Relationship of cyclic stretching of human patellar tendon fibroblasts with abnormal increase of prostaglandins E2 and leukotriene B4

To investigate the relationship between tendinopathy and higher production of prostaglandins E2 (PGE2) and leukotriene B4(LTB4) induced by cyclic stretching of human patellar tendon fibroblasts.Methods We used a novel in vitro model system to mimic in vivo conditions,where human patellar tendon fibroblasts (HPTFs) were uniaxially stretched with different magnitudes of stretching (4%,8% and 12%).Non-stretched fibroblasts were used as control.The productions of PGE2 and LTB4 as well as the expression of cycloxygenase (COX) and 5-lipoxygenase (5-LO) were then measured every four hours of cyclic stretching.In addition,we treated the cells with inhibitors of COX or 5-LO.Results It was found that cyclic stretching of fibroblasts at 8% and 12% of stretching increased PGE2 and LTB4 levels.Blocking the COX enzyme with indomethacin (25 mol/L) decreased PGE2 levels but increased LTB4 production and vice versa.Whereas decreasing LTB4 production with MK-886 (10 μmol/L) could increase PGE2 levels compared to cells tretched without inhibitors.Conclusion Cyclic stretching of HPTFs produces high levels of PGE2 and LTB4,where a balance exists:blocking PGE2 production increases the production of LTB4,and vice versa.Therefore,this study raises the possibility that the routine use of COX inhibitors in clinical treatment of tendinopathy may exacerbate the condition by causing neutrophil-mediated inflammatory and degenerative changes in the tendon due to increased levels of LTB4,which is a potent chemoattractant for neutrophils.17 refs,3 figs.

Pathogenesis of chronic enteropathy associated with the SLCO2A1 gene:Hypotheses and conundrums

Chronic enteropathy associated with the SLCO2A1 gene(CEAS)is a complex gastroenterological condition characterized by multiple ulcers in the small intestine with chronic bleeding and protein loss.This review explores the potential mechanisms underlying the pathogenesis of CEAS,focusing on the role of SLCO2A1-encoded prostaglandin transporter OATP2A1 and its impact on prostaglandin E2(PGE2)levels.Studies have suggested that elevated PGE2 levels contribute to mucosal damage,inflammation,and disruption of the intestinal barrier.The effects of PGE2 on macrophage activation and Maxi-Cl channel functionality,as well as its interaction with nonsteroidal anti-inflammatory drugs play crucial roles in the progression of CEAS.Understanding the balance between its protective and pro-inflammatory effects and the complex interactions within the gastrointestinal tract can shed light on potential therapeutic targets for CEAS and guide the development of novel,targeted therapies.

Thymoquinone suppresses migration of Lo Vo human colon cancer cells by reducing prostaglandin E2 induced COX-2 activation

AIM To identify potential anti-cancer constituents in natural extracts that inhibit cancer cell growth and migration. METHODS Our experiments used high dose thymoquinone (TQ) as an inhibitor to arrest LoVo (a human colon adenocarcinoma cell line) cancer cell growth, which was detected by cell proliferation assay and immunoblotting assay. Low dose TQ did not significantly reduce LoVo cancer cell growth. Cyclooxygenase 2 (COX-2) is an enzyme that is involved in the conversion of arachidonic acid into prostaglandin E2 (PGE2) in humans. PGE2 can promote COX-2 protein expression and tumor cell proliferation and was used as a control. RESULTS Our results showed that 20 mu mol/L TQ significantly reduced human LoVo colon cancer cell proliferation. TQ treatment reduced the levels of p-PI3K, p-Akt, p-GSK3 beta, and beta-catenin and thereby inhibited the downstream COX-2 expression. Results also showed that the reduction in COX-2 expression resulted in a reduction in PGE2 levels and the suppression of EP2 and EP4 activation. Further analysis showed that TG treatment inhibited the nuclear translocation of beta-catenin in LoVo cancer cells. The levels of the cofactors LEF-1 and TCF-4 were also decreased in the nucleus following TQ treatment in a dose-dependent manner. Treatment with low dose TQ inhibited the COX-2 expression at the transcriptional level and the regulation of COX-2 expression efficiently reduced LoVo cell migration. The results were further verified in vivo by confirming the effects of TQ and/or PGE2 using tumor xenografts in nude mice. CONCLUSION TQ inhibits LoVo cancer cell growth and migration, and this result highlights the therapeutic advantage of using TQ in combination therapy against colorectal cancer.

Elevated serum prostaglandin E2 predicts the risk of infection in hepatitis B virus-related acute-on-chronic liver failure patients

Objective: To evaluate the serum Prostaglandin E2(PGE2) level in Acute-on-chronic liver failure(ACLF) and determine its predicative value for infection.Methods: From April 2014 to April 2015, ninety-one patients with hepatitis B virus and ACLF but without infection were enrolled into this prospective study that was carried out at our Hospital. Twenty patients with stable chronic hepatitis B were enrolled from the outpatient department and twenty healthy control subjects without any disease were enrolled from hospital staff. Serum PGE2 levels were determined using ELISA at enrollment. Clinical and laboratory parameters were collected. Receiver operating characteristic(ROC) curves were used to determine optimal cut-off values to predict infection.Results: Significantly higher PGE2 levels were found in patients with ACLF in comparison with healthy controls and patients with stable CHB(P < 0.000 1). In ACLF patients, PGE2 levels were significantly higher in patients that eventually developed infection than those without this complication(P < 0.000 1). ROC analysis showed that serum PGE2(area under the ROC curve, 0.83) could predict infection in patients with ACLF with sensitivity of 78.4% and specificity of 81.5% using a threshold of 141 pg/m L.Conclusions: Serum PGE2 is associated with the susceptibility to secondary infections for patients with ACLF. Increased PGE2 serum levels may serve as a potential biomarker for developing infections in ACLF patients.

Mating behaviors in ovoviviparous black rockfish(Sebastes schlegelii):molecular function of prostaglandin E2 as both a hormone and pheromone

Prostaglandins(PGs)are profound hormones in teleost sexual behavior,especially in mating.PGs act as pheromones that affect the olfactory sensory neurons of males,inducing the initiation of a series of mating behaviors.However,the molecular mechanism by which PGs trigger mating behavior in ovoviviparous teleosts is still unclear.In the present study,we employed the ovoviviparous black rockfish(Sebastes schlegelii),an economically important marine species whose reproductive production is limited by incomplete fertilization,as a model species.The results showed that when the dose of PGE2 was higher than 10 nmol/L,a significant(P<0.05)increase in mating behaviors was observed.Dual-fluorescence in situ hybridization indicated that PGE2 could fire specific neurons in different brain regions and receptor cells in the olfactory sac.After combining with specific neurons in the central nervous system(CNS),a series of genes related to reproduction are activated.The intracerebroventricular administration of PGE_(2) significantly increased lhb levels(P<0.05)in both sexes.Moreover,steroidogenesis in gonads was also affected,inducing an increase(P<0.05)in E_(2) levels in males and T levels in females.PGE_(2) levels were also increased significantly(P<0.05)in both sexes.The present study revealed that PGE2 can activate mating behavior in black rockfish in both hormone and pheromone pathways,leading to variations in sex steroid levels and activation of reproductive behaviors.Our results provide not only novel insight into the onset of mating behaviors in ovoviviparous teleosts but also solutions for the incomplete fertilization caused by natural mating in cage aquaculture.

西黄丸联合紫杉醇抑制人乳腺癌细胞MDA-MB-231的作用机制研究

目的研究西黄丸(Xihuang wan,XHW)联合紫杉醇(paclitaxel,PTX)对人乳腺癌细胞MDA-MB-231增殖、凋亡的影响及其分子机制。方法首先,通过低温浸提法获得西黄丸浸液,用不同浓度的西黄丸浸液单独或联合紫杉醇处理MDA-MB-231细胞系,通过CCK8实验检测细胞增殖,流式细胞术检测其凋亡的变化,ELISA检测细胞上清中前列腺素E2(prostaglandin E2,PGE2)含量。结果单独使用西黄丸即可抑制MDA-MB-231增殖,联用紫杉醇抑制细胞增殖效果更明显;单用西黄丸可诱导MDA-MB-231凋亡,联用紫杉醇诱导凋亡效果也可获得提高;紫杉醇会诱导细胞外液中PGE2含量升高,联用西黄丸可降低升高的PGE2。结论西黄丸联合紫杉醇可更好地诱导人乳腺癌细胞系MDA-MB-231发生凋亡并抑制其增殖,同时还可以抑制受紫杉醇诱导而升高的PGE2,这可能是西黄丸联用化疗药防止肿瘤复发、转移的重要分子机制之一。

复方柴芩退热颗粒对发热大鼠模型退热作用的研究

目的:研究复方柴芩退热颗粒对2,4二硝基苯酚及细菌内毒素所致大鼠发热模型的退热作用,进一步明确该颗粒的退热效果,初步探讨其退热机制。方法:将SPF级SD大鼠随机分为正常对照组、模型组、酚麻美敏片组[给药剂量0.148 g/(kg·d)]、小柴胡冲剂组[给药剂量2.160 g/(kg·d)]、复方柴芩退热颗粒高、中、低剂量组[给药剂量分别为6.480、3.240、1.620 g/(kg·d)]。各给药组按相应剂量灌胃给药,正常对照组、模型组同法给予等体积的蒸馏水,每天1次,连续给药5天,第4天各组动物均开始禁食不禁水24 h,末次给药前开始造模。造模实验一:除正常对照组外,余各组大鼠均皮下注射2,4-二硝基苯酚17 mg/kg,正常对照组皮下注射同体积生理盐水;造模实验二:除正常对照组外,余各组大鼠均腹腔注射细菌内毒素80μg/kg。测大鼠各时间点的体温和血清中白细胞介素-1β(IL-1β)、前列腺素E2(PGE2)、肿瘤坏死因子-α(TNF-α)的含量。结果:实验一:与正常对照组比较,模型组大鼠造模后1 h、2 h、3 h体温上升值均显著升高,大鼠血清IL-1β、PGE2含量均显著升高(P<0.01)。与模型组比较,酚麻美敏片组、小柴胡冲剂组、复方柴芩退热颗粒高、中、低剂量组大鼠血清IL-1β、PGE2含量均明显降低(P<0.05,P<0.01);酚麻美敏片组大鼠在造模后1 h、2 h、3 h体温上升值均显著降低(P<0.05,P<0.01);小柴胡冲剂组大鼠在造模后2 h、3 h体温上升值均显著降低(P<0.05,P<0.01);复方柴芩退热颗粒高、低剂量组在造模后1 h、2 h、3 h体温上升值均明显降低(P<0.05,P<0.01);复方柴芩退热颗粒中剂量组在造模后2 h、3 h体温上升值均明显降低(P<0.05)。实验二:与正常对照组比较,模型组大鼠造模后2 h、4 h、6 h、8 h体温上升值均显著升高,大鼠血清PGE2、TNF-α含量均显著升高(P<0.01)。与模型组比较,酚麻美敏片组、小柴胡冲剂组、复方柴芩退热颗粒高、中、低剂量组大鼠血清PGE2、TNF-α含量均明显降低(P<0.05,P<0.01);酚麻美敏片组大鼠在造模后2 h、4 h、6 h体温上升值均显著降低(P<0.05,P<0.01);小柴胡冲剂组、复方柴芩退热颗粒高、中、低剂量组在造模后2 h、4 h体温上升值均明显降低(P<0.05,P<0.01)。结论:复方柴芩退热颗粒对2,4二硝基苯酚及细菌内毒素所致大鼠发热均有降温作用,能有效降低大鼠血清PGE2、IL-1β和血清TNF-α含量,对大鼠实验性高热模型有较好的解热作用。

Neural pathway for fever generation

Fever is an adaptive host response coordinated by the central nervous system （CNS） during systemic immune challenge. Recent research shed light on the mechanism of fever generation, particularly the underlying neural pathways. In this review, we first briefly summarize current views on the mechanism of sensing microbial infection by the nervous system, and the roles of prostaglandin E2 （PGE2） and its receptors in fever; then we focus on the neural circuits underlying fever generation, particularly their relationship with the distribution of PGE2 receptors within the CNS. At the end, an overall neurochemical model of fever generation is presented, pointing to the direction for future studies.

Association of high expression in rat gastric mucosal heat shock protein 70 induced by moxibustion pretreatment with protection against stress injury

AIM:To study the effect of moxibustion on Zusanli or Liangmeng point on gastric mucosa injury in stress-induced ulcer rats and its correlation with the expression of heat shock protein 70 (HSP70). METHODS:Sixty healthy SD rats (30 males,30 females) were divided into control group,injury model group,Zushanli point group,Liangmeng point group. Stress gastric ulcer model was induced by binding cold stress method. Gastric mucosa ulcer injury (UI) index was calculated by Guth method. Gastric mucosa blood flow (GMBF) was recorded with a biological signal analyzer. Protein content and gene expression in gastric mucosal HSP70 were detected by immunohistochemistry (IHC) and reverse transcription polymerase chain reaction (RT-PCR). Thiobarbital method was used to determine malondialdehyde (MDA) content. Gastric mucosal endothelin (ET) and prostaglandin E2 (PGE2) were analyzed by radioimmunoassay. RESULTS:High gastric mucosal UI index,high HSP70 expression,low GMBF and PGF2,elevated MDA and ET were observed in gastric mucosa of rats subjected to cold stress. Moxibustion on Zusanli or Liangmeng point decreased rat gastric mucosal UI index,MDA and ET. Conversely,the expression of HSP70,GMBF,and PGE2 was elevated in gastric mucosa after pretreatment with moxibustion on Zusanli or Liangmeng point. The observed parameters were significantly different between Zusanli and Liangmeng points. CONCLUSION:Pretreatment with moxibustion on Zusanli or Liangmeng point protects gastric mucosa against stress injury. This protection is associated with the higher expression of HSP70 mRNA and protein,leading to release of PGE2 and inhibition of MDA and ET,impairment of gastric mucosal index.

Short-chain fatty acids act as antiinflammatory mediators by regulating prostaglandin E_2 and cytokines

AIM： To investigate the effect of short-chain fatty acids （SCFAs） on production of prostaglandin E2 （PGE2）, cytokines and chemokines in human monocytes. METHODS： Human neutrophils and monocytes were isolated from human whole blood by using 1-Step Polymorph and RosetteSep Human Monocyte Enrichment Cocktail, respectively. Human GPR41 and GPR43 mRNA expression was examined by quantitative realtime polymerase chain reaction, The calcium flux assay was used to examine the biological activities of SCFAs in human neutrophils and monocytes. The effect of SCFAs on human monocytes and peripheral blood mononuclear cells （PBMC） was studied by measuring PGE2, cytokines and chemokines in the supernatant. The effect of SCFAs in vivo was examined by intraplantar injection into rat paws. RESULTS： Human GPR43 is highly expressed in human neutrophils and monocytes. SCFAs induce robust calcium flux in human neutrophils, but not in human monocytes. In this study, we show that SCFAs can induce human monocyte release of PGE2 and that this effect can be enhanced in the presence of lipopolysaccharide （LPS）. In addition, we demonstrate that PGE2 production induced by SCFA was inhibited by pertussis toxin, suggesting the involvement of a receptor-mediated mechanism. Furthermore, SCFAs can specifically inhibit constitutive monocyte chemotactic protein-1 （MCP-1） production and LPS-induced interleukin-10 （IL-10） production in human monocytes without affecting the secretion of other cytokines and chemokines examined. Similar activities were observed in human PBMC for the release of PGE2, MCP-1 and IL-10 after 5CFA treatment. In addition, SCFAs inhibit LPS-induced production of tumor necrosis factor-α and interferon-7 in human PBIVlC. Finally, we show that SCFAs and LPS can induce PGE2 production in vivo by intraplantar injection into rat paws （P 〈 0.01）. CONCLUSION： SCFAs can have distinct antiinflammatory activities due to their regulation of PGE2, cytokine and chemokine release from human immune cells.

Effects of bile acids on cyclooxygenase-2 expression in a rat model of duodenoesophageal anastomosis

AIM: To examine the expression of cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2) in rat esophageal lesions induced by reflux of duodenal contents.

Genetic variant of cyclooxygenase-2 in gastric cancer:More inflammation and susceptibility

Gastric cancer accounts for the majority cancer-related deaths worldwide.Although various methods have considerably improved the screening,diagnosis,and treatment of gastric cancer,its incidence is still high in Asia,and the 5-year survival rate of advanced gastric cancer patients is only 10%-20%.Therefore,more effective drugs and better screening strategies are needed for reducing the incidence and mortality of gastric cancer.Cyclooxygenase-2(COX-2)is considered to be the key inducible enzyme in prostaglandins(PGs)synthesis,which is involved in multiple pathways in the inflammatory response.For example,inflammatory cytokines stimulate innate immune responses via Toll-like receptors and nuclear factor-kappa B to induce COX-2/PGE2 pathway.In these processes,the production of an inflammatory microenvironment promotes the occurrence of gastric cancer.Epidemiological studies have also indicated that non-steroidal antiinflammatory drugs can reduce the risk of malignant tumors of the digestive system by blocking the effect of COX-2.However,clinical use of COX-2 inhibitors to prevent or treat gastric cancer may be limited because of potential side effects,especially in the cardiovascular system.Given these side effects and low treatment efficacy,new therapeutic approaches and early screening strategies are urgently needed.Some studies have shown that genetic variation in COX-2 also play an important role in carcinogenesis.However,the genetic variation analysis in these studies is incomplete and isolated,pointing out only a few single nucleotide polymorphisms(SNPs)and the risk of gastric cancer,and no comprehensive study covering the whole gene region has been carried out.In addition,copy number variation(CNV)is not mentioned.In this review,we summarize the SNPs in the whole COX-2 gene sequence,including exons,introns,and both the 5’and 3’untranslated regions.Results suggest that COX-2 does not increase its expression through the CNV and the SNPs in COX-2 may serve as the potential marker to establish risk stratification in the general population.This review synthesizes emerging insights of COX-2 as a biomarker in multiple studies,summarizes the association between whole COX-2 sequence variation and susceptibility to gastric cancer,and discusses the future prospect of therapeutic intervention,which will be helpful for early screening and further research to find new approaches to gastric cancer treatment.

Effect of c-fos antisense probe on prostaglandin E_2-induced upregulation of vascular endothelial growth factor mRNA in human liver cancer cells

AIM: To examine the effect of prostaglandin E2 (PGE2) on the expression of vascular endothelial growth factor (VEGF) mRNA in the human hepatocellular carcinoma (HCC) HepG2 cells and the possible involvement of c-fos protein in this process.METHODS: Human HCC HepG2 cells were divided into three groups treated respectively with PGE2, a combination of PGE2 and c-fos antisense oligodeoxynucleotide (ASO),and PGE2 plus c-fos sense oligodeoxynudeotide (SO). The expression of VEGF mRNA in HepG2 cells after different treatments was detected by reverse transcriptase-polymerase chain reaction (RT-PCR). The relative expression level of VEGF mRNA in HepG2 cells in each group was measured.RESULTS: Administration of PGE2 resulted in an increased expression of c-fosand VEGF mRNA in HepG2 cells. The relative expression level of c-fos mRNA reached the peak at 3 h (68.4±4.7%) after PGE2 treatment, which was significantly higher than that at 0 h (20.6±1.7%, P＜0.01).Whereas, the highest expression level of VEGF mRNA was observed at 6 h (100.5±6.1%) after PGE2 treatment, which was significantly higher than that at 0 h (33.2±2.4%,P＜0.01). C-fos ASO significantly reduced PGE2-induced VEGF mRNA expression in HepG2 cells.CONCLUSION: PGE2 increases the expression and secretion of VEGF in HCC cells by activating the transcription factor c-fos, promotes the angiogenesis of HCC and plays an important role in the pathogenesis of liver cancer.

Increased susceptibility of ethanol-treated gastric mucosa to naproxen and its inhibition by DA-9601, an Artemisia asiatica extract

AIM： To examine the effect of DA-9601, a new gastroprotective agent, on the vulnerability of ethanoltreated rat＇s stomach to naproxen （NAP）. METHODS： Male Sprague-Dawley rats were pretreated with 1 mL of 50% ethanol twice a day for 5 d and then NAP （50 mg/kg） was administered. DA-9601 was admin- istered 1 h before NAP. Four hours after NAP, the rats were killed to examine gross injury index （mm2）, histologic change and to determine mucosal levels of malondialdehyde （MDA）, prostaglandin E2 （PGE2）, glutathione （GSH） and myeloperoxidase （MPO）. RESULTS： Pretreatment of ethanol significantly increased NAP-induced gastric lesions, as well as an increase in NDA and MPO. On the contrary, mucosal PGE2 and GSH contents were decreased dramatically by ethanol pretreatment, which were aggravated by NAR DA-9601 significantly reduced NAP-induced gastric injury grossly and microscopically, regardless of pretreatment with ethanol. DA-9601 preserved, or rather, increased mucosal PGE2 and GSH in NAP-treated rats （P〈0.05）, with reduction in mucosal MDA and MPO levels. CONCLUSION： These results suggest that repeated alcohol consumption renders gastric mucosa more susceptible to NSAIDs though, at least in part, reduction of endogenous cytoprotectants including PGE2 and GSH, and increase in MPO activation, and that DA-9601, a new gastroprotectant, can reduce the increased vulnerability of ethanol consumers to NSAIDs-induced gastric damage via the mechanism in which PGE2 and GSH are involved.

Celecoxib Inhibits Proliferation and Induces Apoptosis via Cyclooxygenase-2 Pathway in Human Pancreatic Carcinoma Cells

In order to evaluate the effects and mechanisms of celecoxib in inhibiting proliferation and inducing apoptosis on human pancreatic carcinoma cells, the anti-proliferative effect was measured by using methabenzthiazuron (MTT) assay. Cell cycle and apoptosis were analyzed by using flow cytometry (FCM), and the PGE 2 levels in the supernatant of cultured pancreatic carcinoma cells were quantitated by enzyme-linked immunoabsordent assay (ELISA). Our results showed that celecoxib suppressed the production of PGE 2 and inhibited the growth of JF-305 cells, and the anti-proliferative effect of celecoxib could be abolished by addition of PGE 2. FCM revealed that celecoxib could inhibit proliferation and induce apoptosis by G 1-S cell cycle arrest. It was concluded that cyclooxygenase-2 specific inhibitor celecoxib could inhibit proliferation and induced apoptosis of human pancreatic carcinoma cells via suppression of PGE 2 production in vitro.

Effect of lipopolysaccharide on diarrhea and gastrointestinal transit in mice: Roles of nitric oxide and prostaglandin E_2

AIM: To investigate the effect of lipopolysaccharide (LPS)on the diarrheogenic activity, gastrointestinal transit (GIT),and intestinal fluid content and the possible role of nitric oxide (NO) and prostaglandin E2 (PGE2) in gastrointestinal functions of endotoxin-treated mice.METHODS: Diarrheogic activity, GIT, and intestinal fluid content as well as nitric oxide and PGE2 products were measured after intraperitoneal administration of LPS in mice.RESULTS: LPS dose-dependently accumulated abundant fluid into the small intestine, induced diarrhea, but decreased the GIT. Both nitric oxide and PGE2 were found to increase in LPS-treated mice. Western blot analysis indicated that LPS significantly induced the protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 in mice intestines. Pretreatment with NG-nitro-L-arginine-methyl ester (L-NAME, a non-selective NOS inhibitor) or indomethacin (an inhibitor of prostaglandin synthesis) significantly attenuated the effects of LPS on the diarrheogenic activity and intestine content, but reversed the GIT.CONCLUSION: The present study suggests that the pathogenesis of LPS treatment may mediate the stimulatory effect of LPS on nitric oxide and PGE2 production and NO/prostaglandin pathway may play an important role on gastrointestinal function.

The oral commensal Streptococcus mitis activates the aryl hydrocarbon receptor in human oral epithelial cells

Streptococcus mitis （S. mitis） is a pioneer commensal bacterial species colonizing many of the surfaces of the oral cavity in healthy individuals. Yet, not much information is available regarding its interaction with the host. We used examination of its transcriptional regulation in oral keratinocytes to elucidate some of its potential roles in the oral cavity. Transcription factor analysis of oral keratinocytes predicted S. mitis.mediated activation of aryl hydrocarbon receptor （AhR）, Activation and functionality of AhR was confirmed through nuclear translocation determined by immunofluorescence microscopy and real-time polymerase chain reaction with reverse transcription analysis of CYPIA1, the hallmark gene for AhR activation. Addition of Streptococcus mutans or Streptococcus gordonfi did not induce CYPIA1 transcription in the keratinocyte cultures. Introduction of an AhR-specific inhibitor revealed that S. mitis-mediated transcription of CXCL2 and CXCL8 was regulated by AhR. Elevated levels of pmstaglandin E2 （enzyme-linked immunosorbent assay） in supernatants from S. mitis-treated oral epithelial cells were also attenuated by inhibition of AhR activity. The observed AhR-regulated activities point to a contribution of S. mitis in the regulation of inflammatory responses and thereby to wound healing in the oral cavity. The concept that the oral commensal microbiota can induce AhR activation is important, also in view of the role that AhR has in modulation of T-cell differentiation and as an anti-inflammatory factor in macrophaees.

Amentoflavone protects hippocampal neurons: anti-inflammatory, antioxidative, and antiapoptotic effects

Amentoflavone is a natural biflavone compound with many biological properties, including anti-inflammatory, antioxidative, and neuroprotective effects. We presumed that amentoflavone exerts a neuroprotective effect in epilepsy models. Prior to model establishment, mice were intragastrically administered 25 mg/kg amentoflavone for 3 consecutive days. Amentoflavone effectively prevented pilocarpine-induced epilepsy in a mouse kindling model, suppressed nuclear factor-κB activation and expression, inhibited excessive discharge of hippocampal neurons resulting in a reduction in epileptic seizures, shortened attack time, and diminished loss and apoptosis of hippocampal neurons. Results suggested that amentoflavone protected hippocampal neurons in epilepsy mice via anti-inflammation, antioxidation, and antiapoptosis, and then effectively prevented the occurrence of seizures.

EP4 agonist alleviates indomethacin-induced gastric lesions and promotes chronic gastric ulcer healing

AIM： To investigate EP4-selective agonist effect on indomethacin-induced gastric lesions and on the spontaneous healing of chronic gastric ulcers. METHODS： In a mouse model of gastric bleeding with high dose of indomethacin （20 mg/kg）, an EP4-selective agonist was administered orally. Stomach lesions and gastric mucous regeneration were monitored. In a mouse model of chronic gastric ulcer induced by acetic acid, EP4 agonist effect on the healing of chronic gastric ulcer was evaluated in the presence or absence of low dose indomethadn （3 mg/kg）. In cultured human gastric mucous cells, EP4 agonist effect on indomethacin- induced apoptosis was assessed by flow cytometry. RESULTS： The EP4-selective agonist reduced high dose indomethacin-induced acute hemorrhagic damage and promoted mucous epithelial regeneration. Low-dose indomethacin aggravated ulcer bleeding and inflammation, and delayed the healing of the established chronic gastric ulcer. The EP4 agonist, when applied locally, not only offset indomethacin-induced gastric bleeding and inflammation, but also accelerated ulcer healing. In the absence of indomethacin, the EP4 agonist even accelerated chronic gastric ulcer healing and suppressed inflammatory cell infiltration in the granulation tissue. In vitro, the EP4 agonist protected human gastric mucous cells from indomethacin-induced apoptosis.CONCLUSION： EP4-selective agonist may prevent indomethacin-induced gastric lesions and promote healing of existing and i ulcers, via promoting mucous epithelial cells. proliferation and survival of mucous epithelial cells.