Anti-inflammatory effect of pelubiprofen, 2-[4-(oxocyclohexylidenemethyl)-phenyl]propionic acid, mediated by dual suppression of COX activity and LPS-induced inflammatory gene expression via NF-κB inactivation

Antinociceptive and anti-inflammatory activity of DW-1021, the ionic complex of pelubiprofen and tramadol, in rodents

Although drugs such as acetaminophen, opioids, and nonsteroidal anti-inflammatory drugs (NSAIDs), are commonly used for pain management, the side effects of these drugs such as hepatotoxicity, nephrotoxicity, nausea, and vomiting, can not be neglected. Therefore, combinations of analgesics with different mechanisms raise the possibility of developing novel analgesics. Therefore, the aim of the present study was to evaluate whether DW-1021, the ionic complex of pelubiprofen (NSAID) and tramadol (opioid), has synergic antinociceptive and anti-inflammatory effects in nociceptive as well as inflammation-induced nociceptive models compared to pelubiprofen- or tramadol-only administration. Strong synergistic antinociceptive efficacy of DW-1021 was observed in the mouse writhing test and von Frey paw withdrawal threshold test in the carrageenan-induced rats. The hot plate test in mice and the Randall-Selitto mechanical paw pressure test in carrageenan-induced rats revealed that DW-1021 had a preferable effect on relieving pain to pelubiprofen, but not as much as tramadol. In the carrageenan-induced rats, DW-1021 had a more potent effect on reducing paw inflammation (paw volume, width, and thickness) via the suppression of PGE₂ production than tramadol, but less than that of pelubiprofen. Taken together, our results suggest that the administration of DW-1021, a combination of pelubiprofen and tramadol, exerted a potent effect and can be used as a potential therapeutic agent for relieving pain and inflammation.

Pharmacokinetic and Pharmacodynamic Characteristics of Pelubiprofen Tromethamine vs. Pelubiprofen in Healthy Subjects

Compared to pelubiprofen, a cyclooxygenase-2-selective inhibitor, pelubiprofen tromethamine has been reported to exhibit improved solubility and absorption. Pelubiprofen tromethamine combines the anti-inflammatory effect of pelubiprofen with the gastric protective function of tromethamine salt, making it a relatively safe class of non-steroidal anti-inflammatory drugs with low levels of gastrointestinal side effects in addition to its original analgesic, anti-inflammatory, and antipyretic effects. This study assessed the pharmacokinetic and pharmacodynamic characteristics of pelubiprofen and pelubiprofen tromethamine in healthy subjects. Two independent clinical trials were performed in healthy subjects using a randomized, open-label, oral, single-dose, two-sequence, four-period, crossover design. In Study I and Study II, subjects received 25 mg of pelubiprofen tromethamine and 30 mg of pelubiprofen tromethamine, respectively, with 30 mg of pelubiprofen being the reference. Study I fell within the bioequivalence study criteria. A trend of increased absorption and exposure for 30 mg of pelubiprofen tromethamine vs. the reference in Study II was observed. The maximum cyclooxygenase-2 inhibitory effect of 25 mg of pelubiprofen tromethamine was approximately 98% compared to the reference, showing no significant pharmacodynamic variation. It is thus predicted that 25 mg of pelubiprofen tromethamine would show no clinically significant discrepancies in clinical analgesic and antipyretic effects from 30 mg of pelubiprofen.

Development of Pelubiprofen Tromethamine with Improved Gastrointestinal Safety and Absorption

Pelubiprofen (PEL), which is a commercialized non-steroidal anti-inflammatory drug (NSAID), is associated with the risk of gastrointestinal (GI) adverse events following long-term exposure and has poor water-soluble properties. Here, a new pelubiprofen tromethamine (PEL-T) with improved solubility, permeability, GI safety, and absorption, compared to PEL, has been developed. The nuclear magnetic resonance spectroscopy (NMR), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FT-IR) results confirmed that the PEL-T was well formed. The powder of PEL-T showed the presence of additional 6H protons at δ 3.66-3.61 in the ¹H NMR spectrum, and shifted the sharp endothermic peaks at 129 °C in DSC, and the spectrum of distinct absorption peaks in FT-IR. In addition, compared with PEL, PEL-T showed a significantly improved solubility in various media and an increased permeability coefficient (K_p) in Caco-2 cells. Furthermore, compared to PEL oral administration, PEL-T was found to significantly reduce the damaged area in an acute gastric damage rat model. The pharmacokinetic study of the PEL-T powder showed higher maximum plasma concentration (C_max) and area under the plasma concentration-time curve from 0 h to the last time point (AUC_t) than those of the PEL powder. Taken together, our data suggest that PEL-T is a recommendable candidate with enhanced gastrointestinal safety and better absorption compared with commercial PEL.

Biological Evaluation of Azetidine-2-One Derivatives of Ferulic Acid as Promising Anti-Inflammatory Agents

The purpose of this study was to evaluate the in vivo biological potential of new azetidine-2-one derivatives of ferulic acid (6a–f). First, the in vivo acute toxicity of azetidine-2-one derivatives of ferulic acid on Swiss white mice was investigated and, based on the obtained results, it can be stated that the studied derivatives belong to compounds with moderate toxicity. The in vivo anti-inflammatory potential of these derivatives was determined in a model of acute inflammation induced by carrageenan in rats and in a chronic inflammation model induced in rats using the granuloma test. In the acute inflammation model, all the studied compounds had a maximum anti-inflammatory effect 24 h after administration, which suggests that these compounds may be classified, from a pharmacokinetic point of view, in the category of long-acting compounds. The most active compound in the series was found to be compound 6b. In the case of the chronic inflammation model, it was observed that the studied compounds (6a–f) reduced the formation of granulation tissue compared to the control group, having an intense effect of inhibiting the proliferative component. The most important inhibitory effect of inhibiting the proliferative component was recorded for compound 6b. Additionally, the investigation of liver function was performed by determining the serum levels of liver enzymes aspartate transaminase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH) and bilirubin (total and direct). The results showed that, in the series of azetidin-2-one derivatives, the liver enzymes concentration values were close to those recorded for the reference anti-inflammatories (diclofenac sodium and indomethacin) and slightly higher compared to the values for the healthy control group. At the end of the experiment, the animals were euthanized and fragments of liver, lung, and kidney tissue were taken from all groups in the study. These were processed for histopathological examination, and we noticed no major changes in the groups treated with the azetidine 2-one derivatives of ferulic acid compared to the healthy groups.

Efficacy and safety of short-term use of a pelubiprofen CR and aceclofenac in patients with symptomatic knee osteoarthritis: A double-blinded, randomized, multicenter, active drug comparative, parallel-group, phase IV, non-inferiority clinical trial

INTRODUCTION

At present, information about clinical efficacy and adverse events of controlled release (CR) form of pelubiprofen, a prodrug of 2-arylopropionic acid with relatively selective effects on cyclooxygenase-2 activity, remains scarce. In this study, we sought to determine non-inferiority of pelubiprofen CR 90 mg/day compared to aceclofenac 200 mg/day regarding clinical efficacy and adverse events after a 4-week course of medication in the patients with symptomatic knee osteoarthritis.

MATERIALS AND METHODS

A total of 191 patients were randomly assigned to take either pelubiprofen CR 90 mg (n = 95) or aceclofenac 200 mg (n = 96). The primary outcome variable was non-inferiority of pain reduction between baseline and week 4 when assessed using a 100 mm pain visual analogue scale (VAS). Pelubiprofen was considered non-inferior to aceclofenac if the upper limit of the one-sided 97.5% confidence interval for the difference in terms of pain VAS was above 15 mm (the average change of pain VAS in the pelubiprofen group-pain VAS reduction in the aceclofenac group). Secondary outcome variables were the changes in 100 mm pain VAS at week 2 versus baseline, K-Western Ontario, and McMaster University Arthritis Index (K-WOMAC) changes at weeks 2 and 4 as compared to baseline, patient global assessment at weeks 2 and 4. The frequency and amount of rescue medicine usage at weeks 2 and 4 were also evaluated as the secondary outcome variable. For safety analysis, adverse events, clinical laboratory tests, vital signs, and physical examinations were assessed and conducted at each follow-up visit.

RESULTS

At week 4, the pain VAS values were significantly reduced in both groups receiving either pelubiprofen CR 90 mg or aceclofenac 200 mg as compared to the baseline. However, the pelubiprofen group and the aceclofenac group respectively showed the pain VAS changes of -22 and -21.9 in the pre-protocol set and -20.8 and -21.7 in the full analysis set, confirming non-inferiority. The pelubiprofen CR 90 mg showed a reduced incidence of adverse events compared to the aceclofenac 200 mg (p = 0.005).

CONCLUSIONS

Pelubiprofen CR 90 mg is as effective as aceclofenac 200 mg with reduced adverse events for the treatment of symptomatic knee osteoarthritis.

Alkaloids from Black Pepper (Piper nigrum L.) Exhibit Anti-Inflammatory Activity in Murine Macrophages by Inhibiting Activation of NF-κB Pathway

Black pepper (Piper nigrum L.) has been commonly utilized in food preparation and traditional medicine in several countries. Seven new amide alkaloids, pipernigramides A-G (3, 10, 38, and 41-44), a new piperic ester, pipernigrester A (48), along with 47 known compounds were isolated from the EtOH extract of P. nigrum. The inhibitory effects on nitric oxide (NO) of all compounds were then evaluated. Among the tested compounds, three of them (42-44) significantly inhibited inducible nitric oxide synthase (iNOS)-mediated NO (IC₅₀ = 4.74 ± 0.18, 4.08 ± 0.19, and 3.71 ± 0.32 μM, respectively), and IL-1β, IL-6, TNF-α, and PGE₂ release in RAW 264.7 cells stimulated by lipopolysaccharide. Moreover, 42-44 suppressed IκB degradation and further inhibited the cytosol-nucleus translocation of the p65 subunit by targeting IKK-β. In the carrageenan-induced paw edema test, 42-44 demonstrated anti-inflammatory effects as well. These results indicate that all three compounds from P.nigrum have the potential anti-inflammatory effects.

Sustained-release solid dispersion of pelubiprofen using the blended mixture of aminoclay and pH independent polymers: preparation and in vitro/in vivo characterization

The present study aimed to develop the sustained-release oral dosage form of pelubiprofen (PEL) by using the blended mixture of 3-aminopropyl functionalized-magnesium phyllosilicate (aminoclay) and pH-independent polymers. The sustained-release solid dispersion (SRSD) was prepared by the solvent evaporation method and the optimal composition of SRSD was determined as the weight ratio of drug: Eudragit® RL PO: Eudragit® RS PO of 1:1:2 in the presence of 1% of aminoclay (SRSD(F6)). The dissolution profiles of SRSD(F6) were examined at different pHs and in the simulated intestinal fluids. The drug release from SRSD(F6) was limited at pH 1.2 and gradually increased at pH 6.8, resulting in the best fit to Higuchi equation. The sustained drug release from SRSD(F6) was also maintained in simulated intestinal fluid at fasted-state (FaSSIF) and fed-state (FeSSIF). The structural characteristics of SRSD(F6) were examined by using powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT-IR), indicating the change of drug crystallinity to an amorphous form. After oral administration in rats, SRSD(F6) exhibited the prolonged drug exposure in plasma. For both PEL and PEL-transOH (active metabolite), once a day dosing of SRSD(F6) achieved oral exposure (AUC) comparable to those from the multiple dosing (3 times a day) of untreated drug. In addition, the in vivo absorption of SRSD(F6) was well-correlated with the in vitro dissolution data, establishing a good level A in vitro/in vivo correlation. These results suggest that SRSD(F6) should be promising for the sustained-release of PEL, thereby reducing the dosing frequency.

An in vitro inflammation model to study the Nrf2 and NF-κB crosstalk in presence of ferulic acid as modulator

The aim of this study was to evaluate the crosstalk between Nrf2 and NF-κB signaling pathways and to explore the modulating activity actuated by ferulic acid. In the inflammation process, a key player is the nuclear factor-κB (NF-κB) transcription factor pathway. On the contrary, the activation of Nrf2 inhibits inflammation and impairs degenerative disease providing an interface between redox and anti-inflammatory responses. Recent studies have demonstrated that protein phosphorylation of IKK complex is a potential mechanism for the activation of both Nrf2 and NF-κB pathways. The IKK complex is as an integration point for signals emanating from these different pathways. In this study, we demonstrated that ferulic acid is able to regulate NF-κB and Nrf2 activities. Interestingly, we showed that ferulic acid mimics the potent IKK inhibitor such as BMS, down-regulating the NF-κB response, TAK 1 activation and turning off Nrf2 activities in LPS-stimulated RAW 264.7 cells. Immunoblot data showed that the release of Nrf2 from Keap1 is maintained at low levels also in the presence of LPS stimulus. Nrf2 controls the expression of many antioxidant and detoxification genes, by binding to antioxidant response elements (AREs) that are commonly found in the promoter region of antioxidant (and other) genes. We demonstrated that in the pARE-Luc transfected cells the pre-treatment with FA significantly reduced LPS-induced (p<0.01) and BMS-induced (p<0.01) transcriptional activities. Analysis of well-known Nrf2 transcriptional targets showed that mRNAs expression of Nrf2-dependent antioxidant and phase II enzymes such as dehydrogenase quinone1 (NQO1) and glutathione S-transferase A2 (GSTA2) were up-regulated by BMS and significantly increase more by association with LPS, but are down-regulated in the presence of FA. Interestingly, cells depleted of Keap1 showed increased response of the Nrf2 transcriptional activity also in the presence of FA, strongly suggesting its modulating role in Keap1-Nrf2 signaling pathway.

Pharmacokinetic Interactions Between Pelubiprofen and Eperisone Hydrochloride: A Randomized, Open-label, Crossover Study of Healthy Korean Men

PURPOSE

Pelubiprofen is a novel nonsteroidal anti-inflammatory, analgesic, and antipyretic drug with at least similar efficacy and better tolerability compared with other nonsteroidal anti-inflammatory, analgesic, and antipyretic drugs such as naproxen and aceclofenac. Eperisone hydrochloride is a centrally acting muscle relaxant that performs by blocking calcium channels. The combined use of pelubiprofen and eperisone hydrochloride is increasingly anticipated to promote the clinical effectiveness of pelubiprofen in relieving musculoskeletal symptoms of osteoarthritis, rheumatoid arthritis, and low back pain. No published data are yet available, however, regarding the pharmacokinetic interactions between these 2 drugs when administered concurrently. The objective of this study was to evaluate any pharmacokinetic interactions between pelubiprofen and eperisone hydrochloride in healthy Korean male volunteers.

METHODS

This was a randomized, open-label, crossover study. Each participant was randomly assigned to 1 of 6 treatment sequences and orally received either 45-mg sustained-release pelubiprofen, 75-mg sustained-release eperisone hydrochloride, or both as a single dose in each treatment period, with a 7-day washout period between each treatment. Serial blood samples were collected over 24 hours after dosing, and plasma concentrations of each drug and the major active metabolite of pelubiprofen (trans-alcohol pelubiprofen) were determined by using a validated HPLC-MS/MS system. Pharmacokinetic analyses were conducted by using noncompartmental methods.

FINDINGS

A total of 24 men (mean ± standard deviation of: age, 29 ± 4 years; weight, 72.5 ± 7.8 kg; body mass index, 23.4 ± 1.9 kg/m²) were enrolled, and 23 participants completed the study. For pelubiprofen, the geometric mean ratios (90% CIs) of C_max and AUC_0-∞ were 1.02 (0.87-1.19) and 0.97 (0.88-1.07), respectively. For the major active metabolite of pelubiprofen (trans-alcohol pelubiprofen), the geometric mean ratios (90% CIs) of C_max and AUC_0-∞ were 1.05 (0.98-1.13) and 1.04 (1.01-1.07). For eperisone, the geometric mean ratios (90% CIs) of C_max and AUC_0-∞ were 0.87 (0.67-1.15) and 1.05 (0.85-1.30). None of the study participants experienced serious adverse events during the study.

IMPLICATIONS

No clinically significant changes were noted in the pharmacokinetic interactions of pelubiprofen, the major active metabolite of pelubiprofen (trans-alcohol pelubiprofen), and eperisone hydrochloride between monotherapy and combination therapy with 45-mg sustained-release pelubiprofen and 75-mg sustained-release eperisone hydrochloride.

Formulation of controlled-release pelubiprofen tablet using Kollidon(®) SR

To develop a matrix-type, controlled-release tablet formulation of pelubiprofen (PLB), a recently developed non-steroidal anti-inflammatory drug, polymeric excipients including hypromellose, hydroxypropylcellulose, Eudragit(®) RS PO, and Kollidon(®) SR were screened. A formulation containing 12.4% w/w Kollidon(®) SR (K2 tablet) was found to be the most promising and stable for 6 months in an accelerated stability test. PLB release from K2 tablet was limited at pH 1.2, but gradually increased at pH 6.8 with a surface-erosion, resulting in the best fit to Hixson-Crowell equation. Comparative human PK studies were performed using a randomized, 2-way crossover design. LC-MS/MS assay revealed that the plasma level of PLB-transOH, an active metabolite, was significantly higher than that of PLB. After multiple dosing of immediate-release tablet (R) and K2 tablet (T), the T/R ratios of AUC were 1.02 and 1.04 for PLB and PLB-transOH, respectively. Level A in vitro-in vivo correlation was established for the K2 tablet-administered group. PK profile of PLB-transOH was not influenced by food intake, while that of PLB was altered. We suggest that K2 tablet could be administered twice a day without being affected by food intake, thereby enhancing patient compliance.

Synthesis and Biological Screening of Silicon-Containing Ibuprofen Derivatives: A Study of Their NF-κβ Inhibitory Activity, Cytotoxicity, and Their Ability to Bind IKKβ

The synthesis and characterisation of new silicon-containing amides and esters derived from ibuprofen is reported. These compounds were tested against nuclear transcription factor κβ (NF-κβ). Higher inhibition values than those of ibuprofen were achieved by the new amides 10a–10d; ester derivatives did not show inhibitory activity. The cytotoxicity of these new derivatives was screened; none of them displayed significant toxicity at the screened doses. A molecular docking calculation on IKKβ (an enzyme related to NF-κβ activation) was carried out and the results showed that the amides interact better than ibuprofen with key residues, which are important to the inhibition of IKKβ.

Diacetyloxyl derivatization of the fibroblast growth factor inhibitor dobesilate enhances its anti-inflammatory, anti-angiogenic and anti-tumoral activities

BACKGROUND

Dobesilate (2,5-dihydroxyphenyl sulfonate, DHPS) was recently identified as the most potent member of a family of fibroblast growth factor (FGF) inhibitors headed by gentisic acid, one of the main catabolites of aspirin. Although FGFs were first described as inducers of angiogenesis, they were soon recognized as broad spectrum mitogens. Furthermore, in the last decade these proteins have been shown to participate directly in the onset of inflammation, and their potential angiogenic activity often contributes to the inflammatory process in vivo. The aim of this work was to evaluate the anti-inflammatory, anti-angiogenic and anti-tumoral activities of the derivative of DHPS obtained by acetoxylation of its two hydroxyl groups (2,5-diacetoxyphenyl sulfonate; DAPS).

METHODS

Anti-inflammatory, anti-angiogenic and anti-tumoral activities of DHPS and DAPS were compared using in vivo assays of dermatitis, angiogenesis and tumorigenesis. The effects of both compounds on myeloperoxidase (MPO) and cyclooxygenase (COX) activities, cytokine production and FGF-induced fibroblast proliferation were also determined.

RESULTS

Topical DAPS is more effective than DHPS in preventing inflammatory signs (increased vascular permeability, edema, leukocyte infiltration, MPO activation) caused by contact dermatitis induction in rat ears. DAPS, but not DHPS, effectively inhibits COX-1 and COX-2 activities. DAPS also reduces the increase in serum cytokine concentration induced by lipopolysaccharide in rats. Furthermore, DAPS displays higher in vivo efficacy than DHPS in inhibiting FGF-induced angiogenesis and heterotopic glioma progression, with demonstrated oral efficacy to combat both processes.

CONCLUSIONS

By inhibiting both FGF-signaling and COX-mediated prostaglandin synthesis, DAPS efficiently breaks the vicious circle created by the reciprocal induction of FGF and prostaglandins, which probably sustains undesirable inflammation in many circumstances. Our findings define the enhancement of anti-inflammatory, anti-angiogenic and anti-tumoral activities by diacetyloxyl derivatization of the FGF inhibitor, dobesilate.

Comparison of the efficacy and safety profiles of a pelubiprofen versus celecoxib in patients with rheumatoid arthritis: a 6-week, multicenter, randomized, double-blind, phase III, non-inferiority clinical trial

BACKGROUND

Pelubiprofen is a prodrug of 2-arylpropionic acid with relatively selective effects on cyclooxygenase-2 activity. The aim of this study was to compare the efficacy and safety profiles of pelubiprofen with those of celecoxib in patients with rheumatoid arthritis.

METHODS

This was a 6-week, multicenter, randomized, double-blind, double-dummy, parallel-group, phase III, non-inferiority clinical trial. The primary end point was non-inferiority of pain decrease from baseline to week-6 as determined using a 100 mm pain visual analog scale (VAS). Pelubiprofen was considered non-inferior to celecoxib if the lower limit of the 97.5% confidence interval for treatment difference [(pain reduction in pelubiprofen group) - (pain reduction in celecoxib group)] was more than -10 mm. The secondary end points were as follows: non-inferiority of (1) reduction of Korean health assessment questionnaire (KHAQ) score; (2) decreased duration of morning stiffness; and (3) decrease in the frequency and total dose of rescue drugs after 6 weeks of treatment.

RESULTS

Seventy-seven patients in the pelubiprofen group and 68 patients in the celecoxib group started the study medication. Pelubiprofen was non-inferior to celecoxib with regard to reduction in VAS pain severity (difference, mean ± SD 5.0 ± 20.1; 97.5% CI, -2.3 to ∞). Pelubiprofen was also non-inferior to celecoxib in terms of the secondary end points, such as, decrease in KHAQ score (0.0 ± 0.5, 97.5% CI -0.2 to ∞), decrease in duration of morning stiffness (median 0.0 minute in both groups), and decrease in the frequency (0.7 ± 3.5, 97.5% CI -0.6 to ∞) and total amount (0.7 ± 3.6, 97.5% CI -0.6 to ∞) of rescue medication uses during the 6 week study period. Safety analysis revealed 31.2% patients in the pelubiprofen group and 20.6% patients in the celecoxib group experienced an adverse drug reaction (ADR). The frequency of gastrointestinal ADRs was 20.8 % and 8.8%, respectively.

CONCLUSIONS

Pelubiprofen was found to be as effective as celecoxib at pain reduction and for relieving stiffness in RA patients. However, more patients in the pelubiprofen group experienced ADR and the frequency of gastrointestinal ADRs was higher in the pelubiprofen group. ClinialTrials.gov identifier: NCT01781702.

Fractal analysis of ibuprofen effect on experimental dog peri-implantitis

INTRODUCTION

The aim of this study was to assess the correlation between the fractal analysis of gingival changes and systemic nitro-oxidative stress in a short-term low-dose ibuprofen (IBU) treatment at experimental peri-implantitis (PI).

MATERIALS AND METHODS

Six adult male mixed-breed dogs with PI were randomly treated for 2 weeks, 3 with IBU (5 mg/kg b.w.) and 3 with placebo. Clinical and radiological evaluation were performed. Gingival biopsies were assessed by light microscopy, transmission electron microscopy, and fractal analysis. Blood was collected to assay nitric oxide (NOx), total oxidative status (TOS), total antioxidant response (TAR), and oxidative stress index (OSI).

RESULTS

Specific gingival ultrastructural alterations, bone loss, and systemic nitro-oxidative stress were evident in PI-placebo animals. IBU caused significant clinical, microscopic, fractal dimensions (P < 0.01), NOx, TOS, and OSI improvements. IBU caused no important bone and TAR changes.

CONCLUSION

This study confirms that fractal analysis was a good method to assess the complex morphological changes and correlations with the nitro-oxidative stress in PI. Short-term low-dose IBU treatment consistently improved gingival status and reduced systemic nitro-oxidative stress.

Adenosine 5'-monophosphate ameliorates D-galactosamine/lipopolysaccharide-induced liver injury through an adenosine receptor-independent mechanism in mice

D-galactosamine (GalN)/lipopolysaccharide (LPS)-induced lethality and acute liver failure is dependent on endogenously produced inflammatory cytokines. Adenosine has been proven to be a central role in the regulation of inflammatory response. It is not entirely clear that which adenosine action is actually crucial to limiting inflammatory tissue destruction. Here we showed that GalN/LPS challenge elevated hepatic adenosine and induced lethality in adenosine receptor-deficient mice with equal efficiency as wild-type mice. In GalN/LPS-treated mice, pretreatment with adenosine 5'-monophosphate (5'-AMP) significantly elevated hepatic adenosine level and reduced mortality through decreasing cytokine and chemokine production. In RAW264.7 cells, 5'-AMP treatment inhibited the production of inflammatory cytokines, which is not mediated through adenosine receptors. 5'-AMP failed to attenuate LPS-induced nuclear factor-κB (NF-κB) p65 nuclear translocation, but reduced LPS-induced recruitment of NF-κB p65 to inflammatory gene promoters and decreased LPS-induced enrichment of H3K4 dimethylation at the tumor necrosis factor-α (TNF-α) promoter, which was involved in 5'-AMP-induced elevation of cellular adenosine and a decline of methylation potential. In vitro biochemical analysis revealed that adenosine directly attenuated recruitment of NF-κB to the TNF-α and interleukin-6 promoters. Our findings demonstrate that 5'-AMP-inhibiting inflammatory response is not mediated by adenosine receptors and it may represent a potential protective agent for amelioration of LPS-induced liver injury.

Nitidine chloride inhibits LPS-induced inflammatory cytokines production via MAPK and NF-kappaB pathway in RAW 264.7 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Zanthoxylum nitidium (Roxb.) DC. has long been used as a traditional herbal medicine for inflammatory diseases such as rheumatic arthritis and peridentitis. However, the anti-inflammatory mechanism of Nitidine chloride has not been fully elucidated.

AIM OF THE STUDY

To determine the anti-inflammatory effects and mechanism of Nitidine chloride (NTD), a pentacyclic alkaloid is isolated from the root of Z. nitidium, in murine macrophages.

MATERIALS AND METHODS

Anti-inflammatory properties of NTD were investigated using lipopolysaccharide (LPS)-stimulated Raw 264.7 macrophages as in vitro model. The pro-inflammatory cytokines were evaluated by real-time RT-PCR and ELISA. Furthermore, intracellular signaling pathways were analyzed by Western blot and Immunofluorescence staining using specific antibodies.

RESULTS

NTD significantly reduced the production of pro-inflammatory cytokines such as tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), and IL-6 in both RNA and protein level. Moreover, transcriptional activity of NF-кB as well as the phosphorylation of mitogen-activated protein kinases (MAPKs) in LPS-treated RAW 264.7 was significantly inhibited by NTD in a dose dependent manner. These results suggested that NTD exerts an anti-inflammatory property by inhibiting TNF-α, IL-1β, and IL-6 production in association with reduced NF-κB and MAPK signaling pathways in RAW 264.7 cells.

CONCLUSION

These results suggested that NTD exerts an anti-inflammatory property by inhibiting TNF-α, IL-1β, and IL-6 production in association with reduced NF-κB and MAPK signaling pathways in RAW 264.7 cells. Nitidine chloride inhibits LPS-induced TNF alpha, IL-1beta and IL-6 production via the suppression of phosphorylation of MAPK and the translocation of p65. In addition, these results revealed a novel role of NTD in regulation of inflammatory diseases.