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In recent years, there has been an increasing interest in understanding the mysterious functions of nitric oxide (NO) and how this pleiotropic signaling molecule contributes to tumorigenesis. This review attempts to expose and discuss the information available on the immunomodulatory role of NO in cancer and recent approaches to the role of NO donors in the area of immunotherapy. To address the goal, the following databases were searched to identify relevant literature concerning empirical evidence: The Cochrane Library, Pubmed, Medline, and EMBASE from 1980 through March 2020. Valuable attempts have been made to develop distinctive NO-based cancer therapy. Although the data do not allow generalization, the evidence seems to indicate that low/moderate levels may favor tumorigenesis, while higher levels would exert antitumor effects. In this sense, the use of NO donors could have an important therapeutic potential within immunotherapy, although there are still no clinical trials. The emerging understanding of NO-regulated immune responses in cancer may help unravel the recent features of this “doubleedged sword” in cancer physiological and pathologic processes and its potential use as a therapeutic agent for cancer treatment. In short, in this review, we discuss the complex cellular mechanism in which NO, as a pleiotropic signaling molecule, participates in cancer pathophysiology. We also debate the dual role of NO in cancer and tumor progression and clinical approaches for inducible nitric oxide synthase (iNOS) based therapy against cancer.

To examine the preventive effects of Aloe vera in colorectal cancer patients undergoing radiotherapy. Twenty colorectal cancer patients, who received radiation, were randomized to receive Aloe vera 3% or placebo ointment, 1 g twice daily for 6 weeks. At weekly visits, acute radiation proctitis (ARP) was evaluated by Radiation Therapy Oncology Group and clinical presentation criteria as the primary endpoint. We also evaluated secondary endpoints of quality of life, psychosocial status, by applying Hospital Anxiety-Depression (HAD) Scale and laboratory measures of quantitative measurement of C-reactive protein (CRP) as a marker for systemic inflammation. There was a significant improvement in the symptom index (before treatment vs. after treatment with Aloe vera) for diarrhea (p = 0.029, median score: 0.5 vs. 0.001). The overall primary and secondary outcomes favored Aloe group, while the measures of toxicity did not achieve a statistical significant difference. The lifestyle score improved significantly with A. vera (p = 004), and they also had a lower depression score in HAD scale (p = 0.008). Furthermore, quantitative CRP decreased significantly during the course of treatment with Aloe vera. The use of topical formulation of Aloe vera 3% diminishes the severity of ARP in colorectal cancer patients.

The viral infection due to the new coronavirus or coronavirus disease 2019 (COVID-19), which was reported for the first time in December 2019, was named by the World Health Organization (WHO) as Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV2), because of the very similar genome and also its related symptoms to SARS-CoV1. The ongoing COVID-19 pandemic with significant mortality, morbidity, and socioeconomic impact is considered by the WHO as a global public health emergency. Since there is no specific treatment available for SARS-CoV2 infection, and or COVID-19, several clinical and sub-clinical studies are currently undertaken to find a gold-standard therapeutic regimen with high efficacy and low side effect. Based on the published scientific evidence published to date, we summarized herein the effects of different potential therapies and up-to-date clinical trials. The review is intended to help readers aware of potentially effective COVID-19 treatment and provide useful references for future studies. Electronic supplementary material The online version of this article (10.1007/s43440-020-00152-9) contains supplementary material, which is available to authorized users.

The novel coronavirus 2019-nCoV (SARS-CoV-2) infection that emerged in China in December 2019 has rapidly spread to become a global pandemic. This article summarizes the potential benefits of erythropoietin (EPO) in alleviating SARS-CoV-2 pathogenesis which is now called COVID-19. As with other coronavirus infection, the lethality of COVID-19 is associated with respiratory dysfunction due to overexpression of proinflammatory cytokines induced by the host immune responses. The resulting cytokine storm leads to the development of acute lung injury/acute respiratory distress syndrome (ALI/ARDS). Erythropoietin, well known for its role in the regulation of erythropoiesis, may have protective effects against ALI/ARDS induced by viral and other pathogens. EPO exerts antiapoptotic and cytoprotective properties under various pathological conditions. With a high safety profile, EPO promotes the production of endothelial progenitor cells and reduce inflammatory processes through inhibition of the nuclear factor-κB (NF-κB) and JAK-STAT3 signaling pathways. Thus, it may be considered as a safe drug candidate for COVID-19 patients if given at the early stage of the disease. The potential effects of erythropoietin on different aspects of ALI/ARDS associated with SARS-CoV-2 infection are reviewed.

This article summarizes the effects of sivelestat on ALI/ARDS or ARDS with coagulopathy, both of which are frequently seen in patients with COVID-19. The emergence of the novel 2019-nCoV infection has been a global pandemic. The following databases were searched to identify relevant literature concerning empirical evidence: The Cochrane library, Pubmed, Medline, EMBASE from 1980 through March 2020. COVID-19 patients are more susceptible to thromboembolic diseases including DIC. In this connection, various studies have emphasized on the role of neutrophil elastase (NE) in the development of DIC in patients with ARDS and sepsis. It has been shown that NE inhibition by sivelestat mitigates ALI through amelioration of alveolar epithelium and vascular endothelium injuries as well as reversing the activated neutrophil-mediated increased vascular permeability. Sivelestat is a selective NE inhibitor has not been evaluated for its possible therapeutic effects against SARS-CoV-2 infection and/or COVID-19. Nevertheless, based on its promising beneficial effects in underlying complications of COVID-19, sivelestat could be considered as a promising treatment for the management of ALI/ARDS or coagulopathy in patients with COVID-19.

The global impact of the new coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), infection that caused COVID-19 has been evident in the last few months from the unprecedented socioeconomic disruption to more than 600,000 deaths. The lack of vaccine and effective therapeutic agents for the disease prompted world-wide effort to test those antiviral therapeutics already in use for other diseases. Another interesting approach has been based on the pathological sequel of the disease that involve severe inflammatory reaction (or the cytokine storm) associated with pneumonia in critically ill patients. This article outlines the prophylaxis therapeutic potential of supplements vitamins and micronutrients in COVID-19. By ameliorating the inflammatory and oxidative stress associated with the disease and some direct antiviral effects, the application of these agents as adjuvants and other alternative approaches are discussed. Available clinical trials including those currently registered on these supplements are scrutinized.