Methylene Blue for the Treatment of Intractable Pain Associated with Oral Mucositis

Methylene Blue, a Unique Topical Analgesic: A Case Report

Background: Rectal prolapse is a circumferential, full-thickness protrusion of the rectum through the anus, which, if not properly managed, may become incarcerated and pose a risk of strangulation. This pathology is rarely a medical emergency unless a complication is encountered. Such complications include infection, necrosis, perforation, incarceration, and uncontrolled pain. Case Presentation: We report a case of an elderly patient with pain associated with chronic rectal prolapse. Surgical intervention had been ruled out, and there had been no pain relief after using systemic analgesics. Case Management: Based on increasing reports of analgesic properties, topical methylene blue (MB) 0.1% was applied externally at the prolapsed organ, obtaining pain relief. Case Outcome: The patient experienced immediate and long-lasting pain relief; MB applications were continued every 12 hours as needed. After this therapy, the patient was no longer in need of systemic analgesics. No side effects were reported. Conclusion: Topical MB may be an effective analgesic for the management of pain associated with chronic rectal prolapse. This treatment might be extrapolated to other clinical scenarios of tegumentary pain. Similar use has been shown to be safe and effective in other pathologies, including pain in oral mucositis associated with cancer therapy.

Dental consensus on HSCT - Part II: dental Care during HSCT

During the state of immune vulnerability in hematopoietic stem cell transplantation (HSCT), the patient has an increased risk of developing a vast number of complications, including severe problems in the oral cavity. These situations require professional oral care to act in the diagnosis and treatment of these conditions, as well as to develop prevention protocols to minimize patient's complications. Oral mucositis, opportunistic infections, bleeding, specific microbiota, taste, and salivary alterations are complications that can occur during HSCT and interfere with various aspects, such as pain control, oral intake, nutrition, bacteremia and sepsis, days of hospitalization and morbidity. Several guidelines have been published to address the role of professional oral care during the HSCT, we describe a consensus regarding these recommendations.

Probiotics for the Management of Oral Mucositis: An Interpretive Review of Current Evidence

Mucositis is one of the major side effects of anti-cancer therapies. Mucositis may lead to other abnormalities such as depression, infection, and pain, especially in young patients. Although there is no specific treatment for mucositis, several pharmacological and non-pharmacological options are available to prevent its complications. Probiotics have been recently considered as a preferable protocol to lessen the complications of chemotherapy, including mucositis. Probiotics could affect mucositis by anti-inflammatory and anti-bacterial mechanisms as well as augmenting the overall immune system function. These effects may be mediated through anti microbiota activities, regulating cytokine productions, phagocytosis, stimulating IgA releasement, protection of the epithelial shield, and regulation of immune responses. We have reviewed available literature pertaining to the effects of probiotics on oral mucositis in animal and human studies. While animal studies have reported protective effects of probiotics on oral mucositis, the evidence from human studies is not convincing.

Application of methylene blue combined with ropivacaine intercostal nerve block in postoperative analgesia of autologous costal cartilage augmentation rhinoplasty

OBJECTIVE

To observe the effect of methylene blue combined with ropivacaine intercostal nerve block on postoperative analgesia after autologous costal cartilage augmentation rhinoplasty.

METHODS

In this study 100 female patients who underwent autologous costal cartilage comprehensive augmentation rhinoplasty in Chongqing Huamei Plastic Surgery Hospital from April to November 2021 were randomly divided into an experimental group and a control group, with 50 cases in each group. In the experimental group methylene blue was combined with ropivacaine intercostal nerve block as patient controlled intravenous analgesia (PCIA), and the control group was ropivacaine intercostal nerve block combined with PCIA. The visual analogue scale (VAS) scores of resting and coughing at 6 h (T1), 24 h (T2), 48 h (T3), 72 h (T4) after surgery were recorded and evaluated. At the same time, the number and times of oral analgesics were recorded as well as nausea, vomiting, burning pain and paresthesia.

RESULTS

The VAS scores of the experimental group were lower than those of the control group at all time points. At 6 h, 24 h and 48 h after surgery, the VAS score of the experimental group was lower than that in the control group, but the difference was not statistically significant (P > 0.05). The VAS score of calm 72 h after surgery in the experimental group was significantly lower than that in the control group (P < 0.05). The analgesic effect of the two groups was better when they coughed after surgery. At 6 h after surgery, the VAS score of coughing in the experimental group was lower than that in the control group, but the difference was not statistically significant (P > 0.05); At 24 h, 48 h and 72 h after surgery, the VAS score of the coughing state in the experimental group was significantly lower than that in the control group (P < 0.05).

CONCLUSION

Intercostal nerve block with methylene blue combined with ropivacaine can achieve good postoperative analgesic effects in augmentation rhinoplasty with autologous costal cartilage.

Methylene blue for intractable pain from oral mucositis related to cancer treatment: a randomized phase 2 clinical trial

BACKGROUND

Oral mucositis (OM) in patients receiving cancer therapy is thus far not well managed with standard approaches. We aimed to assess the safety and effectiveness of methylene blue (MB) oral rinse for OM pain in patients receiving cancer therapy.

METHODS

In this randomized, single-blind phase 2 clinical trial, patients were randomized to one of four arms: MB 0.025%+conventional therapy (CTx) (n = 15), MB 0.05%+CTx (n = 14), MB 0.1%+CTx (n = 15), or CTx alone (n = 16). Intervention groups received MB oral rinse every 6 h for 2 days with outcomes measured at days 1-2; safety was evaluated up to 30 days. The primary outcome measured change in the pain numeric rating scale (0-10) from baseline to day 2. Secondary outcome measured change in oral function burden scores from baseline to day 2, World Health Organization OM grades, morphine equivalent daily doses, and adverse events. The trial was registered with ClinicalTrials.gov ID: NCT03469284.

RESULTS

Sixty patients (mean age 43, range 22-62 years) completed the study. Compared with those who received CTx alone, those who received MB had a significant reduction of pain scores at day 2 of treatment (mean ± SD); 0.025%: 5.2 ± 2.9, 0.05%: 4.5 ± 2.9, 0.1%: 5.15 ± 2.6) and reduction of oral function burden scores (0.025%: 2.5 ± 1.55, 0.05%: 2.8 ± 1.7, 0.1%: 2.9 ± 1.60). No serious adverse events were noted, but eight patients reported burning sensation of the oral cavity with the first dose, and this caused one patient to discontinue therapy.

CONCLUSIONS

MB oral rinse showed significant pain reduction and improved oral functioning with minimal adverse effects.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT03469284.

Protein-protein interaction-based high throughput screening for adenylyl cyclase 1 inhibitors: Design, implementation, and discovery of a novel chemotype

Genetic and preclinical studies have implicated adenylyl cyclase 1 (AC1) as a potential target for the treatment of chronic inflammatory pain. AC1 activity is increased following inflammatory pain stimuli and AC1 knockout mice show a marked reduction in responses to inflammatory pain. Previous drug discovery efforts have centered around the inhibition of AC1 activity in cell-based assays. In the present study, we used an in vitro approach focused on inhibition of the protein-protein interaction (PPI) between Ca2+/calmodulin (CaM) and AC1, an interaction that is required for activation of AC1. We developed a novel fluorescence polarization (FP) assay focused on the PPI between an AC1 peptide and CaM and used this assay to screen over 23,000 compounds for inhibitors of the AC1-CaM PPI. Next, we used a cellular NanoBiT assay to validate 21 FP hits for inhibition of the AC1-CaM PPI in a cellular context with full-length proteins. Based on efficacy, potency, and selectivity for AC1, hits 12, 13, 15, 18, 20, and 21 were prioritized. We then tested these compounds for inhibition of AC1 activity in cyclic AMP (cAMP) accumulation assays, using HEK293 cells stably expressing AC1. Hit 15 contained a dithiophene scaffold and was of particular interest because it shared structural similarities with our recently reported benzamide series of AC1 inhibitors. We next tested a small set of 13 compounds containing the dithiophene scaffold for structure-activity relationship studies. Although many compounds were non-selective, we observed trends for tuning AC1/AC8 selectivity based on heterocycle type and substituents. Having an ethyl on the central thiophene caused the scaffold to be more selective for AC8. Cyclization of the alkyl substituent fused to the thiophene significantly reduced activity and also shifted selectivity toward AC8. Notably, combining the fused cyclohexane-thiophene ring system with a morpholine heterocycle significantly increased potency at both AC1 and AC8. Through designing a novel FP screen and NanoBiT assay, and evaluating hits in cAMP accumulation assays, we have discovered a novel, potent, dithiophene scaffold for inhibition of the AC1- and AC8-CaM PPI. We also report the most potent fully efficacious inhibitor of AC8 activity known to-date.

Methylene blue prevents osteoarthritis progression and relieves pain in rats via upregulation of Nrf2/PRDX1

Oxidative stress-related cartilage degeneration, synovitis, and joint pain play vital roles in the progress of osteoarthritis (OA). Anti-oxidative stress agents not only prevent structural damage progression but also relieve OA-related pain. In this study, we investigated the therapeutic effect of methylene blue (MB), a classical and important anti-oxidant with strong neural affinity. Experimental OA was established in rats by radial transection of medial collateral ligament and medial meniscus (MCLT + MMT) of the right knee joint. The OA rats received intra-articular injection of MB (1 mg/kg) every week starting one week after surgery. We showed that MB administration exerted significant cartilage protection, synovitis inhibition as well as pain relief in OA rats. In human chondrocytes and fibroblast-like synoviocytes, MB significantly attenuated tert-butyl hydroperoxide (TBHP)-induced inflammatory response and oxidative stress. We demonstrated that these effects of MB resulted from dual targets of important antioxidant enzymes, Nrf2 and PRDX1, which also mutually reinforcing and participated in an interaction. Furthermore, we found that calcitonin gene-related peptide (CGRP), a neural inflammatory mediator, was accumulated around the vessel in synovium and subchondral bone in OA rats and in TBHP-treated primary cortical neurons; MB administration significantly inhibited CGRP expression through upregulation of Nrf2 and PRDX1. Taken together, these results suggest that MB ameliorates oxidative stress via Nrf2/PRDX1 regulation to prevent progression and relieve pain of OA.

Removal of Dyes by Polymer-Enhanced Ultrafiltration: An Overview

The current problem of contamination caused by colored industrial effluents has led to the development of different techniques to remove these species from water. One of them, polymer-enhanced ultrafiltration (PEUF), has been systematically studied in this mini review, in which research works from 1971 to date were found and analyzed. Dye retention rates of up to 99% were obtained in several cases. In addition, a brief discussion of different parameters, such as pH, interfering salts, type of polymer, dye concentration, and membrane type, and their influence in dye removal is presented. It was concluded from the above that these factors can be adapted depending on the pollutant to be remediated, in order to optimize the process. Finally, theoretical approaches have been used to understand the intermolecular interactions, and development of the studied technique. In this revision, it is possible to observe that molecular docking, molecular dynamics simulations, density functional theory calculations, and hybrid neural-genetic algorithms based on an evolutionary approach are the most usual approximations used for this purpose. Herein, there is a detailed discussion about what was carried out in order to contribute to the research development of this important science field.

Methylene Blue Application to Lessen Pain: Its Analgesic Effect and Mechanism

Methylene blue (MB) is a cationic thiazine dye, widely used as a biological stain and chemical indicator. Growing evidence have revealed that MB functions to restore abnormal vasodilation and notably it is implicated even in pain relief. Physicians began to inject MB into degenerated disks to relieve pain in patients with chronic discogenic low back pain (CDLBP), and some of them achieved remarkable outcomes. For osteoarthritis and colitis, MB abates inflammation by suppressing nitric oxide production, and ultimately relieves pain. However, despite this clinical efficacy, MB has not attracted much public attention in terms of pain relief. Accordingly, this review focuses on how MB lessens pain, noting three major actions of this dye: anti-inflammation, sodium current reduction, and denervation. Moreover, we showed controversies over the efficacy of MB on CDLBP and raised also toxicity issues to look into the limitation of MB application. This analysis is the first attempt to illustrate its analgesic effects, which may offer a novel insight into MB as a pain-relief dye.

Effectiveness of Adjunctive Analgesics in Head and Neck Cancer Patients Receiving Curative (Chemo-) Radiotherapy: A Systematic Review

OBJECTIVE

Our aim was to give an overview of the effectiveness of adjunctive analgesics in head and neck cancer (HNC) patients receiving (chemo-) radiotherapy.

DESIGN

Systematic review.

INTERVENTIONS

This systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed, Embase, Web of Science, the Cochrane Library, and ClinicalTrials.gov were searched for studies concerning "head neck cancer," "adjunctive analgesics," "pain," and "radiotherapy."

OUTCOME MEASURES

Pain outcome, adverse events, and toxicity and other reported outcomes, for example, mucositis, quality of life, depression, etc.

RESULTS

Nine studies were included in our synthesis. Most studies were of low quality and had a high risk of bias on several domains of the Cochrane Collaboration tool. Only two studies comprised high-quality randomized controlled trials in which pregabalin and a doxepin rinse showed their effectiveness for the treatment of neuropathic pain and pain from oral mucositis, respectively, in HNC patients receiving (chemo-) radiotherapy.

CONCLUSIONS

More high-quality trials are necessary to provide clear evidence on the effectiveness of adjunctive analgesics in the treatment of HNC (chemo-) radiation-induced pain.

Radiation-Induced Oral Mucositis in Head and Neck Cancer Patients. Five Years Literature Review

Backround: Radiation-induced oral mucositis consists of a series of relatively frequent side effects after head and neck cancer radiotherapy and has an adverse impact on both regular treatment process and the quality of life of patients.

OBJECTIVE

The purpose of the present review is to optimize the current management of radiation-induced oral mucositis in head and neck cancer patients.

METHODS

PubMed database research was performed on articles published since 2015 that demonstrated efficacy in the management of radiation-induced oral mucositis in head and neck cancer patients. The study selection included observational, prospective, comparative, randomized, double- blind, placebo-controlled or uncontrolled, and retrospective studies, as well as systematic reviews and metanalyses.

RESULTS

From the 931 citations obtained from the search, only 94 articles met the inclusion criteria, including mucosal protectants, anti-inflammatory agents, growth factors, and various miscellaneous and natural agents. Several methods, including both pharmacological and natural agents, have been proposed for the management of oral mucositis. In addition to the already known interventions with strong evidence, according to the Multinational Association of Supportive Care in Cancer and he International Society of Oral Oncology guidelines, further agents have been used. However, a great number of them lack clear evidence, which surely requires the design of more controlled clinical trials for a better assessment of the ideal methods.

CONCLUSION

The management of oral mucositis constitutes an active area of research. In light of these results, it is aimed to illustrate those treatment strategies that are most effective regarding the treatment approach of oral mucositis.

Could methylene blue be used to manage burning mouth syndrome? A pilot case series

Objective: Burning mouth syndrome is a disabling condition of complex pathophysiology characterized by spontaneous pain felt in the oral mucosa in the absence of evident mucosal lesions which lacks efficient treatments to this day. The purpose of this study was to demonstrate the efficacy of methylene blue in the management of burning mouth syndrome. Methods: The study was conducted at the dental clinic of the Anta Diop University and Newtown dental clinic of Dakar, Senegal. A solution of methylene blue as a mouth-rinse (0.5%) was applied for 5 minutes in five patients satisfying the ICHD-3 diagnostic criteria for burning mouth syndrome. This procedure was repeated every 6 hours 3 times per 24h, during 7 days. Using numeric rating scale, pain severity was assessed as the mean pain felt during the last day of application. Results: After 7 days, the pain was significantly reduced by two-thirds and almost absent at 3 and 6 months follow-up. No secondary effects of the use of methylene blue were observed. Putative mechanisms of action and potential implications for treatment are discussed. Conclusion: Methylene blue is an old compound but a novel topical therapy that could prove beneficial in the management of burning mouth syndrome.

Oral pain associated with cancer therapy, a pain medicine perspective

Cancer therapy-induced oral mucositis (CTIOM) can cause intolerable oral pain resulting in difficulty in chewing, swallowing and speaking. Thus, leading to patients requiring aggressive measures, such as parenteral feeding, the placement of gastric feeding tubes and discontinuation of oncologic treatments. Although, pain is the debilitating symptom, current efforts seem to focus independently in the histological damage, not in pain and symptom care. Current strategies for managing pain from CTIOM entail maintaining oral hygiene and the use of oral rinses, topical anesthetics, prophylactic antimicrobials and systemic analgesics such as opioids. Novel therapies, such as methylene blue oral rinse, are being investigated, with positive outcomes. Therefore, there is a need to identify treatment modalities for pain of CTIOM. Ideally, this should be noninvasive, safe and cost-effective, while providing sustained analgesia.

Methylene blue relieves the development of osteoarthritis by upregulating lncRNA MEG3

Methylene blue (MB) is a long-term inhibitor of peripheral nerve axons, thereby alleviating or permanently eliminating pain. However, it remains unknown whether MB is safe and effective method of treating osteoarthritis (OA). MB was injected into the knee joints of rabbits and they were monitored for any histological structural changes. The results revealed no evident changes in the histological structure of the normal knee joint following injection of 1 mg/kg MB at 1, 4, 8 and 24 weeks post-injection. Compared with the vehicle control, MB treatment significantly enhanced the weight distribution and significantly decreased the swelling ratio of the rabbits. Additionally, levels of long non-coding RNA (lncRNA) maternally expressed 3 (MEG3) mRNA were significantly increased following treatment with MB, but the protein expression of P2X purinoceptor 3 (P2X3) was significantly suppressed compared with the vehicle control. The levels of interleukin (IL) 6, tumor necrosis factor (TNF)α, IL-1β and IL-8 were significantly suppressed following MB treatment, indicating that MB protects against OA progression. It was also revealed that MEG3 overexpression significantly suppresses levels of P2X3 protein. ELISA indicated that the MEG3-induced reduction of IL-6, TNFα, IL-1β and IL-8 expression was significantly reversed following P2X3 overexpression. Therefore, the results of the present study demonstrated that MB is an effective method of treating OA-associated pain by upregulating lncRNA MEG3 levels. Additionally, lncRNA MEG3 relieves the OA-associated pain and inflammation in a rabbit model of OA by inhibiting P2X3 expression.

New Frontiers in the Pathobiology and Treatment of Cancer Regimen-Related Mucosal Injury

Mucositis is a common complication of chemotherapy, radiotherapy and targeted agents. It often affects compliance to anticancer therapies as it frequently causes schedule delays, interruptions or discontinuations of treatment. Moreover, the economic impact related to the management of mucositis is topical and several estimations of additional hospital costs due to this clinical condition have been recently reported. The ability to determine risk factors for mucositis, to early detect its onset, to assess correctly the degree of this toxicity and to plan its multidisciplinary management are all key elements to guarantee the quality of life of patients and to avoid useless dose reduction or interruption of treatment. The pathogenesis of mucositis is multifactorial and it is classily subdivided into oral and gastrointestinal mucositis according to its anatomic presentation. Treatment and patients’ related factors might help in predicting the frequency and the potential degree of symptoms onset. Here we discuss about clinical presentation and pathogenesis of mucositis in relation to different kinds of treatments. Moreover, we focus on therapeutic and prevention strategies, describing past and present management according to international guidelines and the most promising new data about agents potentially able to further improve the treatment of mucositis in the next future.