Signal transduction pathways regulating cyclooxygenase-2 expression: potential molecular targets for chemoprevention

Targeting cyclooxygenase-2 for chemoprevention of inflammation-associated intestinal carcinogenesis: An update

Mounting evidence from preclinical and clinical studies suggests that persistent inflammation functions as a driving force in the journey to cancer. Cyclooxygenase-2 (COX-2) is a key enzyme involved in inflammatory signaling. While being transiently upregulated upon inflammatory stimuli, COX-2 has been found to be consistently overexpressed in human colorectal cancer and several other malignancies. The association between chronic inflammation and cancer has been revisited: cancer can arise when inflammation fails to resolve. Besides its proinflammatory functions, COX-2 also catalyzes the production of pro-resolving as well as anti-inflammatory metabolites from polyunsaturated fatty acids. This may account for the side effects caused by long term use of some COX-2 inhibitory drugs during the cancer chemopreventive trials. This review summarizes the latest findings highlighting the dual functions of COX-2 in the context of its implications in the development, maintenance, and progression of cancer.

Curcumin and its nano-formulations combined with exercise: From molecular mechanisms to clinic

Curcumin is a strong substance derived from turmeric, a popular spice, renowned for its antioxidant and anti-inflammatory abilities. The study delved deeply into a thorough examination of various sources to evaluate the impact of both regular curcumin and nano-formulated curcumin on elements that impact physical performance, including muscular strain, discomfort, swelling, and oxidative tension. While engaging in exercise, the body experiences a rise in reactive oxygen species and inflammation. As a result, it is important to ensure a proper balance between internal and external sources of antioxidants to maintain stability in the skeletal muscle. Without this balance, there is a risk of muscle soreness, damage, and ultimately, a decline in exercise performance. Curcumin possesses the ability to enhance physical performance and reduce the symptoms of muscle fatigue and injury by virtue of its antioxidative and anti-inflammatory properties. Including curcumin supplements appears to have advantageous effects on various aspects of exercise, such as enhancing performance, assisting with recovery, lessening muscle damage and discomfort, and lowering levels of inflammation and oxidative stress. However, a thorough assessment is necessary to precisely gauge the healing advantages of curcumin in enhancing exercise ability and reducing recovery time.

Effects of resveratrol on the anthropometric indices and inflammatory markers: an umbrella meta-analysis

BACKGROUND

The evidence for resveratrol's anti-obesity and anti-inflammatory qualities is accumulating, though meta-analyses have reported mixed results. The current umbrella meta-analysis aimed to assess the present evidence and provide an accurate estimate of the overall effects of resveratrol on the anthropometric indices and inflammatory markers.

METHOD

The Web of Science, PubMed, Scopus, and Google Scholar databases were searched till March 2023. The meta-analysis was performed utilizing a random-effects model. Moreover, the overall strength and quality of the evidence were assessed using the GRADE tool.

RESULTS

The results from 19 meta-analyses investigating 81 unique randomized controlled trials with 4088 participants revealed that resveratrol supplementation reduced the body mass index (ES =  - 0.119, 95% CI (- 0.192, - 0.047), p = 0.001), waist circumference (ES =  - 0.405, 95% CI [- 0.664, - 0.147], p = 0.002), serum levels of C-reactive protein (ES =  - 0.390, 95% CI [- 0.474, - 0.306], p < 0.001), and tumor necrosis factor-α (ES =  - 0.455, 95% CI [- 0.592, - 0.318], p < 0.001) in comparison to the control group. The effects of resveratrol on body weight and Interleukin-6 levels of participants were not significant. However, resveratrol administration significantly decreased body weight in trials with intervention duration ≥ 12 weeks [ES =  - 0.160, 95% CI (- 0.268, - 0.052)] and supplement dosage ≥ 500 mg/day [ES =  - 0.130, 95% CI (- 0.238, - 0.022)].

CONCLUSION

The findings suggest the beneficial effects of resveratrol supplementation on reducing general and central obesity, as well as decreasing some inflammatory markers. Nevertheless, further high-quality research is required to prove these achievements and also evaluate resveratrol's effects on other inflammatory markers.

Macrosphelides from Antarctic fungus Pseudogymnoascus sp. (strain SF-7351) and their neuroprotective effects on BV2 and HT22 cells

Strategies for reducing inflammation in neurodegenerative diseases have attracted increasing attention. Herein, we discovered and evaluated the neuroprotective potential of fungal metabolites isolated from the Antarctic fungus Pseudogymnoascus sp. (strain SF-7351). The chemical investigation of the EtOAc extract of the fungal strain isolate revealed a novel naturally occurring epi-macrosphelide J (1), a novel secondary metabolite macrosphelide N (2), and three known compounds, namely macrosphelide A (3), macrosphelide B (4), and macrosphelide J (5). Their structures were established unambiguously using spectroscopic methods, such as one-dimensional and two-dimensional nuclear magnetic resonance (1D and 2D-NMR) spectroscopy, high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), and gauge-including atomic orbital (GIAO) NMR chemical shift calculations, with the support of the advanced statistical method DP4+. Among the isolated metabolites, the absolute configuration of epi-macrosphelide J (1) was further confirmed using single-crystal X-ray diffraction analysis. The neuroprotective effects of the isolated metabolites were evaluated in lipopolysaccharide (LPS)-induced BV2 and glutamate-stimulated HT22 cells. Only macrosphelide B (4) displayed substantial protective effects in both BV2 and HT22 cells. Molecular mechanisms underlying this activity were investigated using western blotting and molecular docking studies. Macrosphelide B (4) inhibited the inflammatory response by reducing the nuclear translocation of NF-κB (p65) in LPS-induced BV2 cells and induced the Nrf2/HO-1 signaling pathway in both BV2 and HT22 cells. The neuroprotective effect of macrosphelide B (4) is related to the interaction between Keap1 and p65. These results suggest that macrosphelide B (4), present in the fungus Pseudogymnoascus sp. (strain SF-7351), may serve as a candidate for the treatment of neurodegenerative diseases.

PSMD4 drives progression of hepatocellular carcinoma via Akt/COX2 pathway and p53 inhibition

The ubiquitin-dependent proteolytic pathway is crucial for cellular regulation, including control of the cell cycle, differentiation, and apoptosis. Proteasome 26S Subunit Ubiquitin Receptor, Non-ATPase 4, (PSMD4) is a member of the ubiquitin proteasome family that is upregulated in multiple solid tumors, including hepatocellular carcinoma (HCC), and the existence of PSMD4 is associated with unfavorable prognosis. In this study, transcriptome sequencing of HCC tissues and non-tumor hepatic tissues from the public database Cancer Genome Atlas (TGCA) revealed a high expression of PSMD4. Additionally, PSMD4 loss in HCC cells suppressed the tumor development in mouse xenograft model. PSMD4, which is maintained by inflammatory factors secreted from tumor matrix cells, positively mediates cell growth and is associated with Akt/GSK-3β/ cyclooxygenase2 (COX2) pathway activation, inhibition of p53 promoter activity, and increased p53 degradation. However, the domain without the C-terminus (VWA+UIM1/2) sustained the activation of p53 transcription. Thus, our findings suggest that PSMD4 is involved in HCC tumor growth through COX2 expression and p53 downregulation. Therapeutic strategies targeting PSMD4 and its downstream effectors could be used for the treatment of PSMD4-abundant HCC patients.

Voltage-gated sodium channels: from roles and mechanisms in the metastatic cell behavior to clinical potential as therapeutic targets

During the second half of the last century, the prevalent knowledge recognized the voltage-gated sodium channels (VGSCs) as the proteins responsible for the generation and propagation of action potentials in excitable cells. However, over the last 25 years, new non-canonical roles of VGSCs in cancer hallmarks have been uncovered. Their dysregulated expression and activity have been associated with aggressive features and cancer progression towards metastatic stages, suggesting the potential use of VGSCs as cancer markers and prognostic factors. Recent work has elicited essential information about the signalling pathways modulated by these channels: coupling membrane activity to transcriptional regulation pathways, intracellular and extracellular pH regulation, invadopodia maturation, and proteolytic activity. In a promising scenario, the inhibition of VGSCs with FDA-approved drugs as well as with new synthetic compounds, reduces cancer cell invasion in vitro and cancer progression in vivo. The purpose of this review is to present an update regarding recent advances and ongoing efforts to have a better understanding of molecular and cellular mechanisms on the involvement of both pore-forming α and auxiliary β subunits of VGSCs in the metastatic processes, with the aim at proposing VGSCs as new oncological markers and targets for anticancer treatments.

Betulinic Acid Exerts Anti-inflammatory Activity in Human Periodontal Ligament Cells Stimulated with Lipopolysaccharide and/or High Glucose

BACKGROUND

Diabetic patients have weakened periodontal ligaments and an increased risk of periodontitis due to uncontrolled glycemia. Betulinic acid (BA), a hypoglycemic drug, has anti-inflammatory activities.

OBJECTIVES

The current study aimed to explore the protective effect of BA on the inflammation in human periodontal ligament cells (PDLCs) stimulated with lipopolysaccharide (LPS) and/or high glucose (HG) status and its mechanisms of action.

METHODS

Human PDLCs were exposed to LPS and/or HG, with or without BA intervention. The production of nitrite oxide (NO) and prostaglandin E2 (PGE2) were quantified by Griess reaction and enzyme-linked immunosorbent assay, respectively. Immunoblotting analyses were employed to detect the expression of inducible nitric oxide synthase (iNOS) and the cyclooxygenase-2 (COX- 2), as well as the activation of mitogen-activated protein kinases (MAPKs) and nuclear factor kappa- B (NF-κB) in human PDLCs.

RESULTS

The increased production of iNOS/NO and COX-2/PGE2 and increased phosphorylated levels of IκBα, JNK, and p38 can be detected in human PDLCs with LPS and/or HG situations, while increased phosphorylated ERK can be seen in cells under only LPS condition. Furthermore, the non-toxic concentration of BA (10 μM) prevented NF-κB and MAPKs activation and partly but significantly reversed the induction of COX-2/ PGE2 and iNOS/NO in human PDLCs with LPS and/or HG loaded.

CONCLUSION

BA was proved for the first time to protect human PDLCs from the LPS-induced and/or HG-induced inflammation, which works through the mechanism involving the action of MAPKs and NF-κB. signaling pathways. Thus, BA could be used to alleviate diabetic complications of periodontitis.

The Role of Resveratrol in Eye Diseases—A Review of the Literature

Resveratrol (3,5,4′-trans-trihydroxystilbene) is a polyphenolic phytoalexin belonging to the stilbene family. It is commonly found in grape skins and seeds, as well as other plant-based foods. Oxidative stress and inflammation play a key role in the initiation and progression of age-related eye disorders (glaucoma, cataracts, diabetic retinopathy, and macular degeneration) that lead to a progressive loss of vision and blindness. Even though the way resveratrol affects the human body and the course of many diseases is still the subject of ongoing scientific research, it has been shown that the broad spectrum of anti-inflammatory and neuroprotective properties of resveratrol has a beneficial effect on eye tissues. In our research, we decided to analyze the current scientific literature on resveratrol, its possible mechanisms of action, and its therapeutic application in order to assess its effectiveness in eye diseases.

Significance of Cyclooxgenase-2 gene polymorphism and related miRNAs in pulmonary arterial hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH) is a rare disease with a poor prognosis. The suppression of cyclooxygenase-2 (COX-2) expression has been known to impair vascular function in endothelial cells; however, the epigenetic factors that cause this are largely obscure. Our aim in this study was to examine the polymorphisms in the gene for COX-2 (PTGS2) and related miRNAs regulating its level in a single-center cohort of patients with PAH.

METHOD

In this study, three SNPs and miRNAs (rs5275, rs689470, rs20417, miR-26b-5p, miR-146a-5p, and miR-101-5p) in the PTGS2 were screened in PAH and controls by qPCR. In addition, the COX-2 level was determined by immunoassay to examine the effects of epigenetic factors on its expression levels.

RESULTS

The non-dominant genotypes of rs20417 and rs5275 were found to be related to PAH (OR = 8.56, 95% CI = 3.39-21.63, p < 0.0001 and OR = 7.82, 95% CI = 3.30-18.53, p < 0.0001, respectively). We also observed a significant increase in the miR-26b-5p and miR-146a-5p levels in PAH patients (2.18 and 2.35-fold, respectively; for both, p < 0.05). In addition, it was found that SNPs influenced the COX-2, miR-26b-5p, and miR-146a-5p levels in PAH. A negative correlation was also found between COX-2 levels and miR-26b-5p and miR-146a-5p.

CONCLUSIONS

As conventional drug therapies may cause lower COX-2 levels, the development of new genetic or epigenetic biomarkers is crucially important for early diagnosis and prognosis. The presence of minor alleles for rs5275 and rs689470 might also be considered as a significant risk factor for developing PAH. Furthermore, locus-specific miRNAs, such as miR-26b-5p and miR-146a-5p, seem to play a critical role in the regulation of PTGS2 expression.

Identification of Potential Anti-Neuroinflammatory Inhibitors from Antarctic Fungal Strain Aspergillus sp. SF-7402 via Regulating the NF-κB Signaling Pathway in Microglia

Microglia play a significant role in immune defense and tissue repair in the central nervous system (CNS). Microglial activation and the resulting neuroinflammation play a key role in the pathogenesis of neurodegenerative disorders. Recently, inflammation reduction strategies in neurodegenerative diseases have attracted increasing attention. Herein, we discovered and evaluated the anti-neuroinflammatory potential of compounds from the Antarctic fungi strain Aspergillus sp. SF-7402 in lipopolysaccharide (LPS)-stimulated BV2 cells. Four metabolites were isolated from the fungi through chemical investigations, namely, 5-methoxysterigmatocystin (1), sterigmatocystin (2), aversin (3), and 6,8-O-dimethylversicolorin A (4). Their chemical structures were elucidated by extensive spectroscopic analysis and HR-ESI-MS, as well as by comparison with those reported in literature. Anti-neuroinflammatory effects of the isolated metabolites were evaluated by measuring the production of nitric oxide (NO), tumor necrosis factor (TNF)-α, and interleukin (IL)-6 in LPS-activated microglia at non-cytotoxic concentrations. Sterigmatocystins (1 and 2) displayed significant effects on NO production and mild effects on TNF-α and IL-6 expression inhibition. The molecular mechanisms underlying this activity were investigated using Western blot analysis. Sterigmatocystin treatment inhibited NO production via downregulation of inducible nitric oxide synthase (iNOS) expression in LPS-stimulated BV2 cells. Additionally, sterigmatocystins reduced nuclear translocation of NF-κB. These results suggest that sterigmatocystins present in the fungal strain Aspergillus sp. are promising candidates for the treatment of neuroinflammatory diseases.

Network pharmacology, molecular docking technology integrated with pharmacodynamic study to reveal the potential targets of Schisandrol A in drug-induced liver injury by acetaminophen

Schisandrae Chinensis Fructus (SCF) was a Traditional Chinese Medicine for protecting liver. However, underlying therapeutic mechanisms of these bioactive lignans from SCF similar hepatoprotective effects against drug-induced liver injury (DILI) by acetaminophen (APAP) are still unclear. This study aims to discover the potential regulation mechanisms of Schisandrol A in the treatment of DILI by APAP. The integrated UPLC-Q-TOF/MS, pharmacodynamic study, histopathological combination with network pharmacology and molecular docking technology were used to explore the potential mechanisms. The results showed that Schisandrol A reduced the level of AST, ALT, MDA, PNP, TNF-α and IL-1β, increased the levels of the GSH against acute liver failure. Additionally, Schisandrol A could improve the morphological characteristics of DILI by APAP in mice with liver tissue. Molecular docking results had showed that Schisandrol A with high scores when docking with COX-2, ALOX5, CYP2E1, CYP2C9, CYP2C19, EGFR SRC, Nrf2, MAPK14 and MAPK8. The study demonstrated that Schisandrol A could play critical roles in DILI by APAP via regulating TNF signaling pathway, inhibiting oxidative stress, inflammation and inhibiting the activities of cytochrome P450 enzymes, which contributed to searching for leading compounds and the development of new drugs for DILI by APAP.

Independent of Calorie Intake, Short-term Alternate-day Fasting Alleviates NASH, With Modulation of Markers of Lipogenesis, Autophagy, Apoptosis, and Inflammation in Rats

Non-alcoholic steatohepatitis (NASH) is a worldwide health problem. Alternate-day fasting (ADF), although thought to be aggressive, has proven safety and efficacy. We aimed to evaluate the effect of short-term ADF against already established high-fat-fructose (HFF)-induced NASH, independent of the amount of calorie intake, and to study the effect of ADF on lipogenesis, apoptosis, and hepatic inflammation. Male Sprague Dawley rats were divided into two groups: (1) negative control and (2) NASH group fed on HFF for 9 weeks, and then randomized into two subgroups of either HFF alone or with ADF protocol for 3 weeks. The ADF could improve HFF-related elevation in serum lactate dehydrogenase and could decrease the mRNA expression of lipogenesis genes; acetyl CoA carboxylase, peroxisome proliferator-activated receptor γ, and peroxisome proliferator-activated receptor α; apoptotic genes caspase-3, p53, and inflammatory cyclo-oxygenase 2; and immunohistochemical staining for their proteins in liver with upregulation of LC3 and downregulation of P62 immunoexpression. Moreover, ADF ameliorated HFF-induced steatosis, inflammation, ballooning, and fibrosis through hematoxylin and eosin, Oil Red O, and Sirius Red staining, confirmed by morphometric analysis, without significant weight loss. Significant correlation of morphometric parameters with levels of gene expression was found. These findings suggest ADF to be a safe effective therapeutic agent in the management of NASH.

Triptolide Modulates the Expression of Inflammation-Associated lncRNA-PACER and lincRNA-p21 in Mycobacterium tuberculosis-Infected Monocyte-Derived Macrophages

Triptolide is a diterpene triepoxide, which performs its biological activities via mechanisms including induction of apoptosis, targeting of pro-inflammatory cytokines, and reshaping of the epigenetic landscape of target cells. However, the targeting of long non-coding RNAs (lncRNAs) by triptolide has not yet been investigated, despite their emerging roles as key epigenetic regulators of inflammation and immune cell function during Mycobacterium tuberculosis (Mtb) infection. Hence, we investigated whether triptolide targets inflammation-associated lncRNA-PACER and lincRNA-p21 and how this targeting associates with Mtb killing within monocyte-derived macrophages (MDMs).Using RT-qPCR, we found that triptolide induced the expression of lincRNA-p21 but inhibited the expression of lncRNA-PACER in resting MDMs in a dose- and time-dependent manner. Moreover, Mtb infection induced the expression of lincRNA-p21 and lncRNA-PACER, and exposure to triptolide before or after Mtb infection led to further increase of Mtb-induced expression of these lncRNAs in MDMs. We further found that contrary to lncRNA-PACER, triptolide time- and dose-dependently upregulated Ptgs-2, which is a proximal gene regulated by lncRNA-PACER. Also, low-concentration triptolide inhibited the expression of cytokine IL-6, a known target of lincRNA-p21. Mtb infection induced the expression of IL-6 and Ptgs-2, and triptolide treatment further increased IL-6 but decreased Ptgs-2 expression in Mtb-infected MDMs. The inverse relation between the expression of these lncRNAs and their target genes is concordant with the conception that these lncRNAs mediate, at least partially, the cytotoxic and/or anti-inflammatory activities of triptolide in both resting and activated MDMs. Using the CFU count method, we found that triptolide decreased the intracellular growth of Mtb HN878. The alamarBlue assay showed that this decreased Mtb HN878 growth was not as a result of direct targeting of Mtb HN878 by triptolide, but rather evoking MDMs’ intracellular killing mechanisms which we speculate could include triptolide-induced enhancement of MDMs’ effector killing functions mediated by lncRNA-PACER and lincRNA-p21. Altogether, these results provide proof of the modulation of lncRNA-PACER and lincRNA-p21 expression by triptolide, and a possible link between these lncRNAs, the enhancement of MDMs’ effector killing functions and the intracellular Mtb-killing activities of triptolide. These findings prompt for further investigation of the precise contribution of these lncRNAs to triptolide-induced activities in MDMs.

Focus on Multi-targeted Role of Curcumin: a Boon in Therapeutic Paradigm

Curcumin is a polyphenolic compound that exhibited good anticancer potential against different types of cancers through its multi-targeted effect like the termination of cell proliferation, inflammation, angiogenesis, and metastasis, thereby acting as antiproliferative and cytotoxic in nature. The present review surveys the various drug combination tried with curcumin or its synthetic analogues and also the mechanism by which curcumin potentiates the effect of almost every drug. In addition, this article also focuses on aromatherapy which is gaining much popularity in cancer patients. After thoroughly studying several articles on combination therapy of curcumin through authenticated book chapters, websites, research, and review articles available at PubMed, ScienceDirect, etc., it has been observed that multi-targeted curcumin possess enormous anticancer potential and, with whatever drug it is given in combination, has always resulted in enhanced effect with reduced dose as well as side effects. It is also capable enough in overcoming the problem of chemoresistance. Besides this, aromatherapy also proved its potency in reducing cancer-related side effects. Combining all the factors together, we can conclude that combination therapy of drugs with curcumin should be explored extensively. In addition, aromatherapy can be used as an adjuvant or supplementary therapy to reduce the cancer complications in patients.

RGS10 physically and functionally interacts with STIM2 and requires store-operated calcium entry to regulate pro-inflammatory gene expression in microglia

Chronic activation of microglia is a driving factor in the progression of neuroinflammatory diseases, and mechanisms that regulate microglial inflammatory signaling are potential targets for novel therapeutics. Regulator of G protein Signaling 10 is the most abundant RGS protein in microglia, where it suppresses inflammatory gene expression and reduces microglia-mediated neurotoxicity. In particular, microglial RGS10 downregulates the expression of pro-inflammatory mediators including cyclooxygenase 2 (COX-2) following stimulation with lipopolysaccharide (LPS). However, the mechanism by which RGS10 affects inflammatory signaling is unknown and is independent of its canonical G protein targeted mechanism. Here, we sought to identify non-canonical RGS10 interacting partners that mediate its anti-inflammatory mechanism. Through RGS10 co-immunoprecipitation coupled with mass spectrometry, we identified STIM2, an endoplasmic reticulum (ER) localized calcium sensor and a component of the store-operated calcium entry (SOCE) machinery, as a novel RGS10 interacting protein in microglia. Direct immunoprecipitation experiments confirmed RGS10-STIM2 interaction in multiple microglia and macrophage cell lines, as well as in primary cells, with no interaction observed with the homologue STIM1. We further determined that STIM2, Orai channels, and the calcium-dependent phosphatase calcineurin are essential for LPS-induced COX-2 production in microglia, and this pathway is required for the inhibitory effect of RGS10 on COX-2. Additionally, our data demonstrated that RGS10 suppresses SOCE triggered by ER calcium depletion and that ER calcium depletion, which induces SOCE, amplifies pro-inflammatory genes. In addition to COX-2, we also show that RGS10 suppresses the expression of pro-inflammatory cytokines in microglia in response to thrombin and LPS stimulation, and all of these effects require SOCE. Collectively, the physical and functional links between RGS10 and STIM2 suggest a complex regulatory network connecting RGS10, SOCE, and pro-inflammatory gene expression in microglia, with broad implications in the pathogenesis and treatment of chronic neuroinflammation.

Harnessing Tumor Necrosis Factor Alpha to Achieve Effective Cancer Immunotherapy

Tumor necrosis factor alpha (TNFα) is a pleiotropic cytokine known to have contradictory roles in oncoimmunology. Indeed, TNFα has a central role in the onset of the immune response, inducing both activation and the effector function of macrophages, dendritic cells, natural killer (NK) cells, and B and T lymphocytes. Within the tumor microenvironment, however, TNFα is one of the main mediators of cancer-related inflammation. It is involved in the recruitment and differentiation of immune suppressor cells, leading to evasion of tumor immune surveillance. These characteristics turn TNFα into an attractive target to overcome therapy resistance and tackle cancer. This review focuses on the diverse molecular mechanisms that place TNFα as a source of resistance to immunotherapy such as monoclonal antibodies against cancer cells or immune checkpoints and adoptive cell therapy. We also expose the benefits of TNFα blocking strategies in combination with immunotherapy to improve the antitumor effect and prevent or treat adverse immune-related effects.

Anti-Inflammatory Action and Mechanisms of Resveratrol

Resveratrol (3,4',5-trihy- droxystilbene), a natural phytoalexin polyphenol, exhibits anti-oxidant, anti-inflammatory, and anti-carcinogenic properties. This phytoalexin is well-absorbed and rapidly and extensively metabolized in the body. Inflammation is an adaptive response, which could be triggered by various danger signals, such as invasion by microorganisms or tissue injury. In this review, the anti-inflammatory activity and the mechanism of resveratrol modulates the inflammatory response are examined. Multiple experimental studies that illustrate regulatory mechanisms and the immunomodulatory function of resveratrol both in vivo and in vitro. The data acquired from those studies are discussed.

Abnormal Pressure Stress Reduces Interleukin-1β-Induced Cyclooxygenase-2 Expression in Cultured Rat Vascular Smooth Muscle Cells

Elevated mechanical stress on blood vessels associated with hypertension has a direct effect on the function of vascular endothelial cells and vascular smooth muscle cells (VSMCs). In the present study, we have identified the effect of pulsatile pressure stress on cyclooxygenase-2 (COX-2) expression induced by interleukin (IL)-1β in cultured rat VSMCs. VSMCs were isolated from aortic media of Wistar rats and cultured. Pulsatile pressure applied to VSMCs was repeatedly given between either 80 and 160 mmHg, which simulates systolic hypertension, or 80 and 120 mmHg, which simulates normal blood pressure, at a frequency of 4 cycles per min using our original apparatus. Pressure loading that simulates systolic hypertension reduced IL-1β-induced COX-2 expression. The pressure also inhibited the rapid and transient phosphorylation of extracellular signal-regulated kinase (ERK) induced by IL-1β. IL-1β-induced COX-2 expression was significantly inhibited by a specific conventional protein kinase C (PKC) inhibitor. Pressure loading that simulates systolic hypertension also reduced phorbol myristate 13-acetate (PMA) (a PKC activator)-induced COX-2 expression and the rapid and transient phosphorylation of ERK. Pressure loading that simulates normal blood pressure had no effect on IL-1β- and PMA-induced COX-2 expression. The present study shows that pressure stress between 80 and 160 mmHg, which simulates systolic hypertension reduces IL-1β-induced COX-2 expression by affecting a mechanism involving PKC and ERK signaling pathways. Downregulation of COX-2 expression in VSMCs by abnormal pressure stress may further worsen local vascular injury associated with hypertension.

Weak acids induce PGE2 production in human oesophageal cells: novel mechanisms underlying GERD symptoms

The role of weak acids with pH values in the range of 4–7 has been implicated in the symptoms of gastroesophageal reflux disease (GERD). Prostaglandin E₂ (PGE₂) is associated with heartburn symptom in GERD patients; however, the precise productive mechanisms remain unclear. In this study, we revealed that exposure to weak acids increases PGE₂ production with a peak at pH 4–5, slightly in human normal oesophageal cells (Het-1A), and robustly in oesophageal squamous carcinoma cells (KYSE-270). Release of PGE₂ from the oesophageal mucosa was augmented by weak acid treatment in rat. Chenodeoxycholic acid (CDCA), a bile acid, upregulated cyclooxygenase-2 (COX-2) expression in Het-1A and KYSE-270 and induced PGE₂ production in KYSE-270 cells. Weak acid-induced PGE₂ production was significantly inhibited by cytosolic phospholipase A2 (cPLA2), ERK, and transient receptor potential cation channel subfamily V member 4 (TRPV4), a pH-sensing ion channel, inhibitors. Hangeshashinto, a potent inhibitor of COX-2, strongly decreased weak acid- and CDCA-induced PGE₂ levels in KYSE-270. These results indicated that weak acids induce PGE₂ production via TRPV4/ERK/cPLA2 in oesophageal epithelial cells, suggesting a role in GERD symptoms like heartburn. Interventions targeting pH values up to 5 may be necessary for the treatment of GERD.

Anthocyanins Derived from Vitis coignetiae Pulliat Contributes Anti-Cancer Effects by Suppressing NF-κB Pathways in Hep3B Human Hepatocellular Carcinoma Cells and In Vivo

We previously demonstrated that anthocyanins from the fruits of Vitis coignetiae Pulliat (AIMs) induced the apoptosis of hepatocellular carcinoma cells. However, many researchers argued that the concentrations of AIMs were too high for in vivo experiments. Therefore, we performed in vitro at lower concentrations and in vivo experiments for the anti-cancer effects of AIMs. AIMs inhibited the cell proliferation of Hep3B cells in a dose-dependent manner with a maximum concentration of 100 µg/mL. AIMs also inhibited the invasion and migration at 100 µg/mL concentration with or without the presence of TNF-α. To establish the relevance between the in vitro and in vivo results, we validated their effects in a Xenograft model of Hep3B human hepatocellular carcinoma cells. In the in vivo test, AIMs inhibited the tumorigenicity of Hep3B cells in the xenograft mouse model without showing any clinical signs of toxicity or any changes in the body weight of mice. AIMs inhibited the activation NF-κB and suppressed the NF-κB-regulated proteins, intra-tumoral microvessel density (IMVD) and the Ki67 activity of Hep3B xenograft tumors in athymic nude mice. In conclusion, this study indicates that AIMs have anti-cancer effects (inhibition of proliferation, invasion, and angiogenesis) on human hepatocellular carcinoma xenograft through the inhibition of NF-κB and its target protein.

Laminar Inflammation Responses in the Oligofructose Overload Induced Model of Bovine Laminitis

Bovine laminitis causes substantial economic losses and animal welfare problems in dairy farms worldwide. Previously published studies have reported that the inflammatory response plays a central role in the pathogenesis of the disease. To our knowledge, inflammation associated with bovine laminitis induced by high levels of exposure to oligofructose (OF) has not been reported and characterized. In fact, the disease manifestations in this model closely approximate those of clinical laminitis. The objective of this study was to characterize the inflammatory response in OF-induced bovine laminitis. A total of 12 Chinese Holstein dairy heifers were utilized in this study. The heifers were randomly divided into two groups, treatment (n = 6) and control (n = 6). The treatment group heifers were administered OF solutions via a stomach tube (dose: 17 g/kg of body weight). Upon development of a lameness score of 2 with consecutive positive reactions in the same claw, they would be humanely euthanized. Control heifers were administered deionized water (dose: 2 L/100 kg of body weight) and humanely euthanized at 72 h. Real-time quantitative PCR (qPCR) assays were performed to determine the messenger RNA (mRNA) concentrations of inflammatory mediators in the lamellae. Concentrations of interleukin (IL)-1β, IL-6, IL-8, C-X-C motif chemokine ligand-1 (CXCL-1), macrophage cationic peptide-2 (MCP-2), E-selectin, intercellular adhesion molecule-1 (ICAM-1), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase-1 (iNOS-1), and plasminogen activator inhibitor-1 (PAI-1) were significantly increased (P < 0.05) in the treatment group. No significant difference was found for tumor necrosis factor alpha (TNF-α), IL-10, CXCL-6, and MCP-1. These results demonstrated and characterized the laminar inflammatory response leading to the pathogenesis of bovine laminitis at the early stages.

The Pre-Implantation Embryo Induces Uterine Inflammatory Reaction in Mice

It has been well established that uterine function during the peri-implantation period is precisely regulated by ovarian estrogen and progesterone. The embryo enters the uterine cavity before implantation. However, the impact of pre-implantation embryo on uterine function is largely unknown. In the present study, we performed RNA-seq analysis of mouse uterus on day 4 morning of natural pregnancy (with embryos in the uterus) and pseudo-pregnancy (without embryos in the uterus). We found that 146 genes were upregulated, and 77 genes were downregulated by the pre-implantation embryo. Gene ontology and gene network analysis highlighted the activation of inflammatory reaction in the uterus. By examining the promoter region of differentially expressed genes, we found that NF-kappaB was a causal transcription factor. Finally, we validated 4 inflammation-related genes by quantitative RT-PCR. These 4 genes are likely the main mediators of the inflammatory reaction in the uterus triggered by the pre-implantation embryo. Our data indicated that the pre-implantation embryo causes uterine inflammatory reaction, which in turn might contribute to the establishment of uterine receptivity and embryo implantation.

The anti-fibrotic and anti-inflammatory effects of 2,4-diamino-5-(1-hydroxynaphthalen-2-yl)-5H-chromeno[2,3-b] pyriine-3-carbonitrile in corneal fibroblasts

BACKGROUND

Although several studies had addressed the anti-inflammatory effects of derivatives of 4H-chromene and chromeno[2,3-b]pyridine in the different types of cells, whether these derivatives would exert beneficial anti-fibrotic effects during corneal fibrotic scar formation was unclear.

METHODS

We examined the cyclooxygenase-2 (COX-2) expression of 2,4-diamino-5-(1-hydroxynaphthalen-2-yl)-5H-chromeno[2,3-b]pyridine-3-carbonitrile (N1) in the human corneal fibroblasts (HCFs) under the treatment TGF-β1. Signaling pathways underlying the mechanism of the N1 effect on the HCFs were determined.

RESULTS

Application of N1 significantly decreased COX-2 expression after 2 h and 4 h in the HCFs stimulated with TGF-β1. Notably, reduced production of extracellular matrix proteins under N1 treatment was found, including fibronectin, collagen I, and matrix metallopeptidase 9. Immunoblot analysis showed that treatment with N1 significantly attenuated phosphorylation of both STAT3 and Smad 2 in the TGF-β1-stimulated HCFs. Upregulated mRNA of Smad2 and downregulated mRNA of Smad3 were observed using the quantitative real-time polymerase chain reaction. In addition, N1 induced significant increases in HO-1 and Nrf2 expression, but inhibited phosphorylation of NF-κB in the HCFs treated with TGF-β1.

CONCLUSIONS

Our findings show for the first time that N1 exerts anti-fibrotic and anti-inflammatory effects through suppression of COX-2, Smad2, STAT3, iNOS and NF-κB expressions as well as upregulation of Nrf2 and HO-1 expressions, which suggests they are potential therapeutic targets in the treatment of corneal fibrosis.

Gene expression and DNA methylation changes in BeWo cells dependent on tumor necrosis factor-α and insulin-like growth factor-I

Pregnant women with increased insulin resistance, characterized by elevated levels of tumor necrosis factor-alpha (TNF-α) and insulin-like growth factor-I (IGF-I), are at high risk of preeclampsia. We hypothesized that TNF-α and IGF-I affect the placentas and cause pathological changes leading to preeclampsia. To understand the genetic and epigenetic effects of TNF-α and IGF-I on trophoblast cells, gene expression microarray and DNA methylation array of BeWo cells stimulated by TNF-α (100 pg/ml, 100 ng/ml) and IGF-I (100 ng/ml) were conducted. Microarray analysis revealed the differential gene expression patterns in BeWo cells co-stimulated by TNF-α and IGF-I. Enrichment analysis identified the terms associated with NF-kappa B signaling pathways and arachidonic acid cascades such as PTGS2 and PTGER2. DNA methylation array revealed the distinct CpG methylation pattern in BeWo cells stimulated by high-TNF-α and IGF-I, while neither of them showed independent effects. Enrichment analysis identified the terms associated with major histocompatibility complex proteins. Integration of transcriptome and DNA methylome analyses identified three differentially expressed genes with significant DNA methylation change: C3, GP1BA, and NFKBIE, which are all possibly associated with pathogenesis of preeclampsia. In conclusion, co-stimulation of TNF-α and IGF-I induced the genetic and epigenetic changes associated with preeclampsia in BeWo cells. The results suggested that BeWo cells stimulated by TNF-α and IGF-I is a good in vitro model of preeclamptic placenta in pregnancy with increased insulin resistance.

Cyclooxygenase-2 in Endometriosis

Endometriosis (EMS) is the most common gynecological disease in women of reproductive age, and it is associated with chronic pelvic pain, dyspareunia and infertility. As a consequence of genetic, immune and environmental factors, endometriotic lesions have high cyclooxygenase (COX)-2 and COX-2-derived prostaglandin E₂ (PGE₂) biosynthesis compared with the normal endometrium. The transcription of the PTGS2 gene for COX-2 is associated with multiple intracellular signals, which converge to cause the activation of mitogen-activated protein kinases (MAPKs). COX-2 expression can be regulated by several factors, such as estrogen, hypoxia, proinflammatory cytokines, environmental pollutants, metabolites and metabolic enzymes, and platelets. High concentrations of COX-2 lead to high cell proliferation, a low level of apoptosis, high invasion, angiogenesis, EMS-related pain and infertility. COX-2-derived PGE₂ performs a crucial function in EMS development by binding to EP2 and EP4 receptors. These basic findings have contributed to COX-2-targeted treatment in EMS, including COX-2 inhibitors, hormone drugs and glycyrrhizin. In this review, we summarize the most recent basic research in detail and provide a short summary of COX-2-targeted treatment.

Titanium dioxide nanoparticles induce COX-2 expression through ROS generation in human periodontal ligament cells

Titanium dioxide nanoparticles (TiO₂-NPs) are used to improve the aesthetic of toothpaste. While TiO₂-NPs have been used safely in toothpaste products for a long time, there haven't been studies to determine whether absorption of TiO₂-NPs by the mucous membranes in the mouth induces pathogenic conditions. Here, we assessed whether TiO₂-NPs induce cyclooxygenase-2 (COX-2) and investigated the molecular mechanisms underlying the pro-inflammatory effect of TiO₂-NPs on human periodontal ligament (PDL) cells. Treatment of PDL cells with TiO₂-NPs led to induction of both COX-2 mRNA and protein expression. TiO₂-NPs stimulated the nuclear translocation of nuclear factor-kappaB (NF-κB) as well as its DNA binding by inducing phosphorylation and subsequent degradation of the inhibitory protein IκBα in PDL cells. TiO₂-NPs treatment resulted in rapid activation of extracellular signal-regulated kinase (ERK)1/2 and Akt, which could be upstream of NF-κB. Treatment of PDL cells with both the MEK1/2 inhibitor U0126 and the PI3K inhibitor LY294002 strongly attenuated TiO₂-NPs-induced activation of NF-κB, and also the expression of COX-2. PDL cells treated with TiO₂-NPs exhibited increased accumulation of intracellular reactive oxygen species (ROS). Pretreatment of cells with ROS scavenger N-acetyl cysteine (NAC) abrogated the stimulatory effect of TiO₂-NPs on p65, p50, and COX-2 expression. In conclusion, ROS, concomitantly overproduced by TiO₂-NPs, induce COX-2 expression through activation of NF-κB signaling, which may contribute to the inflammatory effect of PDL cells.

Natural compounds in the chemoprevention of alcoholic liver disease

Alcoholic liver disease (ALD), caused by excessive consumption of alcohol, is a major cause of chronic liver disease worldwide. Much effort has been expended to explore the pathogenesis of ALD. Hepatic cell injury, oxidative stress, inflammation, regeneration, and bacterial translocation are all involved in the pathogenesis of ALD. Immediate abstinence is the most important therapeutic treatment for affected individuals. However, the medical treatment for ALD had not advanced in a long period. Intriguingly, an increasing body of research indicates the potential of natural compounds in the targeted therapy of ALD. A plethora of dietary natural products such as flavonoids, resveratrol, saponins, and β-carotene are found to exert protective effects on ALD. This occurs through various mechanisms composed of antioxidative, anti-inflammatory, iron chelation, pro-apoptosis, and/or antiproliferation of hepatic stellate cells and hepatocellular carcinoma cells. In this review, we will summarize current knowledge about the pathogenesis and treatments of ALD and focus on the potential of natural compounds in ALD therapies and underlying mechanisms.

Structure characteristics of flavonoids for cyclooxygenase-2 mRNA inhibition in lipopolysaccharide-induced inflammatory macrophages

Flavonoids are natural active components. They distribute widely in edible plants with high activity of anti-inflammation. Inhibition of cyclooxygenase-2(COX-2) was determined by real-time fluorescent quantitative olymerase chain reaction (RTFQ-PCR). And structure characteristics of flavonoids for COX-2 inhibition were mainly analyzed by a quantitative structure activity relationship (QSAR) model. Descriptors such as SMR_VSA5, vsurf_DD12, reactive were the top three important independent variables to COX-2 mRNA inhibiton in RAW264.7. Low SMR_VSA5 value meant a lower molecular refractivity resulting in a lower COX-2 mRNA inhibition. High vsurf_DD12 value related to poor molecular balance and showed profound adverse to COX-2 mRNA inhibition. Reactive group in this paper referred to C2-C3 double bond contributed negatively to COX-2 mRNA inhibition. Glycosidic and C3-OH substitutions may lower SMR_VSA5 value. It indicated that flavanones such as hesperetin, naringenin, liquiritigenin were efficient to repress COX-2 mRNA and they were potential anti-inflammatory natural products. Further, substitution with a glucopyranosyl at C-6 resulted in a poorer molecule balance than that at C-8 and a lower COX-2 mRNA inhibiton accordingly. This may expain why orientin and vitexin exhibited better anti-inflammatory activity than their isomers homoorientin and isovitexin. Also, methoxyl groups at C-4' may also be a favorable flavonoid structural characteristic for COX-2 mRNA inhibiton. These results provide valuable information on understanding the high anti-inflammatory activity of flavonoids.

Mogroside V inhibits LPS-induced COX-2 expression/ROS production and overexpression of HO-1 by blocking phosphorylation of AKT1 in RAW264.7 cells

Momordica grosvenori is a valuable edible plant with medicinal purposes, and it is widely used in medicated diets and traditional Chinese medicine in Asia. Mogroside V (MV), the main bioactive component from M. grosvenori, is commonly used as a natural sweetener. M. grosvenori extracts have been reported to exert potent anti-inflammatory property, however the underlying molecular mechanism still remains unknown. In the present study, the biological effect of MV in inflammation was investigated in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. The ELISA and western blot analysis results showed that MV significantly inhibited LPS-induced prostaglandin E2 (PGE2) production and cyclooxygenase-2 (COX-2) expression. MV markedly decreased the phosphorylation of IκB-α, increased IκB-α, and reduced nuclear p-65 and C/EBPδ. Furthermore, MV attenuated LPS-induced phosphorylation of MAPKs and AKT1, and only the phosphorylation status of AKT1 was found to be consistent with the expression trend of COX-2. Moreover, MV reduced ROS level and restored overexpressed HO-1 and AP-1 to basal level, which can be markedly reversed by AKT1 inhibitor LY294002. These results revealed that AKT1 plays a key role in LPS-induced COX-2 expression, and acts as a mediator to keep the redox balance in LPS-stimulated RAW264.7 cells. MV exerts anti-inflammatory property by blocking AKT1-mediated NF-κB and C/EBPδ activation, ROS generation and AP-1/ HO-1 expression. Therefore, the present study indicated that MV has a significant chemopreventive effect on the inflammatory lesions and suggested that AKT1 is a potential specific target of MV for relieving inflammation.

Curcumin and quercetin synergistically inhibit cancer cell proliferation in multiple cancer cells and modulate Wnt/β-catenin signaling and apoptotic pathways in A375 cells

BACKGROUND

Traditional therapy using natural products, especially flavonoids and alkaloids have been in practice for a long time. Among flavonoids, curcumin, quercetin, berberine, and epigallocatechin have been studied in greater detail in terms of their anticancer and anti-inflammatory activities. Although many studies focused on the PI3K, MAP kinase and NF-κB pathways, a thorough investigation of modulation of players in the apoptotic and Wnt/β-catenin signaling pathway by curcumin and quercetin has not been done. Also, only few studies have been carried out on curcumin and quercetin co-treatment studies.

HYPOTHESIS/PURPOSE

We hypothesized that the combination of natural products will have synergistic effects and the antiproliferative effect will be attenuated via apoptotic as well as Wnt/β-catenin signaling pathways.

STUDY DESIGN AND METHODS

To test our hypothesis, we compared potency of natural anticancer agents in four cancer cell lines, A549, HCT116, MCF7, and A375 by MTT and colony proliferation assays and investigated mechanism of anticancer activities by analyzing players in apoptotic and Wnt/β-catenin signaling pathways in A375 cells treated with test agents individually or in combination.

RESULTS

Epicatechins, up to 100 μM concentration, did not inhibit cancer cell proliferation, while curcumin inhibited proliferation in A549 and HCT116 cancer cell lines with an IC₅₀ of 3 to 8.5 μM. Quercetin showed stronger inhibition of cell proliferation than berberine. Combination study with two most potent agents, curcumin and quercetin, in 4 cancer cell lines, suggested synergistic effect on cell proliferation with several fold decreases in IC₅₀. Further investigation of the mechanism of action of curcumin and quercetin in melanoma cells, A375, suggested that inhibition of cell proliferation occurred through down-regulation of Wnt/β-catenin signaling pathway proteins, DVL2, β-catenin, cyclin D1, Cox2, and Axin2. In addition, both curcumin and quercetin induced apoptosis by down-regulating BCL2 and inducing caspase 3/7 through PARP cleavage.

CONCLUSION

These results demonstrate that curcumin and quercetin inhibit cancer cell proliferation synergistically and Wnt/β-catenin signaling and apoptotic pathways are partly responsible for antiproliferative activities.

Abnormal activation of the Akt signaling pathway in adenoid cystic carcinoma

PURPOSE

Adenoid cystic carcinoma (ACC) is an intriguing lesion because it shows a slow growth in the beginning, but a late poor prognosis due to perineural invasion, metastasis and recurrence. This study aimed to investigate whether Akt signaling would be deregulated in adenoid cystic carcinoma and its consequence in the expression of associated proteins.

METHODS

The expression of the Akt, p-Akt, NFκB, β-catenin, cyclin D1 and COX-2 was assessed by immunohistochemistry in 10 cases of ACC, 17 cases of pleomorphic adenoma (PA), and 7 cases of normal salivary gland (NSG).

RESULTS

p-Akt was overexpressed in ACC when compared to NSG. NFκB, β-catenin, and COX-2 were overexpressed in ACC and PA when compared to NSG. Most proteins were slightly higher expressed in ACC than in PA, but they never reached significance. p-Akt expression positively correlated with NFκB, β-catenin, cyclin D1 and COX-2 in ACC and PA, while this correlation trended to be negative in for these proteins (except for NFκB) in NSG using Person's correlation analysis, but without reaching significance.

CONCLUSIONS

Our results indicate an abnormal activation of Akt signaling pathway, which can be an important regulator of tumor biology in ACC. Activated Akt correlated with the expression of NFκB, β-catenin and COX-2, which can potentially influence cell survival in ACC.

Suppression of cyclooxygenase 2 increases chemosensitivity to sesamin through the Akt‑PI3K signaling pathway in lung cancer cells

Safe, affordable and efficacious agents are urgently required for cancer prevention. Sesamin, a lipid‑soluble lignan from sesame (Sesamum indicum) displays anticancer activities through an unknown mechanism. In the present study, the anticancer activity of sesamin via cyclooxygenase 2 (COX2) was investigated in lung cancer. Quantitative polymerase chain reaction was performed to determine the mRNA expression levels of COX2 in cells, while western blot analysis was used to determine its protein expression levels. Cell proliferation was evaluated by Cell Counting Kit‑8 assay, while apoptosis and cell cycle analyses were conducted by flow cytometry. The results indicated that COX2 expression was upregulated in lung cancer cell lines compared with human normal lung epithelial cell line BEAS‑2B and sesamin was demonstrated to decrease the levels of COX2, inhibit the proliferation of lung cancer cells and promote their apoptosis in a concentration‑dependent manner. Furthermore, decreased COX2 expression potentiated sesamin‑induced apoptosis and G1‑phase arrest, which was correlated with the suppression of gene products associated with cell apoptosis (Bcl‑2 and Bax) and the cell cycle (cyclin E1). In addition, cotreatment with the COX2 inhibitor CAY10404 and sesamin downregulated the expression of downstream molecules of COX2 [including interleukin (IL)1β, IL6 and tumor necrosis factor α] compared with CAY10404 or sesamin alone. Furthermore, cotreatment with sesamin and CAY10404 markedly reduced the levels of phosphorylated protein kinase B (pAkt) and phosoinositide 3 kinase (PI3K) in three lung cancer cell lines. PI3K expression was observed to be under the control of COX2, possibly forming a negative feedback loop. In addition, PI3K depletion induced apoptosis and G1‑phase arrest in A549 cells. These results suggested that sesamin blocked the pAkt‑PI3K signaling pathway by downregulating the expression of COX2, therefore resulting in cell cycle arrest and increased apoptosis in vitro. In conclusion, inhibition of COX2 increased the sensitivity of lung cancer cells to sesamin by modulating pAkt‑PI3K signaling. These results may aid the development of more selective agents to overcome cancer.

Agmatine protects against sodium valproate-induced hepatic injury in mice via modulation of nuclear factor-κB/inducible nitric oxide synthetase pathway

Valproate is a widely used drug against epilepsy and several other neurological disorders although it has deleterious hepatotoxic side effects. The current study was designed to test if agmatine as nitric oxide modulator has protective effects against valproate-induced hepatic injury. Male Swiss albino mice were treated with sodium valproate (SVP) with or without agmatine for 7 days. Serum and liver samples were collected for analysis. Results have revealed that agmatine exerted hepatoprotective effects against SVP-associated hepatic injury. Agmatine ameliorated SVP-induced elevated serum biochemical markers of hepatic damage such as serum transaminases, alkaline phosphatase, γ-glutamyl transferase, and lactate dehydrogenase. Histopathological examination of the liver showed improvement of hepatic lesions in case of agmatine treatment. Furthermore, agmatine attenuated oxidative stress and enhanced antioxidants in liver tissue. Agmatine inhibited the activation of nuclear factor-κB and ameliorated the immunoexpression of inducible nitric oxide synthetase. This was accompanied by decrease in the level of inflammatory markers as nitrite/nitrate, tumor necrosis factor-α, and interleukin-6. These data provide new evidence of the hepatoprotective activity of agmatine against SVP-induced hepatotoxic effects.

Analysis of gene expression and functional changes of adrenal gland in a rat model of kidney yang deficiency syndrome treated with Sini decoction

Sini decoction (SND), a well-known traditional Chinese medicine, has been used to treat kidney Yang deficiency for ~1,800 years. The present study aimed to evaluate the effects of SND treatment on hypothalamic-pituitary-adrenal axis hormones in a rat model of Yang deficiency and to explore the molecular mechanisms using microarray analysis of adrenal glands and in vitro adrenocortical cell culture systems. The results indicated that SND treatment recovered circulating serum cortisol, adrenocortical hormone (ACTH) and testosterone levels in a yang deficiency model. Immunohistochemical analysis of pituitary and hypothalamic tissues confirmed increased expression of ACTH and corticotropin-releasing factor, respectively, in response to SND treatment. Microarray analysis identified a marked upregulation of genes involved in ≤metabolic and stress response pathways in rat adrenal tissues in response to SND treatment, exemplified by cyclooxygenase-2 and nuclear factor (NF)-κB. In vitro, SND exerted a protective effect on mitochondria in response to H₂O₂ exposure also activated NF-κB and cyclic adenosine monophosphate response element binding protein reporter gene activity. These results contributed towards an improved understanding of how SND effectively alleviates the symptoms of kidney Yang deficiency syndrome at the molecular level.

Silicon dioxide nanoparticles induce COX-2 expression through activation of STAT3 signaling pathway in HaCaT cells

Silicon dioxide nanoparticles (SiO₂-NPs) are widely used in biomedicines and consumer products, such as sunscreens and cosmetics. However, SiO₂-NPs can cause adverse effects on human health, depending on the size and concentration of nanoparticles. The present study was aimed at investigating the molecular mechanism underlying SiO₂-NPs-induced inflammation in human keratinocyte (HaCaT) cells. Incubation of HaCaT cells with SiO₂-NPs induced the expression of cyclooxygenase-2 (COX-2) mRNA and protein. Treatment of cells with SiO₂-NPs also induced the phosphorylation, DNA binding and the reporter gene activity of signal transducer and activator of transcription 3 (STAT3). Transfection of cells with STAT3 siRNA abrogated SiO₂-NPs-induced COX-2 expression. Moreover, SiO₂-NPs enhanced the phosphorylation of Janus kinase2 (JAK2), Src and Akt. Pharmacological inhibition of either JAK2, Src or Akt abrogated SiO₂-NPs-induced STAT3 transcriptional activity and the expression of COX-2. Treatment with LY294002 also attenuated SiO₂-NPs-induced Src phosphorylation, while, JAK2 phosphorylation was not changed. In addition, SiO₂-NPs generated reactive oxygen species (ROS) and treatment of N-acetyl cysteine (NAC) attenuated the phosphorylation of JAK2, Src, Akt and STAT3, as well as the expression of COX-2 in SiO₂-NPs-treated HaCaT cells. Taken together, our study provides the first report that SiO₂-NPs induce COX-2 expression in HaCaT cells by activating the STAT3 signaling through ROS-mediated phosphorylation of upstream kinases, Akt/Src and JAK2.

Lobohedleolide suppresses hepatitis C virus replication via JNK/c-Jun-C/EBP-mediated down-regulation of cyclooxygenase-2 expression

Hepatitis C virus (HCV) chronically infects 2–3% people of the global population, which leads to liver cirrhosis and hepatocellular carcinoma. Drug resistance remains a serious problem that limits the effectiveness of US Food and Drug Administration (FDA)-approved direct-acting antiviral (DAA) drugs against HCV proteins. The objective of our study was to discover new antivirals from natural products to supplement current therapeutics. We demonstrated that lobohedleolide, isolated from the Formosan soft coral Lobophytum crassum, significantly reduced HCV replication in replicon cells and JFH-1 infection system, with EC₅₀ values of 10 ± 0.56 and 22 ± 0.75 μM, respectively, at non-toxic concentrations. We further observed that the inhibitory effect of lobohedleolide on HCV replication is due to suppression of HCV-induced cyclooxygenase-2 (COX-2) expression. Based on deletion-mutant analysis of the COX-2 promoter, we identified CCAAT/enhancer-binding protein (C/EBP) as a key transcription factor for the down-regulation of COX-2 by lobohedleolide, through which lobohedleolide decreased the phosphorylation of c-Jun NH2-terminal protein kinase and c-Jun to suppress HCV-induced C/EBP expression. The combination treatment of lobohedleolide with clinically used HCV drugs synergistically reduced HCV RNA replication, indicating that lobohedleolide exhibited a high biomedical potential to be used as a supplementary therapeutic agent to control HCV infection.

Celecoxib-Induced Self-Assembly of Smart Albumin-Doxorubicin Conjugate for Enhanced Cancer Therapy

Recent years have witnessed the great contributions that drug combination therapy has made for enhanced cancer therapy. However, because of the complicated pharmacokinetics of combined drug formulations, the majority of combination strategies show severe adverse effects at high dosage and poor biodistribution in vivo. To overcome these deficiencies and achieve enhanced cancer therapy, we put forward a method to construct a smart albumin-based nanoplatform, denoted as K237-HSA-DC, for codelivery of cyclooxygenase-2 (COX-2) inhibitor (celecoxib) and chemotherapeutic agent (doxorubicin, DOX). Both in vitro and in vivo studies indicate that K237-HSA-DC exhibits the best therapeutic efficacy on tumor cells compared with all the other formulations. Moreover, K237-HSA-DC shows fewer side effects on normal organs in contrast to other formulations. To understand the reasons behind the improved drug efficacy in depth, we performed a cell metabonomics-based mechanism study and found that celecoxib could enhance the inhibitory effect of DOX on the transport of glucose into cells and then lead to subsequent significant energy metabolism inhibition. Considering the above-mentioned advantages of K237-HSA-DC, we believe the smart albumin-based nanoplatform can serve as a promising drug delivery system for enhanced cancer therapy.

Nicotine increases colon cancer cell migration and invasion through epithelial to mesenchymal transition (EMT): COX-2 involvement

Cigarette smoking is a recognized risk factor for colon cancer and nicotine, the principal active component of tobacco, plays a pivotal role in increasing colon cancer cell growth and survival. The aim of this study was to determine the effect of nicotine on cellular Caco-2 and HCT-8 migration and invasion, focusing on epithelial to mesenchymal transition (EMT) induction, and COX-2 pathway involvement. In both these cell lines, treatment with nicotine increased COX-2 expression and the release of its enzymatic product PGE₂ . Moreover, nicotine-stimulated cells showed increased migratory and invasive behavior, mesenchymal markers up-regulation and epithelial markers down-regulation, nuclear translocation of the β-catenin, increase of MMP-2 and MMP-9 activity, and enhanced NF-κB expression. Noticeably, all these effects are largely mediated by COX-2 activity, as simultaneous treatment of both cell lines with nicotine and NS-398, a selective COX-2 inhibitor, greatly reduced the number of migrating and invading cells and reverted nicotine-induced EMT. These findings emphasize that nicotine triggers EMT, leading hence to increased migration and invasiveness of colon cancer cells. Thereby, the use of COX-2 inhibitor drugs might likely counteract nicotine-mediated EMT effects on colon cancer development and progression.

Red Ginseng Oil Inhibits TPA-Induced Transformation of Skin Epidermal JB6 Cells

Red ginseng oil (RGO) has been shown to possess anti-inflammatory and hepatoprotective activity. In this study, we evaluated the inhibitory effect of RGO on 12-O-tetradecanoylphorbol-13-acetate (TPA)-stimulated neoplastic transformation of JB6 P+ cells. RGO pretreatment abolished the transformation of JB6 P+ cells challenged by TPA. RGO suppressed the transactivation of activator protein-1 (AP-1) and nuclear factor kappa B (NF-κB) transcription factors as well as protein levels of cyclooxygenase-2, cyclin D1, cyclin E, and Bcl-2 in the TPA-treated cells. Additionally, TPA-induced phosphorylations of extracellular signal-regulated kinases, 90 kDa ribosomal S6 kinase 2, c-Jun N-terminal kinases, and glycogen synthase kinase 3β were downregulated in the presence of RGO. Furthermore, RGO induced the nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated antioxidant enzyme heme oxygenase-1 (HO-1) expression, and effectively blocked the overproduction of TPA-induced reactive oxygen species. These results suggest that RGO exerts a potent chemopreventive activity in skin cell model.

Annonaceae: Breaking the Wall of Inflammation

Inventories of tropical forests have listed Annonaceae as one of the most diverse plant families. For centuries, it is employed in traditional medicines to cure various pathological conditions including snakebite, analgesic, astringent, diarrhea, dysentery, arthritis pain, rheumatism, neuralgia, and weight loss etc. Phytochemical analysis of Annonaceae family have reported the occurrence of alkaloids, flavonoids, triterpenes, diterpenes and diterpene flavone glycosides, sterols, lignans, and annonaceous acetogenin characteristically affiliated with Annonaceae sp. Numerous past studies have underlined the pleotropic pharmacological activities of the crude extracts and isolated compounds from Annonaceae species. This review is an effort to abridge the ethnobotany, morphology, phytochemistry, toxicity, and particularly focusing on the anti-inflammatory activity of the Annonaceae species.

Anti-inflammatory Effect of Glucagon Like Peptide-1 Receptor Agonist, Exendin-4, through Modulation of IB1/JIP1 Expression and JNK Signaling in Stroke

Glucagon like peptide-1 (GLP-1) stimulates glucose-dependent insulin secretion. Dipeptidyl peptidase-4 (DPP-4) inhibitors, which block inactivation of GLP-1, are currently in clinical use for type 2 diabetes mellitus. Recently, GLP-1 has also been reported to have neuroprotective effects in cases of cerebral ischemia. We therefore investigated the neuroprotective effects of GLP-1 receptor (GLP-1R) agonist, exendin-4 (ex-4), after cerebral ischemia-reperfusion injury. Transient middle cerebral artery occlusion (tMCAO) was induced in rats by intracerebroventricular (i.c.v.) administration of ex-4 or ex9-39. Oxygen-glucose deprivation was also induced in primary neurons, bEnd.3 cells, and BV-2. Ischemia-reperfusion injury reduced expression of GLP-1R. Additionally, higher oxidative stress in SOD2 KO mice decreased expression of GLP-1R. Downregulation of GLP-1R by ischemic injury was 70% restored by GLP-1R agonist, ex-4, which resulted in significant reduction of infarct volume. Levels of intracellular cyclic AMP, a second messenger of GLP-1R, were also increased by 2.7-fold as a result of high GLP-1R expression. Moreover, our results showed that ex-4 attenuated pro-inflammatory cyclooxygenase-2 (COX-2) and prostaglandin E₂ after MCAO. C-Jun NH₂ terminal kinase (JNK) signaling, which stimulates activation of COX-2, was 36% inhibited by i.c.v. injection of ex-4 at 24 h. Islet-brain 1 (IB1), a scaffold regulator of JNK, was 1.7-fold increased by ex-4. GLP-1R activation by ex-4 resulted in reduction of COX-2 through increasing IB1 expression, resulting in anti-inflammatory neuroprotection during stroke. Our study suggests that the anti-inflammatory action of GLP-1 could be used as a new strategy for the treatment of neuroinflammation after stroke accompanied by hyperglycemia.

HMGB1 binding heptamer peptide improves survival and ameliorates brain injury in rats after cardiac arrest and cardiopulmonary resuscitation

Excessive inflammatory response produced after cardiac arrest and cardiopulmonary resuscitation (CA/CPR) is one of major causes of cerebral injury. High mobility group box 1 (HMGB1) is a pro-inflammatory cytokine and its role in brain injury after CA/CPR is unclear. Herein we investigated whether blocking HMGB1 signaling could ease brain injury after CA/CPR. Male Sprague-Dawley rats (n=181) were subjected to 8-min Asphyxia CA model or Sham operation. The ELISA data revealed both resuscitated patients and animals had elevated HMGB1 level in sera, compared with the healthy volunteers or Sham operative rats, respectively (P<0.01). Rats successfully resuscitated from CA were then randomly treated with either membrane permeable (TAT-fused) HMGB1 binding heptamer peptide (HBHP) or Scramble peptide. Results showed that HBHP treatment markedly improved 7-day survival rate, reduced neurological deficit scores, and prevented neuronal and dendrite loss in hippocampal CA1 region. Moreover, HBHP inhibited the activation of microglia and astrocytes and downregulated the mRNA and protein expressions of proinflammatory factors. We finally blocked toll-like receptor-4 (TLR4, one of HMGB1 receptors) with a specific antagonist TAK-242 before CA induction to confirm the detrimental effect of HMGB1 signaling and found blocking TLR4 could also attenuate the neuronal degeneration, as well as reduce NF-κB-mediated inflammatory signaling. Our findings indicate that CA/CPR can induce HMGB1 release to serum, while blocking HMGB1 signaling with peptide may improve the survival and attenuate post-resuscitation brain injury in the rat model of CA/CPR. TLR4 antagonist may also offer neuroprotective effects through weakening HMGB1-mediated proinflammatory reactions.

Pien Tze Huang Gan Bao attenuates carbon tetrachloride‑induced hepatocyte apoptosis in rats, associated with suppression of p53 activation and oxidative stress

Pien Tze Huang Gan Bao (PZH-GB), a traditional Chinese medicine, has been used for thousands of years as a protective remedy effective against liver injury induced by excessive alcohol and smoking. The present study aimed to evaluate the protective effects and potential mechanisms of PZH-GB against carbon tetrachloride (CCl₄)-induced hepatic injury. Rats were pre-treated with silymarin (50 mg/kg) or different doses of PZH-GB (150, 300 or 600 mg/kg) orally administered for 7 days. At the end of treatment, the rats were intraperitoneally injected with CCl₄, or control rats received a corn oil injection. The lactate dehydrogenase (LDH) levels in serum were evaluated. Apoptosis was assessed via terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. p53, B-cell lymphoma 2 (Bcl-2), B cell-lymphoma 2-associated X protein (Bax), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) and cytochrome P450 family 2 subfamily E member 1 (CYP2E1) were measured by reverse transcription-quantitative polymerase chain reaction and western blotting. The activity of caspase-9 and caspase-3 were measured by a colorimetric assay. The results indicated that silymarin and PZH-GB prevented CCl₄-induced serum LDH elevations, and CCl₄ induced high levels of LDH. Compared with the CCl₄ group, silymarin and PZH-GB treatment significantly decreased LDH levels. Histopathological results revealed that silymarin and PZH-GB ameliorated the CCl₄-induced liver histological alterations. The TUNEL results showed that compared with the control group, CCl₄ induced liver cell apoptosis, while silymarin and PZH-GB treatment inhibited apoptosis and the TUNEL-positive cells. The elevated expression of Bax, p53, iNOS, COX-2 and CYP2E1 were reduced by silymarin or PZH-GB pretreatment, whereas reduced Bcl-2 expression levels were increased. CCl₄ increased the activity of caspase-9 and −3 by 6.86- and 7.42-fold, respectively; however, silymarin and PZH-GB ameliorated this effect. In conclusion, silymarin and PZH-GB treatment prevented the deleterious effects on liver functions by attenuation of oxidative stress, inflammation and mitochondrial apoptosis via the p53 signaling pathway.