scholarly journals Nitric oxide for the prevention and treatment of viral, bacterial, protozoal and fungal infections

F1000Research ◽  
2021 ◽  
Vol 10 ◽  
pp. 536
Author(s):  
Philip M. Bath ◽  
Christopher M. Coleman ◽  
Adam L. Gordon ◽  
Wei Shen Lim ◽  
Andrew J. Webb

Although the antimicrobial potential of nitric oxide (NO) is widely published, it is little used clinically. NO is a key signalling molecule modulating vascular, neuronal, inflammatory and immune responses. Endogenous antimicrobial activity is largely mediated by high local NO concentrations produced by cellular inducible nitric oxide synthase, and by derivative reactive nitrogen oxide species including peroxynitrite and S-nitrosothiols. NO may be taken as dietary substrate (inorganic nitrate, L-arginine), and therapeutically as gaseous NO, and transdermal, sublingual, oral, intranasal and intravenous nitrite or nitrate. Numerous preclinical studies have demonstrated that NO has generic static and cidal activities against viruses (including β-coronaviruses such as SARS-CoV-2), bacteria, protozoa and fungi/yeasts in vitro. Therapeutic effects have been seen in animal models in vivo, and phase II trials have demonstrated that NO donors can reduce microbial infection. Nevertheless, excess NO, as occurs in septic shock, is associated with increased morbidity and mortality. In view of the dose-dependent positive and negative effects of NO, safety and efficacy trials of NO and its donors are needed for assessing their role in the prevention and treatment of infections. Trials should test dietary inorganic nitrate for pre- or post-exposure prophylaxis and gaseous NO or oral, topical or intravenous nitrite and nitrate for treatment of mild-to-severe infections, including due to SARS-CoV-2 (COVID-19). This review summarises the evidence base from in vitro, in vivo and early phase clinical studies of NO activity in viral, bacterial, protozoal and fungal infections.

F1000Research ◽  
2021 ◽  
Vol 10 ◽  
pp. 536
Author(s):  
Philip M. Bath ◽  
Christopher M. Coleman ◽  
Adam L. Gordon ◽  
Wei Shen Lim ◽  
Andrew J. Webb

Although the antimicrobial potential of nitric oxide (NO) is widely published, it is little used clinically. NO is a key signalling molecule modulating vascular, neuronal, inflammatory and immune responses. Endogenous antimicrobial activity is largely mediated by high local NO concentrations produced by cellular inducible nitric oxide synthase, and by derivative reactive nitrogen oxide species including peroxynitrite and S-nitrosothiols. NO may be taken as dietary substrate (inorganic nitrate, L-arginine), and therapeutically as gaseous NO, and transdermal, sublingual, oral, intranasal and intravenous nitrite or nitrate. Numerous preclinical studies have demonstrated that NO has generic static and cidal activities against viruses (including β-coronaviruses such as SARS-CoV-2), bacteria, protozoa and fungi/yeasts in vitro. Therapeutic effects have been seen in animal models in vivo, and phase II trials have demonstrated that NO donors can reduce microbial infection. Nevertheless, excess NO, as occurs in septic shock, is associated with increased morbidity and mortality. In view of the dose-dependent positive and negative effects of NO, safety and efficacy trials of NO and its donors are needed for assessing their role in the prevention and treatment of infections. Trials should test dietary inorganic nitrate for pre- or post-exposure prophylaxis and gaseous NO or oral, topical or intravenous nitrite and nitrate for treatment of mild-to-severe infections, including due to SARS-CoV-2 (COVID-19). This review summarises the evidence base from in vitro, in vivo and early phase clinical studies of NO activity in viral, bacterial, protozoal and fungal infections.


2019 ◽  
Vol 20 (15) ◽  
pp. 3757 ◽  
Author(s):  
Beatrice Bachmeier ◽  
Dieter Melchart

The efficacy of the plant-derived polyphenol curcumin, in various aspects of health and wellbeing, is matter of public interest. An internet search of the term “Curcumin” displays about 12 million hits. Among the multitudinous information presented on partly doubtful websites, there are reports attracting the reader with promises ranging from eternal youth to cures for incurable diseases. Unfortunately, many of these reports are not based on scientific evidence, but they feed the desideratum of the reader for a “miracle cure”. This circumstance makes it very difficult for researchers, who work in a scientifically sound and evidence-based manner on the therapeutic benefits (or side effects) of curcumin, to demarcate their results from sensational reports that circulate in the web and in other media. This is only one of many obstacles making it difficult to pave curcumin’s way into clinical application; others are its nonpatentability and low economic usability. A further impediment comes from scientists who never worked with curcumin or any other natural plant-derived compound in their own labs. They have never tested these compounds in any scientific assay, neither in vitro nor in vivo; however, they claim, in a sometimes polemic manner, that everything that has so far been published on curcumin’s molecular effects is based on artefacts. The here presented Special Issue comprises a collection of five scientifically sound articles and nine reviews reporting on the therapeutic benefits and the molecular mechanisms of curcumin or of chemically modified curcumin in various diseases ranging from malignant tumors to chronic diseases, microbial infection, and even neurodegenerative diseases. The excellent results of the scientific projects that underlie the five original papers give reason to hope that curcumin will be part of novel treatment strategies in the near future—either as monotherapy or in combination with other drugs or therapeutic applications.


2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Liangliang Chen ◽  
Tengfei Shen ◽  
Yongqing Liu ◽  
Jiangfei Zhou ◽  
Shuaibing Shi ◽  
...  

Abstract Background The problem of increasing resistance against conventional antibiotics has drawn people’s attention. Therefore, the development of novel antibacterial agents with effective and safe therapeutic effects is imminent. Antimicrobial peptides (AMPs) are considered a promising class of antibacterial agents due to their broad antibacterial spectrum. Results In this study, on the basis of our previously studied peptide PMAP-37(F34-R), a novel antimicrobial peptide Chol-37(F34-R) was developed by N-terminal cholesterol modification to increase hydrophobicity. We observed that the N-terminal cholesterol-modified Chol-37(F34-R) showed higher antimicrobial activity than PMAP-37(F34-R) in vitro. Chol-37(F34-R) also exhibited effective anti-biofilm activity and may kill bacteria by improving the permeability of their membranes. Chol-37(F34-R) exerted high stability in different pH, salt, serum, and boiling water environments. Chol-37(F34-R) also showed no hemolytic activity and substantially low toxicity. Furthermore, Chol-37(F34-R) exhibited good potency of bacteria eradication and promoted wound healing and abscess reduction in infected mice. Meanwhile, in S. aureus ATCC25923-infected peritonitis model, Chol-37(F34-R) exhibited an impressive therapeutic effect by reducing the decrease in systemic bacterial burden and alleviating organ damage. Conclusions Our findings suggested that the N-terminal cholesterol modification of PMAP-37(F34-R) could improve antibacterial activity. Chol-37(F34-R) displayed excellent bactericidal efficacy and impressive therapeutic effect in vivo. Thus, Chol-37(F34-R) may be a candidate for antimicrobial agents against microbial infection in the clinic.


2020 ◽  
Author(s):  
Khandkar Shaharina Hossain ◽  
Md. Golzar Hossain ◽  
Akhi Moni ◽  
Mahbubur Rahman ◽  
Umma Habiba Rahman ◽  
...  

Honey and its various ingredients have been in limelight as an effective natural therapy capable of normalizing the situation by attenuating acute inflammation through encouraging immune response. Several studies have proved its potential healing capability against numerous chronic diseases/conditions, including pulmonary disorders, cardiac disorders, diabetes, hypertension, autophagy dysfunction, bacterial and fungal infections. More importantly, honey showed its virucidal effect on several enveloped viruses such as HIV, influenza virus, herpes simplex, and varicella zoster virus. Honey may be beneficial for patients with COVID-19 caused by an enveloped virus SARS-CoV-2 through simultaneously boosting the host immune system, improving comorbid conditions and antiviral activities. Moreover, a clinical trial of honey on COVID-19 patients has been undergoing. In this review, we summarized the potential benefits of honey and its ingredients in the context of antimicrobial activities, numerous chronic diseases, and host immune system and thereby tried to establish a relationship with honey for the treatment of COVID-19. This review will be helpful to reconsider the insights into the possible potential therapeutic effects of honey in the context of COVID-19 pandemic. However, the effects of honey on SARS-CoV-2 replication and/or host immune system need to be further investigated by in vitro and in vivo studies.


1976 ◽  
Vol 35 (01) ◽  
pp. 049-056 ◽  
Author(s):  
Christian R Klimt ◽  
P. H Doub ◽  
Nancy H Doub

SummaryNumerous in vivo and in vitro experiments, investigating the inhibition of platelet aggregation and the prevention of experimentally-induced thrombosis, suggest that anti-platelet drugs, such as aspirin or the combination of aspirin and dipyridamole or sulfinpyrazone, may be effective anti-thrombotic agents in man. Since 1971, seven randomized prospective trials and two case-control studies have been referenced in the literature or are currently being conducted, which evaluate the effects of aspirin, sulfinpyrazone, or dipyridamole in combination with aspirin in the secondary prevention of myocardial infarction. A critical review of these trials indicates a range of evidence from no difference to a favorable trend that antiplatelet drugs may serve as anti-thrombotic agents in man. To date, a definitive answer concerning the therapeutic effects of these drugs in the secondary prevention of coronary heart disease is not available.


2018 ◽  
Vol 18 (7) ◽  
pp. 985-992 ◽  
Author(s):  
Aysegul Hanikoglu ◽  
Ertan Kucuksayan ◽  
Rana Cagla Akduman ◽  
Tomris Ozben

This systematic review aims to elucidate the role of melatonin (N-acetyl-5-metoxy-tryptamine) (MLT) in the prevention and treatment of cancer. MLT is a pineal gland secretory product, an evolutionarily highly conserved molecule; it is also an antioxidant and an impressive protector of mitochondrial bioenergetic activity. MLT is characterized by an ample range of activities, modulating the physiology and molecular biology of the cell. Its physiological functions relate principally to the interaction of G Protein-Coupled MT1 and MT2 trans-membrane receptors (GPCRs), a family of guanidine triphosphate binding proteins. MLT has been demonstrated to suppress the growth of various tumours both, in vivo and in vitro. In this review, we analyze in depth, the antioxidant activity of melatonin, aiming to illustrate the cancer treatment potential of the molecule, by limiting or reversing the changes occurring during cancer development and growth.


2021 ◽  
Vol 64 (1) ◽  
Author(s):  
Senthil Nagarajan ◽  
Jae Kwon Lee

AbstractSesamolin is one of the lignans derived from sesame oil. It has demonstrated significant antioxidant, anti-aging, and anti-mutagenic properties. It also reportedly augments natural killer (NK) cell lysis activity. We previously reported that sesamolin also exerts anticancer effects in vitro and induces enhanced NK cell cytolytic activity against tumor cells. Herein, we aimed to determine the mechanism by which sesamolin prevents and retards tumorigenesis in BALB/c mouse models of leukemia induced by murine (BALB/c) myelomonocytic leukemia WEHI-3B cells. Banded neutrophils, myeloblasts, and monocytic leukemic cells were more abundant in the leukemia model than in normal mice. Sesamolin decreased the number of leukemic cells by almost 60% in the leukemia model mice in vivo; additionally, sesamolin and the positive control drug, vinblastine, similarly hindered neoplastic cell proliferation. Spleen samples were ~ 4.5-fold heavier in leukemic mice than those obtained from normal mice, whereas spleen samples obtained from leukemic mice treated with sesamolin had a similar weight to those of normal mice. Moreover, sesamolin induced a twofold increase in the cytotoxic activity of leukemic mouse NK cells against WEHI-3B cells. These results indicated that sesamolin exerts anti-leukemic effects in vivo.


Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 3005
Author(s):  
Kanchan Bhardwaj ◽  
Ana Sanches Silva ◽  
Maria Atanassova ◽  
Rohit Sharma ◽  
Eugenie Nepovimova ◽  
...  

Conifers have long been recognized for their therapeutic potential in different disorders. Alkaloids, terpenes and polyphenols are the most abundant naturally occurring phytochemicals in these plants. Here, we provide an overview of the phytochemistry and related commercial products obtained from conifers. The pharmacological actions of different phytochemicals present in conifers against bacterial and fungal infections, cancer, diabetes and cardiovascular diseases are also reviewed. Data obtained from experimental and clinical studies performed to date clearly underline that such compounds exert promising antioxidant effects, being able to inhibit cell damage, cancer growth, inflammation and the onset of neurodegenerative diseases. Therefore, an attempt has been made with the intent to highlight the importance of conifer-derived extracts for pharmacological purposes, with the support of relevant in vitro and in vivo experimental data. In short, this review comprehends the information published to date related to conifers’ phytochemicals and illustrates their potential role as drugs.


2021 ◽  
Vol 1 (1) ◽  
pp. 84-95
Author(s):  
Patience O. Obi ◽  
Jennifer E. Kent ◽  
Maya M. Jeyaraman ◽  
Nicole Askin ◽  
Taiana M. Pierdoná ◽  
...  

Asthma is the most common pediatric disease, characterized by chronic airway inflammation and airway hyperresponsiveness. There are several management options for asthma, but no specific treatment. Extracellular vesicles (EVs) are powerful cellular mediators of endocrine, autocrine and paracrine signalling, and can modulate biophysiological function in vitro and in vivo. A thorough investigation of therapeutic effects of EVs in asthma has not been conducted. Therefore, this systematic review is designed to synthesize recent literature on the therapeutic effects of EVs on physiological and biological outcomes of asthma in pre-clinical studies. An electronic search of Web of Science, EMBASE, MEDLINE, and Scopus will be conducted on manuscripts published in the last five years that adhere to standardized guidelines for EV research. Grey literature will also be included. Two reviewers will independently screen the selected studies for title and abstract, and full text based on the eligibility criteria. Data will be extracted, narratively synthesized and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. This systematic review will summarize the current knowledge from preclinical studies investigating the therapeutic effects of EVs on asthma. The results will delineate whether EVs can mitigate biological hallmarks of asthma, and if so, describe the underlying mechanisms involved in the process. This insight is crucial for identifying key pathways that can be targeted to alleviate the burden of asthma. The data will also reveal the origin, dosage and biophysical characteristics of beneficial EVs. Overall, our results will provide a scaffold for future intervention and translational studies on asthma treatment.


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