In-office tooth bleaching with 38% hydrogen peroxide promotes moderate/severe pulp inflammation and production of ll-1ß, TNF-ß, GPX, FGF-2 and osteocalcin in rats

Abstract Objectives: To study the intensity of inflammatory infiltrate and production of interleukin-1β (ll-1β), tumor necrosis factor-β (TNF-β), fibroblast growth factor-2 (FGF-2), glutathione peroxidase (GPX), and osteocalcin in response to in-office tooth bleaching in rats. Material and Methods: Twenty male Wistar rats were randomized into four groups (n=5) according to the received treatment (tooth bleaching or no treatment - control) and the period of euthanasia after treatment (24 h or 10 days). We performed tooth bleaching using a 38% hydrogen peroxide gel on maxillary and mandibular incisors. After euthanasia, incisors (20 per group) were processed for histological analysis, immunohistochemistry staining of ll-1β, TNF-β, FGF-2 and GPX and osteocalcin by immunofluorescence. We analyzed data using the Mann-Whitney and Kruskal-Wallis/Dunn tests (p<0.05). Results: The bleached groups presented statistically significant differences regarding the pulp inflammation stage compared with the control groups. Bleached teeth showed moderate/severe inflammatory infiltrate and control groups presented absent inflammatory cells or a negligible number of mononuclear cells (p<0.001) at two times (24 h and 10 days). There was strong staining for ll-1β, TNF-β, and GPX in bleached groups at 24 h and strong staining for ll-1β, TNF-β, GPX and FGF-2 at 10 days. After 10 days of tooth bleaching, the bleached group showed a statistically superior amount of osteocalcin than the other groups (p<0.01). Conclusions: Tooth bleaching with 38% hydrogen peroxide causes severe pulp inflammation, but characteristics of tissue repair after 10 days.

Hyperbaric Oxygen Pretreatment Improves Cognition and Reduces Hippocampal Damage Via p38 Mitogen-Activated Protein Kinase in a Rat Model

PURPOSE: To investigate the effects of hyperbaric oxygen (HBO) pretreatment on cognitive decline and neuronal damage in an Alzheimer’s disease (AD) rat model. MATERIALS AND METHODS: Rats were divided into three groups: normal saline (NS), AD, and HBO+AD. In the AD group, amyloid β peptide (Aβ)₁₋₄₀ was injected into the hippocampal CA1 region of the brain. NS rats received NS injection. In the HBO+AD group, rats received 5 days of daily HBO therapy following Aβ₁₋₄₀ injection. Learning and memory capabilities were examined using the Morris water maze task. Neuronal damage and astrocyte activation were evaluated by hematoxylin-eosin staining and immunohistochemistry, respectively. Dendritic spine density was determined by Golgi-Cox staining. Tumor necrosis factor-α, interleukin-1β, and interleukin-10 production was assessed by enzyme-linked immunosorbent assay. Neuron apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling. Protein expression was examined by western blotting. RESULTS: Learning and memory dysfunction was ameliorated in the HBO+AD group, as shown by significantly lower swimming distances and escape latency, compared to the AD group. Lower rates of neuronal damage, astrocyte activation, dendritic spine loss, and hippocampal neuron apoptosis were seen in the HBO+AD than in the AD group. A lower rate of hippocampal p38 mitogen-activated protein kinase (MAPK) phosphorylation was observed in the HBO+AD than in the AD group. CONCLUSION: HBO pretreatment improves cognition and reduces hippocampal damage via p38 MAPK in AD rats.

Human amnion mesenchymal cells inhibit lipopolysaccharide-induced TNF-α and IL-1ß production in THP-1 cells

BACKGROUND: Human amnion mesenchymal cells (hAMCs), isolated from the amniotic membrane of human placenta, are a unique population of mesenchymal stem cells. Recent studies demonstrated that hAMCs could inhibit the activities and functions of several immune cells. However, their effect on inflammatory macrophages is largely unknown. This study investigated the effect of hAMCs on expression of inflammatory cytokines and mitogen-activated protein kinases (MAPKs)/NF-kB pathway in human THP-1 macrophages induced by lipopolysaccharide (LPS). RESULTS: The levels of TNF-α and IL-1ß secreted by LPS- stimulated THP-1 cells were increased significantly compared with those in the control group. After co-culture with different numbers of hAMCs, the levels of TNF-α and IL-1ß in LPS-stimulated THP-1 cells were significantly reduced compared with the LPS group. The mRNA expression of TNF-α and IL-1ß were also markedly inhibited. Moreover, treating LPS-stimulated THP-1 cells with hAMCs supernatants could also suppress TNF-α and IL-1ß production in THP-1 cells. Important signaling pathways involved in the production of TNF-α and IL-1ß were affected by hAMCs co-culture: hAMCs remarkably suppressed NF-kB activation and down-regulated the phosphorylation of ERK and JNK in LPS- stimulated THP-1 cells. CONCLUSIONS: Human amnion mesenchymal cells inhibited the production of TNF-α and IL-1ß secreted by LPS-stimulated THP-1 cells, partly through the suppression of NF-kB activation and ERK and JNK phosphorylation.

Metotrexate como inductor en la producción de citocinas proinflamatorias en células epiteliales / Methotrexate as inducer of proinflammatory cytokines by epithelial cells

El metotrexate (MTX) es uno de los medicamentos frecuentemente utilizados en el cáncer infantil señalándose además, como agente citotóxico de la mucosa bucal, que puede desencadenar el proceso inflamatorio e incremento de la vascularidad en los tejidos epiteliales durante las fases iniciales de la mucositis oral. El presente trabajo tiene como objetivo determinar la producción de citocinas proinflamatorias IL-1b, IL-6 y TNF-a en cultivos de células epiteliales tratadas con MTX. Se realizaron cultivos de células epiteliales de laringe humana obtenidas de la línea celular Hep-2, con diferentes dosis de MTX en distintos tiempos de incubación, y a su vez se analizó la citotoxicidad del fármaco mediante el ensayo colorimétrico, el cual se basa en la reducción metabólica del bromuro de 3-(4,5- dimetiltiazol-2-ilo)-2,5-difeniltetrazol (MTT), y la producción de citocinas proinflamatorias mediante el ensayo inmuno enzimático indirecto (ELISA). En cuanto a los resultados se observó, que los cultivos de células Hep-2 presentaron aumento en la producción de las citocinas proinflamatorias a las 72 horas al utilizar las dosis de 0.32µM MTX. Estos resultados sugieren que la dosis y el tiempo de exposición del MTX alteran la fisiología de las células epiteliales humanas, lo cual podrían desempeñar un papel importante durante las fases de iniciación y de desarrollo de la mucositis oral.

Methotrexate (MTX), a drug commonly used in childhood cancer, has also been indicated as a cytotoxic agent of the oral mucosa, which can trigger the inflammatory process and increase the vascularity of epithelial tissues during the early stages of oral mucositis. The aim of this study was to determine the production of proinflammatory cytokines IL-1b, IL-6 y TNF-a in epithelial cell cultures treated with MTX. Epithelial cells of human larynx, obtained from the cell line Hep-2, were cultured with different doses of MTX during different incubation times. The drug cytotoxicity was analyzed by means of the colorimetric test, which is based on the metabolic reduction of the bromide of 3-(4, 5-dimetiltiazol-2-ilo)-2,5-difeniltetrazol (MTT); and the proinflammatory cytokines production by the test enzyme-linked immunosorbent assay (ELISA). Cultures of HEp-2 cells showed increased production of proinflammatory cytokines at 72 hours with 0.32µM of MTX. These results suggest that depending on the dose and exposure time, MTX alters the physiology of human epithelial cells, which may play an important role during the phases of initiation and development of oral mucositis.

Impairment of the hematological response and interleukin-1β production in protein-energy malnourished mice after endotoxemia with lipopolysaccharide

The objectives of this study were to determine if protein-energy malnutrition (PEM) could affect the hematologic response to lipopolysaccharide (LPS), the interleukin-1β (IL-1β) production, leukocyte migration, and blood leukocyte expression of CD11a/CD18. Two-month-old male Swiss mice were submitted to PEM (N = 30) with a low-protein diet (14 days) containing 4% protein, compared to 20% protein in the control group (N = 30). The total cellularity of blood, bone marrow, spleen, and bronchoalveolar lavage evaluated after the LPS stimulus indicated reduced number of total cells in all compartments studied and different kinetics of migration in malnourished animals. The in vitro migration assay showed reduced capacity of migration after the LPS stimulus in malnourished animals (45.7 ± 17.2 x 10(4) cells/mL) compared to control (69.6 ± 7.1 x 10(4) cells/mL, P ≤ 0.05), but there was no difference in CD11a/CD18 expression on the surface of blood leukocytes. In addition, the production of IL-1β in vivo after the LPS stimulus (180.7 pg·h-1·mL-1), and in vitro by bone marrow and spleen cells (41.6 ± 15.0 and 8.3 ± 4.0 pg/mL) was significantly lower in malnourished animals compared to control (591.1 pg·h-1·mL-1, 67.0 ± 23.0 and 17.5 ± 8.0 pg/mL, respectively, P ≤ 0.05). The reduced expression of IL-1β, together with the lower number of leukocytes in the central and peripheral compartments, different leukocyte kinetics, and reduced leukocyte migration capacity are factors that interfere with the capacity to mount an adequate immune response, being partly responsible for the immunodeficiency observed in PEM.

High-density lipoprotein prevents SAA-induced production of TNF-α in THP-1 monocytic cells and peripheral blood mononuclear cells

In this study, we evaluated whether human serum and lipoproteins, especially high-density lipoprotein (HDL), affected serum amyloid A (SAA)-induced cytokine release. We verified the effects of SAA on THP-1 cells in serum-free medium compared to medium containing human serum or lipoprotein-deficient serum. SAA-induced tumour necrosis factor-alpha (TNF-α) production was higher in the medium containing lipoprotein-deficient serum than in the medium containing normal human serum. The addition of HDL inhibited the SAA-induced TNF-α release in a dose-dependent manner. This inhibitory effect was specific for HDL and was not affected by low-density lipoprotein or very low-density lipoprotein. In human peripheral blood mononuclear cells, the inhibitory effect of HDL on TNF-α production induced by SAA was less pronounced. However, this effect was significant when HDL was added to lipoprotein-deficient medium. In addition, a similar inhibitory effect was observed for interleukin-1 beta release. These findings confirm the important role of HDL and support our previous hypothesis that HDL inhibits the effects of SAA during SAA transport in the bloodstream. Moreover, the HDL-induced reduction in the proinflammatory activity of SAA emphasizes the involvement of SAA in diseases, such as atherosclerosis, that are characterized by low levels of HDL.

Six-shogaol inhibits production of tumour necrosis factor alpha, interleukin-1 beta and nitric oxide from lipopolysaccharide-stimulated RAW 264.7 macrophages / El 6-shogaol inhibe la producción del factor de necrosis tumoral alfa, la interleuquina-1 beta, y el óxido Nítrico de los macrófagos 264.7 RAW estimulados por lipopolisacáridos

OBJECTIVE: We previously reported that 6-shogaol, a phenolic compound from ginger, has anti-inflammatory properties in a Complete Freund's Adjuvant (CFA) model of mono-arthritic rats. In the present study, we investigated the effects of 6-shogaol on the production of inflammatory mediators from lipopolysaccharide (LPS) activated RAW 264.7 macrophages. These mediators (TNF-α, IL-1-and NO) and their output from macrophages are involved in various pathophysiological events of chronic inflammation and arthritis. METHODS: Effects of 6-shogaol were investigated on the production of the mediators TNF-α, IL-1-and NO (measured as nitrate) from macrophages. Lipopolysaccharide activated RAW 264.7 macrophages were cultured in the presence and absence of 6-shogaol (2 M, 10 M and 20 µM) and ELISA was used to quantify the output of the mediators. RESULTS: 6-shogoal (2 M, 10 M and 20 M) significantly inhibited the production of nitric oxide (NO), IL-1 and TNF-α from the LPS activated RAW264.7 macrophages. CONCLUSION: The results suggest that macrophages are targets for the anti-inflammatory effects of 6 shogaol. Also, the inhibitory effects against TNF-α, IL-1 and NO production from LPS activated macrophages are cellular mechanisms by which 6-shogaol produced its anti-inflammatory effects. These mechanisms provide an explanation of the protection by 6-shogaol against development of joint inflammation and cartilage degradation in CFA induced mono-arthritis that we previously demonstrated (1). Based on these results with 6-shogaol, there is evidence that it exhibits exploitable anti-inflammatory properties.

OBJETIVO: Con anterioridad reportamos que el 6-shogaol - un compuesto fenólico del jengibre - posee propiedades anti-inflamatorias en un modelo CFA de ratas monoartríticas. En el presente estudio, investigamos los efectos del 6-shogaol sobre la producción de mediadores inflamatorios de macrófagos 264.7 RAW estimulados por lipopolisacáridos. Estos mediadores (TNF-α, IL-1-y NO) y su producción de macrófagos están involucrados en varios eventos patofisiológicos de inflamación crónica y artritis. MÉTODOS: Se investigaron los efectos del 6-shogaol sobre la producción de los mediadores TNF-α, IL-1-y NO (medidos como nitratos) de los macrófagos. Macrófagos 264.7 RAW estimulados por lipopolisacáridos fueron cultivados en presencia y ausencia de 6-shogaol (2 M, 10 M y 20 M) y se usó la técnica de ensayo por inmunoabsorción ligado a enzimas (ELISA) a fin de cuantificar la producción de mediadores. RESULTADOS: El 6-shogaol (2 M, 10 M y 20 M) inhibieron significativamente la producción de óxido nítrico (NO), IL-1 βy TNF-α de los macrófagos RAW 264.7 activados mediante LPS. CONCLUSIÓN: Los resultados sugieren que los macrófagos son blancos de los efectos anti-inflamatorios del 6-shogaol. Por otro lado, los efectos inhibitorios contra la producción de TNF-α, IL-1 y NO a partir de macrófagos activados por LPS, son mecanismos celulares mediante los cuales 6-shogaol produjo sus efectos anti-inflamatorios. Estos mecanismos ofrecen una explicación de la protección mediante 6-shogaol contra el desarrollo de inflamación en las articulaciones y la degradación de los cartílagos en la monoartritis inducida mediante CFA que demostramos con anterioridad (1). Sobre la base de estos resultados con 6-shogaol, hay evidencia de que posee propiedades anti-inflamatorias explotables.

Lysophosphatidylglycerol inhibits formyl peptide receptor like-1-stimulated chemotactic migration and IL-1beta production from human phagocytes

In this study, we observed that lysophosphatidylglycerol (LPG) completely inhibited a formyl peptide receptor like-1 (FPRL1) agonist (MMK-1)-stimulated chemotactic migration in human phagocytes, such as neutrophils and monocytes. LPG also dramatically inhibited IL-1beta production by another FPRL1 agonist serum amyloid A (SAA) in human phagocytes. However, LPG itself induced intracellular calcium increase and superoxide anion production in human phagocytes. Keeping in mind that phagocytes migration and IL-1beta production by FPRL1 are important for the induction of inflammatory response, our data suggest that LPG can be regarded as a useful material for the modulation of inflammatory response induced by FPRL1 activation.

A study on immunopathogenetic mechanisms of atherosclerotic process caused by chronic infection of Chlamydia pneumoniae in rats (Ratus novergicus).

AIM: this study was aimed to determine the correlations between duration of Chlamydia pneumoniae infection and the development of atherosclerotic process in white-rats' (Ratus novergicus) aorta. METHODS: this is an experimental study which examined the expression of TNFa, IL-1b, IL-8, adhesion molecule of VCAM-1 and the development of foam cells associated with atherosclerotic process in white-rats' aorta. There were 32 male rats, +/- 6 weeks of age, divided into 4 groups: control group (K) without infection, and 3 groups with infection through nasal and oral inoculation of Chlamydia pneumoniae by single dose of 5 x 105 in amount of 35 microl. The first group (P1) was preserved for 5(1/2) months period, the second group (P2) was preserved for 7(1/2) months and the third group (P3) was preserved for 9(1/2) months. At the end of study, histological slides were made from aortic tissues in order to study the development of atherosclerotic process by examining foam cells and cytokines expression of TNFa, IL-1b, IL-8 and VCAM-1. Foam cells examination was performed by Hematoxcillin-eosin staining, while indirect immunohistochemistry staining was used to examine the expression of TNFa, IL-1b, IL-8 and VCAM-1. Afterward, the amount of foam cells and cytokines expression was measured. The study result was analyzed by ANOVA. RESULTS: there was increased expression of TNFa, IL-1b, IL-8, VCAM-1and increased foam cells formation (extended atherosclerosis area) in the aortic tissues infected by Chlamydia pneumoniae (5(1/2) months, 7(1/2) months and 9(1/2) months), which was significantly different compared to the control group. The result of ANOVA revealed that the most important factor in tissue injury is foam cells development induced by VCAM-1 and IL-8 in all of phases (characterized by most abundant neutrophil infiltration). It indicated the infection caused by extracellular pathogenic agent, which established the fatty streak (acute phase) in 5(1/2) months period. In the group with 7(1/2) months infection period, TNFa also had important roles (characterized by increased monocytes and lymphocytes infiltration), indicating that there was negative-gram pathogenic agent with intracellular infection, which caused a progressive atherosclerotic process, and development of fibrosis / atherosclerotic plaque (sub acute phase). In 9(1/2) months infection period, there was large thrombus containing a lot of leukocytes in the aorta (chronic phase). CONCLUSION: based on the result of this study, it may be concluded that Chlamydia pneumoniae may cause atherosclerotic process in aorta. Extracellular infection of Chlamydia pneumoniae occurs in all of phases and intracellular infection begins in sub-acute phase. On 5(1/2) months period, fatty streak is developed (acute phase); on 7(1/2) months period, there is atherosclerotic plaque (sub acute phase); and on 9(1/2) period, there is large thrombus containing a lot of leukocytes (a progressive chronic phase).