase of MPO, TNF-α, and IL-1β; immunostaining increase for RANKL and TRAP; reduction of OPG and leukocytosis, which were significantly prevented by MRE, except for the low levels of BALP and the leukocytosis. Additionally, MRE did not alter organs or body weights of rats.

CONCLUSION

MRE prevented the inflammation and ABR by reducing TNF-α and IL-1β, preventing the osteoclast activation via the RANKL-OPG axis, without interfering with bone anabolism.

Effects of TNF-α on Cementoblast Differentiation, Mineralization, and Apoptosis

Tumor necrosis factor–α (TNF-α) is involved in various inflammatory processes, including periodontitis. Although the influences of TNF-α on periodontal ligament fibroblasts and osteoblasts have been widely documented, its effects on cementoblasts, the cells responsible for cementum production, remain largely unknown. In this study, we found that TNF-α suppressed the mineralization ability of cementoblasts by inhibiting differentiation and inducing apoptosis. Various signaling pathways, such as p53, PP2AC, p38, Erk1/2, JNK, PI3K-Akt, and NF-κB, were activated during this process. The use of a specific inhibitor and siRNA transfection confirmed that the effects of TNF-α on differentiation and apoptosis in cementoblasts were partially abrogated by inhibiting p53 activity. By contrast, the effects of TNF-α were even exacerbated by the inhibition of the p38, Erk1/2, JNK, PI3K-Akt, and NF-κB pathways. Moreover, p53 activity was further enhanced by blocking the p38, Erk1/2, JNK, and PI3K-Akt signaling pathways. Taken together, these results suggested that the differentiation inhibition and apoptosis in cementoblasts induced by TNF-α were partially dependent on p53 activity. The p38, Erk1/2, JNK, PI3K-Akt, and NF-κB pathways were also activated but acted as balancing players to limit rather than conduct the negative effects of TNF-α. These balancing effects were dependent, or at least partially dependent, on p53, except for the NF-κB pathway.

The Effectiveness of Crataegus orientalis M Bieber. (Hawthorn) Extract Administration in Preventing Alveolar Bone Loss in Rats with Experimental Periodontitis

The purpose of this animal study was to evaluate the effects of hawthorn (Crataeus orientalis M Bieber.) extract on serum oxidative status and alveolar bone loss in experimental periodontitis. Twenty-seven Wistar rats were assigned to one of the following groups: non- ligated+placebo (saline) (NL, n = 9), ligature only+placebo (saline) (LO, n = 9), and ligature and treated with hawthorn extract in saline (H, n = 9) (100 mg/kg orogastrically, once a day for 11 days). Periodontitis was induced by submerging a 4/0 silk ligature in the sulcus of the mandibular right first molars of rats, and the animals were sacrificed after 11 days. Micro-CT examinations were performed for linear and volumetric parameter assessment of alveolar bone. Periodontal tissues were histopathologically examined to assess the differences among the study groups. Levels of serum total antioxidant status (TAS)/total oxidant status (TOS), and oxidative stress index (OSI) were also analyzed. Alveolar bone loss was significantly reduced by hawthorn administration compared to LO group (p<0.05). The number of inflammatory cells and osteoclasts in the LO group was significantly higher than that of the NL and H groups (p< 0.05). The number of osteoblasts in the LO and H groups was significantly higher than that of the NL group (p<0.05). TOS and OSI levels were significantly reduced in H group compared to LO group (P <0.05) and TAS levels were similar in H and NL group (p< 0.05). Hawthorn extract showed inhibitory effect on periodontal inflammation and alveolar bone loss by regulating TAS, TOS and OSI levels in periodontal disease in rats when administered systemically.

Atorvastatin and trans-caryophyllene for the prevention of leukopenia in an experimental chemotherapy model in Wistar rats

Malignant neoplasia represents the second cause of disease-related mortality and, among all patients diagnosed with cancer, 70% will receive chemotherapy during the course of treatment. As a consequence, an increasing number of researchers have focused their attention on the search for more specific anticancer therapies associated with fewer side effects. Leukopenia is an important adverse effect associated with chemotherapy. Secondary infection is very common among leukopenic patients, directly affecting the continuity of the chemotherapeutic treatment and leading to possible complications in tumor immune defense. Atorvastatin, a type of statin, is a known agent used to control hypercholesterolemia. Trans-caryophyllene, isolated from a resinous oil extracted from the copaiba tree, possesses anti-inflammatory and analgesic properties. The AIM of the present study was to evaluate, through a complete leukocyte count, the systemic immunomodulation potential of pentoxifylline (PTX), atorvastatin and trans-caryophyllene, as well as the possible prophylactic role of these drugs against secondary leukopenia, in an experimental chemotherapy model induced by 5-fluorouracil (5-FU) in wistar rats. A total of 32 male wistar rats were used, 24 of which were submitted to treatment with atorvastatin, PTX and trans-caryophyllene prior to the administration of chemotherapy. The Shapiro-Wilk test was used to verify normality and the Kruskal-Wallis test was used for negative data in the normality test. Among the drugs selected, atorvastatin exhibited the best preventive potential in regards to leukopenia secondary to experimental chemotherapy induced by 5-FU, in comparison to the group receiving saline solution, while PTX amplified such alterations in the leukograms of the animals in this trial.

Nanoemulgel (NEG) of Ketoprofen with eugenol as oil phase for the treatment of ligature-induced experimental periodontitis in Wistar rats

AIM

The aim of the novel study was to check the efficacy of a locally applied 2%w/w nanoemulgel (NEG) of Ketoprofen (KP) in preventing the periodontitis, and was also checked NEG without KP to ensure the effect of eugenol in NEG as an oil phase.

DESIGN

For experimentally induced periodontitis, sterile silk ligatures (3/0) were placed around the crevices of the first left lower molar teeth of the male Wistar rats. During 8 weeks, all rats were fed with 10%w/v sucrose solution. The experimental assessment was carried out at 11 d after treatment of experimental periodontal disease (EPD) rats by various clinical parameters like gingival index (GI), tooth mobility (TM), alveolar bone loss (ABL), histological analysis, detection of TNF-α, and IL-1β in gingival tissue by ELISA and the roughness were measured by atomic force microscopy (AFM) in tapping modes.

RESULTS

After treatment, comparison studies with EPD were performed. NEG loaded with KP prevents significantly (p < 0.05) various parameters (GI, TM, and ABL), which were responsible for periodontitis. The histopathology of the periodontium showed that Group 3 (NEG loaded with KP) had a more significant reduction in inflammatory cell infiltration, alveolar bones resorption, and cementum (p < 0.05). In the topographical images, significant reduction in roughness of NEG loaded with KP was observed in comparison with EPD without treatment.

CONCLUSION

The study revealed the great synergistic potential of the combined NEG of an anti-inflammatory drug KP along with eugenol as the oil phase, which have potential antibacterial, analgesic, and anesthetic properties to combat periodontal disease.

Host modulation therapy: An indispensable part of perioceutics

Traditionally, only antimicrobials have been used as the chemotherapeutic modality for the treatment of periodontitis. Though bacteria are the primary etiologic factors of periodontal diseases, yet the extent and severity of tissue destruction seen in periodontitis is determined by the host immuno-inflammatory response to these bacteria. This increasing awareness and knowledge of the host-microbial interaction in periodontal pathogenesis has presented the opportunity for exploring new therapeutic strategies for periodontitis by means of targeting host response via host-modulating agents. This has lead to the emergence of the field of "Perioceutics" i.e. the use of parmacotherapeutic agents including antimicrobial therapy as well as host modulatory therapy for the management of periodontitis. These host-modulating agents used as an adjunct tip the balance between periodontal health and disease progression in the direction of a healing response. In this article the host-modulating role of various systemically and locally delivered perioceutic agents will be reviewed.

Metronidazole and Pentoxifylline films for the local treatment of chronic periodontal pockets: preparation, in vitro evaluation and clinical assessment

OBJECTIVE

Periodontitis is one of the most important chronic inflammatory dental diseases arising from the destructive actions caused by a variety of pathogenic organisms presented in the oral cavity. The aim of this study is the preparation and in vitro evaluation of films for the local treatment of periodontal pockets.

METHODS

The prepared films contained either metronidazole (Mtr), for its antimicrobial effect in periodontal diseases, using a mixture of polymers namely hydroxypropyl methyl cellulose, Carbopol 934 or locally applied Pentoxifylline (PTX), for its anti-inflammatory activity, using chitosan. All films were prepared using solvent casting technique and were evaluated for their physical characteristics, drug content uniformity, surface pH, swelling behavior, mechanical properties and in vitro release. Further characterization was done on the selected formulations using differential scanning calorimetry and scanning electron microscopy for surface structure. Clinical evaluation tests were also performed.

RESULT

Appropriate physical characteristics and mechanical properties for most formulations and their suitability for periodontal application were observed. In vitro drug release from most films showed a burst release rate for both Mtr and PTX during the first 2 h after which the release rate was markedly decreased. Clinical trials on patients revealed the advantageous use of Mtr and PTX as an adjunct treatment with traditionally used dental techniques.

CONCLUSION

The effectiveness of the co-therapy of either drug could add benefit in the eradication of chronic periodontal hazards.

Infliximab attenuates inflammatory osteolysis in a model of periodontitis in Wistar rats

Periodontitis is a chronic inflammatory disease related to tooth loss in adults. Infliximab is a chimeric monoclonal antibody against TNF-α and is prescribed for the treatment of systemic inflammatory diseases. This study aimed to investigate the role of infliximab on experimental periodontal disease (EPD). EPD was induced by passing a 3.0 nylon thread around the upper left second molar in Wistar rats. Animals were either treated with intravenous infliximab (1, 5, 7, and 10 mg/kg) or saline solution 30 min before the periodontitis induction and were followed until they were sacrificed on the 11th day. A subset of rats was euthanized on the third day for analysis of gingival myeloperoxidase (MPO) and the blood MPO granulocyte index. In addition, we analyzed the bone loss index (BLI), the periodontal histopathological score, and the periodontal collagen network using confocal microscopy. We also analyzed metalloproteinase-1/-8, RANK, RANK-L, and osteoprotegerin in maxillary tissue by immunohistochemistry Gingival MPO, IL-1β, TNF-α were measured by ELISA. EPD caused leukocytosis, significant increases in BLI and gingival pro-inflammatory cytokines and cell infiltrates, with worse histopathological scores and periodontal collagen derangement. Infliximab (5 mg/kg) reduced granulocyte blood counts, gingival IL-1β, TNF-α, and MPO levels, diminished MMP-1/-8, RANK, and RANK-L bone immunolabeling with better periodontal histopathological scores and collagen network in comparison with the challenged saline group. We concluded that infliximab had significant anti-inflammatory and bone-protective effects in Wistar rats challenged by periodontitis.

Oral mucositis in cancer treatment: Natural history, prevention and treatment

Oral mucositis is a condition that is characterized by ulcerative lesions in the mucosa of patients undergoing radiotherapy or chemotherapy. Oral mucositis is currently considered to be the most severe complication of anticancer therapy, affecting 40-80% of patients undergoing chemotherapy and almost all those undergoing radiotherapy of the head and neck. Although they do not prevent lesions from appearing, drugs for the treatment of oral mucositis are required to minimize its clinical aggressiveness and improve the nutritional status, hydration and quality of life of the affected patients. Furthermore, the prevention and control of oral ulcers is crucial for cancer prognosis, since the establishment of severe lesions may lead to temporary or permanent treatment discontinuation and compromise cancer control. The objective of this study was to present a review on this condition, its causes and its treatment to professional clinical dentists, in order to help minimize patient suffering. A search was conducted through PubMed, Lilacs and MedLine, to retrieve related articles published between 1994 and 2013.

Preventive and therapeutic anti-TNF-α therapy with pentoxifylline decreases arthritis and the associated periodontal co-morbidity in mice

AIMS

The association between rheumatoid arthritis (RA) and periodontal disease (PD) has long been studied and some reports suggest that treating RA may improve the associated PD, and vice versa. This study aimed to evaluate the effects of an anti-tumor necrosis factor (TNF)-α therapy with pentoxifylline (PTX) in an experimental model of RA-associated PD.

MAIN METHODS

Male C57BL/6 mice were subjected to chronic antigen-induced arthritis (AIA) and daily treated with PTX (50mg/kg, i.p.) using preventive (Pre-PTX) or therapeutic (The-PTX) strategies. Fourteen days after the antigen challenge, mice were euthanized and knee joints, maxillae and serum were collected for microscopic and/or immunoenzymatic analysis.

KEY FINDINGS

AIA triggered significant leukocyte recruitment to the synovial cavity, tissue damage and proteoglycan loss in the knee joint. Pre-PTX and The-PTX regimens decreased these signs of joint inflammation. The increased levels of TNF-α and IL-17 in periarticular tissues of AIA mice were also reduced by both PTX treatments. Serum levels of C-reactive protein, which were augmented after AIA, were reduced by the PTX regimens. Concomitantly to AIA, mice presented alveolar bone loss, and recruitment of osteoclasts and neutrophils to periodontal tissues. Pre-PTX and The-PTX prevented and treated these signs of PD. PTX treatment also decreased TNF-α and increased IL-10 expression in the maxillae of AIA mice, although it did not affect the expression of IFN-γ and IL-17.

SIGNIFICANCE

The current study shows the anti-inflammatory and bone protective effects of preventive and therapeutic PTX treatments, which decreased the joint damage triggered by AIA and the associated periodontal co-morbidity.

Oral mucositis in head and neck cancer: risk, biology, and management

Of the toxicities associated with conventional forms of treatment for head and neck cancers, probably none has such a consistent legacy as oral mucositis.1 Despite the fact that mucosal injury was noted as far back as Marie Curie's first forays into therapeutic radiation, an effective intervention has yet to be developed. In addition to its historic link to radiation, new therapeutic strategies including induction chemotherapy often produce mucositis, and targeted therapies appear to alter mucositis risk and its severity and course.2 The symptomatic effect of oral mucositis is profound. Disabling oral and oropharyngeal pain prevents patients from eating normally, requires opiate analgesics, and in some cases results in alteration or discontinuation of anticancer therapy.3 Furthermore, the health and economic consequences of oral mucositis are far from trivial. The incremental cost of oral mucositis in patients with head and neck cancer exceeds $17,000 (USD).4.

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.

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.

Effect of venlafaxine on bone loss associated with ligature-induced periodontitis in Wistar rats

Background

The present study investigated the effects of venlafaxine, an antidepressant drug with immunoregulatory properties on the inflammatory response and bone loss associated with experimental periodontal disease (EPD).

Materials and Methods

Wistar rats were subjected to a ligature placement around the second upper left molar. The treated groups received orally venlafaxine (10 or 50 mg/kg) one hour before the experimental periodontal disease induction and daily for 10 days. Vehicle-treated experimental periodontal disease and a sham-operated (SO) controls were included. Bone loss was analyzed morphometrically and histopathological analysis was based on cell influx, alveolar bone, and cementum integrity. Lipid peroxidation quantification and immunohistochemistry to TNF-α and iNOS were performed.

Results

Experimental periodontal disease rats showed an intense bone loss compared to SO ones (SO = 1.61 ± 1.36; EPD = 4.47 ± 1.98 mm, p < 0.001) and evidenced increased cellular infiltration and immunoreactivity for TNF-α and iNOS. Venlafaxine treatment while at low dose (10 mg/kg) afforded no significant protection against bone loss (3.25 ± 1.26 mm), a high dose (50 mg/kg) caused significantly enhanced bone loss (6.81 ± 3.31 mm, p < 0.05). Venlafaxine effectively decreased the lipid peroxidation but showed no significant change in TNF-α or iNOS immunoreactivity.

Conclusion

The increased bone loss associated with high dose venlafaxine may possibly be a result of synaptic inhibition of serotonin uptake.

Anti-inflammatory effects of apigenin on nicotine- and lipopolysaccharide-stimulated human periodontal ligament cells via heme oxygenase-1

BACKGROUND AND OBJECTIVES

Although apigenin exhibits various biological effects, its anti-inflammatory role in the periodontal field remains unknown. We examined the anti-inflammatory effects of apigenin and the underlying mechanism in nicotine- and lipopolysaccharide (LPS)-stimulated human periodontal ligament (hPDL) cells.

MATERIALS AND METHODS

Western blotting was used to examine the effect of apigenin (10-40 microM) on the LPS- and nicotine-induced expression of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and heme oxygenase-1 (HO-1), as well as the phosphorylation of mitogen-activated protein kinases (MAPKs), in hPDL cells. Pro-inflammatory mediators, including nitric oxide (NO), prostaglandin E2 (PGE2), interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha), IL-6, and IL-12 were monitored using Griess reagents and ELISA.

RESULTS

Incubation of hPDL cells with apigenin decreased LPS- and nicotine-induced HO-1 protein expression and activity. Apigenin significantly inhibited the nicotine- and LPS-induced production of NO, PGE2, IL-1beta, TNF-alpha, IL-6, and IL-12, and the upregulation of iNOS and COX-2 in hPDL cells. Hemin, a selective HO-1 inducer, reversed the apigenin-mediated suppression of nicotine- and LPS-induced NO, PGE2 and cytokine production. Treatment with inhibitors of the phosphoinositide 3-kinase, MAPKs, p38, and JNK, as well as a protein kinase C inhibitor, blocked the anti-inflammatory effects of apigenin in nicotine- and LPS-treated cells.

CONCLUSIONS

Apigenin possesses anti-inflammatory activity in hPDL cells and works through a novel mechanism involving the action of HO-1. Thus, apigenin may have potential benefits as a host modulatory agent in the prevention and treatment of periodontal disease associated with smoking and dental plaque.

AAV2/1-TNFR:Fc gene delivery prevents periodontal disease progression

Periodontal disease is a chronic inflammatory condition induced by tooth-associated microbial biofilms that induce a host immune response. Therapeutic control of progressive tissue destruction in high-risk patients is a significant challenge in therapy. Soluble protein delivery of antagonists to tumor necrosis factor alpha (TNF-α) inhibits alveolar bone resorption due to periodontitis. However, protein therapy raises several concerns, such as recurrence of disease activity after treatment cessation and repeated dosing regimens. In this study, we used pseudotyped adeno-associated virus vector based on serotype 1 (AAV2/1) to deliver the TNF receptor-immunoglobulin Fc (TNFR:Fc) fusion gene to rats subjected to experimental Porphyromonas gingivalis (Pg)-lipopolysaccharide (LPS)-mediated bone loss. Animals received Pg-LPS delivered to the gingivae thrice weekly for 8 weeks, vehicle alone, Pg-LPS and intramuscular delivery of pseudotyped AAV2/1-TNFR:Fc vector (1×10¹¹ DNase I-resistant particles) or AAV2/1-TNFR:Fc vector delivered to naïve animals. AAV2/1-TNFR:Fc therapy led to sustained therapeutic levels of serum TNFR protein and protected against Pg-LPS-mediated loss of bone volume and density. Furthermore, AAV2/1-TNFR:Fc administration reduced local levels of multiple pro-inflammatory cytokines and osteoclast-like cells at the periodontal lesions. These findings suggest that delivery of AAV2/1-TNFR:Fc may be a viable approach to modulate periodontal disease progression.

Naringenin has anti-inflammatory properties in macrophage and ex vivo human whole-blood models

BACKGROUND AND OBJECTIVE

Periodontitis is a chronic inflammatory disease of bacterial etiology, affecting tooth-supporting tissues. The host inflammatory response to periodontopathogens, notably the high and continuous production of cytokines, is considered a major factor causing the local tissue destruction observed in periodontitis. The aim of the present study was to investigate the effect of naringenin, a major flavanone in grapefruits and tomatoes, on the lipopolysaccharide-induced pro-inflammatory cytokine production by host cells, using two different models.

MATERIAL AND METHODS

The effect of naringenin was characterized using macrophages stimulated with the lipopolysaccharide of either Aggregatibacter actinomycetemcomitans or Escherichia coli and using whole blood stimulated with A. actinomycetemcomitans lipopolysaccharide, in the presence or absence of naringenin. Lipopolysaccharide-induced interleukin-1 beta, interleukin-6, interleukin-8 and tumor necrosis factor-alpha production by macrophages and whole-blood samples treated with naringenin were evaluated using an enzyme-linked immunosorbent assay. Changes in the phosphorylation states of macrophage kinases induced by A. actinomycetemcomitans lipopolysaccharide and naringenin were characterized by immunoblot screening.

RESULTS

Our results clearly indicated that naringenin is a potent inhibitor of the pro-inflammatory cytokine response induced by lipopolysaccharide in both macrophages and in whole blood. Naringenin markedly inhibited the phosphorylation on serines 63 and 73 of Jun proto-oncogene-encoded AP-1 transcription factor in lipopolysaccharide-stimulated macrophages.

CONCLUSION

The results from the present study suggest that naringenin holds promise as a therapeutic agent for treating inflammatory diseases such as periodontitis.

Effect of methotrexate on alveolar bone loss in experimental periodontitis in Wistar rats

OBJECTIVE

Interleukin-1 (IL-1) and tumor necrosis factor (TNF) are pro-inflammatory cytokines directly related with tissue destruction in the pathogenesis of periodontitis. Inhibitory effects on IL-1 and TNF production have been attributed to the folate analog methotrexate. The purpose of this study was to evaluate the effect of methotrexate on the pathogenesis of alveolar bone loss in experimental periodontitis in rats.

METHODS

Ligature-induced experimental periodontitis was created in 44 Wistar rats. The animals were randomly divided into four groups and treated with methotrexate (0.1, 0.5, and 1.0 mg x kg(-1)) or saline. Morphometrical registration of alveolar bone loss was carried out after 28 days of ligature placement to determine the effect of methotrexate on the progression of experimental periodontitis.

RESULTS

Intra-group comparisons showed significantly higher alveolar bone loss mean values in maxillary sides with ligature (paired sample t-test; p<0.05). Mean alveolar bone loss was not different between groups and was independent of the dosage (range 0.63-0.67 mm, one-way ANOVA; p>0.05).

CONCLUSION

Although methotrexate has important cytokine-inhibitory properties, its possible use in modulating the host immune-inflammatory response in periodontal disease was not confirmed.

Lippia sidoides and Myracrodruon urundeuva gel prevents alveolar bone resorption in experimental periodontitis in rats

In Brazilian folk medicine, Lippia sidoides (Ls) and Myracrodruon urundeuva (Mu) have gained popularity and reputation as effective antimicrobial and anti-inflammatory agents. This work aimed to evaluate the effect of topical herbal gel from Ls 0.5% (v/w) and Mu 5% (w/w) in experimental periodontal disease (EPD) in rats. Wistar rats were subjected to ligature placement around the second upper left molars. Animals were treated topically with Ls and/or Mu-based gel, immediately after EPD induction and three times/day for 11 days until the rats were sacrificed (11th day). Saline-based gel was utilized as control for all experiments and doxycycline based gel 10% (w/w) was utilized as reference substance. Animals were weighed daily. Alveolar bone loss was measured as the difference (in millimeters) between the cusp tip and the alveolar bone. The periodontum and the surrounding gingivae were examined at histopathology, as well as the neutrophil influx into the gingivae was assayed using myeloperoxidase activity and cytokine production mainly tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) levels by ELISA method. The local bacterial flora was assessed through culture of the gingival tissue in standard aerobic and anaerobic media. Alveolar bone loss was significantly inhibited by Ls and Mu combined treatment compared to the saline control group. Ls and Mu combined treatment reduced tissue lesion at histopathology, with partial preservation of the periodontum, coupled to decreased myeloperoxidase activity as well as significantly inhibited TNF-alpha and IL-1beta production in gingival tissue compared to the saline control group. Ls and Mu combined treatment also prevented the growth of oral microorganisms and the weight loss. Ls and Mu combined based gel treatment preserved alveolar bone resorption and demonstrated anti-inflammatory and antibacterial activities in experimental periodontitis.

Effects of the tumour necrosis factor-alpha inhibitors pentoxifylline and thalidomide in short-term experimental oral mucositis in hamsters

Oral mucositis is a frequent side-effect of cancer therapy. A definitive method of prophylaxis or treatment is not yet available. As pentoxifylline (PTX) and thalidomide (TLD) have been shown to inhibit cytokine synthesis, we studied the effects of these cytokine inhibitors in an experimental oral mucositis model. Oral mucositis was induced in Golden hamsters by the administration of 5-fluorouracil (5-FU) followed by mechanical trauma of the cheek pouch. On days 4, 5, 10, 12, 14 and 16, lesions induced by 5-FU were examined macroscopically and microscopically, and the presence and intensity of hyperemia, erythema, edema, inflammatory cell infiltration, hemorrhagic areas, ulcers and abscesses were recorded. Saline (control), PTX (5, 15, 45 mg kg(-1)) or TLD (10, 30, 90 mg kg(-1)) were administered daily and animals were killed on day 10 for macroscopic and histological analysis and assay of myeloperoxidase (MPO) activity. Animals were weighed daily, and total and differential leukocyte counts were performed on peripheral blood. PTX and TLD were found to reduce the macroscopic and histological parameters of oral mucositis and MPO activity. PTX and TLD also reversed peripheral neutrophilia, but only PTX prevented weight loss. The results indicate a protective effect of PTX and TLD, suggesting an important role for tumour necrosis factor-alpha (TNF-alpha) in the pathophysiology of 5-FU induced-oral mucositis in hamsters.