Beneficial Effects of Adjuvant Melatonin in Minimizing Oral Mucositis Complications in Head and Neck Cancer Patients Receiving Concurrent Chemoradiation

Significance of Melatonin in the Regulation of Circadian Rhythms and Disease Management

Melatonin, the 'hormone of darkness' is a neuronal hormone secreted by the pineal gland and other extra pineal sites. Responsible for the circadian rhythm and seasonal behaviour of vertebrates and mammals, melatonin is responsible for regulating various physiological conditions and the maintenance of sleep, body weight and the neuronal activities of the ocular sites. With its unique amphiphilic structure, melatonin can cross the cellular barriers and elucidate its activities in the subcellular components, including mitochondria. Melatonin is a potential scavenger of oxygen and nitrogen-reactive species and can directly obliterate the ROS and RNS by a receptor-independent mechanism. It can also regulate the pro- and anti-inflammatory cytokines in various pathological conditions and exhibit therapeutic activities against neurodegenerative, psychiatric disorders and cancer. Melatonin is also found to show its effects on major organs, particularly the brain, liver and heart, and also imparts a role in the modulation of the immune system. Thus, melatonin is a multifaceted candidate with immense therapeutic potential and is still considered an effective supplement on various therapies. This is primarily due to rectification of aberrant circadian rhythm by improvement of sleep quality associated with risk development of neurodegenerative, cognitive, cardiovascular and other metabolic disorders, thereby enhancing the quality of life.

Melatonin and oral diseases: possible therapeutic roles based on cellular mechanisms

Oral diseases, including periodontal disorders, oral cancer, periodontitis, and mucositis are the major challenges for both patients and healthcare providers. These conditions often involve inflammation, oxidative stress, and impaired cellular processes, leading to symptoms ranging from discomfort to severe debilitation. Conventional treatments for such oral diseases exhibit constraints, prompting the investigation of innovative therapeutic approaches. Considering the anti-inflammatory, anti-oxidant, and anti-cancer effects of melatonin, this study was carried out to investigate the potential protective effects of melatonin in mitigating the severity of oral diseases. Studies indicate that melatonin influences the differentiation of periodontal stem cells, inhibits oral cancer progression, reduces inflammation associated with periodontitis, and alleviates the severity of oral mucositis. Melatonin has demonstrated potential efficacy in both preclinical and clinical investigations; however, findings are frequently heterogeneous and contingent upon contextual factors. This review provides a comprehensiveoverview of current state of knowledge in this domain, elucidating the multifaceted role that melatonin may assume in combatingoral diseases. Further research should be directed toward determining the most effective dosing, timing, and administration methods for melatonin-based therapies for oral diseases.

Efficacy of nonpharmacological interventions for severe radiation-induced oral mucositis among head and neck cancer patients: A network meta-analysis of randomised controlled trials

AIMS AND OBJECTIVES

To assess the effectiveness of different nonpharmacological treatments for severe radiation-induced oral mucositis in patients with head and neck cancer.

BACKGROUND

Radiation-induced oral mucositis is highly prevalent in patients with head and neck cancer. Current medications for radiation-induced oral mucositis are limited in effectiveness and susceptible to side effects, and while there is an increasing adoption of nonpharmacological interventions, the optimal one remains unclear.

DESIGN

Systematic review and network meta-analysis based on the PRISMA-NMA guidelines.

METHODS

Six databases were searched. Two authors independently performed the literature screening, data extraction and methodological quality assessment of the included studies. Traditional pairwise meta-analysis was performed by R Studio. A network meta-analysis was then conducted to assess the effects of nonpharmacological interventions for severe radiation-induced oral mucositis in patients with head and neck cancer.

RESULTS

Fifty-two studies involving seven types of nonpharmacological interventions were enrolled. The network meta-analysis indicated that natural plant-based therapies might be the most effective, health education interventions might be the second most effective, and honey might be the third most effective interventions for reducing the incidence of severe radiation-induced oral mucositis. For reducing the incidence of severe oral mucositis-related pain, the pairwise meta-analysis showed that only natural plant-based therapies and health education interventions were effective.

CONCLUSIONS

Nonpharmacological interventions are effective in the management of severe radiation-induced oral mucositis among patients with head and neck cancer.

RELEVANCE TO CLINICAL PRACTICE

Nonpharmacological interventions are a category of safe and effective adjunctive therapies that should be encouraged in clinical practice.

TRIAL REGISTRATION DETAILS

CRD42023400745.

Systemic Anti-Inflammatory Agents in the Prevention of Chemoradiation-Induced Mucositis: A Review of Randomised Controlled Trials

Mucositis is a pathological condition characterised by inflammation and ulceration of the mucous membranes lining the alimentary canal, particularly in the mouth (oral mucositis) and the gastrointestinal tract. It is a common side effect of cancer treatments, including chemotherapy and radiotherapy, and it is sometimes responsible for treatment interruptions. Preventing mucositis throughout the alimentary tract is therefore crucial. However, current interventions mainly target either oral or gastrointestinal side effects. This review aimed to investigate the use of systemically administered anti-inflammatory agents to prevent mucositis in cancer patients undergoing cancer treatment. PubMed, Ovid, Scopus, Web of Science, WHO ICTRP and ClinicalTrials.gov were screened to identify eligible randomised controlled trials (RCTs). The published literature on anti-inflammatory agents provides mixed evidence regarding the degree of efficacy in preventing/reducing the severity of mucositis in most anticancer treatments; however, sample size continued to be a significant limitation, alongside others discussed. Our review yielded a list of several anti-inflammatory agents that exhibit potential mucositis-preventive effects in cancer patients undergoing cancer treatment, which can be used to inform clinical practice.

The Potential of Integrative Cancer Treatment Using Melatonin and the Challenge of Heterogeneity in Population-Based Studies: A Case Report of Colon Cancer and a Literature Review

Melatonin is a multifunctional hormone regulator that maintains homeostasis through circadian rhythms, and desynchronization of these rhythms can lead to gastrointestinal disorders and increase the risk of cancer. Preliminary clinical studies have shown that exogenous melatonin alleviates the harmful effects of anticancer therapy and improves quality of life, but the results are still inconclusive due to the heterogeneity of the studies. A personalized approach to testing clinical parameters and response to integrative treatment with nontoxic and bioavailable melatonin in patient-centered N-of-1 studies deserves greater attention. This clinical case of colon cancer analyzes and discusses the tumor pathology, the adverse effects of chemotherapy, and the dynamics of markers of inflammation (NLR, LMR, and PLR ratios), tumors (CEA, CA 19-9, and PSA), and hemostasis (D-dimer and activated partial thromboplastin time). The patient took melatonin during and after chemotherapy, nutrients (zinc, selenium, vitamin D, green tea, and taxifolin), and aspirin after chemotherapy. The patient's PSA levels decreased during CT combined with melatonin (19 mg/day), and melatonin normalized inflammatory markers and alleviated symptoms of polyneuropathy but did not help with thrombocytopenia. The results are analyzed and discussed in the context of the literature on oncostatic and systemic effects, alleviating therapy-mediated adverse effects, association with survival, and N-of-1 studies.

Potential of melatonin to reverse epigenetic aberrations in oral cancer: new findings

It is now an accepted principle that epigenetic alterations cause cellular dyshomeostasis and functional changes, both of which are essential for the initiation and completion of the tumor cycle. Oral carcinogenesis is no exception in this regard, as most of the tumors in the different subsites of the oral cavity arise from the cross-reaction between (epi)genetic inheritance and the huge challenge of environmental stressors. Currently, the biochemical machinery is put at the service of the tumor program, halting the cell cycle, triggering uncontrolled proliferation, driving angiogenesis and resistance to apoptosis, until the archetypes of the tumor phenotype are reached. Melatonin has the ability to dynamically affect the epigenetic code. It has become accepted that melatonin can reverse (epi)genetic aberrations present in oral and other cancers, suggesting the possibility of enhancing the oncostatic capacity of standard multimodal treatments by incorporating this indolamine as an adjuvant. First steps in this direction confirm the potential of melatonin as a countermeasure to mitigate the detrimental side effects of conventional first-line radiochemotherapy. This single effect could produce synergies of extraordinary clinical importance, allowing doses to be increased and treatments not to be interrupted, ultimately improving patients' quality of life and prognosis. Motivated by the urgency of improving the medical management of oral cancer, many authors advocate moving from in vitro and preclinical research, where the bulk of melatonin cancer research is concentrated, to systematic randomized clinical trials on large cohorts. Recognizing the challenge to improve the clinical management of cancer, our motivation is to encourage comprehensive and robust research to reveal the clinical potential of melatonin in oral cancer control. To improve the outcome and quality of life of patients with oral cancer, here we provide the latest evidence of the oncolytic activity that melatonin can achieve by manipulating epigenetic patterns in oronasopharyngeal tissue.

Management of oral mucositis: a systematic review

INTRODUCTION

Oral mucositis is one of the most common complications following chemotherapy and/or head and neck radiotherapy. Various treatments for oral mucositis have been proposed. However, there has still been no review of the most frequent and most effective type of therapy to treat oral mucositis. This systematic review aims to determine the most frequent and effective types of therapy to treat and reduce the severity of oral mucositis.

EVIDENCE ACQUISITION

The literature search was carried out using PRISMA guidelines. Publications included from 2010 to June 2021 with a clinical trial, prospective, and retrospective observational research design. The following databases were used: PubMed, Cochrane Library, and Wiley Online Library. The search was for limited articles published in English, which were screened and analyzed by three authors. The risk of bias of each study was also assessed by three authors simultaneously, using different types of instruments depending on its study design.

EVIDENCE SYNTHESIS

Forty-seven of 1274 journals were included. From 3577 subjects, oral mucositis was more common in males than females (2.12: 1), with a mean age of 56.39 (18-90 years). The most commonly used types of therapy are low-level laser therapy (396 subjects) and lysozyme-based compounds (314 subjects). Meanwhile, the most effective type of therapy is low-level laser therapy.

CONCLUSIONS

Low-level laser therapy is the most commonly used oral mucositis therapy and is also the most effective in reducing the degree of oral mucositis and associated pain.

Quality-of-life outcomes following topical melatonin application against acute radiation dermatitis in patients with early breast cancer: A double-blind, randomized, placebo-controlled trial

The aim of this double-blind, placebo-controlled, randomized study was to investigate whether topical melatonin administered during radiation therapy could increase the quality of life in patients with primary breast cancer. Patients were followed from the first radiation fraction until 3 weeks after the last. The patients applied 1 g of cream to the irradiated area of the skin twice daily, consisting of either 25 mg/g melatonin and 150 mg/g dimethyl sulfoxide, or a placebo cream. Outcomes were the European Organisation for Research and Treatment of Cancer's quality-of-life questionnaires for breast cancer (QLQ-C30 and QLQ-BR23) on the last day of radiation therapy. As a secondary outcome, we evaluated the breast symptom (BS) scores over the entire duration of the trial in a repeated measures linear model. We included 65 patients and had 17 drop-outs, thus totaling 26 and 22 patients in the melatonin and placebo groups, respectively. BS scores on the last day of radiation did not differ between groups (p = .333). However, the linear model analyzing BS for the entire duration showed that melatonin significantly decreased the symptoms (p = .001). There was no difference in the BS score on the last day of radiation, however, we found that the patients in the melatonin group had significantly lower BS scores over the entire duration of the trial.

Effect of melatonin on quality of life and symptoms in patients with cancer: a systematic review and meta-analysis of randomised controlled trials

OBJECTIVE

This study systematically reviewed the effect of melatonin (MLT) on quality of life (QoL) and symptoms among patients with cancer.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Cochrane Library, PubMed, Embase, Web of Science, Medline, CINAHL, Scopus, ClinicalTrials.gov, China Biology Medicine (CBM), ProQuest and Open Grey were searched from inception to November 2021.

ELIGIBILITY CRITERIA

We included randomised controlled trials (RCTs) assessing the effects of MLT on QoL, sleep quality, fatigue, depression, pain, stomatitis rate and stomatitis severity in adult patients with cancer, without language restrictions. Studies that reported the effects of MLT along with other interventions and had incomplete or absent outcome data were excluded.

DATA EXTRACTION AND SYNTHESIS

Two independent reviewers extracted data, and another two reviewers assessed the risk of bias. The risk of bias for each eligible study was assessed using the Cochrane assessment tool. The mean difference or standard mean difference (SMD) with 95% CIs was used in the computation of continuous variables to synthesise data. The relative risk was used for dichotomous outcomes. Heterogeneity was assessed and quantified (I² statistic).

RESULTS

A total of 19 qualified studies that included 2101 patients with cancer (MLT: 1078, control: 1023) were included in the meta-analysis. The results indicated that MLT had no significant effect on QoL (SMD=-0.01, 95% CI (-0.14 to 0.11), p=0.83), sleep quality (SMD=-0.18, 95% CI (-0.62 to 0.26), p=0.42), fatigue (SMD=-0.34, 95% CI (-0.73 to 0.06), p=0.10), pain (SMD=-0.34, 95% CI (-0.7 to 0.02), p=0.06) or stomatitis severity (RR=0.78, 95% CI (0.47 to 1.30), p=0.35). MLT reduced stomatitis rate among patients with cancer (RR=0.47, 95% CI (0.26 to 0.88), p=0.02), except those with head and neck cancer (RR=1.09, 95% CI (0.92 to 1.29), p=0.35). MLT eased depression in patients who received administration for more than 14 days (SMD=-0.14, 95% CI (-0.27 to -0.01), p=0.03) and those who underwent surgery (SMD=-0.17, 95% CI (-0.32 to -0.03), p=0.02).

CONCLUSION

The findings showed that MLT did not improve the QoL, sleep quality, fatigue, pain or stomatitis severity among patients with cancer. It had a limited effect on decreasing the stomatitis rate and easing depression. Different treatments, durations and cancer types were the main sources of heterogeneity. Further large-scale RCTs are urgently needed. In addition, the effects of different combinations of MLT dosage and duration, administration types and joint measures are worthy of further study.

PROSPERO REGISTRATION NUMBER

CRD42021292855.

Investigation of the protective effects of intraperitoneal melatonin in rats receiving laryngeal radiotherapy

OBJECTIVES

To examine the protective effects of melatonin on laryngeal radiation damage.

MATERIALS AND METHODS

31 rats were divided into 4 groups as follows: 1) the control (C) group (n=7), was only injected with intraperitoneal ethanol solution; 2) the melatonin (M) group (n=8), was injected intraperitoneal melatonin solution with 5 mg/kg; 3) the radiotherapy (RT) group (n=8) was given laryngeal radiation after intraperitoneal injection of ethanol solution; 4) the M + RT group (n=8), RT was given 30 minutes after 5 mg/kg dose of melatonin solution was injected. Drug and radiation applications were continued for 5 days. The weight changes of the rats were recorded. At the end of the study, inflammation, neutrophil migration and lymphoid aggregates, collagen distribution, laryngeal glandular structures and biochemical analysis of laryngeal tissues [malondialdehyde (MDA), total oxidant status (TOS) and total antioxidant status (TAS)] were determined.

RESULTS

In the M+RT group, the first day and the 30th weight differences were significantly increased when compared with the RT group (p=0.050). Inflammation, neutrophil migration, lymphoid aggregate, disorganized collagen distribution and loss of glandular tissues were found statistically more in the RT group than in the C group (p<0.05). MDA and TOS levels were in the M + RT group exhibited better values than they did in the RT group (p<0.05). TAS levels was markedly increased in the M + RT group than in the RT group (p<0.001).

CONCLUSION

Administration of melatonin to rats prior receiving laryngeal radiation, decreases the level of oxidative stress markers and increases the level of anti-oxidative markers.

Efficacy of oral and topical antioxidants in the prevention and management of oral mucositis in head and neck cancer patients: a systematic review and meta-analyses

PURPOSE

To evaluate the effectiveness of antioxidants in the prevention and management of oral mucositis in adults undergoing radiotherapy and/or chemotherapy with diagnosed head and neck cancer (HNC) compared to placebo intervention.

METHODS

Cochrane, EMBASE, PubMed, and Web of Science databases were used to search for randomized controlled trials (RCTs) comparing oral or topical antioxidants with placebo in clinically diagnosed HNC adult patients receiving radiotherapy with/without chemotherapy. The primary outcome was to assess the efficacy of the antioxidant to prevent and decrease the incidence/prevalence and severity of oral/oropharyngeal mucositis. The risk of bias was assessed following Cochrane's guidelines.

RESULTS

The database search resulted in 203 records up to February 19, 2021. Thirteen RCTs were included with 650 HNC-diagnosed patients. Included studies showed a statistically significant improvement in mucositis severity score for all antioxidants except melatonin. However, further studies are needed as only one study reported outcomes for zinc, propolis, curcumin, and silymarin. Patients receiving vitamin E were 60% less likely to develop severe mucositis grade 2 or higher than those receiving placebo in one study (P = 0.040). Patients receiving zinc were 95% less likely to develop severe mucositis (grades 3-4) in one study compared to placebo (P = 0.031). One meta-analysis showed no statistical difference in the risk of having severe mucositis (grades 3-4) with 199 patients compared to placebo for honey (n = 2 studies, P = 0.403). Meta-analyses could not be conducted for zinc, propolis, curcumin, melatonin, silymarin, and selenium due to the lack of studies reporting similar outcomes for the same intervention.

CONCLUSION

Though oral and topical antioxidants significantly improved mucositis severity scores in HNC patients receiving radiotherapy with/without chemotherapy in individual studies, the quality of the evidence was low due to the small number of studies and unclear/high-risk bias. Additionally, large RCTs are needed to confirm these results.

Pharmaceutical and nutraceutical activation of FOXO3 for healthy longevity

Life expectancy has increased substantially over the last 150 years. Yet this means that now most people also spend a greater length of time suffering from various age-associated diseases. As such, delaying age-related functional decline and extending healthspan, the period of active older years free from disease and disability, is an overarching objective of current aging research. Geroprotectors, compounds that target pathways that causally influence aging, are increasingly recognized as a means to extend healthspan in the aging population. Meanwhile, FOXO3 has emerged as a geroprotective gene intricately involved in aging and healthspan. FOXO3 genetic variants are linked to human longevity, reduced disease risks, and even self-reported health. Therefore, identification of FOXO3-activating compounds represents one of the most direct candidate approaches to extending healthspan in aging humans. In this work, we review compounds that activate FOXO3, or influence healthspan or lifespan in a FOXO3-dependent manner. These compounds can be classified as pharmaceuticals, including PI3K/AKT inhibitors and AMPK activators, antidepressants and antipsychotics, muscle relaxants, and HDAC inhibitors, or as nutraceuticals, including primary metabolites involved in cell growth and sustenance, and secondary metabolites including extracts, polyphenols, terpenoids, and other purified natural compounds. The compounds documented here provide a basis and resource for further research and development, with the ultimate goal of promoting healthy longevity in humans.

Modulation of the immune system by melatonin; implications for cancer therapy

Immune system interactions within the tumour have a key role in the resistance or sensitization of cancer cells to anti-cancer agents. On the other hand, activation of the immune system in normal tissues following chemotherapy or radiotherapy is associated with acute and late effects such as inflammation and fibrosis. Some immune responses can reduce the efficiency of anti-cancer therapy and also promote normal tissue toxicity. Modulation of immune responses can boost the efficiency of anti-tumour therapy and alleviate normal tissue toxicity. Melatonin is a natural body agent that has shown promising results for modulating tumour response to therapy and also alleviating normal tissue toxicity. This review tries to focus on the immunomodulatory actions of melatonin in both tumour and normal tissues. We will explain how anti-cancer drugs may cause toxicity for normal tissues and how tumours can adapt themselves to ionizing radiation and anti-cancer drugs. Then, cellular and molecular mechanisms of immunoregulatory effects of melatonin alone or combined with other anti-cancer agents will be discussed.

Safety of higher doses of melatonin in adults: A systematic review and meta-analysis

Melatonin is commonly used for sleep and jetlag at low doses. However, there is less documentation on the safety of higher doses, which are being increasingly used for a wide variety of conditions, including more recently COVID-19 prevention and treatment. The aim of this review was to investigate the safety of higher doses of melatonin in adults. Medline, Scopus, Embase and PsycINFO databases from inception until December 2019 with convenience searches until October 2020. Randomised controlled trials investigating high-dose melatonin (≥10 mg) in human adults over 30 years of age were included. Two investigators independently abstracted articles using PRISMA guidelines. Risk of bias was assessed by a committee of three investigators. 79 studies were identified with a total of 3861 participants. Studies included a large range of medical conditions. The meta-analysis was pooled data using a random effects model. The outcomes examined were the number of adverse events (AEs), serious adverse events (SAEs) and withdrawals due to AEs. A total of 29 studies (37%) made no mention of the presence or absence of AEs. Overall, only four studies met the pre-specified low risk of bias criteria for meta-analysis. In that small subset, melatonin did not cause a detectable increase in SAEs (Rate Ratio = 0.88 [0.52, 1.50], p = .64) or withdrawals due to AEs (0.93 [0.24, 3.56], p = .92), but did appear to increase the risk of AEs such as drowsiness, headache and dizziness (1.40 [1.15, 1.69], p < .001). Overall, there has been limited AE reporting from high-dose melatonin studies. Based on this limited evidence, melatonin appears to have a good safety profile. Better safety reporting in future long-term trials is needed to confirm this as our confidence limits were very wide due to the paucity of suitable data.

Hydrogen Ion Dynamics as the Fundamental Link between Neurodegenerative Diseases and Cancer: Its Application to the Therapeutics of Neurodegenerative Diseases with Special Emphasis on Multiple Sclerosis

The pH-related metabolic paradigm has rapidly grown in cancer research and treatment. In this contribution, this recent oncological perspective has been laterally assessed for the first time in order to integrate neurodegeneration within the energetics of the cancer acid-base conceptual frame. At all levels of study (molecular, biochemical, metabolic, and clinical), the intimate nature of both processes appears to consist of opposite mechanisms occurring at the far ends of a physiopathological intracellular pH/extracellular pH (pHi/pHe) spectrum. This wide-ranging original approach now permits an increase in our understanding of these opposite processes, cancer and neurodegeneration, and, as a consequence, allows us to propose new avenues of treatment based upon the intracellular and microenvironmental hydrogen ion dynamics regulating and deregulating the biochemistry and metabolism of both cancer and neural cells. Under the same perspective, the etiopathogenesis and special characteristics of multiple sclerosis (MS) is an excellent model for the study of neurodegenerative diseases and, utilizing this pioneering approach, we find that MS appears to be a metabolic disease even before an autoimmune one. Furthermore, within this paradigm, several important aspects of MS, from mitochondrial failure to microbiota functional abnormalities, are analyzed in depth. Finally, and for the first time, a new and integrated model of treatment for MS can now be advanced.

Vital Signs Monitoring Based on Interferometric Fiber Optic Sensors

Due to the improvement of living standards, people’s attention to health has gradually increased. More and more people are willing to spend money and time on health management. This article reviews work on the vital signs monitoring system based on fiber optic interferometers, including the design of sensor structures, signal demodulation methods and data analysis. After a large number of trials, the system can achieve long-term stable heart rate (HR), respiration rate (RR) and body temperature monitoring, and the collected data can be used for health analysis. Due to the high sensitivity, low cost, and light weight of the interferometric fiber optic sensor, it can be integrated under a mattress or a cushion, which is very suitable for daily use. The system has great application prospects in the field of healthcare.

Usefulness of Melatonin and Other Compounds as Antioxidants and Epidrugs in the Treatment of Head and Neck Cancer

Along with genetic mutations, aberrant epigenetic alterations are the initiators of head and neck cancer carcinogenesis. Currently, several drugs are being developed to correct these epigenetic alterations, known as epidrugs. Some compounds with an antioxidant effect have been shown to be effective in preventing these malignant lesions and in minimizing the complications derived from cytotoxic treatment. Furthermore, in vitro and in vivo studies show a promising role in the treatment of head and neck squamous cell carcinoma (HNSCC). This is the case of supplements with DNA methylation inhibitory function (DNMTi), such as epigallocatechin gallate, sulforaphane, and folic acid; histone deacetylase inhibitors (HDACi), such as sodium butyrate and melatonin or histone acetyltransferase inhibitors (HATi), such as curcumin. The objective of this review is to describe the role of some antioxidants and their epigenetic mechanism of action, with special emphasis on melatonin and butyric acid given their organic production, in the prevention and treatment of HNSCC.

Nattokinase crude extract enhances oral mucositis healing

Background

Nattokinase (NK) is a promising alternative in the prevention and treatment of cardiovascular diseases due to its potent fibrinolytic activity. In this study, we investigated the effect of crude nattokinase extract on the healing of acetic acid-induced oral mucositis in mice.

Methods

Bacillus subtilis culture media (BSCM) was isolated into the supernatant, named nattokinase crude extract (NCE), and the pellet was named Bacillus subtilis mass (BSM). An oral mucositis model was established in mice by applying 50% glacial acetic acid to the buccal mucosa. According to the treatment conditions, the mice were divided into BSCM, NCE, BSM and phosphate buffered saline (PBS) groups. The weight of the mice, oral mucositis healing score and histopathological examination were used to evaluate the treatment.

Results

Fibrinolytic activities of BSCM, NCE and BSM were approximately 8069, 10,800 and 80 U/ml, respectively. The weight gain of mice in the NCE group was significantly different from the PBS group after three days’ treatment (p < 0.05). The oral mucositis score of NCE group was significantly higher than other groups (p < 0.05). The differences in histopathology scores between the NCE and other groups were statistically significant (p < 0.01).

Conclusions

NCE could possess remarkable potential to reduce pain and promote oral mucositis healing with minimal safety concerns. In this study, we first report that NCE from the supernatant of Bacillus subtilis can promote the healing of oral mucositis, which extends the application scope of NK.

The Effects of Melatonin Administration on Intestinal Injury Caused by Abdominal Irradiation from Mice

Intestinal injury caused by ionizing radiation (IR) is a main clinical issue for patients with cancer receiving abdominal or pelvic radiotherapy. Melatonin (N-acetyl-5-methoxytryptamine) is a neurohormone that the pineal gland in the brain normally secretes. The study aimed to disclose the potential function of melatonin in intestinal injury induced by IR and its mechanism. Pretreatment with melatonin enhanced the 30-day survival rate of the irradiated mice and promoted the recovery of the intestinal epithelium and hematopoietic function following abdominal irradiation (ABI). Melatonin altered the gene profile of the small intestines from mice following ABI. The enriched biological process terms for melatonin treatment prior to radiation were mainly involved in the immune process. LPS/IL-1-mediated inhibition of RXR Function, TWEAK signaling, and Toll-like receptor signaling were the most activated canonical pathways targeted by melatonin. An upstream analysis network showed that Tripartite motif-containing 24 (TRIM24) was the most significantly inhibited and S100 calcium binding protein A9 (S100A9) activated. TRIM24 activated atherogenesis and cell viability in breast cancer cell lines and S100A9 inhibited the metabolism of amino acids. Melatonin has radioprotective effects on ABI-caused intestinal injury. The mechanisms behind the beneficial effects of melatonin were involved in activation of the immunity. It is necessary to conduct further experiments to explore the underlying mechanisms.

Salivary Gland Hypofunction and/or Xerostomia Induced by Nonsurgical Cancer Therapies: ISOO/MASCC/ASCO Guideline

PURPOSE

To provide evidence-based recommendations for prevention and management of salivary gland hypofunction and xerostomia induced by nonsurgical cancer therapies.

METHODS

Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology (MASCC/ISOO) and ASCO convened a multidisciplinary Expert Panel to evaluate the evidence and formulate recommendations. PubMed, EMBASE, and Cochrane Library were searched for randomized controlled trials published between January 2009 and June 2020. The guideline also incorporated two previous systematic reviews conducted by MASCC/ISOO, which included studies published from 1990 through 2008.

RESULTS

A total of 58 publications were identified: 46 addressed preventive interventions and 12 addressed therapeutic interventions. A majority of the evidence focused on the setting of radiation therapy for head and neck cancer. For the prevention of salivary gland hypofunction and/or xerostomia in patients with head and neck cancer, there is high-quality evidence for tissue-sparing radiation modalities. Evidence is weaker or insufficient for other interventions. For the management of salivary gland hypofunction and/or xerostomia, intermediate-quality evidence supports the use of topical mucosal lubricants, saliva substitutes, and agents that stimulate the salivary reflex.

RECOMMENDATIONS

For patients who receive radiation therapy for head and neck cancer, tissue-sparing radiation modalities should be used when possible to reduce the risk of salivary gland hypofunction and xerostomia. Other risk-reducing interventions that may be offered during radiation therapy for head and neck cancer include bethanechol and acupuncture. For patients who develop salivary gland hypofunction and/or xerostomia, interventions include topical mucosal lubricants, saliva substitutes, and sugar-free lozenges or chewing gum. For patients with head and neck cancer, oral pilocarpine and oral cevimeline, acupuncture, or transcutaneous electrostimulation may be offered after radiation therapy.Additional information can be found at www.asco.org/supportive-care-guidelines.

Oral Administration of Melatonin or Succinyl Melatonin Niosome Gel Benefits 5-FU-Induced Small Intestinal Mucositis Treatment in Mice

Mucositis is one of the most adverse effects of 5-fluorouracil (5-FU) and had no standard drug for treatment. Melatonin is a neurohormone, and can ameliorate radiotherapy-induced small intestinal mucositis. Melatonin encapsulated in niosomes improved its poor bioavailability. Succinyl melatonin, a melatonin derivative, showed prolonged release compared with melatonin. This study investigated the efficacy of melatonin niosome gel (MNG) and succinyl melatonin niosome gel (SNG) in 5-FU-induced small intestinal mucositis treatment in mice. MNG and SNG with particle sizes of 293 and 270 nm were shown to have mucoadhesive potentials. The effect of a daily oral application of MNG, SNG, or fluocinolone acetonide gel (FAG, positive control) was compared to that of the normal group. The body weight, food consumption, histology, Fourier transform infrared (FTIR) spectroscopy, inflammatory cytokines (tumor necrosis factor (TNF)-α and interleukin (IL)-1β), and malondialdehyde (MDA) in the small intestine were monitored. The results showed decreased %body weight and food consumption in all 5-FU-injected groups compared with the normal group. The MNG and SNG treatments maintained the food consumption and the normal integrity of the small intestines, as evidenced by villus length and crypt depth, similar to the observations in the normal groups. The FTIR spectra showed no change in lipids of the MNG and SNG groups compared with the normal group. Moreover, SNG could reduce IL-1β content to a level that was not different from the level in the normal groups. Therefore, the oral application of MNG and SNG could protect against 5-FU-induced small intestinal mucositis in mice.

Metabolic Rewiring in Radiation Oncology Toward Improving the Therapeutic Ratio

To meet the anabolic demands of the proliferative potential of tumor cells, malignant cells tend to rewire their metabolic pathways. Although different types of malignant cells share this phenomenon, there is a large intracellular variability how these metabolic patterns are altered. Fortunately, differences in metabolic patterns between normal tissue and malignant cells can be exploited to increase the therapeutic ratio. Modulation of cellular metabolism to improve treatment outcome is an emerging field proposing a variety of promising strategies in primary tumor and metastatic lesion treatment. These strategies, capable of either sensitizing or protecting tissues, target either tumor or normal tissue and are often focused on modulating of tissue oxygenation, hypoxia-inducible factor (HIF) stabilization, glucose metabolism, mitochondrial function and the redox balance. Several compounds or therapies are still in under (pre-)clinical development, while others are already used in clinical practice. Here, we describe different strategies from bench to bedside to optimize the therapeutic ratio through modulation of the cellular metabolism. This review gives an overview of the current state on development and the mechanism of action of modulators affecting cellular metabolism with the aim to improve the radiotherapy response on tumors or to protect the normal tissue and therefore contribute to an improved therapeutic ratio.

Narrative review of the management of oral mucositis during chemoradiation for head and neck cancer

Oral mucositis (OM) can be a significant problem for patients undergoing radiation or chemoradiation for head and neck cancer. In modern clinical trials, grade 3-4 OM can be seen in over 40% of patients and can cause a significant impact on their quality of life (QOL). Despite this fact, strategies for the prevention and treatment of OM vary widely, with options including both lifestyle modifications and pharmaceuticals. Here we evaluate and summarize the current clinical interventions for the management of radiation-induced OM. The majority of the current evidence focuses on reducing OM related pain. These agents are detailed over multiple clinical trials including treatment modalities such as: GC4419, doxepin mouthwash, diphenhydramine-lidocaine-antacid (DLA) mouthwash, gabapentin, and methadone. While several strategies have been employed to prevent radiation-induced OM, there is currently no strong evidence for the routine use of these agents in the clinic. After summarization of these treatments, we offer practical guidance for the treatment of OM in the clinic. We recommend a multiagent approach of pharmacological and non-pharmacological treatments including oral rinses, home humidification, escalating doses of gabapentin, doxepin or DLA mouthwash, over the counter analgesics, and lastly methadone. These interventions are tailored to address the expected increase of severity of symptoms during the course of head and neck radiotherapy.

Melatonin indirectly decreases gastric cancer cell proliferation and invasion via effects on cancer-associated fibroblasts

AIMS

Gastric cancer is a malignant tumor with a poor prognosis, and the interaction between tumor cells and cancer-associated fibroblasts (CAFs) further contributes to progression and treatment failure. Recent studies have revealed the potential value of melatonin in cancer therapy, but its role in gastric cancer and CAFs requires further exploration.

MAIN METHODS

CAFs were isolated using the tissue block method. Cell Counting Kit-8 and cell cycle assays were used to determine the cell proliferation ability, while the cell metastatic capacity was detected by a wound healing assay and Transwell migration/invasion assay. Furthermore, the expression levels of proteins involved were examined using quantitative real-time PCR (qRT-PCR) and western blotting.

KEY FINDINGS

Melatonin not only inhibits cell proliferation and metastasis by reducing the production of reactive oxygen species (ROS) in gastric cancer cells but also inhibits CAFs-induced gastric cancer cell progression by reducing the production of metalloproteinase 2 (MMP2) and metalloproteinase 2 (MMP9) in CAFs. The direct and indirect inhibitory effects of melatonin on gastric cancer cells are involved in the NF-kB signaling pathways.

SIGNIFICANCE

This study provides insights into the role of melatonin in the tumor microenvironment, further deepens available knowledge regarding the mechanism of action of melatonin in gastric cancer and suggests the potential value of melatonin in gastric cancer treatment.

Status of Treatment and Prophylaxis for Radiation-Induced Oral Mucositis in Patients With Head and Neck Cancer

Radiation-induced oral mucositis (RIOM) is one of the most frequent complications in head and neck cancer (HNC) patients undergoing radiotherapy (RT). It is a type of mucosal injury associated with severe pain, dysphagia, and other symptoms, which leads to the interruption of RT and other treatments. Factors affecting RIOM include individual characteristics of HNC patients, concurrent chemoradiation therapy, and RT regimen, among others. The pathogenesis of RIOM is not yet fully understood; however, the release of inflammatory transmitters plays an important role in the occurrence and development of RIOM. The five biological stages, including initiation, primary damage response, signal amplification, ulceration, and healing, are widely used to describe the pathophysiology of RIOM. Moreover, RIOM has a dismal outcome with limited treatment options. This review will discuss the epidemiology, pathogenesis, clinical appearance, symptomatic treatments, and preventive measures related to this disease. We hope to provide a reference for the clinical treatment and prevention of RIOM in HNC patients after RT.

Ocoxin as a complement to first line treatments in cancer

Chemotherapy and radiotherapy are the most frequent treatment for patients suffering from malignant progression of cancer. Even though new treatments are now being implemented, administration of these chemotherapeutic agents remains as the first line option in many tumor types. However, the secondary effects of these compounds represent one of the main reasons cancer patients lose life quality during disease progression. Recent data suggests that Ocoxin, a plant extract and natural compound based nutritional complement rich in antioxidants and anti-inflammatory mediators exerts a positive effect in patients receiving chemotherapy and radiotherapy. This mixture attenuates the chemotherapy and radiotherapy-related side effects such as radiation-induced skin burns and mucositis, chemotherapy-related diarrhea, hepatic toxicity and blood-infection. Moreover, it has been proven to be effective as anticancer agent in different tumor models both in vitro and in vivo, potentiating the cytotoxic effect of several chemotherapy compounds such as Lapatinib, Gemcitabine, Paclitaxel, Sorafenib and Irinotecan. The aim of this review is to put some light on the potential of this nutritional mixture as an anticancer agent and complement for the standard chemotherapy routine.

Toxicities Caused by Head and Neck Cancer Treatments and Their Influence on the Development of Malnutrition: Review of the Literature

Malnutrition poses a significant problem for oncology patients, resulting in fatalities within this population. Patients with head and neck cancer (HNC) are at high risk, with up to 90% developing malnutrition. Common treatments used for HNC can often lead to adverse side effects, including oral health conditions, gastrointestinal upsets, and several metabolic changes. Consequently, treatments can cause inadequate nutritional intake, resulting in a reduction in energy consumption, and alterations in energy utilization, contributing to the development of malnutrition. Furthermore, the presence of these treatment toxicities, and the related malnutrition can lead to reduced quality of life, weight loss, and psychological distress. There are interventions available (nutritional, medicinal, and physical therapies) that have demonstrated potential effectiveness in reducing the severity of symptomatic toxicities, reducing the risk of malnutrition, and improving survival outcomes of patients with HNC. Based on the findings of this review, there is an urgent need for the implementation or continuation of multi-disciplinary strategies, as well as updated and improved guidelines to assist in the prevention and treatment of malnutrition caused by treatment-related toxicities in patients with HNC.

Pharmacokinetics and Safety of Intravenous, Intravesical, Rectal, Transdermal, and Vaginal Melatonin in Healthy Female Volunteers: A Cross-Over Study

INTRODUCTION

We aimed to investigate the pharmacokinetic properties and safety of melatonin administered by alternative routes of administration.

METHODS

This study employed a cross-over design in healthy female volunteers. Twenty-five milligrams of melatonin was administered intravenously, intravesically, rectally, transdermally, and vaginally. Blood samples were collected at specified time points up to 24 h following intravenous, intravesical, rectal, and vaginal administration, and up to 48 h following transdermal administration. Plasma melatonin concentrations were determined by radioimmunoassay. Sedation was evaluated by a simple reaction-time test, and sleepiness was assessed by the Karolinska Sleepiness Scale. Adverse events were registered for each route of administration.

RESULTS

Ten participants were included. We documented a mean (SD) time to maximal concentration of 51 (29) min for intravesical, 24 (20) min for rectal, 21 (8) h for transdermal, and 147 (56) min for vaginal administration. The mean (SD) elimination half-life was 47 (6) min for intravenous, 58 (7) min for intravesical, 60 (18) min for rectal, 14.6 (11.1) h for transdermal, and 129 (17) min for vaginal administration. The mean (SD) bioavailability was 3.6 (1.9)% for intravesical, 36.0 (28.6)% for rectal, 10.0 (5.7)% for transdermal, and 97.8 (31.7)% for vaginal administration. No significant changes in reaction times were observed following administration of melatonin by any of the administration routes. Increased tiredness was documented following transdermal administration only. No serious adverse effects were documented.

CONCLUSION

Rectally and vaginally administered melatonin may serve as relevant alternatives to standard oral melatonin therapy. Transdermal delivery of melatonin displayed an extended absorption and can be applied if prolonged effects are intended. Intravesical administration displayed, as expected, a very limited bioavailability. Melatonin administered by these routes of administration was safe.

Melatonin and gastrointestinal cancers: Current evidence based on underlying signaling pathways

Gastrointestinal (GI) cancers, leading causes of cancer-related deaths, have been serious challenging human diseases up to now. Because of high rates of mortality, late-stage diagnosis, metastasis to distant locations, and low effectiveness and adverse events of routine standard therapies, the quality of life and survival time are low in patients with GI cancers. Hence, many efforts need to be done to explore and find novel efficient treatments. Beneficial effects of melatonin have been reported in a wide variety of human diseases. Melatonin has antioxidant, anti-inflammatory, antimicrobial, and anticancer effects. Various studies have showed the regulatory effects of melatonin on apoptotsis, autophagy and angiogenesis; these properties result in the inhibition of invasion, migration, and proliferation of GI cancer cells in vivo and in vitro. Together, this review suggests that melatonin in combination with anticancer agents may improve the efficacy of routine medicine and survival rate of patients with cancer.

Mitigation of radiation-induced hematopoietic system injury by melatonin

BACKGROUND

Increased risks of exposure to accidental radiation events are a concern in today's world. Radiation terror, nuclear explosion, as well as accidental exposure to radioactive sources in some industries pose a threat to the life of exposed persons. Studies have been conducted using some low-toxic agents to mitigate radiation toxicity and increase survival probability for exposed people. In the current study, we aimed to show the mitigation of radiation-induced mortality and bone marrow toxicity using postirradiation treatment with melatonin.

METHOD

Mice whole bodies were exposed to 4 or 7 Gy radiation followed by treatment with melatonin after 24 hours. Survival of mice with or without melatonin, the levels of peripheral cells, transforming growth factor (TGF)-β and 8-hydroxy-2' -deoxyguanosine (8-OHdG) in the bone marrow, as well as the expression of NADPH oxidase (NOX)2 and NOX4 in bone marrow cells were evaluated.

RESULTS

Whole body irradiation led to mortality 30 days after irradiation. However, melatonin treatment reduced mortality. Irradiation also showed severe reduction of lymphocytes, platelets, and red blood cells. The expressions of NOX2 and NOX4, in addition to TGF-β level, were increased after exposure to radiation. Melatonin ameliorated the increased levels of these factors and improved the number of blood cells.

CONCLUSIONS

Melatonin showed ability to mitigate radiation-induced hematopoietic system toxicity and also increased survival rate. These results suggest that melatonin could be a potential mitigator for accidental radiation events.

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.

Oral mucositis among Chinese cancer patients receiving chemotherapy: Effects and management strategies

Oral mucositis is a painful and distressing complication of chemotherapy-induced toxicity in cancer patients that can develop early during the treatment regimen. Previous studies have demonstrated that both oxidative stress and inflammation play a role in the development of the ulceration that is a characteristic of oral mucositis. To date, a few studies have investigated the effect of this complication on the well-being of patients, demonstrating its negative impact on patients' functional ability and quality of life. This effect may entail chemotherapeutic drug dose reduction among patients, in turn reducing their cancer survival rates. Therefore, interventions to address the detrimental effects of oral mucositis on the well-being of cancer patients are required. This review provides an overview of the studies that have examined the negative effects of oral mucositis on Chinese cancer patients undergoing chemotherapy, as well as the interventions shown to be effective in treating this complication, with a focus on interventions utilizing traditional Chinese medicine. Overall, both traditional Chinese medicine-based interventions and interventions involving patient education about effective oral care led by trained nurses were found to be useful in reducing the incidence and severity of oral mucositis among Chinese patients undergoing chemotherapy. Future oral mucositis management plans aiming at effective oral care among cancer patients undergoing chemotherapy should incorporate these types of interventions as integral components to enhance the well-being of these patients.

Melatonin: an endogenous miraculous indolamine, fights against cancer progression

PURPOSE

Melatonin is an amphipathic indolamine molecule ubiquitously present in all organisms ranging from cyanobacteria to humans. The pineal gland is the site of melatonin synthesis and secretion under the influence of the retinohypothalamic tract. Some extrapineal tissues (skin, lens, gastrointestinal tract, testis, ovary, lymphocytes, and astrocytes) also enable to produce melatonin. Physiologically, melatonin regulates various functions like circadian rhythm, sleep-wake cycle, gonadal activity, redox homeostasis, neuroprotection, immune-modulation, and anticancer effects in the body. Inappropriate melatonin secretion advances the aging process, tumorigenesis, visceral adiposity, etc. METHODS: For the preparation of this review, I had reviewed the literature on the multidimensional activities of melatonin from the NCBI website database PubMed, Springer Nature, Science Direct (Elsevier), Wiley Online ResearchGate, and Google Scholar databases to search relevant articles. Specifically, I focused on the roles and mechanisms of action of melatonin in cancer prevention.

RESULTS

The actions of melatonin are primarily mediated by G-protein coupled MT1 and MT2 receptors; however, several intracellular protein and nuclear receptors can modulate the activity. Normal levels of the melatonin protect the cells from adverse effects including carcinogenesis. Therapeutically, melatonin has chronomedicinal value; it also shows a remarkable anticancer property. The oncostatic action of melatonin is multidimensional, associated with the advancement of apoptosis, the arrest of the cell cycle, inhibition of metastasis, and antioxidant activity.

CONCLUSION

The present review has emphasized the mechanism of the anti-neoplastic activity of melatonin that increases the possibilities of the new approaches in cancer therapy.

Safety of dietary supplements use among patients with cancer: A systematic review

Dietary supplements (DS) are commonly taken by patients with cancer, but safety of DS use remains unclear. A systematic literature search was conducted using PubMed, ClinicalTrials.gov, International Pharmaceutical Abstracts and Alt HealthWatch databases from inception through October 12, 2018. Included studies were limited to clinical trials including patients with cancer, DS products as interventions, evaluation of safety endpoints of DS use, and published in English. Sixty-five studies were included to evaluate 20 different DS among patients with 12 types of cancer. Botanical DS (n = 13), vitamins (n = 8), and probiotics/synbiotics (n = 7) were the top 3 types of DS evaluated in these trials. Majority of studied DS appeared safe. Among 19 trials including patients with cancer undergoing chemotherapy, most (n = 18) of studied DS (e.g., vitamins, botanical, omega-3 fatty acid) were found to be safe. Evaluation of DS use and its safety should be regularly incorporated in clinical trials among patients with cancer.

Efficacy of Melatonin in prevention of radiation-induced oral mucositis: A randomized clinical trial

OBJECTIVES

Evaluating the effectiveness of melatonin in prevention of radiation-induced oral mucositis.

MATERIAL AND METHODS

A randomized controlled clinical study was conducted on forty head and neck cancer (HNC) patients undergoing radiotherapy at the Department of Clinical Oncology, Alexandria University, Egypt. Patients were assigned equally to either control group who received conventional treatment or test group who received 20 mg of melatonin along with the conventional treatment. All patients were clinically evaluated for oral mucositis severity and pain at three and six weeks after the start of radiotherapy. Additionally, the total antioxidant capacity (TAC) in patients' saliva samples was assessed at the start of radiotherapy and six weeks later.

RESULTS

92.5% of all patients have experienced oral mucositis with more severity reported in the control group (30%) compared with the test group (5%). Mean pain scores decreased significantly, in the second assessment, in test group rather than the controls. TAC values showed a significant difference between the test and controls with a significant decrease in TAC in the control group.

CONCLUSION

The administration of melatonin with conventional treatment has reduced severe oral mucositis development. It aided in decreasing pain and hindering the reduction of TAC resulting from radiotherapy among the test group compared with controls.

Potential of Melatonin as Adjuvant Therapy of Oral Cancer in the Era of Epigenomics

The wide variety of epigenetic controls available is rapidly expanding the knowledge of molecular biology even overflowing it. At the same time, it can illuminate unsuspected ways of understanding the etiology of cancer. New emerging therapeutic horizons, then, promise to overcome the current antitumor strategies need. The translational utility of this complexity is particularly welcome in oral cancer (OC), in which natural history is alarmingly disappointing due to the invasive and mutilating surgery, the high relapsing rate, the poor quality of life and the reduced survival after diagnosis. Melatonin activates protective receptor-dependent and receptor-independent processes that prevent tissue cancerisation and inhibit progressive tumor malignancy and metastasis. Related evidence has shown that melatonin pleiotropy encompasses gene expression regulation through all the three best-characterized epigenetic mechanisms: DNA methylation, chromatin modification, and non-coding RNA. OC has received less attention than other cancers despite prognosis is usually negative and there are no significant therapy improvements recorded in the past decade. However, a large research effort is being carried out to elucidate how melatonin´s machinery can prevent epigenetic insults that lead to cancer. In the light of recent findings, a comprehensive examination of biochemistry through which melatonin may reverse epigenetic aberrations in OC is an extraordinary opportunity to take a step forward in the clinical management of patients.

Protective Effect of Melatonin Against Radiotherapy-Induced Small Intestinal Oxidative Stress: Biochemical Evaluation

Background and Objectives: Radiation enteritis is a common side effect after radiotherapy for abdominal and pelvic malignancies. The aim of the present study was to investigate the protective effect of melatonin, known for its free radical scavenging ability, against radiotherapy-induced small intestinal oxidative damage. Materials and Methods: Thirty male Wistar rats were randomly assigned to six groups (5 rats in each) as follows: Group I (control group) rats received neither radiation nor melatonin; group II rats received only 8 Gy single dose of gamma radiation to their abdomen and pelvis regions; group III (administered with only 50 mg/kg melatonin); group IV (administered with only 100 mg/kg melatonin); group V (50 mg/kg melatonin + 8 Gy radiation), group VI (100 mg/kg melatonin + 8 Gy radiation). All rats were sacrificed after 5 days for biochemical assessments of their intestinal tissues. Results: Treatment with melatonin post irradiation significantly reduced malondialdehyde (MDA) levels as well as increased both superoxide dismutase (SOD) and catalase (CAT) activities of the irradiated intestinal tissues. In addition, melatonin administration with different doses pre irradiation led to protection of the tissues. Moreover, the 100 mg/kg dose was more effective compared to 50 mg/kg. Conclusions: The results of our study suggest that melatonin has a potent protective effect against radiotherapy-induced intestinal damage, by decreasing oxidative stress and increasing antioxidant enzymes. We recommend future clinical trials for more insights.

Radiation-Induced Heart Diseases: Protective Effects of Natural Products

Cardiovascular diseases (CVDs) account for the majority of deaths worldwide. Radiation-induced heart diseases (RIHD) is one of the side effects following exposure to ionizing radiation (IR). Exposure could be from various forms such as diagnostic imaging, radiotherapy for cancer treatment, as well as nuclear disasters and nuclear accidents. RIHD is mostly observed after radiotherapy for thoracic malignancies, especially left breast cancer. RIHD may affect the supply of blood to heart muscles, leading to an increase in the risk of heart attacks to irradiated persons. Due to its dose-limiting consequence, RIHD has a negative effect on the therapeutic efficacy of radiotherapy. Several methods have been proposed for protection against RIHD. In this paper, we review the use of natural products, which have shown promising results for protection against RIHD.

Potential Therapeutic Effects of Gut Hormones, Ghrelin and Obestatin in Oral Mucositis

Chemotherapy and/or head and neck radiotherapy are frequently associated with oral mucositis. Oral pain, odynophagia and dysphagia, opioid use, weight loss, dehydration, systemic infection, hospitalization and introduction of a feeding tube should be mentioned as the main determinated effect of oral mucositis. Oral mucositis leads to a decreased quality of life and an increase in treatment costs. Moreover, oral mucositis is a life-threatening disease. In addition to its own direct life-threatening consequences, it can also lead to a reduced survival due to the discontinuation or dose reduction of anti-neoplasm therapy. There are numerous strategies for the prevention or treatment of oral mucositis; however, their effectiveness is limited and does not correspond to expectations. This review is focused on the ghrelin and obestatin as potentially useful candidates for the prevention and treatment of chemo- or/and radiotherapy-induced oral mucositis.

Mitochondrial functions and melatonin: a tour of the reproductive cancers

Cancers of the reproductive organs have a strong association with mitochondrial defects, and a deeper understanding of the role of this organelle in preneoplastic-neoplastic changes is important to determine the appropriate therapeutic intervention. Mitochondria are involved in events during cancer development, including metabolic and oxidative status, acquisition of metastatic potential, resistance to chemotherapy, apoptosis, and others. Because of their origin from melatonin-producing bacteria, mitochondria are speculated to produce melatonin and its derivatives at high levels; in addition, exogenously administered melatonin accumulates in the mitochondria against a concentration gradient. Melatonin is transported into tumor cell by GLUT/SLC2A and/or by the PEPT1/2 transporters, and plays beneficial roles in mitochondrial homeostasis, such as influencing oxidative phosphorylation and electron flux, ATP synthesis, bioenergetics, calcium influx, and mitochondrial permeability transition pore. Moreover, melatonin promotes mitochondrial homeostasis by regulating nuclear DNA and mtDNA transcriptional activities. This review focuses on the main functions of melatonin on mitochondrial processes, and reviews from a mechanistic standpoint, how mitochondrial crosstalk evolved in ovarian, endometrial, cervical, breast, and prostate cancers relative to melatonin's known actions. We put emphasis on signaling pathways whereby melatonin interferes within cancer-cell mitochondria after its administration. Depending on subtype and intratumor metabolic heterogeneity, melatonin seems to be helpful in promoting apoptosis, anti-proliferation, pro-oxidation, metabolic shifting, inhibiting neovasculogenesis and controlling inflammation, and restoration of chemosensitivity. This results in attenuation of development, progression, and metastatic potential of reproductive cancers, in addition to lowering the risk of recurrence and improving the life quality of patients.

Melatonin Sensitizes Human Colorectal Cancer Cells to γ-ray Ionizing Radiation In Vitro and In Vivo

Colorectal cancer is the most commonly reported gastrointestinal malignancy, with a recent, rapid increase of the annual incidence all over the world. Enhancing the radiosensitivity of cancer cells while preserving the health of normal cells is one of the most important tasks in clinical radiobiology. However, resistance to radiotherapy for colorectal cancer greatly decreases the therapeutic outcome. Melatonin (N-acetyl-5-methoxytryptamine), a natural secretory product that the pineal gland in the brain normally produces, has been reported to have anticancer properties. In the study, we investigated the combination of melatonin with radiotherapy as a treatment for colorectal cancer. We firstly explored the anti-tumor activity of melatonin combined with ionizing radiation (IR) against colorectal carcinoma in vitro. It was found that melatonin effectively inhibited human colorectal carcinoma cell line HCT 116 cellular proliferation, colony formation rate and cell migration counts following IR. Increasing the radiosensitivity of colorectal cancer cells by melatonin treatment was found to be associated with cell cycle arrest in the G2/M phase, downregulation of proteins involved in DNA double-strand break repair and activation of the caspase-dependent apoptotic pathway. Moreover, we also investigated the combined effect of IR and melatonin on colorectal tumor in vivo. Results from a tumor xenograft showed that melatonin plus IR treatment significantly suppressed tumor cell growth compared with melatonin or IR alone, resulting in a much higher tumor inhibition rate for the combined treatment. The data suggested that melatonin combined with IR could improve the radiosensitivity of colorectal cancer and thus enhance the therapeutic effect of the patients, implying melatonin could function as a potential sensitizer in tumor radiotherapy.

Melatonin May Increase Anticancer Potential of Pleiotropic Drugs

Melatonin (N-acetyl-5-methoxytryptamine) is not only a pineal hormone, but also an ubiquitary molecule present in plants and part of our diet. Numerous preclinical and some clinical reports pointed to its multiple beneficial effects including oncostatic properties, and as such, it has become one of the most aspiring goals in cancer prevention/therapy. A link between cancer and inflammation and/or metabolic disorders has been well established and the therapy of these conditions with so-called pleiotropic drugs, which include non-steroidal anti-inflammatory drugs, statins and peroral antidiabetics, modulates a cancer risk too. Adjuvant therapy with melatonin may improve the oncostatic potential of these drugs. Results from preclinical studies are limited though support this hypothesis, which, however, remains to be verified by further research.

Adverse events associated with oral administration of melatonin: A critical systematic review of clinical evidence

While melatonin was once thought of simply as a sleep-inducing hormone, recent research has resulted in development of a deeper understanding of the complex physiological activity of melatonin in the human body. Along with this understanding has come widespread, increasing use of melatonin supplementation, extending beyond its traditional use as a sleep aid into novel fields of application. This increased use often involves off-label and self-prescription, escalating the importance of safety data. In order to examine the current knowledge relating to safety of the exogenous neurohormone, we conducted a comprehensive, critical systematic review of clinical evidence. We examined controlled studies of oral melatonin supplementation in humans when they presented any statistical analysis of adverse events. Of the fifty articles identified, twenty-six found no statistically significant adverse events, while twenty-four articles reported on at least one statistically significant adverse event. Adverse events were generally minor, short-lived and easily managed, with the most commonly reported adverse events relating to fatigue, mood, or psychomotor and neurocognitive performance. A few studies noted adverse events relating to endocrine (e.g. reproductive parameters, glucose metabolism) and cardiovascular (e.g. blood pressure, heart rate) function, which appear to be influenced by dosage, dose timing and potential interactions with antihypertensive drugs. Oral melatonin supplementation in humans has a generally favourable safety profile with some exceptions. Most adverse effects can likely be easily avoided or managed by dosing in accordance with natural circadian rhythms. Further research is required to explore the potential for melatonin to interact with endogenous hormones and pharmaceuticals.

Depressive symptoms and actigraphy-measured circadian disruption predict head and neck cancer survival

OBJECTIVE

Depressive symptoms have demonstrated prognostic significance among head and neck cancer patients. Depression is associated with circadian disruption, which is prognostic in multiple other cancer types. We hypothesized that depressive symptoms would be associated with circadian disruption in head and neck cancer, that each would be related to poorer 2-year overall survival, and that relationships would be mediated by tumor response to treatment.

METHODS

Patients (N = 55) reported on cognitive/affective and somatic depressive symptoms (PHQ-9) and wore an actigraph for 6 days to continuously record rest and activity cycles prior to chemoradiation. Records review documented treatment response and 2-year survival. Spearman correlations tested depressive symptoms and circadian disruption relationships. Cox proportional hazard models tested the predictive capability of depressive symptoms and circadian disruption, separately, on survival.

RESULTS

Depressive symptoms were significantly associated with circadian disruption, and both were significantly associated with shorter survival (somatic: hazard ratio [HR] = 1.325, 95% confidence interval [CI] = 1.089-1.611, P = .005; rest/activity rhythm: HR = 0.073, 95% CI = 0.009-0.563, P = .012; nighttime restfulness: HR = 0.910, 95% CI = 0.848-0.977, P = .009). Tumor response to treatment appeared to partly mediate the nighttime restfulness-survival relationship.

CONCLUSIONS

This study replicates and extends prior work with new evidence linking a subjective measure of depression and an objective measure of circadian disruption-2 known prognostic indicators-to shortened overall survival among head and neck cancer patients. Continued examination should elucidate mechanisms by which depressive symptomatology and circadian disruption translate to head and neck cancer progression and mortality.

Melatonin as an adjuvant in radiotherapy for radioprotection and radiosensitization

It is estimated that more than half of cancer patients undergo radiotherapy during the course of their treatment. Despite its beneficial therapeutic effects on tumor cells, exposure to high doses of ionizing radiation (IR) is associated with several side effects. Although improvements in radiotherapy techniques and instruments could reduce these side effects, there are still important concerns for cancer patients. For several years, scientists have been trying to modulate tumor and normal tissue responses to IR, leading to an increase in therapeutic ratio. So far, several types of radioprotectors and radiosensitizers have been investigated in experimental studies. However, high toxicity of chemical sensitizers or possible tumor protection by radioprotectors creates a doubt for their clinical applications. On the other hand, the protective effects of these radioprotectors or sensitizer effects of radiosensitizers may limit some type of cancers. Hence, the development of some radioprotectors without any protective effect on tumor cells or low toxic radiosensitizers can help improve therapeutic ratio with less side effects. Melatonin as a natural body hormone is a potent antioxidant and anti-inflammatory agent that shows some anti-cancer properties. It is able to neutralize different types of free radicals produced by IR or pro-oxidant enzymes which are activated following exposure to IR and plays a key role in the protection of normal tissues. In addition, melatonin has shown the ability to inhibit long-term changes in inflammatory responses at different levels, thereby ameliorating late side effects of radiotherapy. Fortunately, in contrast to classic antioxidants, some in vitro studies have revealed that melatonin has a potent anti-tumor activity when used alongside irradiation. However, the mechanisms of its radiosensitive effect remain to be elucidated. Studies suggested that the activation of pro-apoptosis gene, such as p53, changes in the metabolism of tumor cells, suppression of DNA repair responses as well as changes in biosynthesis of estrogen in breast cancer cells are involved in this process. In this review, we describe the molecular mechanisms for radioprotection and radiosensitizer effects of melatonin. Furthermore, some other proposed mechanisms that may be involved are presented.

Mechanisms Underlying Tumor Suppressive Properties of Melatonin

There is considerable evidence that melatonin may be of use in the prevention and treatment of cancer. This manuscript will review some of the human, animal and cellular studies that provide evidence that melatonin has oncostatic properties. Confirmation that melatonin mitigates pathogenesis of cancer will be described from both direct study of its effects on carcinogenesis, and from indirect findings implicating disruption of the circadian cycle. A distinction is made between the role of melatonin in preventing the initiation of the tumorigenic pathway and the ability of melatonin to retard the progression of cancer. Melatonin appears to slow down the rate of advancement of established tumors and there is evidence that it constitutes a valuable complement to standard pharmacological and radiation treatment modalities. There are instances of the beneficial outcomes in cancer treatment which utilize a range of hormones and vitamins, melatonin being among the constituents of the mix. While these complex blends are empirically promising, they are only briefly mentioned here in view of the confounding influence of a multiplicity of agents studied simultaneously. The last section of this review examines the molecular mechanisms that potentially underlie the oncostatic effects of melatonin. Alterations in gene expression following activation of various transcription factors, are likely to be an important mediating event. These changes in gene activity not only relate to cancer but also to the aging process which underlies the onset of most tumors. In addition, epigenetic events such as modulation of histone acetylation and DNA methylation patterns throughout the lifespan of organisms need to be considered. The antioxidant and immunoregulatory roles of melatonin may also contribute to its cancer modulatory properties. Naturally, these mechanisms overlap and interact extensively. Nevertheless, in the interest of clarity and ease of reading, each is discussed as a separate topic section. The report ends with some general conclusions concerning the clinical value of melatonin which has been rather overlooked and understudied.