The role of IP prostanoid receptors in inflammatory pain

Natural-Derived COX-2 Inhibitors as Anticancer Drugs: A Review of their Structural Diversity and Mechanism of Action

Cyclooxygenase-2 (COX-2) is a key-type enzyme playing a crucial role in cancer development, making it a target of high interest for drug designers. In the last two decades, numerous selective COX-2 inhibitors have been approved for various clinical conditions. However, data from clinical trials propose that the prolonged use of COX-2 inhibitors is associated with life-threatening cardiovascular side effects. The data indicate that a slight structural modification can help develop COX-2 selective inhibitors with comparative efficacy and limited side effects. In this regard, secondary metabolites from natural sources offer great hope for developing novel COX-2 inhibitors with potential anticancer activity. In recent years, various nature-derived organic scaffolds are being explored as leads for developing new COX-2 inhibitors. The current review attempts to highlight the COX-2 inhibition activity of some naturally occurring secondary metabolites, concerning their capacity to inhibit COX-1 and COX-2 enzymes and inhibit cancer development, aiming to establish a structure-activity relationship.

Safety Assessment and Pain Relief Properties of Saffron from Taliouine Region (Morocco)

Saffron is the most expensive spice in the world. In addition to its culinary utilization, this spice is used for medicinal purposes such as in pain management. In this study, the analgesic activity of Crocus sativus stigma extract (CSSE) was evaluated in rodents and its possible physiological mechanism was elucidated. The anti-nociceptive effect of CSSE was evaluated using three animal models (hot plate, writhing, and formalin tests). The analgesic pathways involved were assessed using various analgesia-mediating receptors antagonists. The oral administration of CSSE, up to 2000 mg/kg, caused no death or changes in the behavior or in the hematological and biochemical blood parameters of treated animals nor in the histological architecture of the animals’ livers and kidneys. CSSE showed a central, dose-dependent, anti-nociceptive effect in response to thermal stimuli; and a peripheral analgesic effect in the test of contortions induced by acetic acid. The dual (central and peripheral) analgesic effect was confirmed by the formalin test. The anti-nociceptive activity of CSSE was totally or partially reversed by the co-administration of receptor antagonists, naloxone, atropine, haloperidol, yohimbine, and glibenclamide. CSSE influenced signal processing, by the modulation of the opioidergic, adrenergic, and muscarinic systems at the peripheral and central levels; and by regulation of the dopaminergic system and control of the opening of the ATP-sensitive K⁺ channels at the spinal level. The obtained data point to a multimodal mechanism of action for CSSE: An anti-inflammatory effect and a modulation, through different physiological pathways, of the electrical signal generated by the nociceptors. Further clinical trials are required to endorse the potential utilization of Moroccan saffron as a natural painkiller.

Chemical Profiling, Pharmacological Insights and In Silico Studies of Methanol Seed Extract of Sterculia foetida

Sterculia foetida, also known as jangli badam in Bangladesh, is a traditionally used plant that has pharmacological activities. A qualitative phytochemical analysis was performed to assess the metabolites in a methanolic extract of S. foetida seeds (MESF), and the cytotoxic, thrombolytic, anti-arthritics, analgesic, and antipyretic activities were examined using in vitro, in vivo, and in silico experiments. Quantitative studies were performed through gas chromatography-mass spectroscopy (GC-MS) analysis. The brine shrimp lethality bioassays and clot lysis were performed to investigate the cytotoxic and thrombolytic activities, respectively. The anti-arthritics activity was assessed using the albumin denaturation assay. Analgesic activity was determined using the acetic acid-induced writhing test and the formalin-induced paw-licking test. A molecular docking study was performed, and an online tool was used to perform ADME/T (absorption, distribution, metabolism, and excretion/toxicity) and PASS (Prediction of Activity Spectra for Substances). GC-MS analysis identified 29 compounds in MESF, consisting primarily of phenols, terpenoids, esters, and other organic compounds. MESF showed moderate cytotoxic activity against brine shrimp and significant thrombolytic and anti-arthritics activities compared with the relative standards. The extract also showed a dose-dependent and significant analgesic and antipyretic activities. Docking studies showed that 1-azuleneethanol, acetate returned the best scores for the tested enzymes. These findings suggested that MESF represents a potent source of thrombolytic, anti-arthritic, analgesic, antipyretic agents with moderate cytotoxic effects.

Lymph nodes are innervated by a unique population of sensory neurons with immunomodulatory potential

Barrier tissue immune responses are regulated in part by nociceptors. Nociceptor ablation alters local immune responses at peripheral sites and within draining lymph nodes (LNs). The mechanisms and significance of nociceptor-dependent modulation of LN function are unknown. Using high-resolution imaging, viral tracing, single-cell transcriptomics, and optogenetics, we identified and functionally tested a sensory neuro-immune circuit that is responsive to lymph-borne inflammatory signals. Transcriptomics profiling revealed that multiple sensory neuron subsets, predominantly peptidergic nociceptors, innervate LNs, distinct from those innervating surrounding skin. To uncover LN-resident cells that may interact with LN-innervating sensory neurons, we generated a LN single-cell transcriptomics atlas and nominated nociceptor target populations and interaction modalities. Optogenetic stimulation of LN-innervating sensory fibers triggered rapid transcriptional changes in the predicted interacting cell types, particularly endothelium, stromal cells, and innate leukocytes. Thus, a unique population of sensory neurons monitors peripheral LNs and may locally regulate gene expression.

Prostaglandins as potential targets for the treatment of polycystic kidney disease

Polycystic kidney disease (PKD) is characterized by the proliferation of fluid-filled kidney cysts that enlarge over time, causing damage to the surrounding kidney and ultimately resulting in kidney failure. Both increased cell proliferation and fluid secretion are stimulated by increased cyclic adenosine monophosphate (cAMP) in PKD kidneys, so many treatments for the disease target cAMP lowering. Prostaglandins (PG) levels are elevated in multiple animal models of PKD and mediate many of their effects by elevating cAMP levels. Inhibiting the production of PG with cyclooxygenase 2 (COX2) inhibitors reduces PG levels and reduces disease progression. However, COX inhibitors also block beneficial PG and can cause nephrotoxicity. In an orthologous model of the main form of PKD, PGD₂ and PGI₂ were the two PG highest in kidneys and most affected by a COX2 inhibitor. Future studies are needed to determine whether specific blockage of PGD₂ and/or PGI₂ activity would lead to more targeted and effective treatments with fewer undesirable side-effects.

International Union of Basic and Clinical Pharmacology. CIX. Differences and Similarities between Human and Rodent Prostaglandin E2 Receptors (EP1-4) and Prostacyclin Receptor (IP): Specific Roles in Pathophysiologic Conditions

Prostaglandins are derived from arachidonic acid metabolism through cyclooxygenase activities. Among prostaglandins (PGs), prostacyclin (PGI2) and PGE2 are strongly involved in the regulation of homeostasis and main physiologic functions. In addition, the synthesis of these two prostaglandins is significantly increased during inflammation. PGI2 and PGE2 exert their biologic actions by binding to their respective receptors, namely prostacyclin receptor (IP) and prostaglandin E2 receptor (EP) 1-4, which belong to the family of G-protein-coupled receptors. IP and EP1-4 receptors are widely distributed in the body and thus play various physiologic and pathophysiologic roles. In this review, we discuss the recent advances in studies using pharmacological approaches, genetically modified animals, and genome-wide association studies regarding the roles of IP and EP1-4 receptors in the immune, cardiovascular, nervous, gastrointestinal, respiratory, genitourinary, and musculoskeletal systems. In particular, we highlight similarities and differences between human and rodents in terms of the specific roles of IP and EP1-4 receptors and their downstream signaling pathways, functions, and activities for each biologic system. We also highlight the potential novel therapeutic benefit of targeting IP and EP1-4 receptors in several diseases based on the scientific advances, animal models, and human studies. SIGNIFICANCE STATEMENT: In this review, we present an update of the pathophysiologic role of the prostacyclin receptor, prostaglandin E2 receptor (EP) 1, EP2, EP3, and EP4 receptors when activated by the two main prostaglandins, namely prostacyclin and prostaglandin E2, produced during inflammatory conditions in human and rodents. In addition, this comparison of the published results in each tissue and/or pathology should facilitate the choice of the most appropriate model for the future studies.

Etoricoxib decreases subchondral bone mass and attenuates biomechanical properties at the early stage of osteoarthritis in a mouse model

Etoricoxib, a selective Cyclooxygenase-2 (COX-2) inhibitor, is commonly used in osteoarthritis (OA) for pain relief, however, little is known about the effects on subchondral bone. In the current study, OA was induced via destabilization of the medial meniscus (DMM) in C57BL/6 mice. Two days after surgery, mice were treated with different concentrations of Etoricoxib. Four weeks after treatment, micro computed tomography (Micro-CT) analysis, histological analysis, atomic force microscopy (AFM) analysis, and scanning electron microscopy (SEM) were performed to evaluate OA progression. We demonstrated that Etoricoxib inhibited osteophyte formation in the subchondral bone. However, it also reduced the bone volume fraction (BV/TV), lowered trabecular thickness (Tb.Th), and more microfractures and pores were observed in the subchondral bone. Moreover, Etoricoxib reduced the elastic modulus of subchondral bone. Exposure to Etoricoxib further increased the empty/total osteocyte ratio of the subchondral bone. Etoricoxib did not show significant improvement in articular cartilage destruction and synovial inflammation in early OA. Together, our observations suggested that although Etoricoxib can relieve OA-induced pain and inhibit osteophyte formation in the subchondral bone, it can also change the microstructures and biomechanical properties of subchondral bone, promote subchondral bone loss, and reduce subchondral bone quality in early OA mice.

The Protective Effects of Up-Regulating Prostacyclin Biosynthesis on Neuron Survival in Hippocampus

Cellular arachidonic acid (AA), an unsaturated fatty acid found ubiquitously in plasma membranes, is metabolized to different prostanoids, such as prostacyclin (PGI₂) and prostaglandin E₂ (PGE₂), by the three-step reactions coupling the upstream cyclooxygenase (COX) isoforms (COX-1 and COX-2) with the corresponding individual downstream synthases. While the vascular actions of these prostanoids are well-characterized, their specific roles in the hippocampus, a major brain area for memory, are poorly understood. The major obstacle for its understanding in the brain was to mimic the biosynthesis of each prostanoid. To solve the problem, we utilized Single-Chain Hybrid Enzyme Complexes (SCHECs), which could successfully control cellular AA metabolites to the desired PGI₂ or PGE₂. Our in vitro studies suggested that neurons with higher PGI₂ content and lower PGE₂ content exhibited survival protection and resistance to Amyloid-β-induced neurotoxicity. Further extending to an in vivo model, the hybrid of PGI₂-producing transgenic mice and Alzheimer's disease (AD) mice showed restored long-term memory. These findings suggested that the vascular prostanoids, PGI₂ and PGE₂, exerted significant regulatory influences on neuronal protection (by PGI₂), or damage (by PGE₂) in the hippocampus, and raised a concern that the wide uses of aspirin in cardiovascular diseases may exert negative impacts on neurodegenerative protection. Graphic Abstract Our study intended to understand the crosstalk of prostanoids in the hippocampus, a major brain area impacted in AD, by using hybrid enzymes to redirect the synthesis of prostanoids to PGE₂ and PGI₂, respectively. Our data indicated that during inflammation, the vascular mediators, PGI₂ and PGE₂, exerted significant regulatory influences on neuronal protection (by PGI₂), or damage (by PGE₂) in the hippocampus. These findings also raised a concern that the widely uses of non-steroidal anti-inflammatory drugs in cardiovascular diseases may exert negative impacts on neurodegenerative protection.

A novel human pain insensitivity disorder caused by a point mutation in ZFHX2

Chronic pain is a major global public health issue causing a severe impact on both the quality of life for sufferers and the wider economy. Despite the significant clinical burden, little progress has been made in terms of therapeutic development. A unique approach to identifying new human-validated analgesic drug targets is to study rare families with inherited pain insensitivity. Here we have analysed an otherwise normal family where six affected individuals display a pain insensitive phenotype that is characterized by hyposensitivity to noxious heat and painless bone fractures. This autosomal dominant disorder is found in three generations and is not associated with a peripheral neuropathy. A novel point mutation in ZFHX2, encoding a putative transcription factor expressed in small diameter sensory neurons, was identified by whole exome sequencing that segregates with the pain insensitivity. The mutation is predicted to change an evolutionarily highly conserved arginine residue 1913 to a lysine within a homeodomain. Bacterial artificial chromosome (BAC) transgenic mice bearing the orthologous murine p.R1907K mutation, as well as Zfhx2 null mutant mice, have significant deficits in pain sensitivity. Gene expression analyses in dorsal root ganglia from mutant and wild-type mice show altered expression of genes implicated in peripheral pain mechanisms. The ZFHX2 variant and downstream regulated genes associated with a human pain-insensitive phenotype are therefore potential novel targets for the development of new analgesic drugs.awx326media15680039660001.

Prostaglandin E2 mediates sensory nerve regulation of bone homeostasis

Whether sensory nerve can sense bone density or metabolic activity to control bone homeostasis is unknown. Here we found prostaglandin E2 (PGE2) secreted by osteoblastic cells activates PGE2 receptor 4 (EP4) in sensory nerves to regulate bone formation by inhibiting sympathetic activity through the central nervous system. PGE2 secreted by osteoblasts increases when bone density decreases as demonstrated in osteoporotic animal models. Ablation of sensory nerves erodes the skeletal integrity. Specifically, knockout of the EP4 gene in the sensory nerves or cyclooxygenase-2 (COX2) in the osteoblastic cells significantly reduces bone volume in adult mice. Sympathetic tone is increased in sensory denervation models, and propranolol, a β2-adrenergic antagonist, rescues bone loss. Furthermore, injection of SW033291, a small molecule to increase PGE2 level locally, significantly boostes bone formation, whereas the effect is obstructed in EP4 knockout mice. Thus, we show that PGE2 mediates sensory nerve to control bone homeostasis and promote regeneration.

Microglial TNFα Induces COX2 and PGI2 Synthase Expression in Spinal Endothelial Cells during Neuropathic Pain

Prostaglandins (PGs) are typical lipid mediators that play a role in homeostasis and disease. They are synthesized from arachidonic acid by cyclooxygenase 1 (COX1) and COX2. Although COX2 has been reported to be upregulated in the spinal cord after nerve injury, its expression and functional roles in neuropathic pain remain unclear. In this study, we investigated the expression of Cox2, PGI2 synthase (Pgis), and prostaglandin I2 receptor (IP receptor) mRNA in the rat spinal cord after spared nerve injury (SNI). Levels of Cox2 and Pgis mRNA increased in endothelial cells from 24 to 48 h after nerve injury. IP receptor mRNA was constitutively expressed in dorsal horn neurons. A COX2 inhibitor and IP receptor antagonists attenuated pain behavior in the early phase of neuropathic pain. Furthermore, we examined the relationship between COX2 and tumor necrosis factor-α (TNFα) in the spinal cord of a rat SNI model. Levels of TNFα mRNA transiently increased in the spinal microglia 24 h after SNI. The TNF receptors Tnfr1 and Tnfr2 mRNA were colocalized with COX2. Intrathecal injection of TNFα induced Cox2 and Pgis mRNA expression in endothelial cells. These results revealed that microglia-derived TNFα induced COX2 and PGIS expression in spinal endothelial cells and that endothelial PGI2 played a critical role in neuropathic pain via neuronal IP receptor. These findings further suggest that the glia–endothelial cell interaction of the neurovascular unit via transient TNFα is involved in the generation of neuropathic pain.

Positive feedback effect of PGE2 on cyclooxygenase-2 expression is mediated by inhibition of Akt phosphorylation in human follicular dendritic cell-like cells

Prostaglandins (PGs) are bioactive lipid mediators generated from the phospholipids of cell membrane in response to various inflammatory signals. To understand the potential role of PGs in PG production itself during immune inflammatory responses, we examined the effect of PGE₂, PGF_2α, and beraprost on COX-2 expression using follicular dendritic cell (FDC)-like HK cells isolated from human tonsils. Those three PGs specifically augmented COX-2 protein expression in a dose-dependent manner after 4 or 8h of treatment. The enhancing effect was also reflected in the actual production of PGs and the viable cell recovery of germinal center B-cells. To investigate the underlying molecular mechanism, we examined the impact of PI3K inhibitors on PG-induced COX-2 expression. Interestingly, COX-2 induction by PGE₂ and beraprost, but not PGF_2α, was enhanced by wortmannin and LY294002. In line with this result, Akt phosphorylation was inhibited by PGE₂ and beraprost but not by PGF_2α. The distinct effect of PGE₂ and beraprost from PGF_2α was reproduced in Akt-knockdowned HK cells. Our current findings imply that PGE₂ and PGI₂ stimulate COX-2 expression in FDC by inhibiting Akt phosphorylation. Additional studies are warranted to determine the potential role of Akt as a therapeutic target in patients with inflammatory disorders.

Astrocyte-specific overexpressed gene signatures in response to methamphetamine exposure in vitro

BACKGROUND

Astrocyte activation is one of the earliest findings in the brain of methamphetamine (Meth) abusers. Our goal in this study was to identify the characteristics of the astrocytic acute response to the drug, which may be critical in pathogenic outcomes secondary to the use.

METHODS

We developed an integrated analysis of gene expression data to study the acute gene changes caused by the direct exposure to Meth treatment of astrocytes in vitro, and to better understand how astrocytes respond, what are the early molecular markers associated with this response. We examined the literature in search of similar changes in gene signatures that are found in central nervous system disorders.

RESULTS

We identified overexpressed gene networks represented by genes of an inflammatory and immune nature and that are implicated in neuroactive ligand-receptor interactions. The overexpressed networks are linked to molecules that were highly upregulated in astrocytes by all doses of methamphetamine tested and that could play a role in the central nervous system. The strongest overexpressed signatures were the upregulation of MAP2K5, GPR65, and CXCL5, and the gene networks individually associated with these molecules. Pathway analysis revealed that these networks are involved both in neuroprotection and in neuropathology. We have validated several targets associated to these genes.

CONCLUSIONS

Gene signatures for the astrocytic response to Meth were identified among the upregulated gene pool, using an in vitro system. The identified markers may participate in dysfunctions of the central nervous system but could also provide acute protection to the drug exposure. Further in vivo studies are necessary to establish the role of these gene networks in drug abuse pathogenesis.

Sesquiterpene lactone! a promising antioxidant, anticancer and moderate antinociceptive agent from Artemisia macrocephala jacquem

Background

Sesquiterpene lactones (STLs) make a diverse and huge group of bio-active constituents that have been isolated from several plant families. However, the greatest numbers are present in Asteraceae family having more than 3000 different reported structures. Recently several researchers have reported that STLs have significant antioxidant and anticancer potentials.

Methods

To investigate the antioxidant, anticancer and antinociceptive potentials of STLs, gravity column chromatography technique was used for isolation from the biologically rich chloroform fraction of Artemisia macrocephala Jacquem. The antioxidant activity of the isolated STLs was determined by DPPH and ABTS free radical scavenging activity, anticancer activity was determined on 3 T3, HeLa and MCF-7 cells by MTT assay while the antinociceptive activity was determined through acetic acid induced writhings, tail immersion method and formalin induced nociception method.

Results

The results showed that the STLs of Artemisia macrocephala possesses promising antioxidant activity and also it decreased the viability of 3 T3, HeLa and MCF-7 cells and mild to moderate antinociceptive activity.

Conclusion

Sesquiterpenes lactones (STLs) are widely present in numerous genera of the family Asteraceae (compositae). They are described as the active constituents used in traditional medicine for the treatment of various diseases. The present study reveals the significant potentials of STL and may be used as an alternative for the management of cancer. Anyhow, the isolated compound is having no prominent antinociceptive potentials.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-016-1517-y) contains supplementary material, which is available to authorized users.

Antinociceptive effect of methanol extract of Celosia cristata Linn. in mice

BACKGROUND

Celosia cristata Linn. (Amaranthaceae) is used in traditional medicine for the treatment of headache, sores, ulcers, eye inflammations, skin eruption, painful menstruation and carpal tunnel syndrome. This study was performed to evaluate the antinociceptive activity of methanol extract of the whole plant of C. cristata (MECC).

METHODS

The evaluation of the antinociceptive effect of MECC was performed using thermal (hot plate, tail immersion test) and chemical (acetic acid, formalin, and glutamate-induced nociception test) pain models in mice at four different doses (50, 100, 200, 400 mg/kg; p.o.). Involvement of opioid receptors mediated central antinociceptive mechanism of MECC was evaluated using naloxone. Furthermore, the association of ATP-sensitive K+ channel and cGMP pathway were evaluated using glibenclamide and methylene blue respectively.

RESULTS

Oral treatment of MECC produced significant, strong and dose-dependent central and peripheral antinociceptive effect in experimental pain models. MECC significantly increased the latency time of thermal threshold in both hot plate and tail immersion test. The inhibition of writhing syndrome by the extract in the acetic acid-induced writhing test was remarkable. MECC significantly reduced the formalin-induced neurogenic and inflammatory pain. In addition, the inhibition of glutamate-induced paw licking and edema by MECC was significant. The antinociceptive effect was significantly reversed by naloxone and glibenclamide, suggesting the association of opioid and ATP-sensitive K+ channel system respectively. In addition, MECC also demonstrated the involvement of cGMP pathway in the antinociceptive action.

CONCLUSION

The study suggests that C. cristata possess significant antinociceptive effect which is associated with both central and peripheral mechanisms and provides a rationale for its extensive use at different painful conditions in traditional medicine.

Evaluation of the anti-inflammatory action of curcumin analog (DM1): Effect on iNOS and COX-2 gene expression and autophagy pathways

This work describes the anti-inflammatory effect of the curcumin-analog compound, sodium 4-[5-(4-hydroxy-3-methoxyphenyl)-3-oxo-penta-1,4-dienyl]-2-methoxy-phenolate (DM1), and shows that DM1 modulates iNOS and COX-2 gene expression in cultured RAW 264.7 cells and induces autophagy on human melanoma cell line A375.

Antinociceptive and neuropharmacological activities of methanol extract of Phoenix sylvestris fruit pulp

Fruits of Phoenix sylvestris Roxb. (Arecaceae) are used to treat back pain, toothache, headache, arthritis, nervous debility and as sedative. The aim of this study was to evaluate the antinociceptive and neuropharmacological activities of methanol extract of P. sylvestris fruit pulp (MEPS). The antinociceptive activity of MEPS was evaluated by heat-induced (hot plate, tail immersion test) and chemical-induced pain models (acetic acid-induced writhing, formalin-induced nociception, glutamate-induced nociception and paw edema test). The effect of MEPS on central nervous system (CNS) was studied using hole cross test, open field test, sodium thiopental-induced sleeping time and elevated plus maze test. MEPS showed strong, significant and dose-dependent antinociceptive activity in all heat-induced and chemical-induced pain models at all experimental doses. Involvement of opioid receptor mediated analgesia was evident from the reversal of analgesic effect by naloxone. MEPS also showed reduced locomotor activity in both hole cross and open field tests. The increase in sleeping time in sodium thiopental-induced sleeping test and anxiolytic activity in elevated plus maze test were also significant. So, it is evident that MEPS possesses strong central and peripheral antinociceptive activity as well as CNS depressant, sedative and anxiolytic activity. The results justify the ethnomedicinal use of P. sylvestris fruit in different painful conditions and CNS disorders.

Evaluation of Antinociceptive Activity of Ethanol Extract of Leaves of Adenanthera pavonina

Adenanthera pavonina is a deciduous tree commonly used in the traditional medicine to treat inflammation and rheumatism. The aim of this study was to evaluate the antinociceptive activity of ethanol extract of leaves of A. pavonina (EEAP). EEAP was investigated using various nociceptive models induced thermally or chemically in mice including hot plate and tail immersion test, acetic acid-induced writhing, and glutamate- and formalin-induced licking tests at the doses of 50, 100, and 200 mg/kg body weight (p.o.). In addition, to assess the possible mechanisms, involvement of opioid system was verified using naloxone (2 mg/kg) and cyclic guanosine monophosphate (cGMP) signaling pathway by methylene blue (MB; 20 mg/kg). The results have demonstrated that EEAP produced a significant and dose-dependent increment in the hot plate latency and tail withdrawal time. It also reduced the number of abdominal constrictions and paw lickings induced by acetic acid and glutamate respectively. EEAP inhibited the nociceptive responses in both phases of formalin test. Besides, the reversal effects of naloxone indicated the association of opioid receptors on the exertion of EEAP action centrally. Moreover, the enhancement of writhing inhibitory activity by MB suggests the possible involvement of cGMP pathway in EEAP-mediated antinociception. These results prove the antinociceptive activity of the leaves of A. pavonina and support the traditional use of this plant.

What is the evidence for the use of corticosteroids in migraine?

Corticosteroids are widely prescribed for the management of migraine attacks. The earliest clinical studies examining the efficacy of corticosteroid monotherapy for managing migraine attacks date back to 1952. Since then, 26 heterogeneous clinical studies and four meta-analyses have been conducted to assess the efficacy of corticosteroids in either aborting acute migraine attacks, prolonged migraine attacks or recurrent headaches. Most of these (86 %) studies employed different comparator arms with corticosteroids monotherapy administration while some studies (14 %) evaluated adjunctive corticosteroid therapy. The majority of these clinical studies revealed the superior efficacy of corticosteroids as mono- or adjunctive-therapy both for recurrent and acute migraine attacks, while the remaining showed non-inferior efficacy. Different forms of oral and parenteral corticosteroids in either single-dose or short-tapering schedules are prescribed; there are clinical studies supporting the efficacy of both methods. Corticosteroids can be administered safely up to six times annually. Corticosteroids are also useful in managing patients who frequent emergency departments with "medication-seeking behavior." Migraine patients with refractory headaches, history of recurrent headaches, severe baseline disability, and status migrainosus were found to have the most beneficial response from corticosteroid therapy.

Interferon-γ stimulates human follicular dendritic cell-like cells to produce prostaglandins via the JAK-STAT pathway

IFN-γ plays a critical role in the regulation of innate and adaptive immunity. Paying attention to the emerging role of prostaglandins (PGs) as immune regulators, we attempted to establish the effect of IFN-γ on PG production in human follicular dendritic cell-like HK cells and the underlying signaling pathway by using RNA interference technology. IFN-γ induced COX-2 protein expression in HK cells in a time- and dose-dependent manner, which was not observed in peripheral blood monocytes. Although IFN-γ induced phosphorylation of STAT1, STAT3, and STAT5, only STAT1 was essential for the COX-2 augmentation. The JAK kinases responsible for IFN-γ-triggered STAT1 phosphorylation were JAK1 and JAK2, which were also required for the COX-2 induction. The essential requirement of JAK1 and JAK2 was verified by confocal microscopic analysis, since STAT1 phosphorylation and nuclear translocation were impaired in HK cells with these two kinases knocked down. Finally, we demonstrated that JAK1, JAK2, and STAT1 were indispensable for the actual enhancement of PG production in response to IFN-γ stimulation. These results provide a novel insight into our understanding of IFN-γ under inflammatory conditions and support the emerging concept of PGs as important immune regulators.

Interactions between glia, the immune system and pain processes during early development

Pain is a serious problem for infants and children and treatment options are limited. Moreover, infants born prematurely or hospitalized for illness likely have concurrent infection that activates the immune system. It is now recognized that the immune system in general and glia in particular influence neurotransmission and that the neural bases of pain are intimately connected to immune function. We know that injuries that induce pain activate immune function and suppressing the immune system alleviates pain. Despite this advance in our understanding, virtually nothing is known of the role that the immune system plays in pain processing in infants and children, even though pain is a serious clinical issue in pediatric medicine. This brief review summarizes the existing data on immune-neural interactions in infants, providing evidence for the immaturity of these interactions.

Prostacyclin regulates spinal nociceptive processing through cyclic adenosine monophosphate-induced translocation of glutamate receptors

BACKGROUND

Prostacyclin (PGI2) is known to be an important mediator of peripheral pain sensation (nociception) whereas little is known about its role in central sensitization.

METHODS

The levels of the stable PGI2-metabolite 6-keto-prostaglandin F1α (6-keto-PGF1α) and of prostaglandin E2 (PGE2) were measured in the dorsal horn with the use of mass spectrometry after peripheral inflammation. Expression of the prostanoid receptors was determined by immunohistology. Effects of prostacyclin receptor (IP) activation on spinal neurons were investigated with biochemical assays (cyclic adenosine monophosphate-, glutamate release-measurement, Western blot analysis) in embryonic cultures and adult spinal cord. The specific IP antagonist Cay10441 was applied intrathecally after zymosan-induced mechanical hyperalgesia in vivo.

RESULTS

Peripheral inflammation caused a significant increase of the stable PGI2 metabolite 6-keto-PGF1α in the dorsal horn of wild-type mice (n = 5). IP was located on spinal neurons and did not colocalize with the prostaglandin E2 receptors EP2 or EP4. The selective IP-agonist cicaprost increased cyclic adenosine monophosphate synthesis in spinal cultures from wild-type but not from IP-deficient mice (n = 5-10). The combination of fluorescence-resonance-energy transfer-based cyclic adenosine monophosphate imaging and calcium imaging showed a cicaprost-induced cyclic adenosine monophosphate synthesis in spinal cord neurons (n = 5-6). Fittingly, IP activation increased glutamate release from acute spinal cord sections of adult mice (n = 13-58). Cicaprost, but not agonists for EP2 and EP4, induced protein kinase A-dependent phosphorylation of the GluR1 subunit and its translocation to the membrane. Accordingly, intrathecal administration of the IP receptor antagonist Cay10441 had an antinociceptive effect (n = 8-11).

CONCLUSION

Spinal prostacyclin synthesis during early inflammation causes the recruitment of GluR1 receptors to membrane fractions, thereby augmenting the onset of central sensitization.

Evaluation of the antinociceptive and anti-inflammatory effect of Caralluma dalzielii

ETHNOPHARMACOLOGICAL RELEVANCE

Caralluma dalzielii has been used for treating several ailments including convulsion, leprosy, snake bites, otitis (ear pain), fungal diseases and rheumatoid arthritis in Northern Nigeria. However there is no scientific evidence to support its use in literature. To evaluate the antinociceptive and anti-inflammatory properties of the aqueous extract of Caralluma dalzielii in animal models.

MATERIALS AND METHODS

The antinociceptive and anti-inflammatory properties were assessed using acetic acid induced writhing test in mice, sub plantar formalin induced nociception, the tail-flick test and formalin induced oedema in rats. Three doses of the extract (25, 50, 100 mg/kg) were used for the assessment.

RESULTS

Caralluma dalzielii extract demonstrated strong dose-dependent antinociceptive and anti-inflammatory activities in all the models employed. All doses (25, 50, 100 mg/kg) produced a significant percentage inhibition (41.77, 77.11, and 90.76% in the early phase and 52.02, 85.35, 93.93% in the late phase) in the acetic acid writhing test and (42.85, 55.71, 86.43% in the early phase and 23.26, 37.98, 72.87 in the late phase) in the formalin induced nociception test, respectively. The tail-flick test showed a significant increase in the antinociceptive effect of the extract in both early and late phases when compared with the control. The inhibition of oedema in the formalin test was significant when compared to the control.

CONCLUSION

The results indicated that Caralluma dalzielii showed excellent antinociceptive and anti-inflammatory properties suggesting that its traditional use in the treatment of pains and inflammatory diseases may be valid.

Prostacyclin mediates neuropathic pain through interleukin 1β-expressing resident macrophages

Prostacyclin is an important mediator of peripheral pain sensation. Here, we investigated its potential participation in mediating neuropathic pain and found that prostacyclin receptor (IP) knockout mice exhibited markedly decreased pain behavior. Application of an IP antagonist to the injury site or selective IP deficiency in myeloid cells mimicked the antinociceptive effect observed in IP knockout mice. At the site of nerve injury, IP was expressed in interleukin (IL) 1β-containing resident macrophages, which were less common in IP knockout mice. Local administration of the IP agonist cicaprost inhibited macrophage migration in vitro and promoted accumulation of IP- and IL1β-expressing cells as well as an increase of IL1β concentrations at the application site in vivo. Fittingly, the IL1-receptor antagonist anakinra (IL-1ra) decreased neuropathic pain behavior in wild-type mice but not in IP knockout mice. Finally, continuous, but not single administration, of the cyclooxygenase inhibitor meloxicam early after nerve injury decreased pain behavior and the number of resident macrophages. Thus, early synthesis of prostacyclin at the site of injury causes accumulation of IL1β-expressing macrophages as a key step in neuropathic pain after traumatic injury.

Capsaicin 8% patch for treprostinil subcutaneous infusion site pain in pulmonary hypertension patients

BACKGROUND

Treprostinil sodium improves haemodynamics and symptoms in pulmonary arterial hypertension (PAH) patients, but its subcutaneous (s.c.) administration can produce severe local site pain, and lead to discontinuation of vital treatment. Treprostinil is a prostacyclin analogue which stimulates prostacyclin receptors in skin nociceptor terminals, resulting in pain and cutaneous hypersensitivity, for which current pain remedies have limited effect. Capsaicin 8% patch relieves neuropathic pain for 3 months after a single 60 min cutaneous application; we investigated whether its pre-application can reduce s.c. trepostinil-induced pain.

METHODS

A single-centre, double-blind, randomized, placebo-controlled, crossover study was conducted to assess the safety and efficacy of a single capsaicin 8% patch pre-application for s.c. treprostinil pain in 11 PAH patients, relative to control patch with low-dose capsaicin 0.075% cream.

RESULTS

The primary efficacy endpoint, mean difference between the two treatment arms in an 11-point numerical pain rating scale from baseline to 2 weeks after patch applications, was significantly lower on the capsaicin 8% patch treatment arm [P=0.01, mean difference=-1.47 units, 95% credible interval (CI): -2. 59 to -0.38] in the patients who completed the study per protocol, although intention-to-treat analysis did not show significant difference (P=0.28). Heat pain thresholds were decreased (P=0.027, mean difference=5.43°C, 95% CI: 0.71-10.21) and laser Doppler flux increased (P=0.016, mean difference=370 units, 95% CI: 612 to 127.9) at the application site immediately after capsaicin 8% patch, confirming activity.

CONCLUSIONS

Further investigation of the efficacy of capsaicin 8% patch in this indication is warranted.

Inflammation, leukocytes and menstruation

Menstruation has many of the features of an inflammatory process. The complexity and sequence of inflammatory-type events leading to the final tissue breakdown and bleeding are slowly being unravelled. Progesterone has anti-inflammatory properties, and its rapidly declining levels (along with those of estrogen) in the late secretory phase of each non-conception cycle, initiates a sequence of interdependent events of an inflammatory nature involving local inter-cellular interactions within the endometrium. Intracellular responses to loss of progesterone (in decidualized stromal, vascular and epithelial cells) lead to decreased prostaglandin metabolism and loss of protection from reactive oxygen species (ROS). Increased ROS results in release of NFκB from suppression with activation of target gene transcription and increased synthesis of pro-inflammatory prostaglandins, cytokines, chemokines and matrix metalloproteinases (MMP). The resultant leukocyte recruitment, with changing phenotypes and activation, provide further degradative enzymes and MMP activators, which together with a hypoxic environment induced by prostaglandin actions, lead to the tissue breakdown and bleeding characteristic of menstruation. In parallel, at sites where shedding is complete, microenvironmentally-induced changes in phenotypes of neutrophils and macrophages from pro- to anti-inflammatory, in addition to induction of growth factors, contribute to the very rapid re-epithelialization and restoration of tissue integrity.

Regulation of the human prostacyclin receptor gene by the cholesterol-responsive SREBP1

Prostacyclin and its prostacyclin receptor, the I Prostanoid (IP), play essential roles in regulating hemostasis and vascular tone and have been implicated in a range cardio-protective effects but through largely unknown mechanisms. In this study, the influence of cholesterol on human IP [(h)IP] gene expression was investigated in cultured vascular endothelial and platelet-progenitor megakaryocytic cells. Cholesterol depletion increased human prostacyclin receptor (hIP) mRNA, hIP promoter-directed reporter gene expression, and hIP-induced cAMP generation in all cell types. Furthermore, the constitutively active sterol-response element binding protein (SREBP)1a, but not SREBP2, increased hIP mRNA and promoter-directed gene expression, and deletional and mutational analysis uncovered an evolutionary conserved sterol-response element (SRE), adjacent to a known functional Sp1 element, within the core hIP promoter. Moreover, chromatin immunoprecipitation assays confirmed direct cholesterol-regulated binding of SREBP1a to this hIP promoter region in vivo, and immunofluorescence microscopy corroborated that cholesterol depletion significantly increases hIP expression levels. In conclusion, the hIP gene is directly regulated by cholesterol depletion, which occurs through binding of SREBP1a to a functional SRE within its core promoter. Mechanistically, these data establish that cholesterol can regulate hIP expression, which may, at least in part, account for the combined cardio-protective actions of low serum cholesterol through its regulation of IP expression within the human vasculature.

Antinociceptive activity of methanol extract of flowers of Impatiens balsamina

ETHNOPHARMACOLOGICAL RELEVANCE

Impatiens balsamina Linn. (Balsaminaceae), an annual herb locally called "Dopati", is cultivated as an ornamental garden plant in Bangladesh. Flowers of the plant are used in folk medicine to treat lumbago, neuralgia, burns and scalds.

AIM OF THE STUDY

This study evaluated the antinociceptive effect of the methanol extract of I. balsamina flowers (MIB).

MATERIALS AND METHODS

The extract was evaluated for antinociceptive activity using chemical- and heat-induced pain models such as acetic acid-induced writhing, hot plate, tail immersion and formalin test. To verify the possible involvement of opioid receptor in the central antinociceptive effect of MIB, naloxone was used to antagonize the effect. The effect of MIB on central nervous system (CNS) was also studied using hole cross and open field tests.

RESULTS

MIB demonstrated strong and dose-dependent antinociceptive activity in all the chemical- and heat-induced mice models (p<0.05). These findings imply the involvement of both peripheral and central antinociceptive mechanisms. The use of naloxone confirmed the association of opioid receptors in the central antinociceptive effect. MIB also showed significant central nervous system depressant effect (p<0.05).

CONCLUSION

This study reported the peripheral and central antinociceptive activity of the flowers of I. balsamina and rationalized the traditional use of the flower in the treatment of different painful conditions.

Antinociceptive and hypnotic properties of Celastrus orbiculatus

ETHNOPHARMACOLOGICAL RELEVANCE

Celastrus orbiculatus, a woody vine of the Celastraceae family, has been widely used as a traditional medicine for the treatment of many diseases, including rheumatoid arthritis and odontalgia. In this study, we assessed the sedative and antinociceptive activities of the methanolic extract of Celastrus orbiculatus (MCO).

MATERIALS AND METHODS

The antinociceptive effect of MCO was evaluated using several experimental pain models, including thermal nociception methods, such as the tail immersion and the hotplate tests, as well as chemical nociception induced by intraperitoneal acetic acid and subplantar formalin administration in mice. To verify the possible connection of the opioid receptor to the antinociceptive activity of MCO, we performed a combination test with naloxone, a nonselective opioid receptor antagonist. The sedative effect of MCO was studied using the pentobarbital-induced sleeping model.

RESULTS

MCO demonstrated strong and dose-dependent antinociceptive activity compared to tramadol and indomethacin in various experimental pain models. The combination test using naloxone revealed that the antinociceptive activity of MCO is associated with activation of the opioid receptor. MCO also caused decreased sleep latency and increased sleeping time in the pentobarbital-induced sleeping model; however, MCO alone did not induce sleep.

CONCLUSIONS

In the present study, MCO showed potent antinociceptive and sedative activities. Based on these results, MCO may be considered a valuable anti-nociceptive and hypnotic agent for the treatment of various diseases.

International Union of Basic and Clinical Pharmacology. LXXXIII: classification of prostanoid receptors, updating 15 years of progress

It is now more than 15 years since the molecular structures of the major prostanoid receptors were elucidated. Since then, substantial progress has been achieved with respect to distribution and function, signal transduction mechanisms, and the design of agonists and antagonists (http://www.iuphar-db.org/DATABASE/FamilyIntroductionForward?familyId=58). This review systematically details these advances. More recent developments in prostanoid receptor research are included. The DP(2) receptor, also termed CRTH2, has little structural resemblance to DP(1) and other receptors described in the original prostanoid receptor classification. DP(2) receptors are more closely related to chemoattractant receptors. Prostanoid receptors have also been found to heterodimerize with other prostanoid receptor subtypes and nonprostanoids. This may extend signal transduction pathways and create new ligand recognition sites: prostacyclin/thromboxane A(2) heterodimeric receptors for 8-epi-prostaglandin E(2), wild-type/alternative (alt4) heterodimers for the prostaglandin FP receptor for bimatoprost and the prostamides. It is anticipated that the 15 years of research progress described herein will lead to novel therapeutic entities.

Up-regulation of tetrodotoxin-sensitive sodium currents by prostaglandin E₂ in type-4 rat dorsal root ganglion cells

Mechanisms were studied by which prostaglandin E(2) (PGE(2)) up-regulates Na(+) currents (INa) in medium diameter dorsal root ganglion (DRG) cells that express large T-type Ca(2+) currents (type-4 DRG cells). PGE(2) or the adenylyl cyclase (AC) activator forskolin (10 μM) up-regulated peak INa evoked by test potentials (TP) to -10 mV by an average of 13.5% and 21.8%, respectively. The PGE(2) and forskolin induced up-regulation of INa, evoked with TPs to -10 mV, began approximately 15-20 s after initiation of drug exposure and continued gradually over the course of 2-3 min. Both PGE(2) and forskolin significantly increased peak conductance without significantly shifting the voltage at which INa was ½ activated (V(a)) or ½ steady state inactivated. However, although V(a) was not significantly shifted, both PGE(2) and forskolin induced a proportionally greater percent increase in conductance at weak TPs to around -30 mV compared to stronger TPs to around 10 mV. The PGE(2)-induced up-regulation of INa was occluded by prior up-regulation with forskolin, and the up-regulation of INa by both PGE(2) and forskolin was blocked by Rp-cAMPs and 50 nM tetrodotoxin (TTX). In the presence of Rp-cAMPs, both PGE(2) and forskolin induced decreases in INa that peaked around 25 s following initiation of PGE(2)/forskolin application. The decrease induced by PGE(2) averaged 8.5%, which was significantly greater than the average 3.5% decrease induced by forskolin. Estimation of kinetic rate constants by fitting INa with a Markov channel state model, suggested that both PGE(2) and forskolin up-regulated INa by changing channel gating rather than by increasing channel number or unitary conductance. The data suggest that application of PGE(2) may initially induce a relatively rapid down-regulation of TTX-sensitive INa (signaling pathway uncharacterized), followed by a gradual up-regulation of INa via activation of an AC/PKA-dependent signaling pathway. The up-regulation of INa in sensory neurons with type-4 cell bodies may increase excitability and strengthen signaling, and may play some role in the allodynia and hyperalgesia associated with injury to nerves and peripheral tissues.

Anti-inflammatory and antinociceptive properties of the leaves of Eriobotrya japonica

AIM OF THE STUDY

The leaves of Eriobotrya japonica Lindl. have been widely used as a traditional medicine for the treatment of many diseases including coughs and asthma. The present study was designed to validate the anti-inflammatory and antinociceptive properties of the n-BuOH fraction of E. japonica (LEJ) leaves.

MATERIALS AND METHODS

The anti-inflammatory properties of LEJ were studied using IFN-γ/LPS activated murine peritoneal macrophage model. The antinociceptive effects of LEJ were assessed using experimental models of pain, including thermal nociception methods, such as the tail immersion test and the hotplate test, and chemical nociception induced by intraperitoneal acetic acid and subplantar formalin in mice. To examine the possible connection of the opioid receptor to the antinociceptive activity of LEJ, we performed a combination test with naloxone, a nonselective opioid receptor antagonist.

RESULTS

In the IFN-γ and LPS-activated murine peritoneal macrophage model, LEJ suppressed NO production and iNOS expression via down-regulation of NF-κB activation. It also attenuated the expression of COX-2 and the secretion of pro-inflammatory cytokines like TNF-α and IL-6. Moreover, LEJ also demonstrated strong and dose-dependent antinociceptive activity compared to tramadol and indomethacin in various experimental pain models. In a combination test using naloxone, diminished analgesic activities of LEJ were observed, indicating that the antinociceptive activity of LEJ is connected with the opioid receptor.

CONCLUSIONS

The results indicate that LEJ had potent inhibitory effects on the inflammatory mediators including nitric oxide, iNOS, COX-2, TNF-α and IL-6 via the attenuation of NF-κB translocation to the nucleus. LEJ also showed excellent antinociceptive activity in both central and peripheral mechanism as a weak opioid agonist. Based on these results, LEJ may possibly be used as an anti-inflammatory and an analgesic agent for the treatment of pains and inflammatory diseases.

Inflammatory pathways in endometrial disorders

Complex interactions between the endocrine and immune systems govern the key endometrial events of implantation and menstruation. In contrast to other tissue sites, cyclical endometrial inflammation is physiological. However, dysregulation of this inflammatory response can lead to endometrial disorders. This review examines the inflammatory processes occurring in the normal endometrium during menstruation and implantation, highlighting recent advances in our understanding and gaps in current knowledge. Subsequently, the role of inflammatory pathways in the pathology of various common endometrial conditions is discussed, including heavy menstrual bleeding, dysmenorrhoea (painful periods), uterine fibroids, endometriosis and recurrent miscarriage.

Beraprost enhances the APC function of B cells by upregulating CD86 expression levels

Lipid mediators are emerging as important regulators of the immune system. Based on our previous result that shows strong expression of prostacyclin synthase in the germinal center, we investigated whether prostacyclin would regulate the APC function of B cells. Owing to the very short half-life of prostacyclin in experimental conditions, we used a more stable analog, beraprost. Beraprost increased the amounts of the costimulatory molecule CD86 but not CD80 on the surface of activated B cells in time- and dose-dependent manners. However, the enhancing effect of beraprost was not observed on memory B cells, centroblasts, and centrocytes. Beraprost required BCR and CD40 signals to upregulate CD86 expression levels. Other prostanoids such as PGE(2), 6-keto-PGF(1α), and PGF(2α) failed to alter CD86 expression levels, whereas other prostacyclin analogs were as potent as beraprost. Results carried out with receptor antagonists revealed that beraprost enhanced CD86 levels by binding to prostacyclin receptor IP and by increasing intracellular cAMP concentrations. Beraprost-treated B cells potently stimulated allogeneic T cells, which was significantly abolished by CD86 neutralization. Our data imply an unrecognized cellular and molecular mechanism about the germinal center reactions.

Rapakinin, Arg-Ile-Tyr, derived from rapeseed napin, shows anti-opioid activity via the prostaglandin IP receptor followed by the cholecystokinin CCK(2) receptor in mice

Rapakinin, Arg-Ile-Tyr, is a vasorelaxing, anti-hypertensive and anorexigenic peptide derived from rapeseed napin. In this study, we found that rapakinin intracerebroventricularly administered to mice inhibited the analgesic effect of morphine, evaluated by the tail-pinch test. The anti-opioid activity of rapakinin was blocked by LY225910, an antagonist of the cholecystokinin (CCK) CCK(2) receptor, but not by lorglumide, an antagonist of the CCK(1) receptor. The anti-opioid activity of rapakinin was also blocked by CAY10441, an antagonist of the prostaglandin (PG) IP receptor. These results suggest that the anti-opioid activity of rapakinin is mediated by the CCK(2) and IP receptors. The anti-opioid activity induced by ciprostene, an IP receptor agonist, was blocked by LY225910, while that of CCK-8 was not blocked by CAY10441. Thus, it is demonstrated that the CCK-CCK(2) system was activated downstream of the PGI(2)-IP receptor system. Taken together, rapakinin shows anti-opioid activity via the activation of the PGI(2)-IP receptor system followed by the CCK-CCK(2) receptor system.

Identification of a novel endoplasmic reticulum export motif within the eighth α-helical domain (α-H8) of the human prostacyclin receptor

The human prostacyclin receptor (hIP) undergoes agonist-dependent trafficking involving a direct interaction with Rab11a GTPase. The region of interaction was localised to a 14 residue Rab11a binding domain (RBD) within the proximal carboxyl-terminal (C)-tail domain of the hIP, consisting of Val(299)-Val(307) within the eighth helical domain (α-H8) adjacent to the palmitoylated residues at Cys(308)-Cys(311). However, the factors determining the anterograde transport of the newly synthesised hIP from the endoplasmic reticulum (ER) to the plasma membrane (PM) have not been identified. The aim of the current study was to identify the major ER export motif(s) within the hIP initially by investigating the role of Lys residues in its maturation and processing. Through site-directed and Ala-scanning mutational studies in combination with analyses of protein expression and maturation, functional analyses of ligand binding, agonist-induced intracellular signalling and confocal image analyses, it was determined that Lys(297), Arg(302) and Lys(304) located within α-H8 represent the critical determinants of a novel ER export motif of the hIP. Furthermore, while substitution of those critical residues significantly impaired maturation and processing of the hIP, replacement of the positively charged Lys with Arg residues, and vice versa, was functionally permissible. Hence, this study has identified a novel 8 residue ER export motif within the functionally important α-H8 of the hIP. This ER export motif, defined by "K/R(X)(4)K/R(X)K/R," has a strict requirement for positively charged, basic Lys/Arg residues at the 1st, 6th and 8th positions and appears to be evolutionarily conserved within IP sequences from mouse to man.

Optimal management of chronic cyclical pelvic pain: an evidence-based and pragmatic approach

This article reviews the literature on management of chronic cyclical pelvic pain (CCPP). Electronic resources including Medline, PubMed, CINAHL, The Cochrane Library, Current Contents, and EMBASE were searched using MeSH terms including all subheadings and keywords: "cyclical pelvic pain", "chronic pain", "dysmenorrheal", "nonmenstrual pelvic pain", and "endometriosis". There is a dearth of high-quality evidence for this common problem. Chronic pelvic pain affects 4%-25% of women of reproductive age. Dysmenorrhea of varying degree affects 60% of women. Endometriosis is the commonest pathologic cause of CCPP. Other gynecological causes are adenomyosis, uterine fibroids, and pelvic floor myalgia, although other systems disease such as irritable bowel syndrome or interstitial cystitis may be responsible. Management options range from simple to invasive, where simple medical treatment such as the combined oral contraceptive pill may be used as a first-line treatment prior to invasive management. This review outlines an approach to patients with CCPP through history, physical examination, and investigation to identify the cause(s) of the pain and its optimal management.

Eicosanoids in inflammation and cancer: the role of COX-2

Eicosanoids, a family of oxygenated metabolites of eicosapolyenoic fatty acids, such as arachidonic acid, formed via the lipoxygenase, cyclooxygenase (COX) and epoxygenase pathways, play an important role in the regulation of various pathophysiological processes, including inflammation and cancer. COX-2, the inducible isoform of COX, has emerged as the key enzyme regulating inflammation, and promises to play a considerable role in cancer. Although NSAIDs have been in use for centuries, the COX-2 selective inhibitors - coxibs - have emerged as potent anti-inflammatory drugs with fewer gastric side effects. As COX-2 plays a major role in neoplastic transformation and cancer growth, by downregulating apoptosis and promoting angiogenesis, invasion and metastasis, coxibs have a potential role in the prevention and treatment of cancer. Recent studies indicate their possible application in overcoming drug resistance by downregulating the expression of MDR-1. However, the cardiac side effects of some of the coxibs have limited their application in treating various inflammatory disorders and warrant the development of COX-2 inhibitors without side effects. This review will focus on the role of COX-2 in inflammation and cancer, with an emphasis on novel approaches to the development of COX-2 inhibitors without side effects.