Identification of blood leukotrienes in classical migraine

Consensus of the Brazilian Headache Society (SBCe) for prophylactic treatment of episodic migraine: part II

BACKGROUND

Migraine affects 1 billion people worldwide and > 30 million Brazilians; besides, it is an underdiagnosed and undertreated disorder.

OBJECTIVE

The need to disseminate knowledge about the prophylactic treatment of migraine is known, so the Brazilian Headache Society (SBCe, in the Portuguese acronym) appointed a committee of authors with the objective of establishing a consensus with recommendations on the prophylactic treatment of episodic migraine based on articles from the world literature as well as from personal experience.

METHODS

Meetings were held entirely online, with the participation of 12 groups that reviewed and wrote about the pharmacological categories of drugs and, at the end, met to read and finish the document. The drug classes studied in part II of this Consensus were: antihypertensives, selective serotonin reuptake inhibitors, serotonin and norepinephrine reuptake inhibitors, calcium channel blockers, other drugs, and rational polytherapy.

RESULTS

From this list of drugs, only candesartan has been established as effective in controlling episodic migraine. Flunarizine, venlafaxine, duloxetine, and pizotifen were defined as likely to be effective, while lisinopril, enalapril, escitalopram, fluvoxamine, quetiapine, atorvastatin, simvastatin, cyproheptadine, and melatonin were possibly effective in prophylaxis of the disease.

CONCLUSIONS

Despite an effort by the scientific community to find really effective drugs in the treatment of migraine, given the large number of drugs tested for this purpose, we still have few therapeutic options.

Redox Mechanisms in Migraine: Novel Therapeutics and Dietary Interventions

SIGNIFICANCE

Migraine represents the third most prevalent and the seventh most disabling human disorder. Approximately 30% of migraine patients experience transient, fully reversible, focal neurological symptoms (aura) preceding the attack. Recent Advances: Awareness of the hypothesis that migraine actually embodies a spectrum of illnesses-ranging from episodic to chronic forms-is progressively increasing and poses novel challenges for clarifying the underlying pathophysiological mechanisms of migraine as well as for the development of novel therapeutic interventions. Several theories have evolved to the current concept that a combination of genetic, epigenetic, and environmental factors may play a role in migraine pathogenesis, although their relative importance is still being debated.

CRITICAL ISSUES

One critical issue that deserves a particular attention is the role of oxidative stress in migraine. Indeed, potentially harmful oxidative events occur during the migraine attack and long-lasting or frequent migraine episodes may increase brain exposure to oxidative events that can lead to chronic transformation. Moreover, a wide variety of dietary, environmental, physiological, behavioral, and pharmacological migraine triggers may act through oxidative stress, with clear implications for migraine treatment and prophylaxis. Interestingly, almost all current prophylactic migraine agents exert antioxidant effects.

FUTURE DIRECTIONS

Increasing awareness of the role of oxidative stress and/or decreased antioxidant defenses in migraine pathogenesis and progression to a chronic condition lays the foundations for the design of novel prophylactic approaches, which, by reducing brain oxidative phenomena, could favorably modify the clinical course of migraine. Antioxid. Redox Signal. 28, 1144-1183.

Urinary leukotriene E4 and prostaglandin F2a concentrations in children with migraine: a randomized study

OBJECTIVES

Pro-inflammatory mediators are thought to play both peripheral and central roles in migraine pathophysiology. Prostaglandins and leukotrienes, known as the eicosanoids, are degradation products of arachidonic acid and constitute signalization components of inflammatory pathways. This study was designed to assess concentrations of leukotriene E4 (LT-E4) and prostaglandin F2a (PG-F2a) in children with migraine.

MATERIALS AND METHODS

This study involved patients aged ≤18 years who presented to the Ondokuz Mayis University Children's Hospital with migrainous headache between January and October 2011. Urinary LT-E4 and PG-F2a concentrations were measured in patients during a headache episode and at a headache-free time and in a control group.

RESULTS

The patient group consisted of 38 girls and 26 boys aged 5-18 years diagnosed with migraine and having at least 6 months of headache, whereas the control group consisted of 21 girls and 29 boys. Mean ± standard deviation (SD) urinary LT-E4 concentrations were significantly higher in patients during a migraine episode than in controls (1466.8±1052.5 pg/ml vs 811.6±460.0 pg/ml, P<0.001). In patients with migraine, both urinary LT-E4 (P<0.001) and PG-F2a (P=0.021) levels were significantly higher during headache than during non-headache periods.

CONCLUSION

Urinary LT-E4 and PG-F2a were both significantly higher in children with migraine during headache than during non-headache periods. The elevation in the levels of these inflammatory mediators was compatible with the hypothesis relating neuroinflammation in trigeminal vascular blood vessels with migraine pathophysiology. Leukotriene antagonists may be effective in the prophylaxis of migraine attacks.

Biological correlates of migraine and cluster headaches: an overview of their potential use in diagnosis and treatment

Current diagnostic criteria for headaches are based on the International Classification for Headache Disorders, second edition, which is largely built on data obtained from clinical examinations and patients' medical histories. Despite decades of vigorous basic and clinical research, we still lack reliable clinical laboratory diagnostic markers for headaches, which clearly obstructs the physician's ability to optimize and follow the patient's response to treatment protocols as well as holds back the discovery and implementation of new therapeutic modalities. In this paper, we review and discuss current efforts to identify and characterize biochemical and immunological changes in biological fluids and tissue that may be specifically associated with the etiology and/or pathophysiology of migraine and cluster headaches; we also discuss some of the recent genetic findings and ion channel modulation studies that may help to distinguish among various headache populations.

The effect of aqueous garlic extract on the levels of arachidonic acid metabolites (leukotriene C4 and prostaglandin E2) in rat forebrain after ischemia-reperfusion injury

Leukotriene C4 (LTC4) and prostaglandin E2 (PGE2) are known to be highly potent cerebral vasoconstrictors which are formed from arachidonic acid (AA). They enhance vascular permeability, inducing vasogenic edema that may damage the ischemic penumbra after ischemia and reperfusion. The inhibitory effect of aqueous garlic extract (AGE) on AA metabolism in human platelets is known. In this study, following the global ischemic model application to the rats, all underwent 10 min ischemia and were reperfused for different periods. The levels of LTC4 and PGE2 in rat forebrain were then measured. One rat group consisted of 8 rats. In the combined reperfused groups both metabolites increased significantly when compared with the 10 min ischemia alone, no reperfusion group (p < 0.05). In the 8 min reperfused group, PGE2 and LTC4 levels increased significantly at 60 min of reperfusion compared with each corresponding control group (P < 0.005). PGE2 and LTC4 levels were reduced significantly at 60 min of reperfusion compared with the 8 min reperfused group (P < 0.005). AGE (1 ml/kg) reduced both LTC4 and PGE2 levels significantly in the 8 min and 60 min reperfused group (P < 0.001, P < 0.001, P < 0.05, P < 0.01). In conclusion, AGE reduced LTC4 and PGE2 levels at a dosage of 1 ml/kg following 8 and 60 min reperfusion. It may be helpful in reducing AA metabolite levels and preventing injury after ischemic phenomena.

Tolfenamic acid and migraine--aspects on prostaglandins and leukotrienes

Migraine is a paroxysmal disorder characterized by recurrent attacks of headache, with or without associated visual and gastrointestinal disturbances. Migraine can be classified in two main groups, common and classic. Theories trying to explain the pathogenesis of a migraine attack may emphasize either the central or peripheral aspects of the disease. The vascular theory may stress the importance of either central or peripheral blood flow or both. Cerebral vasoconstriction in the early phases of the attack is followed by vasodilatation and pain. Biochemical mediators of vascular responses are not exactly known, but platelets and 5-hydroxytryptamine and thromboxane released from them as well as noradrenaline are potent vasoconstrictors, while kinins and prostaglandins can explain the vasodilatory phase of migraine attacks. This review presents evidence for the role of arachidonic acid metabolites, prostaglandins and leukotrienes in migraine. The evidence comes from the measurements of eicosanoids in biological fluids during and after the attack, infusion studies where vasodilatory prostaglandins mimic the migraneous symptoms, and the good effect of non-steroidal anti-inflammatory drugs in the treatment and prophylaxis of migraine attacks. Additional data are based on experimental biochemical studies in which catecholamines and indolamines have been shown to increase the synthesis of vasodilatory prostaglandins. However, the final evidence still awaits its confirmation.

The effect of nordihydroguaiaretic acid on leukotriene C4 and prostaglandin E2 production following different reperfusion periods in rat brain after forebrain ischemia correlated with morphological changes

Leukotriene C4 (LTC4) and prostaglandin E2 (PGE2) are the 5-lipoxygenase and cyclooxygenase metabolites of arachidonic acid (AA). They constrict blood vessels and enhance vascular permeability inducing vasogenic edema that may hurt the ischemic penumbra after cerebral ischemia and reperfusion. Nordihydroguaiaretic acid (NDGA) is known as the most potent inhibitor of 5-lipoxygenase in different tissues. Furthermore, it has considerable inhibitory activity against cyclooxygenase. In this study, after developing a global ischemic model in the rat, the levels of LTC4 and PGE2 in the forebrain were measured, following different reperfusion periods after 10 min ischemia including 8 rats for each reperfused group. Sham operations were performed for each corresponding control group (n = 8). AA metabolites were then correlated with neuropathological findings. In the combined reperfused groups both metabolites increased significantly when compared with 10 min, ischemic group (P < 0.05). In the 8 min reperfused group, PGE2 and LTC4 increased significantly compared with each corresponding control group (P < 0.005). These mediators also increased to high levels compared with the 4 min reperfused group (P < 0.05, P < 0.005). PGE2 and LTC4 were reduced significantly at the 15th and 60th min of reperfusion compared with the 8 min reperfused group (P < 0.05, P < 0.005). NDGA (0.1 mg/kg) reduced both metabolites in the 8 min reperfused group significantly (P < 0.05). Brain cortex specimens were taken for light and electromicroscopical investigations. No significant differences were noted between the structural changes in the 4, 8 and 15 min of reperfusion and NDGA administered groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Prostaglandin E2 and leukotriene C4 levels following different reperfusion periods in rat brain correlated with morphological changes

Prostaglandin E2 (PGE2) and leukotriene C4 (LTC4) are the metabolites of arachidonic acid (AA) that increase in forebrain following global ischemia and reperfusion. These mediators are highly potent vasoconstrictors of cerebral arteries leading to enhanced vascular permeability that induces the formation of vasogenic edema. In this study, after developing an experimental animal model simulating the concept of ischemic penumbra in the rat, the levels of PGE2 and LTC4 produced in the forebrain were measured and the effects of these mediators in short duration and prolonged reperfusion were investigated and then correlated with neuropathological findings. We found statistically significant reduction both in PGE2 and LTC4-like activities after just 10 min ischemia (p less than 0.05, p less than 0.05). PGE2-like activity significantly increased in the 4th and 60th min of reperfusion (p less than 0.05, p less than 0.05). In the 15th min of reperfusion, PGE2 was found to be significantly reduced (p less than 0.005) that may be due to the formation of free oxygen radicals by activation of PG hydroperoxidase reaction that inhibits PGE2 production in the cyclooxygenase pathway. LTs were not significantly increased in any reperfused group. Inhibition of the lipoxygenase pathway of AA metabolism may occur as a result of 15-HPETE (15-hydroperoxyeicosatetraenoic acid) production. Pathologically, edema and degeneration of brain tissue were seen beginning from the 4th min of reperfusion that reached a peak in the 60th min of reperfusion which is in accordance with biochemical changes in the damaged tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Leukotriene C4 and prostaglandin E2 activities in the serum and cerebrospinal fluid during acute cerebral ischemia

Lipoxygenase pathway products of arachidonic acid (AA) metabolism (known as leukotrienes, LTs) are produced in the brain during pathologic conditions such as ischemia, hemorrhage, trauma, and seizure in which the release of AA is sustained by the activation of local phospholipases. The most common type of LT in the central nervous system is an LTC4 which is a highly potent vasoconstrictor leading to increase in vascular permeability. In this study, we compared the serum (S) and cerebrospinal fluid (CSF) prostaglandin E2 (PGE2) and LTC4 levels in 13 consecutively admitted patients with acute cerebral ischemia aged 55-80 years with 10 age-matched controls. Patients with previous glucocorticosteroid and antiinflammatory drug usage were not included in the study. S and CSF samples were drawn during the first 72 h of the attack, and samples were evaluated by bioassay. There was no significant difference in S PGE2 and LTC4 values, whereas a significant difference was observed between CSF PGE2 and LTC4 values as compared with the control group. The high levels of CSF PGE2 and LTC4-like activity in acute cerebral ischemia may indicate that these mediators have a role to play in cerebral edema. The CSF PGE2/LTC4 ratio was also found to be reduced in the ischemic group implying higher LTC4 synthesis than PGE2 synthesis. In the light of these findings, we suggest that use of a selective antagonist of LTs may be helpful in reducing the ischemic penumbra during acute cerebral ischemia by controlling the vasogenic edema.

The alterations of leukotriene C4 and prostaglandin E2 levels following different ischemic periods in rat brain tissue

Leukotrienes and prostaglandins are formed from arachidonic acid by activation of local phospholipases in pathological conditions such as cerebral ischemia, subarachnoid hemorrhage, cerebral tumors and seizures. These mediators, especially leukotrienes have a very potent vasoconstrictor effect on cerebral arteries. Experimental studies have shown that this effect, by increasing vascular permeability causes vasogenic edema that contributes to the ischemic penumbra. In this study, after developing an experimental animal model simulating the concept of ischemic penumbra in the rat, the levels of leukotriene C and prostaglandin E2 produced in the forebrain were measured and the effects of these mediators in prolonged ischemia were investigated. The results, in the first 4 min of ischemia, showed that the arachidonic acid metabolites, particularly, leukotriene C4, reached a peak in the ischemic cerebral tissue in association with leukocyte accumulation. Later in the 15th min, significant decreases in leukotriene C4 and prostaglandin E2 levels were seen. In the 1st and 4th h, probably due to the stimulation of the relevant enzymes by free oxygen radicals in the ischemic tissue; the levels increase again, returning to control values by the 12th h. It is concluded that the use of lipoxygenase inhibitors and free radical scavengers may be helpful to limit the infarct area in the first 4 h of ischemia.

Eicosanoids in primary dysmenorrhea, endometriosis and menstrual migraine

This paper summarizes what has been learned over the years about the role of eicosanoids in the pathogenesis of primary dysmenorrhea, endometriosis and menstrual migraine. The role of prostaglandins (PGs) in the pathogenesis of primary dysmenorrhea is inferred from four main observations: firstly, the clinical symptoms of primary dysmenorrhea are similar to those induced by the administration of PGF2 alpha and PGE2 for the induction of labour; secondly, the increased production of PGs by the endometrium during the luteal and menstrual phases of ovulatory cycles is consistent with the occurrence of primary dysmenorrhea mainly in ovulatory cycles; thirdly, the concentrations of PGF2 alpha and PGE2 in the endometrium and menstrual fluid of dysmenorrheic women are significantly higher than in controls; fourthly, certain PG inhibitors have been proved to be effective in the treatment of dysmenorrhea. The change in PG production can explain the major symptoms of primary dysmenorrhea, including the increased uterine contractility, uterine ischemia and the lowering of the pain threshold to chemical and physical stimuli in the pelvic nerve terminals. Moreover, recent experimental data suggest that leukotrienes (LTs) might be among the alternative pathogenetic causes of primary dysmenorrhea. The data which support a relationship between eicosanoids and endometriosis are as follows: endometriotic tissue produces PGs; the peritoneal fluid concentration of PGF2 alpha increases significantly after the induction of endometriosis in laboratory animals; the concentration of PGs in peritoneal fluid of some patients with endometriosis is greater than in controls and, finally, the number and activation of pelvic macrophages which are able to synthesize eicosanoids increase in patients with endometriosis. Possible roles for eicosanoids in the pathogenesis of infertility and secondary dysmenorrhea induced by endometriosis have been suggested. Eicosanoids are probably also involved in the pathogenesis of menstrual migraine. Different types of PGs might play a role both in the initial vasoconstriction during the prodromal phase of migraine and in the vasodilation and sensitization to pain typical of the pain phase.