Stability of dentin matrix treated with caffeic acid phenethyl ester at different concentrations

Aim: The aim of this study was to investigate the impact of pretreatment with ethanolic solutions of caffeic acid phenethyl ester (CAPE) at varying concentrations on the dentin collagen matrix, specifically focusing on its biomodification potential. This was assessed through evaluations of the modulus of elasticity and changes in mass. Methods: Seventy dentin collagen matrices (demineralized sticks) were prepared to receive treatments with ethanolic solutions of CAPE at concentrations of 0.05%, 0.1%, 0.5%, or 2.5%, or with control treatment solutions (distilled water or ethanol) for one hour. The dentin matrices were evaluated for modulus of elasticity and mass before (baseline), immediately after treatment (immediately), and after storage in Simulated Body Fluid (SBF) for time intervals of 1 and 3 months. Results: Generalized linear models for repeated measures over time indicated no significant differences between groups (p=0.7530) or between different time points (p=0.4780) in terms of the modulus of elasticity. Regarding mass variation, no differences were observed in the time interval between 1 month and the immediate time (p=0.0935). However, at the 3-month mark compared to the immediate time, the 0.1% CAPE group exhibited less mass loss compared to the water group (p=0.0134). Conclusion: This study concludes that various concentrations of CAPE in an ethanolic solution did not affect the modulus of elasticity of dentin, suggesting that CAPE lacks biomodifying potential in this context. However, it was observed that 0.1% CAPE positively influenced the variation in mass over different evaluation time intervals

The Effects of Green Tea Catechins in Hematological Malignancies.

Green tea catechins are bioactive polyphenol compounds which have attracted significant attention for their diverse biological activities and potential health benefits. Notably, epigallocatechin-3-gallate (EGCG) has emerged as a potent apoptosis inducer through mechanisms involving caspase activation, modulation of Bcl-2 family proteins, disruption of survival signaling pathways and by regulating the redox balance, inducing oxidative stress. Furthermore, emerging evidence suggests that green tea catechins can modulate epigenetic alterations, including DNA methylation and histone modifications. In addition to their apoptotic actions, ROS signaling effects and reversal of epigenetic alterations, green tea catechins have shown promising results in promoting the differentiation of leukemia cells. This review highlights the comprehensive actions of green tea catechins and provides valuable insights from clinical trials investigating the therapeutic potential of green tea catechins in leukemia treatment. Understanding these multifaceted mechanisms and the outcomes of clinical trials may pave the way for the development of innovative strategies and the integration of green tea catechins into clinical practice for improving leukemia patient outcomes.

Wet-bonding technique with ethanol may reduce protease activity in dentin-resin interface following application of universal adhesive system.

Background: Greater degradation of the hybrid layer is expected when a universal adhesive system is used, especially in the conventional application strategy. Therefore, it would important to evaluate the effect of the ethanol (ETH) and a potential matrix protease inhibitor (caffeic acid phenethyl ester/ CAPE) to maximize the ability to achieve stable dentin bond strength. The aim of this study was to evaluated the effect of ETH on a wet-bonding technique, and dentin pretreatments with different concentrations of CAPE in ethanolic solution, followed by application of a universal adhesive system (Single Bond Universal) to inhibit proteolytic activity. Material and Methods: Dentin blocks were allocated to eight experimental groups according to the strategy (total-etch our self-etch) and treatments: ETH, or dentin pretreatment with CAPE (at 0.5%, 2.5%; and 5.0%). Half of each block (each hemiblock) served as the control (without dentin pretreatments) for the same group. The bonding strategy was performed (adhesive system/ restoration with composite resin). Two slices were obtained from each hemiblock and evaluated using in situ zymography. The proteolytic activity was analyzed by quantifying the green photons of the images obtained under a fluorescence microscope in three dentin locations close to the dentin-resin interface: hybrid layer (HL), underlying dentin (UD) and deep dentin (DD). Results: Wilcoxon tests (for comparison between experimental and control groups) and Friedman and Nemenyi tests (for comparisons between interface locations) showed that there was no difference between the groups with different CAPE concentrations and the respective control groups (p>0.05). ETH reduced the proteolytic activity at the HL and UD (p<0.05). Conclusions: The wet-bonding technique with ETH proved effective in reducing the proteolytic activity. The use of CAPE in different concentrations solubilized in ethanol did not have a favorable effect on proteolytic inhibition. Key words:Adhesives, Hybrid layer, Dentin, Metalloproteinases.

Titanium dioxide nanotubes in a hydrogen peroxide-based bleaching agent: physicochemical properties and effectiveness of dental bleaching under the influence of a poliwave led light activation.

OBJECTIVES: The effects of different concentrations of titanium dioxide (TiO2) into 40% hydrogen peroxide (HP) were evaluated as regards the effectiveness of dental color change either associated with activation by polywave LED light or not. MATERIALS AND METHODS: TiO2 (0, 1, 5, or 10%) was incorporated into HP to be applied during in-office bleaching (3 sessions/40 min each). Polywave LED light (Valo Corded/Ultradent) was applied or not in activation cycles of 15 s (total time of 2 min). The color of 80 third molars separated into groups according to TiO2 concentration and light activation (n = 10) was evaluated at baseline and at time intervals after the 1st, 2nd, and 3rd bleaching sessions. RESULTS: WID value was significantly higher when using HP with 5% TiO2 in the 2nd session than the values in the other groups (p < 0.05). After the 2nd and 3rd sessions, the ΔEab value was significantly higher when activated with light (p < 0.05) for all agents containing TiO2 or not. Zeta potential and pH of the agents were not modified by incorporating TiO2 at the different concentrations. CONCLUSIONS: The 5% TiO2 in the bleaching agent could enhance tooth bleaching, even without light application. Association with polywave LED light potentiated the color change, irrespective of the presence of TiO2 in the bleaching gel. CLINICAL SIGNIFICANCE: HP with 5% TiO2 could lead to a greater tooth bleaching response in the 2nd clinical session, as well as the polywave light can enhance color change.

Physicochemical evaluation of hydrogen peroxide bleaching gels containing titanium dioxide catalytic agent, and their influence on dental color change associated with violet LED.

BACKGROUND: The purpose of this study was: 1) to analyze the physical-chemical properties of hydrogen peroxide (HP) agents at 7.5% (HP7) and 35% (HP35), and the association with or without TiO2 nanotubes; 2) to evaluate dental bleaching effectiveness by using HP7 and HP35 together with or without TiO2 nanotubes, and applied with or without violet LED (VL). METHODOLOGY: 80 bovine incisors were treated according to groups (n = 10): HP35; HP35 + VL; HP35T (HP35 + TiO2); HP35T + VL; HP7; HP7 + VL; HP7T (HP7 + TiO2); HP7T + VL. Bleaching effectiveness was measured at 4 time points according to the Vita Classical, CIEL*a*b*, CIEDE2000, and WID parameters. HP35, HP35T, HP7, and HP7T were evaluated for mass change, pH, mean particle size (P), polydispersity (PDI), and zeta potential (ZP), over 6 months of storage. RESULTS: The pH of HP35 thickener was higher when associated to TiO2. At baseline, both of the bleaching gels containing TiO2 had lower P, PDI, and PZ (p < 0.05). All groups showed a significant decrease in Vita Classical color scores (p = 0.0037). There was a higher L* value, and lower b* values for HP7 when associated to VL after the 3rd session. (p < 0.05). HP35T showed higher color change (ΔEab, ΔE00), and lower a* value in the presence of VL (p < 0.05). ΔWID presented lower values for both gels, when TiO2 was incorporated (p ≤ 0.05). CONCLUSION: The incorporation of TiO2 to the bleaching gel showed good stability with minimal variations in physical-chemical properties. The color change in HP35 was more effective than in HP7, but the VL boosted the bleaching effectiveness of HP7, whereas TiO2 did not increase bleaching effectiveness.

Cytoprotective effect of Fridericia chica (Bonpl.) L.G. Lohmann extract associated with geranylgeraniol enriched-fraction from Bixa orellana L. on epithelial cells treated with bisphosphonate.

Bisphosphonates are drugs used to treat bone disorders. The chronic use of bisphosphonates is associated with the occurrence of medication-related osteonecrosis of the jaw (MRONJ). Previous data reported the positive effects of Geranylgeraniol on different cell types treated with Bisphosphonates. Foregoing work done by our research group demonstrated the wound healing capacity of Fridericia chica (Bonpl.) L.G.Lohmann standardized ethanol extract. Herein in vitro cytoprotective synergistic effect of the association of F. chica extract associated with an enriched geranylgeraniol fraction on keratinocytes exposed to zoledronic acid is reported. An association of F. chica at 1 and 5 µg/mL with geranylgeraniol at 15 µg/mL, increased cell viability by 73.5% and 71.1%, respectively. This treatment did not increase tumor cells viability; whereas the clonogenic potential assessment showed that, the association with F. chica (5 µg/mL) reversed the effects of zoledronic acid on the cells. This study provides data for a potential treatment for MRONJ.

Peroxisome proliferator-activated receptor-gamma (PPARγ) and its immunomodulation function: current understanding and future therapeutic implications.

INTRODUCTION: Pain is a multidimensional experience involving the biological, psychological, and social dimensions of each individual. Particularly, the biological aspects of pain conditions are a response of the neuroimmunology system and the control of painful conditions is a worldwide challenge for researchers. Although years of investigation on pain experience and treatment exist, the high prevalence of chronic pain is still a fact. AREAS COVERED: Peroxisome proliferator-activated receptor-gamma (PPARγ) is a ligand-activated transcription factor belonging to the nuclear hormone receptor superfamily. It regulates several metabolic pathways, including lipid biosynthesis and glucose metabolism, when activated. However, PPARγ activation also has a critical immunomodulatory and neuroprotective effect. EXPERT OPINION: This review summarizes the evidence of synthetic or natural PPARγ ligands such as 15d-PGJ2, epoxyeicosatrienoic acids, thiazolidinediones, and specialized pro-resolving mediators, representing an interesting therapeutic tool for pain control.

Evaluation of non-clinical toxicity of extract and vouacapans from fruits of Pterodon pubescens Benth.

Pterodon pubescens Benth. is widely used in folk medicine for the treatment of inflammatory conditions, with the activity attributed to the compounds with a vouacapan moiety, however, few studies report the toxicological evaluation of the extract and safety issues related to the species. Herein the non-clinical toxicity, in in vivo and in vitro tests, of dichloromethane crude extract of Pterodon pubescens fruits (PPE) and vouacapan diterpene furan isomer´s mixture (1:1) 6α-hydroxy-7ß-acetoxy-vouacapan-17ß-oate methyl ester and 6α-acetoxy-7ß-hydroxy-vouacapan-17ß-oate methyl ester isomers (VDFI mixture) is reported. Toxicological evaluation of 110-day repeated dose oral toxicity study, as hematological, biochemical, and histopathological parameters demonstrated that animals (male and female Wistar rats) treated with PPE presented no signs of toxicity, nevertheless daily high dose administration (500 mg/Kg) altered the metabolic homeostasis of animals that manifested microgoticular hepatic steatosis. Biochemical and histopathological results of animals (female Swiss mice) treated daily with VDFI mixture, at the highest dose (300 mg/Kg), indicated liver toxicity in one animal causing acute hepatotoxicity. Alkaline Comet assay demonstrated that PPE and VDFI mixture increased the percentage of DNA fragmentation without interfering with the tail moment parameter, but only VDFI mixture (30 µg/mL) presented statistical difference. In the micronucleus induction test, PPE and VDFI mixture did not demonstrate mutagenic potential. Our data provide evidence for the safety use of PPE and VDFI mixture in lower doses enabling further clinical studies and the development of herbal medicine.

Phenolic extract of Libidibia ferrea inhibits dentin endogenous enzymatic activity depending on the adhesive system strategy.

This study evaluated the influence of Libidibia ferrea (Lf) extract used as dentin pretreatment on the resin-dentin bond strength stability and dentin endogenous enzymatic activity. The phytochemical profile (PP) of the Lf extract was evaluated by liquid chromatography; particle size, polydispersity index (PdI), and zeta potential (ZP) were evaluated by dynamic light scattering. The tested groups were ER-Scotchbond Universal (SBU) in the etch-and-rinse (ER) mode; ERLf-SBU in the ER mode + Lf after etching; SE- SBU in the self-etch (SE) mode; and LfSE-Lf before SBU in the SE mode. Sticks were obtained for microtensile bond strength tests and failure mode (24 hr and 12 months). The hybrid layer was evaluated using scanning electron microscopy. The endogenous enzymatic activity of the underlying dentin was analyzed by in situ zymography with the same treatments. The PP showed the presence of quercetin (2.6% w/w). Lf particles were considered large after the analysis of the PdI. The ZP remained stable over time. The ER and ERLf groups had lower bond strength after 12 months, but SE and LfSE remained stable. The predominant failure mode was adhesive for both times. ER and ERLf had longer resin tags and a thicker hybrid layer. The ER and LfSE groups showed higher enzymatic activity than the ERLf and SE groups after 12 months. The Lf extract may contribute to inhibit the dentin endogenous enzymatic activity when associated with an adhesive system in the ER mode.

Photobiomodulation inhibits inflammation in the temporomandibular joint of rats.

Photobiomodulation (PBM) has been applied as a non-invasive technique for treating temporomandibular joint symptoms, especially on painful condition's relief, however the anti-inflammatory mechanism underlying the effect of PBM remains uncertain. This study aims to evaluate the mechanisms of action of PBM (808 nm) in a carrageenan-induced inflammation on temporomandibular joint (TMJ) of rats. In this study male Wistar rats were pre-treated with irradiation of a low-power diode laser for 15 s on TMJ (infra-red 808 nm, 100 mW, 50 J/cm2 and 1.5 J) 15 min prior an injection in the temporomandibular joint of carrageenan (100 µg/TMJ). 1 h after the TMJ treatments, the rats were terminally anesthetized for joint cavity wash and periarticular tissues collect. Samples analysis demonstrated that PBM inhibit leukocytes chemotaxis in the TMJ and significantly reduces amounts of TNF-α, IL-1ß and CINC-1. In addition, Western blotting analysis demonstrated that PBM significantly decreased the protein levels of P2X3 and P2X7 receptors in the periarticular tissues. On the other hand, PBM was able to increase protein level of IL-10 (anti-inflammatory cytokine). In summary, it is possible to suggest that PBM inhibit inflammatory chemotaxis, modulation the balance of the pro- and anti-inflammatory characteristics of inflammatory cells.

Fast and accurate protocol for histology and immunohistochemistry reactions in temporomandibular joint of rats.

OBJECTIVE: Propose a standard, fast and accurate protocol for the processing of the temporomandibular joint (TMJ) of adults' rats for histology and immunohistochemistry reactions. DESIGN: Wistar male rats were perfused with paraformaldehyde (4 %). The heads were fixed in formaldehyde 10 % solution for 48 h. After that, the heads were sectioned in a sagittal plane and fixed for plus 48 h. Decalcification was performed using 20 % formic acid for 96 h and delimitation of TMJ area was done. Detailed methodology to a standard extraction and processing of TMJ to histological sections is described. Different buffers, equipment, temperature and time were tested to optimize immunostaining. Morphological preservation and antigenicity were evaluated by hematoxylin and eosin staining and immunohistochemistry reaction. RESULTS: The current findings demonstrated that TMJ fixed in 10 % formaldehyde and decalcified in 20 % formic acid optimized decalcification processing time with preservation of cell morphology. Antigen retrieval with citrate buffer in pressure cooker (2 min at 100 °C and 5 min at room temperature) demonstrated the best protocol to preservation of the structures of TMJ. CONCLUSIONS: This work demonstrates in detail a methodology of a fast and accurate TMJ processing for histology and immunohistochemistry reactions that guarantee tissue integrity and quality of staining.

Physicochemical characterization, water sorption and solubility of adhesive systems incorporated with titanium tetrafluoride, and its influence on dentin permeability.

Titanium tetrafluoride (TiF4) in an aqueous solution can decrease dentin permeability, but some effects of its incorporation into adhesive systems are not yet known. Therefore, the aim of this study was to characterize the physicochemical, water sorption (WS) and solubility (SL) properties of two adhesive systems (Clearfil SE Bond/C and Scotchbond Universal/S) incorporated with 0.0% (T0), 2.5% (T2) and 4.0% (T4) titanium tetrafluoride (TiF4), and determine dentin permeability (L) after application of these adhesive systems both immediately afterwards (baseline) and after 6 months of storage. The physicochemical analyses of the incorporated solutions were performed based on evaluating particle size (PS), polydispersity index (PDI) by dynamic light scattering, and zeta potential (ZP) by electrophoresis. WS and SL tests followed ISO 4049 standards, and used a 7-day water storage period. The L test was performed by analyzing human dentin discs before and after adhesive system application, and after storage. PS and PDI were higher for CT0 and ST4 (p < 0.0001; ANOVA, Tukey). ZP was lower for CT4, ST2 and ST4 (p < 0.0001; ANOVA, Tukey). A 4.0% TiF4 incorporation showed higher WS (p < 0.05; Mann Whitney, Kruskal Wallis, Dunn). Higher SL was observed for CT0 and ST4 (p < 0.05; Mann Whitney, Kruskal Wallis, Dunn). The L value at baseline was lower for ST4, but was not different from the CT4 groups after storage (p < 0.05; Mann Whitney, Kruskal Wallis, Dunn). It can be concluded that TiF4 affected the colloidal stability of Scotchbond, but did not alter the other properties. The 2.5% TiF4 did not affect the PDI, WS or L of the Clearfil, and can be considered an alternative for reducing hybrid layer degradation.

Bixa orellana L. by-products' fractions from an industrial process: antiproliferative activity on tumor cells and chemical profile.

This study evaluated the phytochemical characterization of Bixa orellana (BO extract) unsaponifiable extract and resulting fractions (F fraction - FF, Geranyl fraction - GF and R fraction- RF) obtained as by-products of an industrial process investigating in vitro antiproliferative activities in human tumoral cells. The main compounds identified by GC-MS for BO extract were Geranylgeraniol (61.51%); for FF: Geranylgeraniol (70.23%); for GF: Geranylgeraniol (78.92%) and for RF: ß-cubebene (27.75%). Quantifications of geranylgeraniol by GC-FID presented the percentage content: BO 27.52%; FF 38.52%; GF 51.44% and RF 1.81%. BO extract showed a significant antiproliferative activity, with GI50 up to 4 µg/mL. All fractions had a remarkably similar antiproliferative activity profile (GI50 27-47 µg/mL). Data reported herein showed an important cytostatic effect for BO extract, nevertheless this activity is not attributed exclusively to geranylgeraniol. In conclusion, this by-product becomes of great value, being a potential candidate for development of new anti-tumor ingredients.

Antiproliferative Effects of Pterodon pubescens Extract and Isolated Diterpenes in HaCaT Cells.

Pterodon pubescens fruits are popularly used because of their analgesic and anti-inflammatory actions, which are attributed to the isolated compounds with a vouacapan skeleton. This work aimed to evaluate the antiproliferative and anti-inflammatory effects of a P. pubescens fruit dichloromethane extract and the vouacapan diterpene furan isomer's mixture (1 : 1) (6α-hydroxy-7ß-acetoxy-vouacapan-17ß-oate methyl ester and 6α-acetoxy-7ß-hydroxy-vouacapan-17ß-oate methyl ester isomers) in HaCaT cells using the cell migration and the BrDU incorporation assay. Levels of IL-8 were measured by ELISA after TNF-α stimulation. HPLC/DAD analysis of the extract revealed the expressive presence of vouacapan diterpene furan isomer's mixture. P. pubescens extract (1.5625 - 25 µg/mL) and vouacapan diterpene furan isomer's mixture (3.125 - 50 µM) inhibited cell proliferation as indicated by a decreased BrdU-incorporation. For the evaluation of cell migration, time-lapse microscopy was used. P. pubescens presented inhibition on cell migration at all concentrations tested (3.125 - 12.5 µg/mL), whereas for the VDFI mixture, the inhibition was only observed at the highest concentrations (12.5 and 25 µM) tested. Furthermore P. pubescens extract and vouacapan diterpene furan isomer's mixture significantly decreased IL-8 levels. Our results showed antiproliferative and anti-inflammatory effects on HaCaT cells treated with the extract and the vouacapan isomer's mixture, without affecting cell viability. These activities could be attributed to the voucapan molecular structures. In conclusion, topical products developed of P. pubescens extract or the voucapan isomer's mixture should be further studied as a potential product for local treatment against hyperproliferative lesions as in psoriasis vulgaris, representing an alternative treatment approach.

Peripheral soluble epoxide hydrolase inhibition reduces hypernociception and inflammation in albumin-induced arthritis in temporomandibular joint of rats.

Rheumatoid arthritis (RA) is characterized by chronic inflammation of the synovial tissue, joint dysfunction, and damage. Epoxyeicosatrienoic acids (EETs) are endogenous anti-inflammatory compounds, which are quickly converted by the soluble epoxide hydrolase (sEH) enzyme into a less active form with decreased biological effects. The inhibition of the sEH enzyme has been used as a strategy to lower nociception and inflammation. The goal of this study was to investigate whether the peripheral treatment with the sEH enzyme inhibitor 1- trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea (TPPU) could prevent the hypernociception and inflammation in the albumin-induced arthritis model in rats' temporomandibular joint (TMJ). After the induction of experimental arthritis, animals were assessed for nociceptive behavior test, leukocyte infiltration counts and histologic analysis, ELISA to quantify several cytokines and Western blotting. The peripheral pretreatment with TPPU inhibited the arthritis-induced TMJ hypernociception and leukocyte migration. Moreover, the local concentrations of proinflammatory cytokines were diminished by TPPU, while the anti-inflammatory cytokine interleukin-10 was up-regulated in the TMJ tissue. Finally, TPPU significantly decreased protein expression of iNOS, while did not alter the expression of MRC1. This study provides evidence that the peripheral administration of TPPU reduces hypernociception and inflammation in TMJ experimental arthritis.

Polyphenol-enriched extract of Arrabidaea chica used as a dentin pretreatment or incorporated into a total-etching adhesive system: Effects on bonding stability and physical characterization.

The aim of this paper was to evaluate the physical properties and the long-term bond strength of a 2.5% polyphenol-enriched extract of Arrabidaea chica (AC) incorporated into both the phosphoric acid and the primer of a three-step total-etch adhesive, or into an aqueous solution as a dentin pretreatment. Fifty dentin surfaces received the treatments (n = 10): CON (control) - application of the three-step adhesive system (Adper Scotchbond Multipurpose, 3M ESPE); WAT - distilled water used as a pretreatment after dentin etching and before application of the adhesive system; ACPA - AC incorporated into the phosphoric acid; ACW - dentin pre-treatment with AC incorporated into an aqueous solution after etching; ACP - AC incorporated into the primer. Microtensile bond strength tests were performed after 24 h, 6 and 12 months of storage. Slices from the resin-dentin interface were obtained for scanning electron microscopy analysis of the hybrid layer. Degree of conversion of AC incorporated into the primer was evaluated. The particle size, polydispersity index and zeta potential of all the solutions prepared by incorporating AC (phosphoric acid, primer and distilled water) were measured by dynamic light scattering, which brought about changes after incorporation. Degree of conversion of the primer was not affected after incorporating AC. ACP showed lower microtensile bond strength values than the other groups. Bond strength decreased after 6 months of storage, stabilizing at the 12-month evaluation. Therefore, use of AC incorporated into the primer led to lower bond strength values, since AC modified the physical properties (particle size, polydispersity index and zeta potential) of the primer, but did not change the degree of conversion. Application of AC as a dentin pretreatment did not affect bond strength or the micromorphological characteristics of the hybrid layer.

Titanium dioxide nanotubes incorporated into bleaching agents: physicochemical characterization and enamel color change.

OBJECTIVE: Titanium dioxide nanotubes are nanostructures that can accelerate the oxidation reaction of bleaching procedures and promote a more effective whitening effect. This study evaluated physicochemical properties of bleaching agents incorporated with titanium dioxide (TiO2) nanotubes, and the effects on tooth color change at different periods. METHODOLOGY: 40 premolars were treated according to the following groups (n=10): CP - 10% carbamide peroxide (1 hour daily/21 days); CPN - CP incorporated into TiO2; HP - 40% hydrogen peroxide (three 40-minute sessions/7 days apart); HPN - HP incorporated into TiO2. Color shade was evaluated at five different periods (baseline, after 7, 14 and 21 days of bleaching, and 7 days after end of treatment) according to Vita Classical, CIELab and CIEDE2000 scales. Mean particle size (P), polydispersity (PO) and zeta potential (ZP) were evaluated using dynamic light scattering. Data on the different variables were analyzed by mixed model tests for measures repeated in time (ZP e L*), generalized linear models for measures repeated in time (P, PO, Vita Classical and b*), and Friedman and Mann-Whitney tests (a* and color change/ΔE and ΔE00). RESULTS: CP and CPN presented higher P, higher PO and lower ZP than HP and HPN (p≤0.05). All groups showed a significant decrease in Vita Classical color scores after 7 days of bleaching (p<0.05), and HPN presented a greater significant reduction than the other groups. L* increased in TiO2 presence, in all groups, without any differences (p>0.05) in bleaching time. A significant reduction occurred in the a* and b* values for all the groups, and HPN presented lower a* and b* values (p<0.05) than CPN. ΔE was clinically noticeable after 7 days, in all groups, and all groups resulted in a perceptible color change according to ΔE00. CONCLUSION: TiO2 did not influence physicochemical properties of the bleaching agents. HPN presented more effective tooth bleaching than CPN.

Titanium dioxide nanotubes incorporated into bleaching agents: physicochemical characterization and enamel color change

Abstract Titanium dioxide nanotubes are nanostructures that can accelerate the oxidation reaction of bleaching procedures and promote a more effective whitening effect. Objective This study evaluated physicochemical properties of bleaching agents incorporated with titanium dioxide (TiO2) nanotubes, and the effects on tooth color change at different periods. Methodology 40 premolars were treated according to the following groups (n=10): CP - 10% carbamide peroxide (1 hour daily/21 days); CPN - CP incorporated into TiO2; HP - 40% hydrogen peroxide (three 40-minute sessions/7 days apart); HPN - HP incorporated into TiO2. Color shade was evaluated at five different periods (baseline, after 7, 14 and 21 days of bleaching, and 7 days after end of treatment) according to Vita Classical, CIELab and CIEDE2000 scales. Mean particle size (P), polydispersity (PO) and zeta potential (ZP) were evaluated using dynamic light scattering. Data on the different variables were analyzed by mixed model tests for measures repeated in time (ZP e L*), generalized linear models for measures repeated in time (P, PO, Vita Classical and b*), and Friedman and Mann-Whitney tests (a* and color change/ΔE and ΔE00). Results CP and CPN presented higher P, higher PO and lower ZP than HP and HPN (p≤0.05). All groups showed a significant decrease in Vita Classical color scores after 7 days of bleaching (p<0.05), and HPN presented a greater significant reduction than the other groups. L* increased in TiO2 presence, in all groups, without any differences (p>0.05) in bleaching time. A significant reduction occurred in the a* and b* values for all the groups, and HPN presented lower a* and b* values (p<0.05) than CPN. ΔE was clinically noticeable after 7 days, in all groups, and all groups resulted in a perceptible color change according to ΔE00. Conclusion TiO2 did not influence physicochemical properties of the bleaching agents. HPN presented more effective tooth bleaching than CPN.

Pterodon pubescens and Cordia verbenacea association promotes a synergistic response in antinociceptive model and improves the anti-inflammatory results in animal models.

This study evaluated the pharmacological effect of the association of crude extract from the fruits of Pterodon pubescens (Pp) with the essential oil of Cordia verbenacea (Cv) in antinociception and anti-inflammatory experimental models. The effective doses of each extract and the combinations used in the associations of extracts were defined by acetic acid-induced writhing test. The separate extracts were also evaluated on formalin test. Interaction between extracts was assessed by isobologram method. The effects of different concentrations of associations (A50, A100 and A200) were evaluated on formalin test, tail flick and hot plate. The anti-inflammatory activity was evaluated in paw edema induced by carrageenan and PGE2, carrageenan-induced peritonitis and mechanical allodynia induced by Complete Freund's Adjuvant (CFA). The associations were markedly synergistic, as assessed using isobolographic analyses. On formalin and on acetic acid-induced writhing tests, associations demonstrated greater efficacy when compared to extracts separately. In paw edema models, significant reductions of edema were observed. On mechanical allodynia induced by CFA, associations were effective at acute phase with pronounced effect at chronic phase. The associations were not effective in hot plate, tail flick and carrageenan-induced peritonitis tests. Phytochemical analysis by HPLC-DAD and FID showed important concentrations of α-Humulene, trans-Caryophyllene, geranylgeraniol, isomers 6α-hydroxy-7ß-acetoxy-vouacapan-17ßoate methyl ester and 6α-acetoxy-7ß-hydroxy-vouacapan-17ß-oate methyl ester (compounds m/z 404) and 6α,7ß-dihydroxyvouacapan-17ß-oate methyl ester (m/z 362). These findings demonstrate that the associations promote synergistic antinociceptive effect and important anti-inflammatory activities, especially on chronic inflammation conditions, at lower doses than the separate crude extracts, without demonstrating side effects, probably acting in different pharmacological receptors. The inhibition of inflammation suggests a relationship with inflammatory mediators and PGE2 pathway and might be exploited to achieve greater anti-inflammatory efficacy, being considered as a potential phytotherapy.

Antifungal, antibiofilm, and antiproliferative activities of Guapira graciliflora Mart.

The aim of this study was to evaluate in vitro the antifungal, antibiofilm and antiproliferative activities of the extract from the leaves of Guapira graciliflora Mart. The phytochemical characterization of the extract was performed using electrospray ionization mass spectrometry (ESI-MS). The antimicrobial activity of the extract and its fractions was evaluated using the broth microdilution method against species of Candida. The inhibition of C. albicans biofilm was evaluated based on the number of colony-forming units (CFU) and metabolic activity (MTT). The antiproliferative activity of the extract and its fraction was evaluated in the presence of human tumor and non-tumor cells, and the cytotoxicity of the extract was determined on the RAW 264.7 macrophage line - both using the sulforhodamine B method. The phytochemical characterization indicated the presence of the flavonoids rutin and kaempferol. The extract and the methanol fraction exhibited moderate antifungal activity against C. albicans, C. krusei, and C. glabrata, and strong activity against C. dubliniensis. In the biofilms at 24 and 48 hours, the concentration of 12500 µg/mL of the extract was the most effective at reducing the number of CFU s/mL (44.4% and 42.9%, respectively) and the metabolic activity of C. albicans cells (34.6% and 52%, respectively). The extract and its fractions had no antiproliferative effect on the tumor lines tested, with mean activity (log GI50) equal to or greater than 1.71 µg/mL. Macrophage cell viability remained higher than 80% for concentrations of the extract of up to 62.5 µg/mL. G. graciliflora has flavonoids in its chemical composition and demonstrates potential antifungal and antibiofilm activity, with no evidence of a significant change in the viability of human tumor and non-tumor cell lines.