Does fructose have a protective role on migraine?-experimental evidence in a rat model of metabolic syndrome under omega-3 supplementation.

Background: Migraine is a highly disabling disease, for which current therapies are limited to symptom alleviation. There is compelling evidence linking migraine with metabolic disorders, but the causal relationship is not clear. Omega-3 (n-3) fatty acids have anti-inflammatory properties, with clear benefits in metabolic disorders, but its effects on migraine remains to be tested. We hypothesized that fructose-induced metabolic syndrome could aggravate migraine by increasing neuroinflammation and that n-3 treatment could mitigate it. Methods: Male Wistar rats were used. Animals that received 10% high fructose diet (HFD) or tap water were subdivided into two additional groups: with or without n-3 supplementation. Fifteen days before euthanasia, each group was subdivided into two additional groups: with or without nitroglycerin (NTG)-induced migraine. Results: HFD lessened the migraine-like painful symptoms, as indicated by decreased grimace scores, which paralleled with reduced CGRP and leptin serum levels, increased hypothalamic CGRP, and decreased hypothalamic adiponectin and IL-6. There was a recovery of body and adipose tissue weight, besides a reduction of crown-like structures (CLS) in the inguinal adipose tissue. N-3 supplementation had no effect on NTG-related pain, but it decreased body and adipose tissue weight of HFD and tap water NTG-injected rats. N-3 improved NTG-related affective behavior and inflammatory parameters in tap water NTG-injected rats, with decreased hypothalamic TNF, serum CGRP and inguinal adipose-tissue CLS. Conclusions: HFD relieved NTG-induced pain, possibly due to decreased energy expenditure, minimizing migraine energy needs. N-3 exhibited favorable effects regarding affective behavior and central and peripheral inflammation, irrespective of HFD.

Chronic Pain in the Elderly: Mechanisms and Perspectives.

Chronic pain affects a large part of the population causing functional disability, being often associated with coexisting psychological disorders, such as depression and anxiety, besides cognitive deficits, and sleep disturbance. The world elderly population has been growing over the last decades and the negative consequences of chronic pain for these individuals represent a current clinical challenge. The main painful complaints in the elderly are related to neurodegenerative and musculoskeletal conditions, peripheral vascular diseases, arthritis, and osteoarthritis, contributing toward poorly life quality, social isolation, impaired physical activity, and dependence to carry out daily activities. Organ dysfunction and other existing diseases can significantly affect the perception and responses to chronic pain in this group. It has been proposed that elderly people have an altered pain experience, with changes in pain processing mechanisms, which might be associated with the degeneration of circuits that modulate the descending inhibitory pathways of pain. Aging has also been linked to an increase in the pain threshold, a decline of painful sensations, and a decrease in pain tolerance. Still, elderly patients with chronic pain show an increased risk for dementia and cognitive impairment. The present review article is aimed to provide the state-of-art of pre-clinical and clinical research about chronic pain in elderly, emphasizing the altered mechanisms, comorbidities, challenges, and potential therapeutic alternatives.

Central and peripheral effects of environmental enrichment in a mouse model of arthritis.

This study analyzed whether environmental enrichment (EE) modulates the nociceptive and inflammatory responses in the mouse model of arthritis induced by Complete Freund's Adjuvant (CFA). Ninety male mice (C57BL/6-JUnib, 4-weeks-old; 20-25 g) were distributed into EE and standard (SE) groups. For EE, mice were kept in bigger cages using an alternation of materials to chew (wood and paper), for nesting (cotton), to use as hiding places (plastic tunnels), and for voluntary exercise (wheel running). Arthritis was induced by an injection of CFA (50 µL) into the right hind paw or saline solution in the control group. Separate groups received the anti-inflammatory drug dexamethasone (0.5 mg/kg; every 48 h). Inflammatory and pain measurements were performed from 1 to 35 days after CFA administration. EE per se reduced the acute paw edema formation and arthritis scores. The serum levels of tumor necrosis factor (TNF) were undetectable in any experimental groups. EE diminished the immunopositivity for the microglia marker IBA1 in the pre-frontal cortex, with slight changes for hippocampal GFAP-positive activated astrocytes. Finally, EE induced a marked increment of brain-derived nerve factor (BDNF) expression in the hippocampus, an effect that was fully prevented by dexamethasone. These data bring novel evidence on the peripheral and central effects of EE in a mouse arthritis model.

Psychological symptoms and salivary inflammatory biomarkers in patients with dentofacial deformities: a case-control study.

Individuals with dentofacial deformities often display a low quality of life (QoL) through biological mechanisms that remain unraveled. In this case-control study, the salivary levels of cytokines, glutamate, and kynurenine metabolites were assessed in patients undergoing orthognathic surgery (OS), while correlating these parameters with QoL and psychological symptoms. Thirty-six patients were enrolled in control (under orthodontic treatment) and test (undergoing OS) groups, matched by age and sex. The QoL was assessed through the World Health Organization Quality of Life BREF (WHOQOL-BREF) and the Orthognathic Quality of Life Questionnaire (OQLQ). The psychological symptoms were evaluated by the Satisfaction with Life Scale, the Rosenberg Self-Esteem Scale (RSES), and the Depression, Anxiety, and Stress Scale-21 (DASS-21). The salivary levels of IL-1ß, IL-6, IL-10, glutamate, and kynurenine metabolites were evaluated. The OQLQ demonstrated increased QoL scores in the test group, regarding social aspects, facial esthetics, and function domains, without significant differences in respect to the other surveys. These patients displayed higher IL-1ß and glutamate levels; conversely, the kynurenine metabolites were unaltered. The glutamate levels positively correlated with the OQLQ function scores. The data brings novel evidence about the psychobiological features of patients with dentofacial deformities, showing salivary variations of inflammatory biomarkers in these individuals.

The role of kinin B1 and B2 receptors in the mouse model of oxazolone-induced atopic dermatitis.

This study evaluated the role of kinin B1 and B2 receptors in the pre-clinical mouse model of oxazolone-induced atopic dermatitis. The B1 R715 or B2 HOE140 receptor antagonists were dosed at different schemes of treatment. After assessment of clinical lesion scores and pruritus, lesional skin samples were collected for histopathological analysis. The plasma extravasation and the expression of the metalloproteinase ADAMTS5 were also assessed. The immunopositivity for kinin receptors was evaluated in the skin, dorsal root ganglion (DRG), thoracic spinal cord and brain cortex sections. Marked upregulation of B1 and B2 receptors was observed in the skin of oxazolone-treated mice. The induction of atopic dermatitis led to a downregulation of both receptors in the DRG, without any alteration in the spinal cord and brain cortex. The repeated administration of HOE140 (50 nmol/kg; i.p.) partially inhibited the oxazolone-related pruritus, associated with a reduction of ADAMTS5 immunolabelling in the skin. Alternatively, R715 (438 nmol/kg; i.p.) produced a mild inhibition of plasma extravasation in oxazolone-challenged mice. Noteworthy, the repeated i.d. injection of R715 (30 nmol/site) or HOE140 (3 nmol/site) significantly reduced the histiocyte numbers, according to the histopathological analysis. Either B1 or B2 kinin antagonists, irrespective of the protocol of treatment, did not alter any other evaluated clinical or histological parameters. Data brings novel evidence about the role of kinin receptors in allergy-related conditions, such as atopic dermatitis. Further studies to test different protocols of treatment with kinin antagonists on in-depth cellular alterations underlying oxazolone-induced atopic dermatitis remain to be performed.