Some oxidative and antioxidative parameters and their relationship with clinical symptoms in women with fibromyalgia syndrome

Ameliorative effect of nano-pregabalin in gastrocnemius muscle of gamma irradiated rats with an experimental model of fibromyalgia: Crosstalk of Sirt3, IL-1β and PARP1 pathways

BACKGROUND

Fibromyalgia (FM) is a complex syndrome with somatic symptoms connected to the operational state of muscles. Although radiotherapy is a cornerstone in cancer treatment, it is implicated in the aggravation of FM. Lately, formulation of medicines in nano-forms become of great prominence due to their prospective applications in medicine. So, this study aimed to assess possible therapeutic benefits of formulating pregabalin in a nono-form (N-PG) for managing FM during exposure to gamma radiation.

METHODS

Gamma rays administered in fractionated doses (2 Gy/day) to male rats after one hour of s.c. injection of reserpine (1 mL/kg per day) to induce FM, then treated with single daily dose of (30 mg/kg, p.o.) PG or N-PG for ten successive days. Rats were subjected to behavioral tests, then sacrificed to obtain serum and gastrocnemius muscles.

RESULTS

N-PG significantly antagonized reserpine-induced FM as proved by; the immobility and performance times in forced swim and rotarod performance tests, respectively were restored near to the normal time, serum IL-8 and MCP-1 chemokines were nearby the normal levels, mitigated oxidative stress through increasing total thiol, Sirt3, CAT enzyme and decreasing COX-1, inhibition of inflammation via IL-1β and MIF significant reduction, it possessed anti-apoptotic effect verified by decreasing PARP-1 and increasing Bcl-XL, gastrocnemius muscles had minimal fibrosis levels as seen after Masson trichrome staining. Histopathological results were coincidence with biochemical inspection.

CONCLUSION

This study identifies N-PG as a novel drug that could be of a value in the management of FM particularly in cancer patients undergoing radiotherapy.

Pharmacotherapeutic advances in fibromyalgia: what's new on the horizon?

INTRODUCTION

This review delves into Fibromyalgia Syndrome (FMS), a chronic pain condition demanding thorough understanding for precise diagnosis and treatment. Yet, a definitive pharmacological solution for FMS remains elusive.

AREAS COVERED

In this article, we systematically analyze various pharmacotherapeutic prospects for FMS treatment, organized into sections based on the stage of drug development and approval. We begin with an overview of FDA-approved drugs, discussing their efficacy in FMS treatment. Next, we delve into other medications currently used for FMS but still undergoing further study, including opioids and muscle relaxants. Further, we evaluate the evidence behind medications that are currently under study, such as cannabinoids and naltrexone. Lastly, we explore new drugs that are in phase II trials. Our research involved a thorough search on PUBMED, Google Scholar, and clinicaltrials.gov. We also discuss the action mechanisms of these drugs and their potential use in specific patient groups.

EXPERT OPINION

A focus on symptom-driven, combination therapy is crucial in managing FMS. There is also a need for ongoing research into drugs that target neuroinflammation, immunomodulation, and the endocannabinoid system. Bridging the gap between benchside research and clinical application is challenging, but it holds potential for more targeted and effective treatment strategies.

Pelvic pain symptoms and endometriosis characteristics in relation to oxidative stress among adolescents and adults with and without surgically-confirmed endometriosis

Background: While the majority of reproductive-aged females will experience pelvic pain during their lives, biological mechanisms underlying pelvic pain are not well understood. We investigated associations between pelvic pain symptoms and oxidative stress among people with and without surgically-confirmed endometriosis. Methods: Using an enzyme-linked immunosorbent assay, we measured 8-Hydroxy-2'-deoxyguanosine (8-OHdG) in urine samples and corrected for creatinine levels in 434 surgically-confirmed endometriosis participants compared to 605 participants never diagnosed with endometriosis. At enrollment, participants reported details of their pelvic pain symptoms. Linear regression was used to compute geometric mean (GM) creatinine-corrected 8-OHdG levels with 95% confidence intervals (CI) among all participants and those with and without endometriosis separately, adjusting for potential confounders. Interactions by surgically-confirmed endometriosis status were tested by Wald statistics. Results: No trends in 8-OHdG were observed among those with or without endometriosis for severity or frequency of dysmenorrhea, acyclic pelvic pain, dyspareunia or pain with bowel movements. Among endometriosis participants, lower 8-OHdG levels were observed for participants with any white, blue/black, or brown lesions (GM=76.7 versus 82.9 ng/mg; p=0.10), which was primarily driven by lower levels of 8-OHdG for any blue/black lesions (GM=72.8 versus 81.6 ng/mg; p=0.05). Conclusion: While no associations were observed between 8-OHdG and pelvic pain symptoms, future research is needed to assess how other pathways of oxidative damage, e.g. through proteins or lipids, may affect endometriosis-associated symptoms. Additionally, further research is needed to understand differences in oxidative stress among endometriosis lesion sub-phenotypes.

Implication of intestinal microbiota in the etiopathogenesis of fibromyalgia: A systematic review

Fibromyalgia (FM) is a highly prevalent chronic disease. About 4.7% of the world's population suffers from generalized pain and hypersensitivity, in addition to a wide range of physical and psychological symptoms. The etiopathogenesis of this disease is multifactorial, which makes its diagnosis and treatment challenging. Recently, the increase in the number of studies on microbiota has provided new data that can help to understand the onset and development of FM. An updated systematic review of the causes of FM has been carried out in this work. Particularly in the last decade, research has focused on the gut-brain axis, which has emerged as a crucial mechanism for microbiota-host crosstalk. In FM patients, quantitative imbalances of the intestinal microbiota (dysbiosis) and bacterial metabolites with differential relative abundance have been found, especially short-chain fatty acids and lipopolysaccharides. Furthermore, the microbiota has been found to indirectly influence host neurotransmitter mechanisms, mainly through the serotonin precursor, glutamate, and gamma-aminobutyric acid. Thus, all these mechanisms and their influence on the etiopathogenesis of FM are discussed in this review.

Prevalence of tinnitus in juvenile fibromyalgia patients visiting a pediatric rheumatology clinic

Juvenile fibromyalgia (JFMS) is a common disorder in the adolescent population with a prevalence of 1-6%. Our study looked at the prevalence of tinnitus in JFMS patients seen at a pediatric rheumatology clinic between 2016 and 2021. The objective of this study was to retrospectively assess prevalence of tinnitus and compare that with prevalence in non- JFMS patients presenting to the clinic. We also assessed prevalence of other sensory and pain symptoms, Widespread pain index >6 and abdominal pain in these two groups. Of the 290 forms evaluated, tinnitus was present in 31.1 % of JFMS subjects, versus only 3.5 % in non-JFMS subjects. There was a significant association between tinnitus and tingling and numbness among subjects with JFM (p = 0.005). On logistic regression analysis, the odds of having JFMS were 5.2 times higher among tinnitus patients compared to non-tinnitus (p = 0.003, 95 % CI 1.77-15.55). Tingling/numbness were also associated with 21.78 times increased odds for diagnosis of JFMS (p = 0.0003, 95 % CI 4.05-117.21). The odds of having JFMS were 22.6 times higher among patients with Widespread Pain Index >6 (p < 0.0001, 95 % CI 7.88-64.71). Tinnitus is a commonly prevalent condition in patients with JFMS. In patients with JFMS, there is a significant association between tinnitus and tingling/numbness. Further studies are needed to explore the underlying pathogenesis of these symptoms.

Skin Bioimpedance Analysis to Determine Cellular Integrity by Phase Angle in Women with Fibromyalgia: A Cross-Sectional Study

Oxidative stress has been proposed as a significant part of the pathogenesis of fibromyalgia, and the phase angle in bioelectrical impedance analysis has been explored as a potential technique to screen oxidative abnormalities. This study recruited 35 women with fibromyalgia and 35 healthy women, who underwent bioelectrical impedance analysis and maximum isometric handgrip strength tests. Women with fibromyalgia showed lower bilateral handgrip strength (right hand: 16.39 ± 5.87 vs. 27.53 ± 4.09, p < 0.001; left hand: 16.31 ± 5.51 vs. 27.61 ± 4.14, p < 0.001), as well as higher body fat mass (27.14 ± 10.21 vs. 19.94 ± 7.25, p = 0.002), body fat percentage (37.80 ± 8.32 vs. 30.63 ± 7.77, p < 0.001), and visceral fat area (136.76 ± 55.31 vs. 91.65 ± 42.04, p < 0.01) compared with healthy women. There was no statistically significant difference in muscle mass between groups, but women with fibromyalgia showed lower phase angles in all body regions when compared with healthy control women (right arm: 4.42 ± 0.51 vs. 4.97 ± 0.48, p < 0.01; left arm: 4.23 ± 0.48 vs. 4.78 ± 0.50, p < 0.001; trunk: 5.62 ± 0.77 vs. 6.78 ± 0.84, p < 0.001; right leg: 5.28 ± 0.56 vs. 5.81 ± 0.60, p < 0.001; left leg: 5.07 ± 0.51 vs. 5.69 ± 0.58, p < 0.001; whole body: 4.81 ± 0.47 vs. 5.39 ± 0.49, p < 0.001). Moreover, whole-body phase-angle reduction was only predicted by the presence of fibromyalgia (R2 = 0.264; β = 0.639; F(1,68) = 24.411; p < 0.001). Our study revealed significantly lower phase angle values, lower handgrip strength, and higher fat levels in women with fibromyalgia compared to healthy controls, which are data of clinical relevance when dealing with such patients.

Effectiveness of traditional Chinese exercise in patients with fibromyalgia syndrome: A systematic review and meta-analysis of randomized clinical trials

BACKGROUND AND OBJECTIVE

Fibromyalgia syndrome (FMS) is a common disorder characterized by heterogeneous symptoms that leads to decreased functioning, work productivity, and quality of life. Exercise has been recommended for fibromyalgia treatment. Traditional Chinese exercise (TCE), including Taichi, Qigong, Badunjin, Wuqinxi, etc., as a kind of mind-body exercise, plays an important role in alleviating symptoms of FMS. The objective of this study is to summarize the available evidence, through meta-analysis, on the pain relief, quality of life, sleep improvement, and emotion regulation of FMS in TCE.

METHODS

Databases of PubMed, EMBASE, Cochrane library, Google scholar, CNKI, WANFANG DATA, VIP, etc. were used to search eligible studies that were published from the time of their inception to February 11, 2022, in English and Chinese. The included studies were divided into two groups: TCE group (experimental group) and control group. The Cochrane collaboration's tool was used to assess the risk of bias, and Revman5.4.1 software was used to synthesize and analyze the data.

RESULTS

A total of 12 literatures were included in this study, which contained 781 patients, and 448 of them were included in the treatment group, 333 of others in control group. TCE significantly alleviated pain [SMD = -0.83, 95% CI (-1.15, -0.51), p < .00001], improved quality of life [SMD = -0.53, 95% CI (-0.86, -0.19), p = .002] and improved qualities of sleep [SMD = -0.41, 95% CI (-0.57, -0.24), p < .00001] and relieved depression [SMD = -0.40, 95% CI (-0.69, -0.10), p < .008].

CONCLUSION

TCE may be a way to reduce pain, improve the quality of life and sleep, and relieve depression for FMS, and it could be part of the FMS treatment.

Microbiota and Mitochondrial Sex-Dependent Imbalance in Fibromyalgia: A Pilot Descriptive Study

Fibromyalgia is a widespread chronic condition characterized by pain and fatigue. Among the long list of physiological disturbances linked to this syndrome, mitochondrial imbalance and oxidative stress stand out. Recently, the crosstalk between mitochondria and intestinal microbiota has caught the attention of biomedical researchers, who have found connections between this axis and several inflammatory and pain-related conditions. Hence, this pilot descriptive study focused on characterizing the mitochondrial mass/mitophagy ratio and total antioxidant capacity in PBMCs, as well as some microbiota components in feces, from a Peruvian cohort of 19 females and 7 males with FM. Through Western blotting, electrochemical oxidation, ELISA, and real-time qPCR, we determined VDAC1 and MALPLC3B protein levels; total antioxidant capacity; secretory immunoglobulin A (sIgA) levels; and Firmicutes/Bacteroidetes, Bacteroides/Prevotella, and Roseburia/Eubacterium ratios; as well as Ruminococcus spp., Pseudomonas spp., and Akkermansia muciniphila levels, respectively. We found statistically significant differences in Ruminococcus spp. and Pseudomonas spp. levels between females and males, as well as a marked polarization in mitochondrial mass in both groups. Taken together, our results point to a mitochondrial imbalance in FM patients, as well as a sex-dependent difference in intestinal microbiota composition.

A Comprehensive Review of the Genetic and Epigenetic Contributions to the Development of Fibromyalgia

This narrative review summarizes the current knowledge of the genetic and epigenetic contributions to the development of fibromyalgia (FM). Although there is no single gene that results in the development of FM, this study reveals that certain polymorphisms in genes involved in the catecholaminergic pathway, the serotonergic pathway, pain processing, oxidative stress, and inflammation may influence susceptibility to FM and the severity of its symptoms. Furthermore, epigenetic changes at the DNA level may lead to the development of FM. Likewise, microRNAs may impact the expression of certain proteins that lead to the worsening of FM-associated symptoms.

Relationship Between Vitamin D Receptor Gene BsmI Polymorphism and Fibromyalgia Syndrome

Purpose

Vitamin D receptor (VDR) has been proposed as a possible marker for fibromyalgia syndrome (FMS). The purpose of this study is to characterize the expression pattern of BsmI polymorphism (rs1544410) in the VDR gene in women with FMS and the genotype-phenotype association.

Methods

A total of 105 FMS patients and 105 controls were included in this study. VDR gene BsmI polymorphism was assessed by polymerase chain reaction (PCR) and restriction fragment length polymerase (RFLP) method.

Results

There was no significant difference in the frequency distribution of both genotypes and alleles for VDR gene BsmI polymorphism between FMS patients and controls (p>0.05). The frequencies of BB, Bb, and bb in the VDR gene BsmI polymorphism were 19%, 43%, and 37% in patients, while in controls were 22.9%, 55.2%, and 21.9%. However, we did not find any significant association between the clinical symptoms of this disease and VDR BsmI genotypes among FMS patients (p>0.05).

Conclusions

The relationship between the VDR gene BsmI polymorphism and FMS could not be determined in this study. However, further studies with a larger sample size may be required to show a relation between the VDR gene BsmI polymorphism and FMS.

The relationship between dietary total antioxidant capacity, clinical parameters, and oxidative stress in fibromyalgia syndrome: A novel point of view

Objectives

This study aims to reveal the relationship between serum total antioxidant status (TAS), clinical parameters, and nutrition (dietary total antioxidant capacity [TAC]) in patients with fibromyalgia.

Patients and methods

This cross-sectional study was conducted with a total of 60 female participants (mean age: 44.7±9.7 years; range, 18 to 50 years) at Gaziler Physical Medicine and Rehabilitation Hospital between July 2020 and February 2021. Thirty female patients with fibromyalgia were compared with 30 age-, sex-, and body mass index-matched healthy individuals. The short-form McGill Pain Questionnaire, Fibromyalgia Impact Questionnaire (FIQ), and Pittsburg Sleep Quality Index were used. Total antioxidant status, total oxidant status (TOS), and oxidative stress index (OSI) were measured. Dietary TAC was calculated using the ferric reducing ability of plasma according to a food frequency questionnaire.

Results

Total antioxidant status showed no significant difference between groups (p=0.080). Total oxidant status and OSI were significantly higher in the patient group (p<0.001 and p=0.005, respectively). The mean dietary TAC was 16.5±6.5 in the patient group and 17.2±6.2 in the control group, and it was similar between groups (p=0.492). Pittsburg Sleep Quality Index global score was significantly higher in the patient group than in the control group (p<0.001). Dietary TAC showed a moderate positive correlation with serum TAS in both groups (r=0.373, p=0.042 for the patient group, and r=0.380, p=0.038 for the control group). In the patient group, TOS and OSI showed a moderate positive correlation with FIQ total scores (r=0.420, p=0.021 and r=0.450, p=0.013, respectively). The mean polyunsaturated fatty acid and omega-6 intake of the patient group was significantly lower than the control group (p=0.025 for both). Dietary antioxidant intake from vegetables (p=0.025), legumes/nuts (p=0.049), and meat (p<0.001) was significantly lower, whereas dietary antioxidant intake from cereal and potatoes was significantly higher in the patient group compared to the control group (p=0.028).

Conclusion

The results indicate that oxidative stress can be reduced by increasing dietary antioxidant intake in fibromyalgia.

Effects of Antioxidants on Pain Perception in Patients with Fibromyalgia-A Systematic Review

In recent years, antioxidant supplements have become popular to counteract the effects of oxidative stress in fibromyalgia and one of its most distressing symptoms, pain. The aim of this systematic review was to summarize the effects of antioxidant supplementation on pain levels perceived by patients diagnosed with fibromyalgia. The words used respected the medical search terms related to our objective including antioxidants, fibromyalgia, pain, and supplementation. Seventeen relevant articles were identified within Medline (PubMed), Scopus, Web of Science (WOS), the Cochrane Database of Systematic Review, and the Cochrane Central Register of Controlled Trials. This review found that antioxidant supplementation is efficient in reducing pain in nine of the studies reviewed. Studies with a duration of supplementation of at least 6 weeks showed a benefit on pain perception in 80% of the patients included in these studies. The benefits shown by vitamins and coenzyme Q10 are remarkable. Further research is needed to identify the effects of other types of antioxidants, such as extra virgin olive oil and turmeric. More homogeneous interventions in terms of antioxidant doses administered and duration would allow the effects on pain to be addressed more comprehensively.

The Role of Nutrient Supplementation in the Management of Chronic Pain in Fibromyalgia: A Narrative Review

INTRODUCTION

The multifaceted clinical presentation of fibromyalgia (FM) supports the modern understanding of the disorder as a more global condition than one simply affecting pain sensation. The main pharmacologic therapies used clinically include anti-epileptics and anti-depressants. Conservative treatment options include exercise, myofascial release, psychotherapy, and nutrient supplementation.

METHODS

Narrative review.

RESULTS

Nutrient supplementation is a broadly investigated treatment modality as numerous deficiencies have been linked to FM. Additionally, a proposed link between gut microbiome patterns and chronic pain syndromes has led to studies investigating probiotics as a possible treatment. Despite positive results, much of the current evidence regarding this topic is of poor quality, with variable study designs, limited sample sizes, and lack of control groups.

CONCLUSIONS

The etiology of FM is complex, and has shown to be multi-factorial with genetics and environmental exposures lending influence into its development. Preliminary results are promising, however, much of the existing evidence regarding diet supplementation is of poor quality. Further, more robust studies are needed to fully elucidate the potential of this alternative therapeutic option.

Metal-induced oxidative stress level in patients with fibromyalgia syndrome and its contribution to the severity of the disease: A correlational study

BACKGROUND

Fibromyalgia syndrome (FMS) is an extra-articular rheumatological disease characterised by widespread chronic musculoskeletal pain. Metal-induced oxidative stress contributes to the severity of FMS.

AIMS

First, this study evaluated the association between plasma levels of toxic heavy metals and essential metals with oxidative stress (OS) markers. Second, the OS markers and metal contents were correlated with the disease severity by assessing the Fibromyalgia Impact Questioner Revised (FIQR) and tender points (TP).

METHOD

A total of 105 FMS patients and 105 healthy controls of similar age and sex were recruited. OS parameter such as lipid peroxidation (LPO), protein carbonyl group (PCG), nitric oxide (NO) and essential metals such as zinc (Zn), magnesium (Mg), manganese (Mn), copper (Cu) and toxic heavy metals such as aluminium (Al), arsenic (As), lead (Pb) were estimated.

RESULTS

Levels of LPO, PCG, NO (p< 0.001) and Cu, Mn, and Al (p< 0.001), were significantly higher, and Mg (p< 0.001) and Zn (p< 0.001) were significantly lower in patients compared to controls. A positive association was observed between OS parameters, FIQR and TP with Cu, Al and Mn. A significant negative association was observed between Zn and Mg with FIQR, TP and OS parameters.

CONCLUSION

Heavy metals such as Al induce OS parameters and decrease the levels of essential trace elements such as Mg and Zn, which may be responsible for the severity of FMS.

Cationic liposome-encapsulated carotenoids as a potential treatment for fibromyalgia in an animal model

The present study investigated the efficacy of cationic liposome-encapsulated carotenoids (lutein or beta-carotene) as a treatment in an animal model of fibromyalgia (FM). Preparation and characterization of the nano-sized cationic liposomal carotenoids have been carried out. FM has been induced in the experimental animals via successive subcutaneous reserpine injection (1 mg/kg). Animals were divided into four groups; control, reserpinized (Res), reserpinized and cationic liposomal lutein-treated (Res + CL-Lut), and reserpinized and liposomal beta-carotene-treated (Res + CL-Bc). Levels of norepinephrine (NE), dopamine (DA), and serotonin (5-HT), and oxidative stress markers (MDA, H₂O₂, NO, and GSH) were determined in the brain's cortical tissue of the different groups of animals. Furthermore, the spectral analysis of the electrocorticogram (ECoG) was carried out. Animal behavior was tested for different animal groups. Results showed a significant reduction in monoamines, an elevation of oxidative stress markers, a shift in the ECoG frequency band power, and a change in pain threshold of the reserpinized animals. A return to a non-significant difference from the control values of all the measured parameters has been obtained after two weeks of cationic liposomal carotenoid preparations treatment. The present findings shed more light on the validity of the reserpine model of FM and provide evidence for the antidepressant, antioxidant, and anti-nociceptive potential of the cationic liposomal carotenoids. The present results proofed that the natural product preparations on a nano-sized scale could be a good alternative to the pharmacological interventions for FM treatment.

Influence of Oxidative Stress-Related Genes on Susceptibility to Fibromyalgia

BACKGROUND

Fibromyalgia (FM) is a complex syndrome to diagnose and treat because of its unknown etiology. However, previous studies reported that patients with FM experience oxidative stress.

OBJECTIVES

In this study, we investigated single-nucleotide polymorphisms (SNPs) in genes encoding enzymes involved in oxidative stress (superoxide dismutase 1 [SOD1], catalase, and NADPH oxidase [CYBA]) in patients with FM and in healthy subjects, as well as the possible relation with demographic and clinical manifestations of FM.

METHODS

A total of 141 patients with FM and 73 healthy subjects participated in this case-control study. For DNA extraction, buccal swabs were collected from patients with FM, and a peripheral blood sample was extracted from controls. We analyzed SNPs in genes related to oxidative stress (rs10432782 in SOD1, rs1001179 in catalase, and rs4673 in CYBA) using TaqMan probes. In patients with FM, severity of FM, fatigue, and pain were assessed by Fibromyalgia Impact Questionnaire, Multidimensional Fatigue Inventory, and Visual Analogue Scale (VAS), respectively. Physical (PCS-12) and mental (MCS-12) health statuses were evaluated by the 12-Item Short-Form Health Survey.

RESULTS

The selected SNPs did not show significant differences between patients with FM and controls. The rs10432782 (SOD1) was associated with Fibromyalgia Impact Questionnaire scores in patients with FM, whereas the rs4673 (CYBA) was associated with the Multidimensional Fatigue Inventory score, MCS-12 score, and duration of the disease.

DISCUSSION

We have identified significant correlations between SOD1 and CYBA variants with clinical manifestations of FM. These results provide new insights into the pathogenesis of FM that could be useful for guiding future studies along the way to find the cause(s) of this syndrome.

Dynamic thiol and disulphide homoeostasis in fibromyalgia

INTRODUCTION

Thiol and disulphide levels are biomarkers that provide useful information about oxidative stress and antioxidant capacity, showing a different homoeostasis in inflammatory and proliferative diseases. We aimed to clarify the possible aetiology of this disease by using thiol and disulphide levels in patients with fibromyalgia, the basis of which has not yet been clearly elucidated.

MATERIAL AND METHODS

A total of 156 individuals: 86 patients with fibromyalgia and 70 age-matched controls were included in this prospective non-randomised case-control study. Demographic characteristics including smoking status, body mass index (BMI), the duration of complaints, and pain levels were carefully recorded. Dynamic thiol-disulphide homoeostasis in blood samples was determined by an automatic-spectrophotometric method. The Mann-Whitney U and Student's t-test were used to determine the differences between the groups.

RESULTS

Sex, BMI, and smoking status were similar between the groups (p = 0.62, p = 0.09, and p = 0.64, respectively). While native thiol levels were found to be high in patients with fibromyalgia (p = 0.018), disulphide levels and the rates of disulphide/native thiol and disulphide/total thiol were significantly low (p = 0.049, p = 0.007, and p = 0.007, respectively). Correlation analysis showed no significant relationship between thiol-disulphide levels and duration of complaints or pain level.

CONCLUSIONS

Thiol-disulphide balance in fibromyalgia was found to be similar to benign proliferative diseases, suggesting that the underlying mechanism is more likely to be of proliferative pattern rather than inflammatory. Additionally, fibromyalgia is not directly associated with increase in oxidative stress. The molecular mechanisms need to be elucidated.

Melatonin Plus Folic Acid Treatment Ameliorates Reserpine-Induced Fibromyalgia: An Evaluation of Pain, Oxidative Stress, and Inflammation

Background: Fibromyalgia is a chronic condition characterized by increased sensory perception of pain, neuropathic/neurodegenerative modifications, oxidative, and nitrosative stress. An appropriate therapy is hard to find, and the currently used treatments are able to target only one of these aspects. Methods: The aim of this study is to investigate the beneficial effects of melatonin plus folic acid administration in a rat model of reserpine-induced fibromyalgia. Sprague–Dawley male rats were injected with 1 mg/kg of reserpine for three consecutive days and later administered with melatonin, folic acid, or both for twenty-one days. Results: Administration of reserpine led to a significant decrease in the nociceptive threshold as well as a significant increase in depressive-like symptoms. These behavioral changes were accompanied by increased oxidative and nitrosative stress. Lipid peroxidation was significantly increased, as well as nitrotyrosine and PARP expression, while superoxide dismutase, nonprotein thiols, and catalase were significantly decreased. Endogenously produced oxidants species are responsible for mast cell infiltration, increased expression pro-inflammatory mediators, and microglia activation. Conclusion: Melatonin plus acid folic administration is able to ameliorate the behavioral defects, oxidative and nitrosative stress, mast cell infiltration, inflammatory mediators overexpression, and microglia activation induced by reserpine injection with more efficacy than their separate administration.

Does whole body vibration exercise improve oxidative stress markers in women with fibromyalgia?

The objective of this study was to investigate the effect of whole body vibration (WBV) exercise on oxidative stress markers in a group of women with fibromyalgia (FM) compared to a group of healthy women (CT). Twenty-one women diagnosed with FM and 21 age- and weight-matched healthy women were enrolled the study. Plasma oxidative stress markers (primary outcomes) were evaluated at rest and after WBV, and included thiobarbituric acid reactive substances (TBARS), iron reduction capacity (FRAP), superoxide dismutase antioxidant enzymes activity (SOD), and catalase (CAT). At rest, the FM group had higher TBARS (P<0.001) and FRAP (P<0.001), and lower CAT (P=0.005) compared to the CT. In the CT group, the WBV had no effect on TBARS (P=0.559) and FRAP (P=0.926), whereas it increased both SOD (P<0.001) and CAT (P<0.001). In the FM group, the WBV reduced TBARS (p <0.001), FRAP (P<0.001), and CAT (P=0.005), while it increased SOD (P=0.019). There was an interaction effect (moments vs groups) in the TBARS (effect size=1.34), FRAP (effect size=0.93), CAT (effect size=1.45), and SOD (effect size=1.44) (P<0.001). A single trial of WBV exercise improved all oxidant and antioxidant parameters towards a greater adaptation to the stress response in FM women.

Nociceptin/orphanin FQ receptor modulates painful and fatigue symptoms in a mouse model of fibromyalgia

Generalized pain and fatigue are both hallmarks of fibromyalgia, a syndrome with an indefinite etiology. The treatment options for fibromyalgia are currently limited, probably because of its intricate pathophysiology. Thus, further basic and clinical research on this condition is currently needed. This study investigated the effects of nociceptin/orphanin FQ (N/OFQ) receptor (NOPr) ligands and the modulation of the NOP system in the preclinical mouse model of reserpine-induced fibromyalgia. The effects of administration of the natural agonist N/OFQ and the selective NOPr antagonists (UFP-101 and SB-612111) were evaluated in fibromyalgia-related symptoms in reserpine-treated mice. The expression of prepronociceptin/orphanin FQ and NOPr was assessed in central and peripheral sites at different time points after reserpine administration. Nociceptin/orphanin FQ displayed dual effects in the behavioral changes in the reserpine-elicited fibromyalgia model. The peptide NOPr antagonist UFP-101 produced analgesic and antifatigue effects, by preventing alterations in brain activity and skeletal muscle metabolism, secondary to fibromyalgia induction. The nonpeptide NOPr antagonist SB-612111 mirrored the favorable effects of UFP-101 in painful and fatigue alterations induced by reserpine. A time-related up- or downregulation of prepronociceptin/orphanin FQ and NOPr was observed in supraspinal, spinal, and peripheral sites of reserpine-treated mice. Our data shed new lights on the mechanisms underlying the fibromyalgia pathogenesis, supporting a role for N/OFQ-NOP receptor system in this syndrome.

Alteration of Thiol-Disulfide Homeostasis in Fibromyalgia Syndrome

BACKGROUND

Fibromyalgia syndrome (FMS) is an extra-articular rheumatological disease, characterized by widespread pain and somatic symptoms. The etiology has not yet been clarified. Oxidative stress may play an important role in FMS etiology. Thiol group is a very strong antioxidant. We aimed to investigate whether thiol/disulfide homeostasis in FMS is altered or not.

MATERIAL AND METHODS

A total of 80 female FMS patients and 64 healthy female control individuals were included in this study. Thiol and disulfide values were measured by Erel's novel methods.

RESULTS

Native thiol (330.6 ± 46.1 vs. 356.8 ± 55.5 μmol/L, p = 0.005) and native thiol/total thiol (89.4 ± 3.2 vs. 93.3 ± 4.0, p < 0.001) levels of FMS patients were significantly lower when compared to the values of control group. However, disulfide (19.4 ± 6.3 vs. 12.2 ± 6.3 μmol/L, p < 0.001) levels of FMS patients were significantly higher than healthy individuals. A negative correlation was found between the native thiol/total thiol and fibromyalgia impact questionnaire (FIQ) score among the FMS patients. A positive correlation was found between disulfide values and FIQ score among the patients.

CONCLUSIONS

In FMS patients, there was a significant correlation between the decrease in the thiol levels and an increase in the disulfide levels with the FIQ scores. We determined that thiol-disulfide rate was deteriorated in FMS patients and it increases in favor of disulfide amounts.

Fibromyalgia: Genetics and epigenetics insights may provide the basis for the development of diagnostic biomarkers

Fibromyalgia is a disease characterized by chronic widespread pain with additional symptoms, such as joint stiffness, fatigue, sleep disturbance, cognitive dysfunction, and depression. Currently, fibromyalgia diagnosis is based exclusively on a comprehensive clinical assessment, according to 2016 ACR criteria, but validated biological biomarkers associated with fibromyalgia have not yet been identified. Genome-wide association studies investigated genes potentially involved in fibromyalgia pathogenesis highlighting that genetic factors are possibly responsible for up to 50% of the disease susceptibility. Potential candidate genes found associated to fibromyalgia are SLC64A4, TRPV2, MYT1L, and NRXN3. Furthermore, a gene-environmental interaction has been proposed as triggering mechanism, through epigenetic alterations: In particular, fibromyalgia appears to be characterized by a hypomethylated DNA pattern, in genes implicated in stress response, DNA repair, autonomic system response, and subcortical neuronal abnormalities. Differences in the genome-wide expression profile of microRNAs were found among multiple tissues, indicating the involvement of distinct processes in fibromyalgia pathogenesis. Further studies should be dedicated to strength these preliminary findings, in larger multicenter cohorts, to identify reliable directions for biomarker research and clinical practice.

Epigenetics insights into chronic pain: DNA hypomethylation in fibromyalgia-a controlled pilot-study

To evaluate changes in DNA methylation profiles in patients with fibromyalgia (FM) compared to matched healthy controls (HCs). All individuals underwent full clinical and neurophysiological assessment by cortical excitability (CE) parameters measured by transcranial magnetic stimulation. DNA from the peripheral blood of patients with FM (n = 24) and HC (n = 24) were assessed using the Illumina-HumanMethylation450 BeadChips. We identified 1610 differentially methylated positions (DMPs) in patients with FM displaying a nonrandom distribution in regions of the genome. Sixty-nine percent of DMP in FM were hypomethylated compared to HC. Differentially methylated positions were enriched in 5 genomic regions (1p34; 6p21; 10q26; 17q25; 19q13). The functional characterization of 960 genes related to DMPs revealed an enrichment for MAPK signaling pathway (n = 18 genes), regulation of actin cytoskeleton (n = 15 genes), and focal adhesion (n = 13 genes). A gene-gene interaction network enrichment analysis revealed the participation of DNA repair pathways, mitochondria-related processes, and synaptic signaling. Even though DNA was extracted from peripheral blood, this set of genes was enriched for disorders such as schizophrenia, mood disorders, bulimia, hyperphagia, and obesity. Remarkably, the hierarchical clusterization based on the methylation levels of the 1610 DMPs showed an association with neurophysiological measurements of CE in FM and HC. Fibromyalgia has a hypomethylation DNA pattern, which is enriched in genes implicated in stress response and DNA repair/free radical clearance. These changes occurred parallel to changes in CE parameters. New epigenetic insights into the pathophysiology of FM may provide the basis for the development of biomarkers of this disorder.

Ambroxol for the treatment of fibromyalgia: science or fiction?

Fibromyalgia appears to present in subgroups with regard to biological pain induction, with primarily inflammatory, neuropathic/neurodegenerative, sympathetic, oxidative, nitrosative, or muscular factors and/or central sensitization. Recent research has also discussed glial activation or interrupted dopaminergic neurotransmission, as well as increased skin mast cells and mitochondrial dysfunction. Therapy is difficult, and the treatment options used so far mostly just have the potential to address only one of these aspects. As ambroxol addresses all of them in a single substance and furthermore also reduces visceral hypersensitivity, in fibromyalgia existing as irritable bowel syndrome or chronic bladder pain, it should be systematically investigated for this purpose. Encouraged by first clinical observations of two working groups using topical or oral ambroxol for fibromyalgia treatments, the present paper outlines the scientific argument for this approach by looking at each of the aforementioned aspects of this complex disease and summarizes putative modes of action of ambroxol. Nevertheless, at this point the evidence basis for ambroxol is not strong enough for clinical recommendation.

Specific proteins of the trapezius muscle correlate with pain intensity and sensitivity - an explorative multivariate proteomic study of the trapezius muscle in women with chronic widespread pain

Chronic widespread pain (CWP) including fibromyalgia syndrome (FMS) has a high prevalence and is associated with prominent negative consequences. CWP/FMS exhibits morphological and functional alterations in the central nervous system. The importance of peripheral factors for maintaining the central alterations are under debate. In this study, the proteins from biopsies of the trapezius muscle from 18 female CWP/FMS patients and 19 healthy female controls were analyzed. Pain intensity and pressure pain thresholds (PPT) over the trapezius muscles were registered. Twelve proteins representing five different groups of proteins were important regressors of pain intensity in CWP/FMS (R²=0.99; P<0.001). In the regression of PPT in CWP/FMS, it was found that 16 proteins representing six groups of proteins were significant regressors (R²=0.95, P<0.05). Many of the important proteins were stress and inflammation proteins, enzymes involved in metabolic pathways, and proteins associated with muscle damage, myopathies, and muscle recovery. The altered expression of these proteins may reflect both direct and indirect nociceptive/inflammatory processes as well as secondary changes. The relative importance of the identified proteins and central alterations in CWP need to be investigated in future research. Data from this and the previous study concerning the same cohorts give support to the suggestion that peripheral factors are of importance for maintaining pain aspects in CWP/FMS.