Therapeutic potential of melatonin and melatonergic drugs on K18-hACE2 mice infected with SARS-CoV-2

As the COVID-19 pandemic grows, several therapeutic candidates are being tested or undergoing clinical trials. Although prophylactic vaccination against SARS-CoV-2 infection has been shown to be effective, no definitive treatment exists to date in the event of infection. The rapid spread of infection by SARS-CoV-2 and its variants fully warrants the continued evaluation of drug treatments for COVID-19, especially in the context of repurposing of already available and safe drugs. Here, we explored the therapeutic potential of melatonin and melatonergic compounds in attenuating COVID-19 pathogenesis in mice expressing human ACE2 receptor (K18-hACE2), strongly susceptible to SARS-CoV-2 infection. Daily administration of melatonin, agomelatine, or ramelteon delays the occurrence of severe clinical outcome with improvement of survival, especially with high melatonin dose. Although no changes in most lung inflammatory cytokines are observed, treatment with melatonergic compounds limits the exacerbated local lung production of type I and type III interferons, which is likely associated with the observed improved symptoms in treated mice. The promising results from this preclinical study should encourage studies examining the benefits of repurposing melatonergic drugs to treat COVID-19 and related diseases in humans.     

氯喹药理特点及用于新型冠状病毒肺炎治疗的建议

2019年底,我国湖北省武汉市出现了新型冠状病毒肺炎疫情,随后在全国扩散并成为全球大流行。由于尚无针对新型冠状病毒的特效治疗药物和疫苗,我国新型冠状病毒感染救治临床专家团队在救治新型冠状病毒感染患者的同时,积极研究和筛选有效抗病毒治疗药物,发现一种古老的抗疟药--氯喹有一定抗新型冠状病毒效果,随后纳入我国新型冠状病毒肺炎诊疗方案。目前,临床应用的是氯喹衍生物磷酸氯喹和硫酸羟氯喹,这两种药物虽药理机制相近,但其治疗对象、疗效和不良反应均存在一定差异。本文拟通过对氯喹类药物已有研究和在疟疾临床治疗中的经验总结,为我国临床专家更科学合理地使用氯喹类药物进行新型冠状病毒肺炎治疗提供参考。     

Melatonin treatment following stroke induction modulates L-arginine metabolism

The efficacy of melatonin treatment in experimental stroke has been established. Some of the neuroprotective properties have been attributed to its anti-oxidant and anti-inflammatory effects. Nitric oxide synthases (NOS) and cyclooxygenases (COX) are considered to have a significant role in the inflammatory milieu occurring in acute stroke. While previous reports have shown that pretreatment with melatonin in a stroke model can modulate NOS isoforms, the effect of post-treatment with melatonin on l-arginine metabolism has not been investigated. This study initially examined the effect of melatonin (1 nm-1 mm) on l-arginine metabolism pathways in human fibrosarcoma fibroblasts (HT-1080) fibroblasts. Evidence of neuroprotection with melatonin was evaluated in rats subjected to middle cerebral artery occlusion (MCAO). Animals were treated with three daily doses of 5 mg/kg i.p., starting 1 hr after the onset of ischemia. Constitutive NOS activity but not expression was significantly increased by in vitro exposure (72 hr) to melatonin. In addition, melatonin treatment increased arginase activity by increasing arginase II expression. In vivo studies showed that melatonin treatment after MCAO significantly inhibited inducible NOS activity and attenuated expression of the inducible isoform, resulting in decreased total NOS activity and tissue nitrite levels. COX activity was significantly reduced with melatonin treatment. The neuroprotective anti-inflammatory effects of melatonin were consistent with the substantial reduction in infarct volume throughout the cortex and striatum and recovery of mitochondrial enzyme activities. The evidence presented here suggests that modulation of l-arginine metabolism by melatonin make it a valuable neuroprotective therapy for stroke.     

COVID-19-related myocarditis and cholinergic anti-inflammatory pathways

Coronavirus disease-2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2, is currently in a pandemic outbreak and has become a global health issue. In addition to the primarily involvement of the respiratory system, myocarditis is considered an important and fatal lesion in patients with COVID-19. However, effective therapeutic methods are currently lacking. The cholinergic anti-inflammatory pathway (CAP) has been demonstrated to suppress pro-inflammatory cytokine production and control inflammation in sepsis and other medical conditions. Therefore, the CAP may be a potential and effective therapeutic method for COVID-19-related myocarditis. This article reviews the relationship between COVID-19-related myocarditis and the CAP and discusses the CAP as a potential therapeutic modality in the treatment of COVID-19-related myocarditis.     

Chloroquine and hydroxychloroquine in the treatment of COVID-19 with or without diabetes: A systematic search and a narrative review with a special reference to India and other developing countries

Background and aimsNo drugs are currently approved for Coronavirus Disease-2019 (COVID-19), although some have been tried. In view of recent studies and discussion on chloroquine and hydroxychloroquine (HCQ), we aimed to review existing literature and relevant websites regarding these drugs and COVID-19, adverse effects related to drugs, and related guidelines.Aims and methodsWe systematically searched the PubMed database up till March 21, 2020 and retrieved all the articles published on chloroquine and HCQ and COVID-19.ResultsTwo small human studies have been conducted with both these drugs in COVID-19, and have shown significant improvement in some parameters in patients with COVID-19.ConclusionConsidering minimal risk upon use, a long experience of use in other diseases, cost-effectiveness and easy availability across India, we propose that both these drugs are worthy of fast track clinical trial for treatment, and may be carefully considered for clinical use as experimental drugs. Since HCQ has been approved for treatment of diabetes in India, it should be further researched in diabetes and COVID-19, a subgroup where significant mortality has been shown.     

Therapeutic potential of melatonin in traumatic central nervous system injury

Abstract:  A vast literature extolling the benefits of melatonin has accumulated during the past four decades. Melatonin was previously considered of importance to seasonal reproduction and circadian rhythmicity. Currently, it appears to be a versatile anti-oxidative and anti-nitrosative agent, a molecule with immunomodulatory actions and profound oncostatic activity, and also to play a role as a potent neuroprotectant. Nowadays, melatonin is sold as a dietary supplement with differential availability as an over-the-counter aid in different countries. There is a widespread agreement that melatonin is nontoxic and safe considering its frequent, long-term usage by humans at both physiological and pharmacological doses with no reported side effects. Endeavors toward a designated drug status for melatonin may be enormously rewarding in clinics for treatment of several forms of neurotrauma where effective pharmacological intervention has not yet been attained. This mini review consolidates the data regarding the efficacy of melatonin as an unique neuroprotective agent in traumatic central nervous system (CNS) injuries. Well-documented actions of melatonin in combating traumatic CNS damage are compiled from various clinical and experimental studies. Research on traumatic brain injury and ischemia/reperfusion are briefly outlined here as they have been recently reviewed elsewhere, whereas the studies on different animal models of the experimental spinal cord injury have been extensively covered in this mini review for the first time.     

Self-prescribed Ivermectin use is associated with a lower rate of seroconversion in health care workers diagnosed with COVID,in a dose-dependent response

BackgroundOver-the-counter use of ivermectin amongst other drugs as SARS-CoV-2 treatment has been increasingly common, despite the lack of evidence on its clinical efficacy.ObjectiveTo evaluate the effect of ivermectin use on production of antibodies against SARS-CoV-2 in health care workers (HCW) diagnosed with COVID-19 and of Th1/Th2 cytokines by stimulated peripheral blood mononuclear cells of the same cohort (PBMCs).MethodsThis cross-sectional study evaluated seroconversion and neutralizing antibodies production in HCW at Complexo Hospitalar Universitário Professor Edgard Santos (Salvador, Brazil), diagnosed with COVID-19 from May to July, 2020, as well as in vitro production of antibody against SARS-CoV-2 and Th1/Th2 cytokines. Analyses were performed between December 2020 and February 2021. Participants were stratified according to the use of ivermectin (≤ 1 dose vs. multiple doses) for treatment of COVID-19.Results45 HCW were included (62% women). Mean age was 39 years, and disease severity was similar across groups. Neutralizing antibodies were detected less frequently in multiple doses (70%) vs. ≤ 1 dose (97%) groups, p = 0.02). PBMCs of patients in multiple doses group also were less likely to produce antibodies against SARS-CoV-2 following in vitro stimulation with purified spike protein in comparison with patients in ≤ 1 dose group (p < 0.001). PBMC´s production of Th1/Th2 cytokines levels was similar across groups. Abdominal pain (15% vs 46%, p = 0.04), diarrhea (21% vs. 55%, p = 0.05) and taste perversion (0% vs. 18%, p = 0.05) were more frequently reported by participants that used multiple doses of ivermectin.ConclusionsAlthough there was no evidence for differential disease severity upon ivermectin use for treatment of COVID-19 it was associated with more gastro-intestinal side-effects and impairment of anti-SARS-CoV2 antibodies production, in a dose dependent manner. This potentially impacts the effectiveness of immune response and the risk of reinfection and warrants additional studies for clarifying the mechanisms and consequences of such immunomodulatory effects.     

High-dose vitamin C intravenous infusion in the treatment of patients with COVID-19: A protocol for systematic review and meta-analysis

Background:Patients infected with a virus usually lack vitamin C. High-dose vitamin C has an antiviral effect, and has been used by several researchers to treat COVID-19 by intravenous infusion, achieving good results. However, the efficacy and safety of vitamin C in the treatment of patients with COVID-19 remain unclear. Thus, the aim of the present study was to investigate the efficacy of high-dose vitamin C infusion in the treatment of patients with COVID-19.Methods:Electronic databases were searched, including PubMed, EMBASE, Cochrane Central Register of Controlled Trials, Web of Science, China National Knowledge Infrastructure database, Chinese Wanfang database, and Chinese Biomedical Literature database. The aim was to collect randomized controlled trials of high-dose vitamin C infusion in the treatment of patients with COVID-19, with the retrieval time being from the establishment of the database to March 2021. In accordance with the pre-designed inclusion/exclusion criteria, all data were extracted independently by 2 researchers. To assess the risk bias in the studies, the Cochrane collaboration''s tool for assessing risk of bias was used to assess the risk bias in the studies, while meta-analysis was performed using Revman 5.3 software.Results:In the present study, a high-quality comprehensive evaluation is provided of high-dose vitamin C infusion in the treatment of patients with COVID-19.Conclusion:Further convincing evidence for the clinical treatment of COVID-19 is provided, in addition to evidence-based guidance for clinical practice.PROSPERO Registration Number:CRD42021246342.     

新型冠状病毒肺炎抗病毒药物与心律失常的关系

新型冠状病毒肺炎(COVID-19)于2019年12月,在中国武汉部分地区爆发以来,疫情来势凶猛,对人类健康构成严重威胁,其病原体为一种β属的新型冠状病毒(2019-nCoV)。针对冠状病毒的治疗目前暂缺乏特效药物,随着疾病认识的深入和诊疗经验的积累,国家卫健委已推出《新型冠状病毒肺炎诊疗方案》试行第六版指导疾病的诊治。目前所试用的抗病毒药物多基于体外试验的结果,尚未经过随机双盲对照试验的检验,其疗效需在临床应用中进一步评价。这些抗病毒药物的心律失常不良反应应予重视。     

COVID-19 vaccination and liver disease

Various vaccines against severe acute respiratory syndrome coronavirus 2 have been developed in response to the coronavirus disease 2019 (COVID-19) global pandemic, several of which are highly effective in preventing COVID-19 in the general population. Patients with chronic liver diseases (CLDs), particularly those with liver cirrhosis, are considered to be at a high risk for severe COVID-19 and death. Given the increased rates of disease severity and mortality in patients with liver disease, there is an urgent need to understand the efficacy of vaccination in this population. However, the data regarding efficacy and safety of COVID-19 vaccination in patients with CLDs is limited. Indeed, several organ-specific or systemic immune-mediated side effects following COVID-19 vaccination, including liver injury similar to autoimmune hepatitis, have been recently reported. Although the number of cases of vaccine-related liver injury is increasing, its frequency, clinical course, and mechanism remain unclear. Here, we review the current findings on COVID-19 vaccination and liver disease, focusing on: (1) The impact of COVID-19 in patients with CLD; (2) The efficacy, safety, and risk-benefit profiles of COVID-19 vaccines in patients with CLD; and (3) Liver injury following COVID-19 vaccination.     

Melatonin and its analogs in insomnia and depression

Benzodiazepine sedative-hypnotic drugs are widely used for the treatment of insomnia. Nevertheless, their adverse effects, such as next-day hangover, dependence and impairment of memory, make them unsuitable for long-term treatment. Melatonin has been used for improving sleep in patients with insomnia mainly because it does not cause hangover or show any addictive potential. However, there is a lack of consistency on its therapeutic value (partly because of its short half-life and the small quantities of melatonin employed). Thus, attention has been focused either on the development of more potent melatonin analogs with prolonged effects or on the design of slow release melatonin preparations. The MT(1) and MT(2) melatonergic receptor ramelteon was effective in increasing total sleep time and sleep efficiency, as well as in reducing sleep latency, in insomnia patients. The melatonergic antidepressant agomelatine, displaying potent MT(1) and MT(2) melatonergic agonism and relatively weak serotonin 5HT(2C) receptor antagonism, was found effective in the treatment of depressed patients. However, long-term safety studies are lacking for both melatonin agonists, particularly considering the pharmacological activity of their metabolites. In view of the higher binding affinities, longest half-life and relative higher potencies of the different melatonin agonists, studies using 2 or 3mg/day of melatonin are probably unsuitable to give appropriate comparison of the effects of the natural compound. Hence, clinical trials employing melatonin doses in the range of 50-100mg/day are warranted before the relative merits of the melatonin analogs versus melatonin can be settled.     

Efficacy and safety of Reyanning mixture combined with conventional Western medicine for treating COVID-19: A protocol for systematic review and meta-analysis

Background:Since its first report in December 2019, coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has rapidly emerged as a pandemic affecting nearly all countries worldwide. So far, there is no specific anti-coronavirus therapy approved for the treatment of COVID-19. In China, some traditional Chinese medicines (TCM) have been successfully applied to the treatment of SARS-CoV-2 and have achieved good clinical results, including the Reyanning mixture, but there is no systematic review about it. This study will systematically evaluate its efficacy and safety in the treatment of COVID-19.Methods:The following electronic bibliographic databases will be searched to identify relevant studies: PubMed, MEDLINE, EMBASE, CNKI, CBM, and Wanfang databases. We will use the Cochrane Handbook for Systematic Reviews of Interventions to assess the risk of bias. The protocol will be conducted according to the approach and Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P). Manager 5.3 software and STATA 16.0 software were used to perform the meta-analysis.Results:The systematic review and meta-analysis aims to review and pool current clinical outcomes of Reyanning mixture for the treatment of COVID-19.Conclusion:The conclusion of this review will provide evidence to judge whether Reyanning mixture combined with Conventional Western Medicine is an effective and safe intervention for COVID-19.INPLASY registration number:INPLASY2020120044.     

Neutralizing Antibody Therapeutics for COVID-19

The emergence of SARS-CoV-2 and subsequent COVID-19 pandemic has resulted in a significant global public health burden, leading to an urgent need for effective therapeutic strategies. In this article, we review the role of SARS-CoV-2 neutralizing antibodies (nAbs) in the clinical management of COVID-19 and provide an overview of recent randomized controlled trial data evaluating nAbs in the ambulatory, hospitalized and prophylaxis settings. Two nAb cocktails (casirivimab/imdevimab and bamlanivimab/etesevimab) and one nAb monotherapy (bamlanivimab) have been granted Emergency Use Authorization by the US Food and Drug Administration for the treatment of ambulatory patients who have a high risk of progressing to severe disease, and the European Medicines Agency has similarly recommended both cocktails and bamlanivimab monotherapy for use in COVID-19 patients who do not require supplemental oxygen and who are at high risk of progressing to severe COVID-19. Efficacy of nAbs in hospitalized patients with COVID-19 has been varied, potentially highlighting the challenges of antiviral treatment in patients who have already progressed to severe disease. However, early data suggest a promising prophylactic role for nAbs in providing effective COVID-19 protection. We also review the risk of treatment-emergent antiviral resistant “escape” mutants and strategies to minimize their occurrence, discuss the susceptibility of newly emerging SARS-COV-2 variants to nAbs, as well as explore administration challenges and ways to improve patient access.     

Remdesivir in COVID-19: A critical review of pharmacology,pre-clinical and clinical studies

Background & aimsRemdesivir is a broad spectrum anti-viral drug that has shown to inhibit SARS-CoV-2, in vitro and in vivo. In absence of any effective treatment for SARS-CoV-2 infection (COVID-19), remdesivir has been tried for a compassionate use in severe COVID-19. Newer randomized controlled studies that have recently become available, showed a mixed result. We aimed to systematically search the literature to understand the pharmacology and clinical effects of remdesivir in patients with COVID-19.MethodsWe systematically searched the PubMed, ClinicalTrial.Org and MedRxiv database up till May 5, 2020 using specific key words such as “Remdesivir” or ‘GS-5734″ AND “COVID-19” or “SARS-CoV-2” and retrieved all the article published in English language, that have reported the pharmacology and the clinical outcomes of remdesivir in patients with COVID-19.ResultsInitial compassionate use of remdesivir has shown a fairly good result, but difficult to quantify, in the absence of control arm. While the very first double-blind, placebo-controlled, randomized trial conducted in Wuhan, did not find any significant benefit compared to the control, the preliminary result of another similar multi-country trial has shown a significant faster time to recovery but without any difference in mortality.ConclusionsRemdesivir has shown a mixed result in patients with COVID-19 with an acceptable side effect. However, jury is still out while awaiting the results from the forthcoming trials.     

Glucosamine and chondroitin sulfate

Glucosamine and chondroitin sulfate, components of normal cartilage that are marketed as dietary supplements in the United States, have been evaluated for their potential role in the treatment of osteoarthritis. Due to claims of efficacy, increased prevalence of osteoarthritis, and a lack of other effective therapies, there has been substantial interest in using these dietary supplements as therapeutic agents for osteoarthritis. Though pharmacokinetic and bioavailability data are limited, use of these supplements has been evaluated for management of osteoarthritis symptoms and modification of disease progression. Relevant clinical trial efficacy and safety data are reviewed and summarized.     

COVID-19 and hepatorenal syndrome

Coronavirus disease 2019 (COVID-19) is a highly infectious disease which emerged into a global pandemic. Although it primarily causes respiratory symptoms for affected patients, COVID-19 was shown to have multi-organ manifestations. Elevated liver enzymes appear to be commonly observed during the course of COVID-19, and there have been numerous reports of liver injury secondary to COVID-19 infection. It has been established that patients with pre-existing chronic liver disease (CLD) are more likely to have poorer outcomes following COVID-19 infection compared to those without CLD. Co-morbidities such as diabetes, hypertension, obesity, cardiovascular and chronic kidney disease frequently co-exist in individuals living with CLD, and a substantial population may also live with some degree of frailty. The mechanisms of how COVID-19 induces liver injury have been postulated. Hepatorenal syndrome (HRS) is the occurrence of kidney dysfunction in patients with severe CLD/fulminant liver failure in the absence of another identifiable cause, and is usually a marker of severe decompensated liver disease. Select reports of HRS following acute COVID-19 infection have been presented, although the risk factors and pathophysiological mechanisms leading to HRS in COVID-19 infection or following COVID-19 treatment remain largely unestablished due to the relative lack and novelty of published data. Evidence discussing the management of HRS in high-dependency care and intensive care contexts is only emerging. In this article, we provide an overview on the speculative pathophysiological mechanisms of COVID-19 induced HRS and propose strategies for clinical diagnosis and management to optimize outcomes in this scenario.     

Acupuncture for nasal congestion in COVID-19: A protocol for systematic review and meta-analysis

Background:From the end of 2019 to now, coronavirus disease 2019 (COVID-19) has put enormous strain on the world''s health systems, causing significant deaths and economic losses worldwide. Nasal congestion, one of the symptoms of COVID-19, poses considerable problems for patients. In China, acupuncture has been widely used to treat nasal congestion caused by COVID-19, but there is still a lack of evidence-based medical evaluation.Methods:According to the retrieval strategies, randomized controlled trials on the acupuncture for COVID-19 nasal congestion were obtained from China National Knowledge Infrastructure, WanFang, VIP, PubMed, Embase, and Cochrane Library, regardless of publication date, or language. Studies were screened based on inclusion and exclusion criteria, and the Cochrane risk bias assessment tool was used to evaluate the quality of the studies. The meta-analysis was performed using Review Manager (RevMan 5.3) and STATA 14.2 software. Ultimately, the evidentiary grade for the results will be evaluated.Results:The study will provide a high-quality and convincing assessment of the efficacy and safety of acupuncture in the treatment of COVID-19''s nasal congestion and will be published in peer-reviewed journals.Conclusion:Our findings will provide references for future clinical decision and guidance development.PROSPERO registration number:NO.CRD42021299482.     

Clinical outcomes of corticosteroids for COVID-19 patients at the National Center for Global Health and Medicine during the first wave of infections

BackgroundCoronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2, has been a significant concern worldwide since its outbreak in December 2019. Various treatments are being researched and developed, and there are reports that dexamethasone has reduced the mortality rate and improved the clinical course of critically ill patients with COVID-19. In this study, we examined the clinical efficacy of corticosteroid therapy for patients with COVID-19 in our hospital during the first wave of infections.MethodsWe retrospectively reviewed the medical records of patients with COVID-19 who were treated with or without corticosteroid therapy at the National Center for Global Health and Medicine in Japan between February and April 2020. The primary outcome was improvement in the patients’ clinical course using a seven-category ordinal scale. We collected data on patient characteristics, treatment, and clinical course, and compared them between two groups: the steroid-using group and the non-steroid-using group.ResultsBetween February and April 2020, 110 patients were diagnosed with COVID-19. Despite poor conditions during admission into the steroid group, there were no statistical differences in clinical course between both groups, as measured using the scale. There were no statistical differences between the two groups in the number of days to fever resolution or negative polymerase chain reaction results.ConclusionsThere was no difference in the clinical course between both groups. Because of the difference in background, corticosteroids may potentially make the clinical course of severely ill patients similar to that of mildly ill patients.     

Systematic review and meta-analysis of the efficacy of melatonin in experimental stroke

Melatonin is a candidate neuroprotective drug for ischaemic stroke. Any decision to proceed to clinical trial for such drugs should be based on an unbiased assessment of all available data. Such an assessment should include not only the efficacy of a drug but also the in vivo characteristics and limits--in terms of time window, dose, species and model of ischaemia used--to that efficacy. Here we use a systematic approach to establish the limits to and characteristics of the neuroprotective efficacy of melatonin in experimental stroke. We have used systematic review and meta-analysis to assess the evidence for a protective effect of melatonin in animal models of focal cerebral ischaemia. Fourteen studies were identified describing procedures involving 432 animals. The point estimate for the effect of melatonin was a 42.8% (95% CI 39.3-46.3%) improvement in outcome. Efficacy was greater when ketamine anaesthesia was used, and melatonin was equally effective in permanent or temporary ischaemia. Study quality was generally poor by clinical trial standards, and no evidence was found regarding the efficacy of melatonin in focal cerebral ischaemia in aged, hypertensive or diabetic animals, in species other than rats, or at time windows beyond 2 hr. These findings demonstrate a marked efficacy of melatonin in animal models of focal cerebral ischaemia, identify priority areas for future animal research, and suggest melatonin as a candidate neuroprotective drug for human stroke.