Citocinas pró-inflamatórias e dor

Cuminaldehyde Effects in a MIA-Induced Experimental Model Osteoarthritis in Rat Knees

Osteoarthritis (OA) is a chronic degenerative disease that has a significant global impact. It is associated with aging and characterized by widespread joint destruction. Cuminaldehyde is a biologically active component of essential oils that has shown promise in the treatment of nociceptive and inflammatory diseases. This study investigated the effects of cuminaldehyde on an experimental model of osteoarthritis induced in rat knees. Cuminaldehyde was found to be as effective as indomethacin in reducing pain in all evaluated tests, including forced walking, functional disability of weight distribution on the legs, and spontaneous pain in animals with osteoarthritis. The knees of animals treated with cuminaldehyde had significantly higher radiographic and histopathological scores than those of animals that did not receive the treatment. Cuminaldehyde also modulated the production of pro-inflammatory cytokines. In vitro assays showed that cuminaldehyde preferentially inhibits COX-2 enzyme activity. In silico studies demonstrated that cuminaldehyde has satisfactory energy affinity parameters with opioid receptors and COX-2. These findings suggest that cuminaldehyde's anti-inflammatory activity is multifactorial, acting through multiple pathways. Its nociceptive activity occurs via central and peripheral mechanisms. Cuminaldehyde modulates the immune response of the inflammatory process and may be considered a leading compound for the development of new anti-inflammatory and analgesic drugs.

Reduction on Proinflammatory Cytokines after Application of Transcutaneous Electrical Nerve Stimulation (TENS) in Patients with a Breast Cancer: A Nonrandomized, Open, and Single-Arm Study Protocol with Paired Analysis

Background. Transcutaneous electrical nerve stimulation (TENS) has been used as analgesic therapy in many diseases. It is already known that studies that have observed the relationship between pain and cytokines have found that patients who report less severe pain have less production of proinflammatory cytokines. However, one another accepted mechanism is that decreasing proinflammatory cytokines results in decreased pain intensity. Analyzing the literature, the authors describe that, in addition to the analgesic effect, TENS has shown systemic effects, and clinically, the reduction of proinflammatory cytokines could be a protective factor against inflammation. To test the inflammatory effect of TENS, we researched the literature for clinical conditions that suggest that proinflammatory cytokines are one of the main mediators of the disease process. Chronic inflammation is one of the risk factors mentioned for the development of a new cancer; at the same time, it is indicated as an indicator of the worst prognosis. Studies also suggest that the worst prognosis of breast cancer, one of the types with the highest incidence in the world, may be related to increased inflammatory activity. Considering that inflammation is increased in breast cancer and that TENS can reduce proinflammatory cytokines even without blocking the pain pathway, our hypothesis is that the anti-inflammatory effect of TENS can bring benefits to these patients. The aim of this study will be to evaluate the effect of TENS on blood reduction of proinflammatory cytokines in breast cancer patients. Methods. This study will evaluate at least 59 patients, over 18 years of age, diagnosed with breast cancer, but who have not yet started any treatment. All patients will be submitted to TENS intervention (Ibramed, Model Neurodyn III, parameters: VIF—turn on, frequency—2-247 Hz, pulse size—50-500 μs, and intensity (mA)—maximum tolerated by the patient), and the data will be analyzed in the pre- and postintervention of each patient. The application has a total duration of 30 minutes, and 8 ml of blood will be collected before and after the intervention. Proinflammatory (IL-1, IL-2, IL-6, IL-7, and TNF-α) and anti-inflammatory (IL-4, IL-10, IL-13, and FTCβ) cytokines will be analyzed. As a primary endpoint, we will analyze the reduction in blood concentration of proinflammatory cytokines, and as secondary endpoints, we will analyze the size of the effect according to each type of proinflammatory cytokine, describe the effect size of the reduction according to the breast cancer immunohistochemistry, and analyze the effect of TENS on anti-inflammatory cytokines. This study is approved by the Research Ethics Committee (Centro Universitário FMABC, Brazil) and registered in the Brazilian Clinical Trials (Search text: RBR-10jbwh47).

Therapeutic Use of Scoparia dulcis Reduces the Progression of Experimental Osteoarthritis

Pain is recognized as one of the main symptoms in knee osteoarthritis and is the main reason why patients seek medical attention. Scoparia dulcis has been popularly used to relieve discomfort caused by various painful conditions. The objective of the study is to evaluate the analgesic and anti-inflammatory effect of the crude extract of S. dulcis, in an experimental model of osteoarthritis. The experiment was performed with Wistar rats divided into 4 groups with 5 animals each: healthy, saline, crude extract, and meloxicam groups. Knee osteoarthritis was induced by intra-articular injection of sodium mono-iodoacetate. First, clinical parameters of pain were assessed at days 0, 5, 10, 15, and 20 after induction. Second, the potential cyclooxygenase inhibition was evaluated, and the cytokines of the synovial fluid were quantified. An in silico test and Molecular Docking tests were performed. A histopathological evaluation was made on articular cartilage with safranin O staining. The results showed that a 15-day treatment with crude extract reduced edema, spontaneous pain, peripheral nociceptive activity, and proinflammatory cytokines in the synovial fluid. The highest inhibition of cyclooxygenase 2 in the crude extract occurred at 50 µg/mL. The crude extract of S. dulcis presents therapeutic potential for the treatment of osteoarthritis due to its anti-inflammatory and anti-nociceptive action.

Association between inflammatory mediators, grip strength and mobility in community-dwelling elderly

Abstract Introduction: Aging is associated with loss of muscle mass, immunosenescence and increased production of inflammatory mediators, high levels being predictors of a decline in functional capacity in the elderly. Objective: To assess the association between inflammatory mediators, interleukin 6 (IL-6) and C-reactive protein (CRP) and functional capacity in the elderly. Methods: Cross-sectional study with 308 community-dwelling elderly. The study was approved by the Research Ethics Committee, under protocol number 067/2010. Grip strength (GS) was measured using a JAMAR® dynamometer and functional capacity by the Timed Up and Go (TUG) test. Blood tests were performed and serum levels of C-reactive protein and interleukin 6 assessed. Spearman’s coefficient was applied to analyze the correlation between variables and the Mann-Whitney for intergroup comparison. Significance was set at 0.05. Results: There was no significant correlation between GS, the TUG and inflammatory mediators (CRP and IL-6). However, by adjusting for variables such as age, sex and muscle mass, a significant and inverse correlation (p = 0.023) was observed between GS and CPR. Conclusion: Elderly subjects with low C-reactive protein levels performed better in the grip strength test. It is important to investigate the adverse effects on functional capacity that can be influenced by inflammatory cytokines in the elderly during aging.

Eugenia brasiliensis leaves extract attenuates visceral and somatic inflammatory pain in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Eugenia brasiliensis Lam. (Myrtaceae) is a Brazilian tree distributed throughout Atlantic rain forest, since Bahia until Santa Catarina state, and is popularly known as "grumixaba, grumixameira, cumbixaba, ibaporoiti, and cereja-brasileira". The bark and leaves of Eugenia brasiliensis are used in folk medicine as adstringent, diuretic, energizing, anti-rheumatic and anti-inflammatory. This study aimed at investigating the chemical composition, antinociceptive and anti-inflammatory effect of the hydroalcoholic extract of Eugenia brasiliensis (HEEb).

MATERIAL AND METHODS

Chemical composition of the HEEb was determined by High Performance Liquid Chromatography/ESI-Mass Spectrometry (HPLC-ESI-MS/MS). The antinociceptive and anti-inflammatory effects of HEEb (30-300 mg/kg) was verified in mice after oral administration by intra-gastric gavage (i.g.) 60 min prior to experimentation. It was investigated whether HEEb decreases visceral pain and leukocyte migration induced by an intraperitoneal (i.p.) injection of acetic acid (0.6%). We also evaluated whether HEEb decreases nociceptive behavior induced by formalin (including paw edema and temperature), prostaglandin E₂ (PGE₂), histamine, and compound 48/80. Finally, we evaluated the effect of HEEb in the chronic inflammatory (mechanical and thermal hypersensitivity) pain induced by complete Freund's adjuvant (CFA), as well as quantifying the concentration of the pro-inflammatory cytokines TNF-α and IL-6 in the paw by ELISA method.

RESULTS

Seven polyphenols were identified in HEEb by HPLC-ESI-MS/MS analysis. HEEb treatment alleviated nocifensive behavior and leukocyte migration caused by acetic acid. Moreover, HEEb also reduced the inflammatory pain and paw temperature induced by formalin, as well as it decreased nociceptive behavior induced by histamine and compound 48/80. Finally, acute and repeated treatment of animals with HEEb (100 mg/kg, i.g.) markedly reduced the mechanical and thermal (heat) hypersensitivity, besides decrease paw edema and temperature induced by CFA, and this effect was evident until the day 7. Moreover, repeated treatment with HEEb (100 mg/kg, i.g.) significantly reduced the levels of IL-6 and TNF-α in the paw when compared to the CFA group.

CONCLUSIONS

This is the first report showing that HEEb presents antinociceptive and anti-inflammatory effects in the visceral and somatic inflammatory pain in mice, possibly involving the inhibition of histamine receptors and pro-inflammatory cytokines activated pathways. Our results are of interest because they support the use of Eugenia brasiliensis as a potential source of phytomedicine for inflammatory diseases and pain.

Effects of Transcutaneous Electrical Nerve Stimulation on Proinflammatory Cytokines: Systematic Review and Meta-Analysis

The mechanism of pain reduction involves bidirectional processes of pain blocking (nociception) and reductions in the levels of proinflammatory cytokines in the blood. Does transcutaneous electrical nerve stimulation (TENS) reduce blood levels of proinflammatory cytokines? For this systematic review, we searched in six databases to identify randomized controlled trials with the criteria: humans older than 18 years (adults), use of TENS in the experimental group, and having at least one pre- and postintervention blood level of at least one proinflammatory cytokine. The risk of bias and the level of evidence were assessed. Five studies were included involving 240 participants. The heterogeneity of the studies was high (I²: 85%); therefore, we used a random-effects meta-analysis. It was observed through the meta-analysis synthesis measures that there were statistically significant differences following the use of TENS to reduce the general group of cytokines. When grouped by chronic disease, by postoperative settings, or by individual studies in the case of IL-6, it was observed that the significant reduction of cytokines related to the use of TENS was maintained. The use of TENS reduced the blood levels of proinflammatory cytokines (we observed a protective factor of TENS in relation to inflammation). The protocol of the systematic review was registered in PROSPERO, CRD42017060379.

Effects of transcutaneous electrical nerve stimulation (TENS) on proinflammatory cytokines: protocol for systematic review

BACKGROUND

Pain reduction can be achieved by lowering proinflammatory cytokine levels in the blood. Transcutaneous electrical nerve stimulation (TENS) is a non-invasive physiotherapeutic resource for pain management, but evidence on the effectiveness of this device at reducing proinflammatory cytokines in the blood is unclear. This study systematically reviews the literature on the effect of TENS on proinflammatory cytokines.

METHODS

A systematic review protocol was developed based on searches of articles in six electronic databases and references of retrieved articles, contact with authors, and repositories of clinical trials. Eligibility criteria: publication in peer-reviewed journals, randomized clinical trials, use of TENS in the experimental group, and pre- and post-measurements of proinflammatory cytokines in the blood. Selection of the studies and extraction of the data will be carried out by two reviewers independently. Characteristics of the study, participants, interventions and outcomes were extracted and described. Assessments were performed on the risk of bias, level of evidence and the size of the intervention effect in the studies, according to GRADE guidelines and the Cochrane Handbook for Systematic Reviews. Clinical and statistical assessments compared the effects of the interventions (meta-analysis), taking into consideration any influencing characteristics of the studies (e.g., methods and application sites).

DISCUSSION

We anticipate that this review will strengthen evidence-based knowledge of the effect of TENS on proinflammatory cytokines and, as a result, direct new studies to benefit patients with specific pathologies.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42017060379 .

Predictors for Moderate to Severe Acute Postoperative Pain after Cesarean Section

Background. Moderate to severe postoperative pain affects performance of daily activities and it contributes to persistent postoperative pain. In patients submitted to cesarean section, this pain can also interfere with women's ability to care for their babies, to effectively breastfeed, and to satisfactorily interact with their children. Factors influencing the pain perception during the immediate postoperative period have not been widely pursued. Objective. To investigate the incidence and predicting factors of postoperative pain after cesarean section. Methods. A prospective longitudinal study with 1,062 women submitted to cesarean section. We collected sociodemographic, clinical, surgical, and health behavior data. We used the 11-point Numerical Pain and the Hospital Anxiety and Depression Scales. We performed logistic analysis to identify predictors of moderate to severe postoperative pain. Results. The incidence of moderate-severe postoperative pain was 78.4% (CI: 95%: 75.9%–80.8%). The preoperative anxiety (OR = 1.60; CI 95%: 1.22–2.30) and intrathecal morphine with fentanyl (OR = 0,23; CI 95%: 0.08–0.66) were significantly associated with moderate-severe postoperative pain report. Conclusion. The preoperative anxiety increases the risk of moderate-severe postoperative pain in women submitted to cesarean section. The intrathecal morphine with fentanyl added to bupivacaine was a protective factor against this pain.

Chemical composition and antinociceptive effect of aqueous extract from Rourea induta Planch. leaves in acute and chronic pain models

ETHNOPHARMACOLOGICAL RELEVANCE

Rourea induta Planch. is a small tree or shrub growing wild in Brazil and belonging to the Connaraceae family. It is used for the treatment of Chagas disease and as antirheumatic in folk medicine. This study was designed to investigate the antinociceptive activity of the aqueous extract (AERi) of Rourea induta leaves in rodents, as well as isolate and identify components that can be responsible for its effect.

MATERIAL AND METHODS

The antinociceptive effect of orally administered AERi was evaluated in behavioral models of acute (formalin) and chronic [complete Freund׳s adjuvant (CFA)] pain in mice. We also investigated the possible involvement of opioid receptors and proinflammatory cytokines (interleukin-1β and tumor necrosis factor-α) in the antinociceptive effect of the AERi. In addition, a nonspecific effect of AERi was evaluated by measuring locomotor activity and corporal temperature. Finally, we performed a phytochemical analysis of AERi.

RESULTS

HPLC titration revealed the presence of hyperin (21.6 mg/g), quercetin-3-O-β-xyloside (4.4 mg/g), quercetin-3-O-α-arabinofuranoside (12.0 mg/g), and quercetin (2.1 mg/g). It was also possible to isolate minor constituents׳ chlorogenic acid, neochlorogenic acid and procyanidin C1. The oral administration of AERi (100 mg/kg) significantly inhibited the neurogenic (37 ± 5%) and inflammatory (34 ± 7%) phases of formalin-induced pain. Acute and repeated treatment of animals with AERi (100 mg/kg, p.o.) once a day markedly reduced the mechanical hypersensitivity response induced by CFA, and this effect was evident until the day 10. Moreover, repeated treatment with AERi (100 mg/kg, p.o.) significantly reduced the levels of IL-1β and TNF-α in the paw (22 ± 7% and 50 ± 19%) and in the spinal cord (100% and 100%) when compared to the CFA group. The AERi (100 mg/kg, p.o.) markedly reduced biting behavior induced by intrathecal injection of TNF-α (81 ± 11%). Finally, the effect of AERi was not associated with changes in locomotor activity or the corporal temperature of animals.

CONCLUSION

These data show that aqueous extract of Rourea induta has significant antinociceptive action, which seems to be associated with an inhibition of pro-inflammatory cytokines activated pathways. These findings support the ethnomedical uses of this plant.