Anti-inflammatory Dexamethasone Research Articles

Down-regulation of Cytokine-induced Interleukin-8 Requires Inhibition of p38 Mitogen-activated Protein Kinase (MAPK) via MAPK Phosphatase 1-dependent and -independent Mechanisms

Down-regulation of overabundant interleukin (IL)-8 present in cystic fibrosis (CF) airways could ease excessive neutrophil burden and its deleterious consequences for the lung. IL-8 production in airway epithelial cells, stimulated with e.g. inflammatory cytokines IL-1β and tumor necrosis factor (TNF)-α, is regulated by several signaling pathways including nuclear factor (NF)-κB and p38 mitogen-activated protein kinase (MAPK). We previously demonstrated that the anti-inflammatory drugs dexamethasone and ibuprofen suppress NF-κB; however, only dexamethasone down-regulates cytokine-induced IL-8, highlighting the importance of non-NF-κB mechanisms. Here, we tested the hypothesis that down-regulation of cytokine-induced IL-8 requires modulation of the MAPK phosphatase (MKP)-1/p38 MAPK/mRNA stability pathway. The effects of dexamethasone (5 nm) and ibuprofen (480 μm) on this pathway and IL-8 were studied in CF (CFTE29o-, CFBE41o-) and non-CF (1HAEo-) airway epithelial cells. We observed that dexamethasone, but not ibuprofen, destabilizes IL-8 mRNA and up-regulates MKP-1 mRNA. Further, siRNA silencing of MKP-1, via p38 MAPK, leads to IL-8 overproduction and diminishes the anti-IL-8 potential of dexamethasone. However, MKP-1 overexpression does not significantly alter IL-8 production. By contrast, direct inhibition of p38 MAPK (inhibitor SB203580) efficiently suppresses IL-8 with potency comparable with dexamethasone. Similar to dexamethasone, SB203580 decreases IL-8 mRNA stability. Dexamethasone does not affect p38 MAPK activation, which excludes its effects upstream of p38 MAPK. In conclusion, normal levels of MKP-1 are necessary for a full anti-IL-8 potential of pharmacological agents; however, efficient pharmacological down-regulation of cytokine-induced IL-8 also requires direct effects on p38 MAPK and mRNA stability independently of MKP-1.

Synergistic effect of HPMA copolymer-bound doxorubicin and dexamethasone in vivo on mouse lymphomas

N-(2-Hydroxypropyl)methacrylamide (HPMA) copolymer—drug conjugates bearing the antiinflammatory and anti-proliferative drug dexamethasone (DEX) and the anti-cancer drug doxorubicin (DOX) bound to either the polymer carrier separately or in combination, were synthesized. Both the in vitro and in vivo anti-cancer activity on mouse B-cell (38C13) and T-cell (EL4) lymphoma was studied. The conjugates were fairly stable in model buffers at pH 7.4, simulating blood pH, and the drug was released by chemical hydrolysis at pH values based on the endosomal and lysosomal environments in the target cells (pH 5—6). As a control, polymer conjugates containing only a single-drug (DOX or DEX) attached to the HPMA copolymer carrier were synthesized and tested. Contrary to the treatment with either single drug conjugate, where no significant long-term survival was observed, a synergistic effect of the two drugs was manifested in vivo. Treatment of mice bearing B-cell lymphoma 38C13 formulated as a mixture of both single drug-containing conjugates or a as a conjugate with both drugs in combination gave long-term survivors.

Adjunctive dexamethasone affects the expression of genes related to inflammation, neurogenesis and apoptosis in infant rat pneumococcal meningitis.

Streptococcus pneumoniae is the most common pathogen causing non-epidemic bacterial meningitis worldwide. The immune response and inflammatory processes contribute to the pathophysiology. Hence, the anti-inflammatory dexamethasone is advocated as adjuvant treatment although its clinical efficacy remains a question at issue. In experimental models of pneumococcal meningitis, dexamethasone increased neuronal damage in the dentate gyrus. Here, we investigated expressional changes in the hippocampus and cortex at 72 h after infection when dexamethasone was given to infant rats with pneumococcal meningitis. Nursing Wistar rats were intracisternally infected with Streptococcus pneumoniae to induce experimental meningitis or were sham-infected with pyrogen-free saline. Besides antibiotics, animals were either treated with dexamethasone or saline. Expressional changes were assessed by the use of GeneChip® Rat Exon 1.0 ST Arrays and quantitative real-time PCR. Protein levels of brain-derived neurotrophic factor, cytokines and chemokines were evaluated in immunoassays using Luminex xMAP® technology. In infected animals, 213 and 264 genes were significantly regulated by dexamethasone in the hippocampus and cortex respectively. Separately for the cortex and the hippocampus, Gene Ontology analysis identified clusters of biological processes which were assigned to the predefined categories “inflammation”, “growth”, “apoptosis” and others. Dexamethasone affected the expression of genes and protein levels of chemokines reflecting diminished activation of microglia. Dexamethasone-induced changes of genes related to apoptosis suggest the downregulation of the Akt-survival pathway and the induction of caspase-independent apoptosis. Signalling of pro-neurogenic pathways such as transforming growth factor pathway was reduced by dexamethasone resulting in a lack of pro-survival triggers. The anti-inflammatory properties of dexamethasone were observed on gene and protein level in experimental pneumococcal meningitis. Further dexamethasone-induced expressional changes reflect an increase of pro-apoptotic signals and a decrease of pro-neurogenic processes. The findings may help to identify potential mechanisms leading to apoptosis by dexamethasone in experimental pneumococcal meningitis.

β-Sitosterol Isolated from Cocoa Powder Functions to Increase Expression of Anti-Inflammatory Proteins in Trigeminal Neurons: Implications for Treatment of Migraine and TMJ Disorders

Previously published findings from our laboratory have shown that cocoa extract inhibits activation of trigeminal neurons in culture and in animals fed a cocoa enriched diet. Activation of trigeminal neurons is implicated in the underlying pathology of migraine, rhinosinusitis, and TMJ or jaw joint disorders. Within trigeminal neurons, proteins known as phosphatases restore cellular homeostasis and thus, suppress inflammatory and nociceptive responses. The goal of this study was to purify and identify the compound in cocoa powder responsible for increased phosphatase activity in trigeminal neurons. Crude extracts from cocoa powder were prepared using silica gel column chromatography and biological activity tested on primary cultures of trigeminal ganglia. Using immunocytochemistry, cultures were stained for the phosphatase MKP-1, which is a protein upregulated in response to treatment with the anti-inflammatory drug dexamethasone. Extracts displaying increased MKP-1 staining were then further purified and retested for MKP-1 activity. The greatest increase in MKP-1 activity was seen in a cocoa fraction containing β-Sitosterol that has a similar chemical structure to dexamethasone. This fraction was isolated with flash chromatography and quantified with LC/MS. β-Sitosterol was found to be 0.0234% (0.936mg/4g) the mass of cocoa powder. In conclusion, data from our study provide evidence for a mechanism by which cocoa exerts its anti-inflammatory and anti-nociceptive effects by inducing MKP-1 expression in trigeminal neurons. Furthermore, we speculate that the inclusion of β-Sitosterol as a dietary supplement would suppress activation of trigeminal neurons, and thus may be beneficial in the treatment of migraine and TMJ disorders.

Electrically controlled drug release from nanostructured polypyrrole coated ontitanium

Previous studies have demonstrated that multi-walled carbon nanotubes grown out ofanodized nanotubular titanium (MWNT–Ti) can be used as a sensing electrode for variousbiomedical applications; such sensors detected the redox reactions of certain molecules,specifically proteins deposited by osteoblasts during extracellular matrix bone formation.Since it is known that polypyrrole (PPy) can release drugs upon electrical stimulation, inthis study antibiotics (penicillin/streptomycin, P/S) or an anti-inflammatory drug(dexamethasone, Dex), termed PPy[P/S] or PPy[Dex], respectively, were electrodepositedin PPy on titanium. The objective of the present study was to determine if such drugs canbe released from PPy on demand and (by applying a voltage) control cellular behaviorimportant for orthopedic applications. Results showed that PPy films possessednanometer-scale roughness as analyzed by atomic force microscopy. X-ray photoelectronspectroscopy confirmed the presence of P/S and Dex encapsulated within the PPy films.Results from cyclic voltammetry showed that 80% of the drugs were released ondemand when sweep voltages were applied for five cycles at a scan rate of 0.1 V s − 1. Furthermore, osteoblast (bone-forming cells) and fibroblast (fibrous tissue-forming cells)adhesion were determined on the PPy films. Results showed that PPy[Dex] enhancedosteoblast adhesion after 4 h of culture compared to plain Ti. PPy–Ti (with or withoutanionic drug doping) inhibited fibroblast adhesion compared to plain Ti. These in vitroresults confirmed that electrodeposited PPy[P/S] and PPy[Dex] can release drugs ondemand to potentially fight bacterial infection, reduce inflammation, promote bone growthor reduce fibroblast functions, further implicating the use of such materials as implantsensors.

Anti-inflammatory and antioxidant activities of the leaves of Wissadula amplissima var Rostrata.

The present study determined the anti-inflammatory activity of Wissadula amplissima var rostrata (Schum. & Thonn.), and calculated the total phenolic content and total antioxidant capacity of the plant in an attempt to justify the traditional uses of the plant in the Ashanti region of Ghana for the management of spider,wasps and bee stings. Powdered dried leaves of Wissadula amplissima were Soxhlet extracted with Petroleum Ether (PWA, yield: 1.46% (w)/(w)); Chloroform (CWA, yield: 1.18% (w)/(w)) and Methanol (MWA, yield: 3.39% (w)/(w)). These fractions were tested for anti-inflammatory activity using carrageenan-induced foot edema in 7 day old chicks. The effect before the induction of inflammation (pre-emptive protocol) paradigm was used for the assessment. Oral administration of PWA, CWA and MWA (30 - 300 mg/kg) dose dependently reduced edema with maximal effects of 68.25±2.03%, 77.83±0.81% and 62.21±2.61% respectively. Similarly the NSAID, Diclofenac (10 - 100 mg/Kg, i.p) and the steroidal anti-inflammatory drug dexamethasone (0.3 - 3 mg/Kg, i.p) used as positive controls, dose-dependently inhibited the edema with maximal effect of 87.96±1.11% and 67.47±3.51% respectively. The potencies exhibited by all three extracts were comparable to that shown by Diclofenac but higher than that of Dexamethasone. Phenols were detected in all three extracts with the highest concentration in the MWA. The extracts also scavenged DPPH with EC(50) values of 0.9784, 0.9096 and 0.2767 for PWA, CWA, MWA respectively. The results of this study give scientific credence to the local use of Wissadula amplissima to modulate inflammation induced by stings of animals.

Videoradiographic analysis of the range of motion in unilateral experimental knee joint arthritis in rats

IntroductionThe translational and predictive value of animal models highly depends on the validity of respective readout parameters. In arthritis research, there has been a shift from sole threshold testing for pain-related behavior, as well as from swelling and histology assessment for inflammation, toward an analysis of joint function as indicated, for instance, by an increasing number of studies on gait abnormalities. Clinically, the range of motion (ROM) of the affected joint plays a major role in diagnosis and the assessment of treatment benefits. This parameter, however, is only insufficiently detected by currently used analytic systems in animals.MethodsHere we used high-resolution videoradiographic analysis to assess ROM in experimental knee joint arthritis in rats. This parameter is described during the 21-day course of antigen-induced arthritis in rats. Furthermore, the therapeutic effects of antinociceptive (morphine) and anti-inflammatory (dexamethasone) treatment on ROM are documented. To obtain additional information on the implications of ROM in animal models, correlations were performed to measure pain-related behavior and inflammation.ResultsThe study animals showed a significant reduction in ROM of the inflamed knee joint in the acute phase of arthritis. This was accompanied by an increase in knee joint movement on the contralateral side, indicating a compensational mechanism. Both morphine and dexamethasone treatment increased and thus normalized ROM. Changes in ROM were further stage-dependently correlated with weight bearing and joint swelling, that is, with both pain-related behavior and signs of inflammation.ConclusionsThe dynamic ROM observed in freely moving rats in our model of knee joint arthritis might serve as a parameter for global disease activity and might thus represent a promising readout parameter for preclinical assessment regarding the overall efficacy not only of antiarthritic but also of antinociceptive compounds.

Mesenchymal Stem Cell-Conditioned Medium Triggers Neuroinflammation and Reactive Species Generation in Organotypic Cultures of Rat Hippocampus

Cell therapy using bone marrow-derived mesenchymal stem cells (MSCs) seems to be a new alternative for the treatment of neurodegenerative diseases. Despite several promising results with their use, possible side effects are still unknown. In a previous work, we have shown that MSC-conditioned medium is toxic to hippocampal slice cultures and aggravates cell death induced by oxygen and glucose deprivation. In this work, we investigated whether the inflammatory response and/or reactive species formation could be involved in that toxicity. Rat organotypic hippocampal cultures were exposed for 24 h to conditioned medium from MSCs isolated from rat bone marrow. A marked glial activation was observed after exposure of cultures to MSC-conditioned medium, as evidenced by glial fibrillary acid protein (GFAP) and isolectin B(4) increase. Tumor necrosis factor-α and interleukin-6 levels were increased in the culture medium, and 2,7-dihydrodichlorofluorescein diacetate oxidation (indicating reactive species generation) and inducible nitric oxide synthase (iNOS) immunocontent were also higher after exposure of cultures to MSC-conditioned medium. Antioxidants (ascorbic acid and TROLOX(®)), N(ω)-nitro-l-arginine methyl ester hydrochloride, and anti-inflammatory drugs (indomethacin and dexamethasone) reduced cell death in hippocampal organotypic cultures after their exposure to MSC-conditioned medium. The results obtained here suggest that MSC-secreted factors trigger reactive species generation and neuroinflammation in organotypic cultures of hippocampus, introducing a note of caution in the use of these cells for neurological application.

In vitro and in vivo evaluation of anti-inflammatory agents using nanoengineered alginate carriers: Towards localized implant inflammation suppression

The aim of this research was to develop nanoengineered alginate microspheres for localized delivery of anti-inflammatory drugs (dexamethasone and diclofenac sodium) for implantable “Smart tattoo” glucose biosensor used for continuous glucose monitoring. The formulation was prepared and characterized for in vitro drug release from uncoated and polyelectrolyte-coated microparticles. Biocompatibility was then tested using L929 cell-line; pilot in vivo studies with Sprague–Dawley (SD) rat subjects were performed to test the suppression of inflammation and fibrosis associated with implantation and was analyzed using standard hematoxylin and eosin staining method. The drug-loaded microspheres were able to deliver the drug for 30 days at a controlled rate with zero-order kinetics. The layer-by-layer self-assembly technique was used to effectively limit the burst release of drug from the matrix. Cell culture studies prove that the material are not cytotoxic and showed acceptable >80% cell viability in all the tested samples. In vivo studies show that both drugs were successful in controlling the implant/tissue interface by suppressing inflammation at the implant site. It was clearly evident that the combined approach of drug loaded carriers along with implanted biosensor shows promise in improving sensor biocompatibility and functionality. Thus, suggesting potential application of alginate microspheres as “smart-tattoo” glucose sensors.

PHARMACOLOGIC TREATMENT OF HYPERALGESIA EXPERIMENTALLY INDUCED BY NUCLEUS PULPOSUS

Objective: To evaluate the effect of anti-inflammatory drugs (dexamethasone, indomethacin, atenolol and indomethacin plus atenolol) and analgesic drugs (morphine) on hyperalgesia experimentally induced by the nucleus pulposus (NP) in contact with the L5 dorsal root ganglion (DRG). Methods: Thirty male Wistar rats of weights ranging from 220 to 250 g were used in the study. Hyperalgesia was induced by means of a fragment of NP removed from the sacrococcygeal region that was placed in contact with the L5 dorsal root ganglion. The 30 animals were divided into experimental groups according to the drug used. The drugs were administered for two weeks after the surgical procedure to induce hyperalgesia. Mechanical and thermal hyperalgesia was evaluated using the paw pressure test, von Frey electronic test and Hargreaves test, over a seven-week period. Results: The greatest reduction of hyperalgesia was observed in the group of animals treated with morphine, followed by dexamethasone, indomethacin and atenolol. Reductions in hyperalgesia were observed after drug administration ceased, except for the group of animals treated with morphine, in which there was an increase in hyperalgesia after discontinuation of the treatment. Conclusion: Hyperalgesia induced by NP contact with the DRG can be reduced through administration of anti-inflammatory and analgesic drugs, but a greater reduction was observed with the administration of dexamethasone.

Expression of Na–H exchanger-8 isoform is suppressed in experimental colitis in adult rat: lack of reversibility by dexamethasone

Objectives. Mechanism of the apical transporter Na–H exchanger-8 (NHE-8) regulation was investigated by examining the effects of anti-inflammatory dexamethasone in experimental colitis. In addition, its localization was investigated in the lipid rich membrane domain called membrane rafts. Material and methods. Colitis was induced by trinitrobenzene sulfonic acid (TNBS) and colon segments were removed from 5 day post-TNBS and used to estimate the levels of NHE-8 protein and mRNA using ECL western blot analysis and a competitive RT-PCR method. Myeloperoxidase activity, malondialdehyde levels and histologic changes were evaluated. Results. NHE-8 protein level was decreased in inflamed colon and was not reversed by dexamethasone. However, mRNA levels remained unchanged in inflamed colon. The levels of NHE-8 protein and mRNA were not significantly different in non-colitic control as compared to dexamethasone treated non-colitis. Elevation of myeloperoxidase activity, malondialdehyde and infiltration of inflammatory cells in inflamed colon were suppressed by dexamethasone treatment of colitis significantly. Furthermore, NHE-8 protein was not detected in the detergent resistant membrane (DRM) or lipid rafts, but was present in the detergent sensitive membrane (DRS) fractions. Actin showed its partition similar to NHE-8. On the contrary, NHE-3 was present in both DRM and DRS fractions. Flotillin-1 and caveolin were enriched in the fractions designated as lipid rafts. Conclusions. These findings demonstrate the suppression of NHE-8 protein in inflamed adult rat colon, which seems to be regulated post-transcriptionlly. Furthermore, the absence of NHE-8 in lipid rafts suggests its regulation independent of cAMP or recycling through endocytosis unlike NHE-3 isoform.

Altered sialylation on the cell-surface proteins of dexamethasone-treated human macrophages contributes to augmented uptake of apoptotic neutrophils

Macrophages eliminate apoptotic granulocytes before their secondary necrosis during resolution of inflammation. A well-known glucocorticoid, the anti-inflammatory dexamethasone augments phagocytosis capacity of macrophages with a so far not fully clarified mechanism. We have found that sialylation of cell-surface proteins on human macrophages is markedly altered by dexamethasone. Compared to non-treated cells, dexamethasone-treated macrophages can bind significantly less Sambucus nigra lectin specific for sialic acids on their surfaces as a result of undersialylation of annexin-II and an HLA-II protein. Non-treated macrophages covered by S. nigra lectin had increased uptake of apoptotic cells; however, the significantly higher phagocytosis capacity of dexamethasone-treated macrophages could not be stimulated further this way. Our results suggest that dexamethasone treatment leads to decreased number of sialic acids on the surfaces of human macrophages promoting recognition and uptake of apoptotic cells.

Electrochemical deposition of conducting polymer coatings on magnesium surfaces in ionic liquid

A conducting polymer-based smart coating for magnesium (Mg) implants that can both improve the corrosion resistance of Mg and release a drug in a controllable way is reported. As the ionic liquid is a highly conductive and stable solvent with a very wide electrochemical window, the conducting polymer coatings can be directly electrodeposited on the active metal Mg in ionic liquid under mild conditions, and Mg is highly stable during the electrodeposition. The electrodeposited poly(3,4-ethylenedioxythiophene) (PEDOT) coatings on Mg are uniform and can significantly improve the corrosion resistance of Mg. In addition, the PEDOT coatings can load the anti-inflammatory drug dexamethasone during the electrodeposition, which can be subsequently released upon electric stimulation.

Early severe inflammatory responses to uropathogenic E. coli predispose to chronic and recurrent urinary tract infection.

Chronic infections are an increasing problem due to the aging population and the increase in antibiotic resistant organisms. Therefore, understanding the host-pathogen interactions that result in chronic infection is of great importance. Here, we investigate the molecular basis of chronic bacterial cystitis. We establish that introduction of uropathogenic E. coli (UPEC) into the bladders of C3H mice results in two distinct disease outcomes: resolution of acute infection or development of chronic cystitis lasting months. The incidence of chronic cystitis is both host strain and infectious dose-dependent. Further, development of chronic cystitis is preceded by biomarkers of local and systemic acute inflammation at 24 hours post-infection, including severe pyuria and bladder inflammation with mucosal injury, and a distinct serum cytokine signature consisting of elevated IL-5, IL-6, G-CSF, and the IL-8 analog KC. Mice deficient in TLR4 signaling or lymphocytes lack these innate responses and are resistant, to varying degrees, to developing chronic cystitis. Treatment of C3H mice with the glucocorticoid anti-inflammatory drug dexamethasone prior to UPEC infection also suppresses the development of chronic cystitis. Finally, individuals with a history of chronic cystitis, lasting at least 14 days, are significantly more susceptible to redeveloping severe, chronic cystitis upon bacterial challenge. Thus, we have discovered that the development of chronic cystitis in C3H mice by UPEC is facilitated by severe acute inflammatory responses early in infection, which subsequently are predisposing to recurrent cystitis, an insidious problem in women. Overall, these results have significant implications for our understanding of how early host-pathogen interactions at the mucosal surface determines the fate of disease.

Expression, regulation and functional activities of aminopeptidase N (EC 3.4.11.2; APN; CD13) on murine macrophage J774 cell line

Aminopeptidase N (APN; CD13) is a ubiquitous membrane-bound enzyme. Expressed on haematopoietic cells APN participates in inflammatory and immune responses by regulating local concentration of chemotactic peptides and by fine-tuning antigen presentation. The data of this study have shown for the first time that cells of murine macrophage line, J774, often used as a model cell line, express CD13 both at transcriptional level and at the level of membrane protein with aminopeptidase N (APN) activity. The level of transcriptional expression of CD13/APN on J774 cells was compared to that found on normal cells participating in immune responses. The highest CD13/APN level was found in peritoneal macrophages, followed by J774 cells and splenocytes, whereas lymph node, thymus and bone-marrow cells expressed low level of CD13/APN mRNA. Further, the CD13 (mRNA, protein and APN) on J774 cells could be up-regulated by pro-inflammatory IFN-γ which is in agreement with the known role of CD13/APN in inflammatory responses. Co-regulation of CD13 with MHC-II and CD86 is in line with the reported role of APN expressed on human cells in antigen presentation. CD13 on J774 cells co-localize with mannose receptors (MR), and co-internalize upon MR ligation by ovalbumin, suggesting a new function of CD13 in MR-mediated phagocytosis. That function of CD13 is independent of APN enzyme activity. Anti-inflammatory drug dexamethasone diminished the IFN-γ-induced increase of CD13. The observed down-regulation of CD13 on J774 cells by dexamethasone might be relevant as a possible mechanism involved in action of anti-inflammatory drugs on normal macrophages.

The Skin Cancer Chemotherapeutic Agent Ingenol-3-Angelate (PEP005) Is a Substrate for the Epidermal Multidrug Transporter (ABCB1) and Targets Tumor Vasculature

Ingenol-3-angelate (Ing3A), extracted from Euphorbia peplus, is currently in clinical trials for eradicating basal cell carcinoma, actinic keratosis, and squamous cell carcinoma (SCC) in situ by topical application. Although structurally related to phorbol esters and a protein kinase C activator, topical Ing3A, but not phorbol 12-myristate 13-acetate (PMA), inhibited the growth of subcutaneous tumors derived from PAM212 (mouse SCC) and B16 (mouse melanoma). Ing3A and PMA both induced acute neutrophilic inflammation on mouse skin, but only Ing3A caused subcutaneous hemorrhage and vascular damage. Both Ing3A and PMA activated extracellular signal-regulated kinase 1/2 (ERK1/2) in epidermis, but Ing3A also activated ERK1/2 in skin dermal fibroblasts and endothelial cells. Pretreatment with topical cyclosporin A (CsA), verapamil, or XR9576, modulators of P-glycoprotein (P-gp), prevented Ing3A-induced hemorrhage but not neutrophil infiltration. CsA also impaired the anticancer activity of Ing3A, whereas the anti-inflammatory dexamethasone did not. Ing3A, but not PMA, blocked photoaffinity labeling of human P-gp with [(125)I]iodoaryazidoprazosin and inhibited P-gp-mediated drug resistance to HCT-15 cells. The intracellular levels of Ing3A were significantly lower in P-gp-expressing cells, and treatment with XR9576 increased the levels to those of cells that do not express P-gp, showing that Ing3A binds to and is transported by P-gp. Taken together, our results suggest that P-gp-mediated absorptive transport, dermal penetration, and vascular damage contribute to the anticancer activity of Ing3A in vivo.

Anti-inflammatory effect of crude extract and isolated compounds from Baccharis illinita DC in acute skin inflammation

Ethnopharmacologycal relevance The tea from the leaves of Baccharis illinita DC ( Asteraceae family) is commonly used by the population as anti-inflammatory (including topically), protective gastric and anti-infectious. However, no studies have been done with this species to confirm its topical anti-inflammatory action. Aim This study evaluated he topical effects of crude extract of leaves (CE) and its active constituents in 12-O-tetradecanoilforbol acetate (TPA)-induced ear oedema. Methodology CE and compounds effects were tested in commonly used models of TPA-, arachidonic acid (AA)- and capsaicin-ear oedema. Polymorphonuclear (PMN) cell migration was evaluated by mieloperoxidase and analyzed histologically. Results CE (0.1–1 mg/ear) caused a dose-related inhibition of TPA-induced ear oedema and PMN influx similarly to that produced by topical application of the steroidal anti-inflammatory drug dexamethasone. The active constituents of the AcOEt fraction kaurenoic acid, α-spinasterol, oleanolic acid and baurenol also inhibited TPA-induced ear edema. Histological analysis of the ear of CE-treated animals confirmed the reduction of edema and of PMN infiltration. Both CE and the nosteroidal anti-inflammatory drug indomethacin inhibited the AA-induced ear oedema, but did not change capsaicin-induced oedema. Conclusion These results indicate that the CE and the active constituents have a topical anti-inflammatory effect and the possible mechanisms for the pharmacological effects are discussed.

Abstract 1777: The skin cancer chemotherapeutic agent PEP005 is a substrate for the epidermal multidrug transporter (ABCB1) and targets tumor vasculature

Abstract Ingenol-3-angelate (PEP005), extracted from Euphorbia peplus, is currently in clinical trials for eradicating basal cell carcinoma (BCC), actinic keratosis and squamous cell carcinoma (SCC) in situ by topical application. Although structurally related to phorbol esters and a PKC activator, topical PEP005, but not phorbol 12-myristate 13-acetate (PMA), inhibited the growth of subcutaneous tumors derived from PAM212 (mouse SCC) and B16 (mouse melanoma). PEP005 and PMA both induced acute neutrophilic inflammation on mouse skin, but only PEP005 caused subcutaneous hemorrhage and vascular damage. Both PEP005 and PMA activated Erk1/2 in epidermis, but PEP005 also activated Erk1/2 in skin dermal fibroblasts and endothelial cells. Pretreatment with topical cyclosporin A (CsA), verapamil or XR9576, modulators of P-glycoprotein (P-gp), prevented PEP005-induced hemorrhage but not neutrophil infiltration. CsA also impaired Ing3A's anti-cancer activity while the anti-inflammatory dexamethasone did not. PEP005, but not PMA, blocked photoaffinity labeling of human P-gp with [125I]-Iodoaryazidoprazosin and inhibited P-gp mediated drug resistance to HCT-15 cells. The intracellular levels of PEP005 were significantly lower in P-gp expressing cells and treatment with XR9576 increased the levels to those of cells that do not express P-gp, demonstrating that PEP005 binds to and is transported by P-gp. Taken together, our results suggest that P-gp mediated absorptive transport, dermal penetration and vascular damage contribute to the anti-cancer activity of PEP005 in vivo. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1777.

Anti-Inflammatory Effect of Low-Level Laser and Light-Emitting Diode in Zymosan-Induced Arthritis

The aim of this work was to investigate the effect of low-level laser therapy (LLLT) and light-emitting diode (LED) on formation of edema, increase in vascular permeability, and articular joint hyperalgesia in zymosan-induced arthritis. It has been suggested that low-level laser and LED irradiation can modulate inflammatory processes. Arthritis was induced in male Wistar rats (250-280 g) by intra-articular injection of zymosan (1 mg in 50 microL of a sterile saline solution) into one rear knee joint. Animals were irradiated immediately, 1 h, and 2 h after zymosan administration with a semiconductor laser (685 nm and 830 nm) and an LED at 628 nm, with the same dose (2.5 J/cm(2)) for laser and LED. In the positive control group, animals were injected with the anti-inflammatory drug dexamethasone 1 h prior to the zymosan administration. Edema was measured by the wet/dry weight difference of the articular tissue, the increase in vascular permeability was assessed by the extravasation of Evans blue dye, and joint hyperalgesia was measured using the rat knee-joint articular incapacitation test. Irradiation with 685 nm and 830 nm laser wavelengths significantly inhibited edema formation, vascular permeability, and hyperalgesia. Laser irradiation, averaged over the two wavelengths, reduced the vascular permeability by 24%, edema formation by 23%, and articular incapacitation by 59%. Treatment with LED (628 nm), with the same fluence as the laser, had no effect in zymosan-induced arthritis. LLLT reduces inflammatory signs more effectively than LED irradiation with similar irradiation times (100 sec), average outputs (20 mW), and energy doses (2 J) in an animal model of zymosan-induced arthritis. The anti-inflammatory effects of LLLT appear to be a class effect, which is not wavelength specific in the red and infrared parts of the optical spectrum.

Tratamento farmacológico da hiperalgesia experimentalmente induzida pelo núcleo pulposo

OBJETIVO: Avaliar o efeito de drogas anti-inflamatórias (dexametasona, indometacina, atenolol, indometacina e atenolol) e analgésica (morfina) sobre a hiperalgesia experimentalmente induzida pelo núcleo pulposo em contato com o gânglio da raiz dorsal de L5. MÉTODOS: Trinta ratos Wistar machos com peso de 220 a 250g foram utilizados no estudo. A indução da hiperalgesia foi realizada por meio do contato de fragmento de núcleo pulposo retirado da região sacrococcígea e colocado sobre o gânglio da raiz dorsal de L5. Os 30 animais foram divididos em grupos experimentais de acordo com a droga utilizada. As drogas foram administradas durante duas semanas a partir da realização do procedimento cirúrgico para a indução da hiperalgesia. A hiperalgesia mecânica e térmica foram avaliadas por meio do teste da pressão constante da pata, von Frey eletrônico e Hargraves por um período de sete semanas. RESULTADOS: A maior redução da hiperalgesia foi observada no grupo de animais tratados pela morfina, seguido pela dexametasona, indometacina e atenolol. A redução da hiperalgesia foi observada após a interrupção da administração das drogas, com exceção do grupo de animais tratados com morfina, nos quais ocorreu aumento da hiperalgesia após a interrupção do tratamento. CONCLUSÕES: A hiperalgesia induzida pelo contato do núcleo pulposo com o gânglio da raiz dorsal pode ser reduzida com a administração de anti-inflamatórios e analgésicos, tendo sido observado a maior redução da hiperalgesia com a administração da morfina e dexametasona.