Pleiotropic Effects of Tetracyclines in the Management of COVID-19: Emerging Perspectives

Repurposing of antimycobacterium drugs for COVID-19 treatment by targeting SARS CoV-2 main protease: An in-silico perspective

The global mortality rate has been significantly impacted by the COVID-19 pandemic, caused by the SARS CoV-2 virus. Although the pursuit for a potent antiviral is still in progress, experimental therapies based on repurposing of existing drugs is being attempted. One important therapeutic target for COVID-19 is the main protease (Mpro) that cleaves the viral polyprotein in its replication process. Recently minocycline, an antimycobacterium drug, has been successfully implemented for the treatment of COVID-19 patients. But it's mode of action is still far from clear. Furthermore, it remains unresolved whether alternative antimycobacterium drugs can effectively regulate SARS CoV-2 by inhibiting the enzymatic activity of Mpro. To comprehend these facets, eight well-established antimycobacterium drugs were put through molecular docking experiments. Four of the antimycobacterium drugs (minocycline, rifampicin, clofazimine and ofloxacin) were selected by comparing their binding affinities towards Mpro. All of the four drugs interacted with both the catalytic residues of Mpro (His41 and Cys145). Additionally, molecular dynamics experiments demonstrated that the Mpro-minocyline complex has enhanced stability, experiences reduced conformational fluctuations and greater compactness than other three Mpro-antimycobacterium and Mpro-N3/lopinavir complexes. This research furnishes evidences for implementation of minocycline against SARS CoV-2. In addition, our findings also indicate other three antimycobacterium/antituberculosis drugs (rifampicin, clofazimine and ofloxacin) could potentially be evaluated for COVID-19 therapy.

Minocycline as a prospective therapeutic agent for cancer and non-cancer diseases: a scoping review

Minocycline is an FDA-approved secondary-generation tetracycline antibiotic. It is a synthetic antibiotic having many biological effects, such as antioxidant, anti-inflammatory, anti-cancer, and neuroprotective functions. This study discusses the pharmacological mechanisms of preventive and therapeutic effects of minocycline. Specifically, it provides a comprehensive overview of the molecular pathways by which minocycline acts on the different cancers, including ovarian, breast, glioma, colorectal, liver, pancreatic, lung, prostate, melanoma, head and neck, leukemia, and non-cancer diseases such as Alzheimer's disease, Parkinson, schizophrenia, multiple sclerosis, Huntington, polycystic ovary syndrome, and coronavirus disease 19. Minocycline may be a potential medication for these disorders due to its strong blood-brain barrier penetrance. It is also widely accepted as a specific medication, has a well-known side-effect characteristic, is reasonably priced, making it appropriate for continuous use in managing diseases, and has been demonstrated as an oral approach because it is effectively absorbed and accomplished almost all of the body's parts.

The possible role of nuclear factor erythroid-2-related factor 2 activators in the management of Covid-19

COVID-19 is caused by a novel SARS-CoV-2 leading to pulmonary and extra-pulmonary manifestations due to oxidative stress (OS) development and hyperinflammation. COVID-19 is primarily asymptomatic though it may cause acute lung injury (ALI), acute respiratory distress syndrome (ARDS), systemic inflammation, and thrombotic events in severe cases. SARS-CoV-2-induced OS triggers the activation of different signaling pathways, which counterbalances this complication. One of these pathways is nuclear factor erythroid 2-related factor 2 (Nrf2), which induces a series of cellular interactions to mitigate SARS-CoV-2-mediated viral toxicity and OS-induced cellular injury. Nrf2 pathway inhibits the expression of pro-inflammatory cytokines and the development of cytokine storm in COVID-19. Therefore, Nrf2 activators may play an essential role in reducing SARS-CoV-2 infection-induced inflammation by suppressing NLRP3 inflammasome in COVID-19. Furthermore, Nrf2 activators can attenuate endothelial dysfunction (ED), renin-angiotensin system (RAS) dysregulation, immune thrombosis, and coagulopathy. Thus this mini-review tries to clarify the possible role of the Nrf2 activators in the management of COVID-19. Nrf2 activators could be an effective therapeutic strategy in the management of Covid-19. Preclinical and clinical studies are recommended in this regard.

Investigating the different transformations of tetracycline using birnessite under different reaction conditions and various humic acids

Prior studies have successfully used manganese oxides to facilitate the transformation of tetracycline in aqueous solution. To further understand the kinetic and the transformation pathway of tetracycline via birnessite (δ-MnO2) under different conditions, experiments were conducted at pH levels of 3, 6, and 9 in the presence or absence of Aldrich humic acid (ADHA). Tetracycline removal followed the pseudo-second-order reaction model in all investigated cases, and the removal efficiency (g mg-1 h -1) followed the following trend: pH 3 (0.45/0.27) > pH 6 (0.036/0.087) > pH 9 (0.036/0.103) in the absence/presence of ADHA. Liquid chromatography-mass spectrometry/mass spectrometry results identified five main transformation products at m/z 495, 477, 493, 459, and 415, produced by the transformation reactions, including hydration, oxidation, desaturation, and oxy reduction. Notably, in the presence of ADHA at pH 3, products with higher toxicity secondary (m/z 477 and 495) were reduced, while less toxicity products (m/z 459 and 415) were enhanced. The experiments utilizing tetracycline and δ-MnO2 with varied humic acids (HA) revealed that HA with high polar organic carbon groups, such as O-alkyl, exhibited higher removal efficiency at pH 6. This research offers the first comprehensive insights into the pathway transformations of tetracycline via δ-MnO2 under different pH conditions and HA types. For further understanding, future work should investigate the binding of HA, TTC, and/or Mn2+ and the oxidation capacity of MnO2 after the reaction to clarify Mn2+ elution mechanisms.

New insights on the potential effect of progesterone in Covid-19: Anti-inflammatory and immunosuppressive effects

BACKGROUND

Coronavirus disease 2019 (COVID-19) is a pandemic disease caused by severe acute respiratory syndrome CoV type 2 (SARS-CoV-2). COVID-19 is higher in men than women and sex hormones have immune-modulator effects during different viral infections, including SARS-CoV-2 infection. One of the essential sex hormones is progesterone (P4).

AIMS

This review aimed to reveal the association between P4 and Covid-19.

RESULTS AND DISCUSSION

The possible role of P4 in COVID-19 could be beneficial through the modulation of inflammatory signaling pathways, induction of the release of anti-inflammatory cytokines, and inhibition release of pro-inflammatory cytokines. P4 stimulates skew of naïve T cells from inflammatory Th1 toward anti-inflammatory Th2 with activation release of anti-inflammatory cytokines, and activation of regulatory T cells (Treg) with decreased interferon-gamma production that increased during SARS-CoV-2 infection. In addition, P4 is regarded as a potent antagonist of mineralocorticoid receptor (MR), it could reduce MRs that were activated by stimulated aldosterone from high AngII during SARS-CoV-2. P4 active metabolite allopregnanolone is regarded as a neurosteroid that acts as a positive modulator of γ-aminobutyric acid (GABAA ) so it may reduce neuropsychiatric manifestations and dysautonomia in COVID-19 patients.

CONCLUSION

Taken together, the anti-inflammatory and immunomodulatory properties of P4 may improve central and peripheral complications in COVID-19.

SARS-CoV-2 infection and dysregulation of nuclear factor erythroid-2-related factor 2 (Nrf2) pathway

Coronavirus disease 2019 (COVID-19) is a recent pandemic caused by a novel severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) leading to pulmonary and extra-pulmonary manifestations due to the development of oxidative stress (OS) and hyperinflammation. The underlying cause for OS and hyperinflammation in COVID-19 may be related to the inhibition of nuclear factor erythroid 2-related factor 2 (Nrf2), a master regulator of antioxidative responses and cellular homeostasis. The Nrf2 pathway inhibits the expression of pro-inflammatory cytokines and the development of cytokine storm and OS in COVID-19. Nrf2 activators can attenuate endothelial dysfunction (ED), renin-angiotensin system (RAS) dysregulation, immune thrombosis, and coagulopathy. Hence, this review aimed to reveal the potential role of the Nrf2 pathway and its activators in the management of COVID-19. As well, we tried to revise the mechanistic role of the Nrf2 pathway in COVID-19.

Receptor-dependent effects of sphingosine-1-phosphate (S1P) in COVID-19: the black side of the moon

Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection leads to hyper-inflammation and amplified immune response in severe cases that may progress to cytokine storm and multi-organ injuries like acute respiratory distress syndrome and acute lung injury. In addition to pro-inflammatory cytokines, different mediators are involved in SARS-CoV-2 pathogenesis and infection, such as sphingosine-1-phosphate (S1P). S1P is a bioactive lipid found at a high level in plasma, and it is synthesized from sphingomyelin by the action of sphingosine kinase. It is involved in inflammation, immunity, angiogenesis, vascular permeability, and lymphocyte trafficking through G-protein coupled S1P receptors. Reduction of the circulating S1P level correlates with COVID-19 severity. S1P binding to sphingosine-1-phosphate receptor 1 (S1PR1) elicits endothelial protection and anti-inflammatory effects during SARS-CoV-2 infection, by limiting excessive INF-α response and hindering mitogen-activated protein kinase and nuclear factor kappa B action. However, binding to S1PR2 opposes the effect of S1PR1 with vascular inflammation, endothelial permeability, and dysfunction as the concomitant outcome. This binding also promotes nod-like receptor pyrin 3 (NLRP3) inflammasome activation, causing liver inflammation and fibrogenesis. Thus, higher expression of macrophage S1PR2 contributes to the activation of the NLRP3 inflammasome and the release of pro-inflammatory cytokines. In conclusion, S1PR1 agonists and S1PR2 antagonists might effectively manage COVID-19 and its severe effects. Further studies are recommended to elucidate the potential conflict in the effects of S1P in COVID-19.

Unveiling the Osteogenic Potential of Tetracyclines: A Comparative Study in Human Mesenchymal Stem Cells

Tetracyclines (TCs) are a class of broad-spectrum antibiotics with diverse pharmacotherapeutic properties due to their various functional groups being attached to a common core structure. Beyond their antibacterial activity, TCs trigger pleiotropic effects on eukaryotic cells, including anti-inflammatory and potentially osteogenic capabilities. Consequently, TCs hold promise for repurposing in various clinical applications, including bone-related conditions. This study presents the first comprehensive comparison of the in vitro osteogenic potential of four TCs-tetracycline, doxycycline, minocycline, and sarecycline, within human mesenchymal stem cells. Cultures were characterized for metabolic activity, cell morphology and cytoskeleton organization, osteogenic gene expression, alkaline phosphatase (ALP) activity, and the activation of relevant signaling pathways. TCs stimulated actin remodeling processes, inducing morphological shifts consistent with osteogenic differentiation. Osteogenic gene expression and ALP activity supported the osteoinduction by TCs, demonstrating significant increases in ALP levels and the upregulation of RUNX2, SP7, and SPARC genes. Minocycline and sarecycline exhibited the most potent osteogenic induction, comparable to conventional osteogenic inducers. Signaling pathway analysis revealed that tetracycline and doxycycline activate the Wnt pathway, while minocycline and sarecycline upregulated Hedgehog signaling. Overall, the present findings suggest that TCs promote osteogenic differentiation through distinct pathways, making them promising candidates for targeted therapy in specific bone-related disorders.

Insights on Covid-19 with superimposed pulmonary histoplasmosis: The possible nexus

A novel coronavirus (CoV) known as severe acute respiratory syndrome CoV type 2 is the causative agent for the development of CoV disease 2019 (Covid-19). Covid-19 may increase the risk of developing pulmonary histoplasmosis due to immune dysregulation. In addition, Covid-19 may enhance the propagation of acute pulmonary histoplasmosis due to lung injury and inflammation, and using corticosteroids in severely affected Covid-19 patients may reactivate latent pulmonary histoplasmosis. Likewise, activation of inflammatory signaling pathways during H. capsulatum infection may increase the severity of Covid-19 and vice versa. Furthermore, lymphopenia in Covid-19 may increase the risk for the progress of pulmonary histoplasmosis besides activation of inflammatory signaling pathways during H. capsulatum infection may increase the severity of Covid-19 and vice versa. Therefore, this critical review aimed to find the potential link between Covid-19 pneumonia and pulmonary histoplasmosis concerning the immunological response.

The Potential Nexus between Helminths and SARS-CoV-2 Infection: A Literature Review

Chronic helminth infections (CHIs) can induce immunological tolerance through the upregulation of regulatory T cells. In coronavirus disease 2019 (COVID-19), abnormal adaptive immune response and exaggerated immune response may cause immune-mediated tissue damage. Severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) and CHIs establish complicated immune interactions due to SARS-CoV-2-induced immunological stimulation and CHIs-induced immunological tolerance. However, COVID-19 severity in patients with CHIs is mild, as immune-suppressive anti-inflammatory cytokines counterbalance the risk of cytokine storm. Since CHIs have immunomodulatory effects, therefore, this narrative review aimed to clarify how CHIs modulate the immunoinflammatory response in SARS-CoV-2 infection. CHIs, through helminth-derived molecules, may suppress SARS-CoV-2 entry and associated hyperinflammation through attenuation of the inflammatory signaling pathway. In addition, CHIs may reduce the COVID-19 severity by reducing the SARS-CoV-2 entry points in the initial phase and immunomodulation in the late phase of the disease by suppressing the release of pro-inflammatory cytokines. In conclusion, CHIs may reduce the severity of SARS-CoV-2 infection by reducing hyperinflammation and exaggerated immune response. Thus, retrospective and prospective studies are recommended in this regard.

The potential role of scavenger receptor B type I (SR-BI) in SARS-CoV-2 infection

Scavenger receptor type B I (SR-BI), the major receptor for high-density lipoprotein (HDL) mediates the delivery of cholesterol ester and cholesterol from HDL to the cell membrane. SR-BI is implicated as a receptor for entry of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2). SR-BI is colocalized with the angiotensin-converting enzyme 2 (ACE2) increasing the binding and affinity of SARS-CoV-2 to ACE2 with subsequent viral internalization. SR-BI regulates lymphocyte proliferation and the release of pro-inflammatory cytokines from activated macrophages and lymphocytes. SR-BI is reduced during COVID-19 due to consumption by SARS-CoV-2 infection. COVID-19-associated inflammatory changes and high angiotensin II (AngII) might be possible causes of repression of SR-BI in SARS-CoV-2 infection. In conclusion, the downregulation of SR-BI in COVID-19 could be due to direct invasion by SARS-CoV-2 or through upregulation of pro-inflammatory cytokines, inflammatory signaling pathways, and high circulating AngII. Reduction of SR-BI in COVID-19 look like ACE2 may provoke COVID-19 severity through exaggeration of the immune response. Further studies are invoked to clarify the potential role of SR-BI in the pathogenesis of COVID-19 that could be protective rather than detrimental.

Mixed storm in SARS-CoV-2 infection: A narrative review and new term in the Covid-19 era

Coronavirus disease 2019 (Covid-19) is caused by a novel severe acute respiratory syndrome coronavirus virus type 2 (SARS-CoV-2) leading to the global pandemic worldwide. Systemic complications in Covid-19 are mainly related to the direct SARS-CoV-2 cytopathic effects, associated hyperinflammation, hypercytokinemia, and the development of cytokine storm (CS). As well, Covid-19 complications are developed due to the propagation of oxidative and thrombotic events which may progress to a severe state called oxidative storm and thrombotic storm (TS), respectively. In addition, inflammatory and lipid storms are also developed in Covid-19 due to the activation of inflammatory cells and the release of bioactive lipids correspondingly. Therefore, the present narrative review aimed to elucidate the interrelated relationship between different storm types in Covid-19 and the development of the mixed storm (MS). In conclusion, SARS-CoV-2 infection induces various storm types including CS, inflammatory storm, lipid storm, TS and oxidative storm. These storms are not developing alone since there is a close relationship between them. Therefore, the MS seems to be more appropriate to be related to severe Covid-19 than CS, since it develops in Covid-19 due to the intricate interface between reactive oxygen species, proinflammatory cytokines, complement activation, coagulation disorders, and activated inflammatory signaling pathway.

Network-based drug repurposing for the treatment of COVID-19 patients in different clinical stages

In the severe acute respiratory coronavirus disease 2019 (COVID-19) pandemic, there is an urgent need to develop effective treatments. Through a network-based drug repurposing approach, several effective drug candidates are identified for treating COVID-19 patients in different clinical stages. The proposed approach takes advantage of computational prediction methods by integrating publicly available clinical transcriptome and experimental data. We identify 51 drugs that regulate proteins interacted with SARS-CoV-2 protein through biological pathways against COVID-19, some of which have been experimented in clinical trials. Among the repurposed drug candidates, lovastatin leads to differential gene expression in clinical transcriptome for mild COVID-19 patients, and estradiol cypionate mainly regulates hormone-related biological functions to treat severe COVID-19 patients. Multi-target mechanisms of drug candidates are also explored. Erlotinib targets the viral protein interacted with cytokine and cytokine receptors to affect SARS-CoV-2 attachment and invasion. Lovastatin and testosterone block the angiotensin system to suppress the SARS-CoV-2 infection. In summary, our study has identified effective drug candidates against COVID-19 for patients in different clinical stages and provides comprehensive understanding of potential drug mechanisms.

Monkeypox epidemic at the door: should we remain idly by or prepare strongly?

Monkeypox (MPX) is a common zoonotic disease caused by a double-strand DNA MPX virus (MPXV). MPX was considered a sporadic rare disease causing a mild disease with a low capacity to spread among humans. The clinical picture of human MPX highly resembles smallpox, though early lymphadenopathy in human MPX is the distinguishing sign not present in smallpox. The incubation period is 1-3 weeks, and fever, headache, joint pain, myalgia, and nausea for about 3 days. Skin lesions that appear 1-3 days following fever and lymphadenopathy usually appear simultaneously on the face and periphery. By cross-reactivity and protection, the smallpox vaccine produced 85% protection against infection with Orthopoxviruses, including MPX. Antiviral drugs like tecovirimate and brincidofovir could be effective agents against the development of MPX. MPX epidemics are less reported and described as other life-threatening epidemics, leading to an unclear picture of this disease's pathogenesis, epidemiology, and management. With the recent wide range of MPX outbreaks, immense research is mandatory to revise the importance of MPX pathogenesis and risk for epidemic development worldwide. Therefore, this critical study aimed to review MPX's pathogenesis, epidemiology, and management with possible repurposed drugs.

The potential link between Covid-19 and multiple myeloma: A new saga

BACKGROUND

Covid-19 is considered a primary respiratory disease-causing viral pneumonia and, in severe cases, leads to acute lung injury and acute respiratory distress syndrome (ARDS). In addition, though, extra-pulmonary manifestations of Covid-19 have been shown. Furthermore, severe acute respiratory distress syndrome coronavirus type 2 (SARS-CoV-2) infection may coexist with several malignancies, including multiple myeloma (MM).

METHODS

This critical literature review aimed to find the potential association between SARS-CoV-2 infection and MM in Covid-19 patients with underlying MM. Narrative literature and databases search revealed that ARDS is developed in both MM and Covid-19 due to hypercalcemia and proteasome dysfunction.

RESULTS

Notably, the expression of angiogenic factors and glutamine deficiency could link Covid-19 severity and MM in the pathogenesis of cardiovascular complications. MM and Covid-19 share thrombosis as a typical complication; unlike thrombosis in Covid-19, which reflects disease severity, thrombosis does not reflect disease severity in MM. In both conditions, thromboprophylaxis is essential to prevent pulmonary thrombosis and other thromboembolic disorders. Moreover, Covid-19 may exacerbate the development of acute kidney injury and neurological complications in MM patients.

CONCLUSION

These findings highlighted that MM patients might be a risk group for Covid-19 severity due to underlying immunosuppression and most of those patients need specific management in the Covid-19 era.

The role of berberine in Covid-19: potential adjunct therapy

Coronavirus disease 2019 (Covid-19) is a global diastrophic disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Covid-19 leads to inflammatory, immunological, and oxidative changes, by which SARS-CoV-2 leads to endothelial dysfunction (ED), acute lung injury (ALI), acute respiratory distress syndrome (ARDS), and multi-organ failure (MOF). Despite evidence illustrating that some drugs and vaccines effectively manage and prevent Covid-19, complementary herbal medicines are urgently needed to control this pandemic disease. One of the most used herbal medicines is berberine (BBR), which has anti-inflammatory, antioxidant, antiviral, and immune-regulatory effects; thus, BBR may be a prospective candidate against SARS-CoV-2 infection. This review found that BBR has anti-SARS-CoV-2 effects with mitigation of associated inflammatory changes. BBR also reduces the risk of ALI/ARDS in Covid-19 patients by inhibiting the release of pro-inflammatory cytokines and inflammatory signaling pathways. In conclusion, BBR has potent anti-inflammatory, antioxidant, and antiviral effects. Therefore, it can be utilized as a possible anti-SARS-CoV-2 agent. BBR inhibits the proliferation of SARS-CoV-2 and attenuates the associated inflammatory disorders linked by the activation of inflammatory signaling pathways. Indeed, BBR can alleviate ALI/ARDS in patients with severe Covid-19. In this sense, clinical trials and prospective studies are suggested to illustrate the potential role of BBR in treating Covid-19.

The role of ivabradine in doxorubicin-induced cardiotoxicity: exploring of underlying argument

This study investigated the potential role of ivabradine (IVN) in the attenuation of doxorubicin (DXR)-induced cardiotoxicity in rats. A total of 28 Swiss-Albino male mice were used, divided into four equal groups: the negative control did not receive any agents (n = 7), the DXR group received a single dose of DXR 20 mg/kg (n = 7), the treated group A was pretreated with IVN 5 mg/kg plus DXR (n = 7), and the treated group B was pretreated with IVN 10 mg/kg plus DXR (n = 7). The duration of this study was 10 days. Inflammatory biomarkers, including tumor necrosis factor alpha (TNF-α), lactate dehydrogenase (LDH), malondialdehyde (MDA), and cardiac troponin (cTn-I) serum levels were measured. TNF-α, LDH, MDA, and cTn-I serum levels were higher in the DXR-treated mice compared with the control (P˂0.01). IVN produced a dose-dependent effect in the reduction of MDA and cTn-I compared to DXR-treated mice (P˂0.05). Our findings suggest that IVN is an effective agent in mitigating DXR-induced cardiotoxicity due to its anti-inflammatory and antioxidant effects. IVN illustrated a dose-dependent effect in the attenuation of DXR-induced cardiotoxicity through inhibition of lipid peroxidation and cardiomyocyte injury.

Ginkgo biloba in the management of the COVID-19 severity

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection is linked with inflammatory disorders and the development of oxidative stress in extreme cases. Therefore, anti-inflammatory and antioxidant drugs may alleviate these complications. Ginkgo biloba L. folium extract (EGb) is a herbal medicine containing various active constituents. This review aims to provide a critical discussion on the potential role of EGb in the management of coronavirus disease 2019 (COVID-19). The antiviral effect of EGb is mediated by different mechanisms, including blocking SARS-CoV-2 3-chymotrypsin-like protease that provides trans-variant effectiveness. Moreover, EGb impedes the development of pulmonary inflammatory disorders through the diminution of neutrophil elastase activity, the release of proinflammatory cytokines, platelet aggregation, and thrombosis. Thus, EGb can attenuate the acute lung injury and acute respiratory distress syndrome in COVID-19. In conclusion, EGb offers the potential of being used as adjuvant antiviral and symptomatic therapy. Nanosystems enabling targeted delivery, personalization, and booster of effects provide the opportunity for the use of EGb in modern phytotherapy.

Central Effects of Ivermectin in Alleviation of Covid-19-induced Dysauto-nomia

Covid-19 may be associated with various neurological disorders, including dysautonomia, a dysfunction of the autonomic nervous system (ANS). In Covid-19, hypoxia, immunoinflammatory abnormality, and deregulation of the renin-angiotensin system (RAS) may increase sympathetic discharge with dysautonomia development. Direct SARS-CoV-2 cytopathic effects and associated inflammatory reaction may lead to neuroinflammation, affecting different parts of the central nervous system (CNS), including the autonomic center in the hypothalamus, causing dysautonomia. High circulating AngII, hypoxia, oxidative stress, high pro-inflammatory cytokines, and emotional stress can also provoke autonomic deregulation and high sympathetic outflow with the development of the sympathetic storm. During SARS-CoV-2 infection with neuro-invasion, GABA-ergic neurons and nicotinic acetylcholine receptor (nAChR) are inhibited in the hypothalamic pre-sympathetic neurons leading to sympathetic storm and dysautonomia. Different therapeutic modalities are applied to treat SARS-CoV-2 infection, like antiviral and anti-inflammatory drugs. Ivermectin (IVM) is a robust repurposed drug widely used to prevent and manage mild-moderate Covid-19. IVM activates both GABA-ergic neurons and nAChRs to mitigate SARS-CoV-2 infection- induced dysautonomia. Therefore, in this brief report, we try to identify the potential role of IVM in managing Covid-19-induced dysautonomia.

Prostaglandins and non-steroidal anti-inflammatory drugs in Covid-19

In response to different viral infections, including SARS-CoV-2 infection, pro-inflammatory, anti-inflammatory cytokines, and bioactive lipids are released from infected and immune cells. One of the most critical bioactive lipids is prostaglandins (PGs) which favor perseverance of inflammation leading to chronic inflammation as PGs act as cytokine amplifiers. PGs trigger the release of pro-inflammatory cytokines, activate Th cells, recruit immune cells, and increase the expression of pro-inflammatory genes. Therefore, PGs may induce acute and chronic inflammations in various inflammatory disorders and viral infections like SARS-CoV-2. PGs are mainly inhibited by non-steroidal anti-inflammatory drugs (NSAIDs) by blocking cyclooxygenase enzymes (COXs), which involve PG synthesis. NSAIDs reduce inflammation by selective or non-selective blocking activity of COX2 or COX1/2, respectively. In the Covid-19 era, there is a tremendous controversy regarding the use of NSAIDs in the management of SARS-CoV-2 infection. As well, the possible role of PGs in the pathogenesis of SARS-CoV-2 infection is not well-defined. Thus, the objective of the present study is to review the potential role of PGs and NSAIDs in Covid-19 in a narrative review regarding the preponderance of assorted views.

Dysregulated miRNAs network in the critical COVID-19: An important clue for uncontrolled immunothrombosis/thromboinflammation

Known as a pivotal immunohemostatic response, immunothrombosis is activated to restrict the diffusion of pathogens. This beneficial intravascular defensive mechanism represents the close interaction between the immune and coagulation systems. However, its uncontrolled form can be life-threatening to patients with the critical coronavirus disease 2019 (COVID-19). Hyperinflammation and ensuing cytokine storm underlie the activation of the coagulation system, something which results in the provocation of more immune-inflammatory responses by the thrombotic mediators. This vicious cycle causes grave clinical complications and higher risks of mortality. Classified as an evolutionarily conserved family of the small non-coding RNAs, microRNAs (miRNAs) serve as the fine-tuners of genes expression and play a key role in balancing the pro/anticoagulant and pro-/anti-inflammatory factors maintaining homeostasis. Therefore, any deviation from their optimal expression levels or efficient functions can lead to severe complications. Despite their extensive effects on the molecules and processes involved in uncontrolled immunothrombosis, some genetic agents and uncontrolled immunothrombosis-induced interfering factors (e.g., miRNA-single nucleotide polymorphysms (miR-SNPs), the complement system components, nicotinamide adenine dinucleotide phosphate (NADPH) oxidases, and reactive oxygen species (ROS)) have apparently disrupted their expressions/functions. This review study aims to give an overview of the role of miRNAs in the context of uncontrolled immunothrombosis/thromboinflammation accompanied by some presumptive interfering factors affecting their expressions/functions in the critical COVID-19. Detecting, monitoring, and resolving these interfering agents mafy facilitate the design and development of the novel miRNAs-based therapeutic approaches to the reduction of complications incidence and mortality in patients with the critical COVID-19.

5-HT/CGRP pathway and Sumatriptan role in Covid-19

Coronavirus disease 2019 (Covid-19) is a pandemic caused by severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2). In Covid-19, there is uncontrolled activation of immune cells with a massive release of pro-inflammatory cytokines and the development of cytokine storm. These inflammatory changes induce impairment of different organ functions, including the central nervous system (CNS), leading to acute brain injury and substantial changes in the neurotransmitters, including serotonin (5-HT) and calcitonin gene-related peptide (CGRP), which have immunomodulatory properties through modulation of central and peripheral immune responses. In Covid-19, 5-HT neurotransmitters and CGRP could contribute to abnormal and atypical vascular reactivity. Sumatriptan is a pre-synaptic 5-HT (5-HT1D and 5-HT1B) agonist and inhibits the release of CGRP. Both 5-HT and CGRP seem to be augmented in Covid-19 due to underlying activation of inflammatory signaling pathways and hyperinflammation. In virtue of its anti-inflammatory and antioxidant properties with inhibition release of 5-HT and CGRP, Sumatriptan may reduce Covid-19 hyperinflammation. Therefore, Sumatriptan might be a novel potential therapeutic strategy in managing Covid-19. In conclusion, Sumatriptan could be an effective therapeutic strategy in managing Covid-19 through modulation of 5-HT neurotransmitters and inhibiting CGRP.

Fenofibrate for COVID-19 and related complications as an approach to improve treatment outcomes: the missed key for Holy Grail

Introduction

Fenofibrate is an agonist of peroxisome proliferator activated receptor alpha (PPAR-α), that possesses anti-inflammatory, antioxidant, and anti-thrombotic properties. Fenofibrate is effective against a variety of viral infections and different inflammatory disorders. Therefore, the aim of critical review was to overview the potential role of fenofibrate in the pathogenesis of SARS-CoV-2 and related complications.

Results

By destabilizing SARS-CoV-2 spike protein and preventing it from binding angiotensin-converting enzyme 2 (ACE2), a receptor for SARS-CoV-2 entry, fenofibrate can reduce SARS-CoV-2 entry in human cells Fenofibrate also suppresses inflammatory signaling pathways, which decreases SARS-CoV-2 infection-related inflammatory alterations. In conclusion, fenofibrate anti-inflammatory, antioxidant, and antithrombotic capabilities may help to minimize the inflammatory and thrombotic consequences associated with SARSCoV-2 infection. Through attenuating the interaction between SARS-CoV-2 and ACE2, fenofibrate can directly reduce the risk of SARS-CoV-2 infection.

Conclusions

As a result, fenofibrate could be a potential treatment approach for COVID-19 control.

Ursolic acid and SARS-CoV-2 infection: a new horizon and perspective

SARS-CoV-2 (severe acute respiratory syndrome coronavirus type 2) has been identified as the source of a world coronavirus pandemic in 2019. Covid-19 is considered a main respiratory disease-causing viral pneumonia and, in severe cases, leads to acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). Although, extrapulmonary manifestations of Covid-19 like neurological, cardiovascular, and gastrointestinal have been confirmed. Exaggerated immune response and release of a high amount of pro-inflammatory cytokines may progress, causing a cytokine storm. Consequently, direct and indirect effects of SARS-CoV-2 infection can evolve into systemic complications due to the progression of hyper inflammation, oxidative stress and dysregulation of the renin-angiotensin system (RAS). Therefore, anti-inflammatory and antioxidant agents could be efficient in alleviating these disorders. Ursolic acid has anti-inflammatory, antioxidant, and antiviral effects; it reduces the release of pro-inflammatory cytokines, improves anti-inflammatory cytokines, and inhibits the production of reactive oxygen species (ROS). In virtue of its anti-inflammatory and antioxidant effects, ursolic acid may minimize SARS-CoV-2 infection-induced complications. Also, by regulating RAS and inflammatory signaling pathways, ursolic acid might effectively reduce the development of ALI in ARDS in Covid-19. In this state, this perspective discusses how ursolic acid can mitigate hyper inflammation and oxidative stress in Covid-19.

Changes in the Blood Viscosity in Patients With SARS-CoV-2 Infection

Coronavirus disease 2019 (COVID-19) is caused by a novel virus known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2-induced hyperinflammation together with alteration of plasma proteins, erythrocyte deformability, and platelet activation, may affect blood viscosity. Thus, this review aimed to study the link between SARS-CoV-2 infection and alteration of blood viscosity in COVID-19 patients. In order to review findings related to hyperviscosity in COVID-19, we suggested a protocol for narrative review of related published COVID-19 articles. Hyperviscosity syndrome is developed in different hematological disorders including multiple myeloma, sickle cell anemia, Waldenstorm macroglobulinemia, polycythemia, and leukemia. In COVID-19, SARS-CoV-2 may affect erythrocyte morphology via binding of membrane cluster of differentiation 147 (CD147) receptors, and B and 3 proteins on the erythrocyte membrane. Variations in erythrocyte fragility and deformability with endothelial dysfunction and oxidative stress in SARS-CoV-2 infection may cause hyperviscosity syndrome in COVID-19. Of interest, hyperviscosity syndrome in COVID-19 may cause poor tissue perfusion, peripheral vascular resistance, and thrombosis. Most of the COVID-19 patients with a blood viscosity more than 3.5 cp may develop coagulation disorders. Of interest, hyperviscosity syndrome is more commonly developed in vaccine recipients who had formerly received the COVID-19 vaccine due to higher underlying immunoglobulin concentrations, and only infrequently in those who have not received the COVID-19 vaccine. Taken together, these observations are untimely too early to give a final connotation between COVID-19 vaccination and the risk for development of hyperviscosity syndrome, consequently prospective and retrospective studies are necessary in this regard.

Hyperviscosity syndrome in COVID-19 and related vaccines: exploring of uncertainties

Hyperviscosity syndrome (HVS) recently emerged as a complication of coronavirus disease 2019 (COVID-19) and COVID-19 vaccines. Therefore, the objectives of this critical review are to establish the association between COVID-19 and COVID-19 vaccines with the development of HVS. HVS may develop in various viral infections due to impairment of humoral and cellular immunity with elevation of immunoglobulins. COVID-19 can increase blood viscosity (BV) through modulation of fibrinogen, albumin, lipoproteins, and red blood cell (RBC) indices. HVS can cause cardiovascular and neurological complications in COVID-19 like myocardial infarction (MI) and stroke. HVS with or without abnormal RBCs function in COVID-19 participates in the reduction of tissue oxygenation with the development of cardio-metabolic complications and long COVID-19. Besides, HVS may develop in vaccine recipients with previous COVID-19 due to higher underlying Ig concentrations and rarely without previous COVID-19. Similarly, patients with metabolic syndrome are at the highest risk for propagation of HVS after COVID-19 vaccination. In conclusion, COVID-19 and related vaccines are linked with the development of HVS, mainly in patients with previous COVID-19 and underlying metabolic derangements. The possible mechanism of HVS in COVID-19 and related vaccines is increasing levels of fibrinogen and immunoglobulins. However, dehydration, oxidative stress, and inflammatory reactions are regarded as additional contributing factors in the pathogenesis of HVS in COVID-19. However, this critical review cannot determine the final causal relationship between COVID-19 and related vaccines and the development of HVS. Prospective and retrospective studies are warranted in this field.

Vinpocetine is the forthcoming adjuvant agent in the management of COVID-19

Vinpocetine (VPN) is an alkaloid derivative of vincamine inhibits phosphodiesterase type 1 that increase cyclic guanosine monophosphate and cyclic adenosine monophosphate. VPN have anti-inflammatory and antioxidant effects with suppression release of pro-inflammatory cytokines. Moreover, VPN mitigates oxidative stress (OS) and inflammatory reactions through inhibition of mitogen-activated protein kinase (MAPK) signaling pathway. Therefore, VPN may decrease hyper-inflammation-induced acute lung injury in COVID-19 through modulation of NF-κB pathway. Taken together, VPN has pulmonary and extra-pulmonary protective effects against COVID-19 through mitigation of OS and hyperinflammation. In conclusion, VPN has noteworthy anti-inflammatory and anti-oxidant effects through inhibition of NF-κB/MAPK signaling pathway so, it may reduce SARS-CoV-2-induced hyper inflammatory and OS.

Vinpocetine (VPN) is an alkaloid from vincamine with a potent anti-inflammatory and antioxidant effects. VPN has the possibility of inhibiting substances that cause inflammation and oxidative stress and as a result, may be beneficial in COVID-19 treatment. Due to the anti-inflammatory effect of VPN, acute lung injury in COVID-19 may reduce as a result of the inhibition of agent that causes lungs inflammation in COVID-19. VPN may have potential to reduce difficulty in breathing and damage to the lungs. Conclusively, VPN when administered with other therapy may improve the outcome of treatment of COVID-19.

The Anticancer Potential of Doxycycline and Minocycline-A Comparative Study on Amelanotic Melanoma Cell Lines

Malignant melanoma is still a serious medical problem. Relatively high mortality, a still-growing number of newly diagnosed cases, and insufficiently effective methods of therapy necessitate melanoma research. Tetracyclines are compounds with pleiotropic pharmacological properties. Previously published studies on melanotic melanoma cells ascertained that minocycline and doxycycline exerted an anti-melanoma effect. The purpose of the study was to assess the anti-melanoma potential and mechanisms of action of minocycline and doxycycline using A375 and C32 human amelanotic melanoma cell lines. The obtained results indicate that the tested drugs inhibited proliferation, decreased cell viability, and induced apoptosis in amelanotic melanoma cells. The treatment caused changes in the cell cycle profile and decreased the intracellular level of reduced thiols and mitochondrial membrane potential. The exposure of A375 and C32 cells to minocycline and doxycycline triggered the release of cytochrome c and activated initiator and effector caspases. The anti-melanoma effect of analyzed drugs appeared to be related to the up-regulation of ERK1/2 and MITF. Moreover, it was noticed that minocycline and doxycycline increased the level of LC3A/B, an autophagy marker, in A375 cells. In summary, the study showed the pleiotropic anti-cancer action of minocycline and doxycycline against amelanotic melanoma cells. Considering all results, it could be concluded that doxycycline was a more potent drug than minocycline.

Neutrophil Extracellular Traps (NETs) and Covid-19: A new frontiers for therapeutic modality

Coronavirus disease 2019 (Covid-19) is a worldwide infectious disease caused by severe acute respiratory coronavirus 2 (SARS-CoV-2). In severe SARS-CoV-2 infection, there is severe inflammatory reactions due to neutrophil recruitments and infiltration in the different organs with the formation of neutrophil extracellular traps (NETs), which involved various complications of SARS-CoV-2 infection. Therefore, the objective of the present review was to explore the potential role of NETs in the pathogenesis of SARS-CoV-2 infection and to identify the targeting drugs against NETs in Covid-19 patients. Different enzyme types are involved in the formation of NETs, such as neutrophil elastase (NE), which degrades nuclear protein and release histones, peptidyl arginine deiminase type 4 (PADA4), which releases chromosomal DNA and gasdermin D, which creates pores in the NTs cell membrane that facilitating expulsion of NT contents. Despite of the beneficial effects of NETs in controlling of invading pathogens, sustained formations of NETs during respiratory viral infections are associated with collateral tissue injury. Excessive development of NETs in SARS-CoV-2 infection is linked with the development of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) due to creation of the NETs-IL-1β loop. Also, aberrant NTs activation alone or through NETs formation may augment SARS-CoV-2-induced cytokine storm (CS) and macrophage activation syndrome (MAS) in patients with severe Covid-19. Furthermore, NETs formation in SARS-CoV-2 infection is associated with immuno-thrombosis and the development of ALI/ARDS. Therefore, anti-NETs therapy of natural or synthetic sources may mitigate SARS-CoV-2 infection-induced exaggerated immune response, hyperinflammation, immuno-thrombosis, and other complications.

Effects of β-Blockers on the Sympathetic and Cytokines Storms in Covid-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a causative virus in the development of coronavirus disease 2019 (Covid-19) pandemic. Respiratory manifestations of SARS-CoV-2 infection such as acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) leads to hypoxia, oxidative stress, and sympatho-activation and in severe cases leads to sympathetic storm (SS). On the other hand, an exaggerated immune response to the SARS-CoV-2 invasion may lead to uncontrolled release of pro-inflammatory cytokine development of cytokine storm (CS). In Covid-19, there are interactive interactions between CS and SS in the development of multi-organ failure (MOF). Interestingly, cutting the bridge between CS and SS by anti-inflammatory and anti-adrenergic agents may mitigate complications that are induced by SARS-CoV-2 infection in severely affected Covid-19 patients. The potential mechanisms of SS in Covid-19 are through different pathways such as hypoxia, which activate the central sympathetic center through carotid bodies chemosensory input and induced pro-inflammatory cytokines, which cross the blood-brain barrier and activation of the sympathetic center. β2-receptors signaling pathway play a crucial role in the production of pro-inflammatory cytokines, macrophage activation, and B-cells for the production of antibodies with inflammation exacerbation. β-blockers have anti-inflammatory effects through reduction release of pro-inflammatory cytokines with inhibition of NF-κB. In conclusion, β-blockers interrupt this interaction through inhibition of several mediators of CS and SS with prevention development of neural-cytokine loop in SARS-CoV-2 infection. Evidence from this study triggers an idea for future prospective studies to confirm the potential role of β-blockers in the management of Covid-19.

Evaluation of minocycline combined with favipiravir therapy in coronavirus disease 2019 patients: A case-series study

The aim of this study was to investigate the efficacy and safety of minocycline (MIN) and favipiravir combination therapy in patients with coronavirus disease 2019 (COVID-19) admitted to our hospital in Fukui Prefecture, Japan, in March and April of 2020. In this retrospective study, a favipiravir monotherapy group (Control group, n = 9) was compared with a combined favipiravir plus MIN therapy group (MIN group, n = 12). No severe cases were present. The primary comparative endpoints evaluated were duration of fever, duration of hospitalization, duration from treatment initiation to severe acute respiratory syndrome coronavirus 2 polymerase chain reaction (PCR)-negative results, and changes in cytokine and chemokine production. Median duration from start of treatment to negative PCR test was significantly shorter in the MIN group than in the Control group. Mean rates of cytokine and chemokine reduction were significantly greater for interleukin-6 and interleukin-8 in the MIN group. No difference in adverse event rates were seen between groups, and only minor adverse events were encountered. MIN has been reported to have not only broad antibacterial activity, but also antiviral and anti-inflammatory activity. The present results support the efficacy and safety of MIN plus favipiravir therapy for the treatment of COVID-19.

Doxycycline in the Coronavirus Disease 2019 Therapy

Acute respiratory syndrome, associated with coronavirus 2 (SARS-CoV-2), is the most important medical and epidemic problem of today. The biggest challenge is to find an effective treatment and to reduce the need for hospitalisation. In the article, the patients with mild to moderate coronavirus disease 2019 (COVID-19) treated with doxycycline with significant improvement have been discussed. Doxycycline is a known antibiotic, but also an anti-inflammatory and immunomodulatory drug, so it seems to be ideal for the treatment of COVID-19. Doxycycline, as an easily available and low-cost medication, should be considered as a COVID-19 therapy in all patients in the first days of the symptoms of a SARS-CoV-2 infection. Due to its immunomodulatory, anti-inflammatory, cardioprotective and antiviral effects, it seems to be an ideal drug for patients with mild, moderate and severe disease. A large multicentre study is needed to evaluate the effects of this medication.

Impact of Sitagliptin in Non-Diabetic Covid-19 Patients

OBJECTIVE

In Coronavirus disease 2019 (Covid-19), SARS-CoV-2 may use dipeptidyl peptidase 4 (DPP4) as an entry-point in different tissues expressing these receptors. DPP4 inhibitors (DPP4Is), also named gliptins like sitagliptin, have anti-inflammatory and antioxidant effects; thereby lessen inflammatory and oxidative stress in diabetic Covid-19 patients. Therefore, the present study aimed to illustrate the potential beneficial effect of sitagliptin in managing Covid-19 in non-diabetic patients.

METHODS

A total number of 89 patients with Covid-19 were recruited from a single-center at the time of diagnosis. The recruited patients were assigned according to the standard therapy for Covid-19 and our interventional therapy into two groups; Group A: Covid-19 patients on the standard therapy (n=40) and Group B: Covid-19 patients on the standard therapy plus sitagliptin (n=49). The duration of this interventional study was 28 days according to the guideline in management patients with Covid-19. Routine laboratory investigations, serological tests, complete blood count (CBC), C-reactive protein (CRP), D-dimer, lactate dehydrogenase (LDH), and serum ferritin were measured to observed Covid-19 severity and complications. Lung computed tomography (CT) and clinical scores were evaluated.

RESULTS

The present study illustrated that sitagliptin add-on standard therapy improved clinical outcomes, radiological scores, and inflammatory biomarkers than standard therapy alone in non-diabetic patients with Covid-19 (P<0.01).

CONCLUSIONS

Sitagliptin add-on standard therapy in managing non-diabetic Covid-19 patients may have a robust beneficial effect by modulating inflammatory cytokines with subsequent good clinical outcomes.

Maternal Transmission of SARS-CoV-2: Safety of Breastfeeding in Infants Born to Infected Mothers

Coronavirus disease 2019 (COVID-19) is a recent epidemic disease caused by severe acute respiratory syndrome virus type 2 (SARS-CoV-2). In pregnancy, SARS-Cov-2 infection creates additional alarm due to concerns regarding the potential for transmission from the mother to the baby during both the antenatal and postpartum times. In general, breastfeeding is seldom disallowed because of infection of the mother. However, there are few exceptions with regards to certain infectious organisms with established transmission evidence from mother to infant and the link of infection of a newborn with significant morbidity and mortality. It is confirmed that pregnant women can become infected with SARS-CoV-2, although the debate on the possible vertical transmission of SARS-CoV-2 infection during pregnancy is still open. In this regard, the literature is still poor. On the contrary, the information on the safety of breastfeeding even during infections seems reassuring when the mother takes the necessary precautions. However, there are still answered questions regarding the precautions to be taken during breastfeeding by COVID-19 patients. This paper reviews the existing answers to these and many other questions. This review therefore presents a summary of the present-day understanding of infection with SARS-CoV-2 and discusses the answers around the maternal transmission of COVID-19 and the potential threat of breastfeeding to babies born to infected pregnant mothers. In conclusion, intrauterine transmission of SARS-CoV-2 infection is less likely to occur during pregnancy. Most studies suggest that COVID-19 is not transmitted through breast milk. Correspondingly, COVID-19-infected neonates might acquire the infection via the respiratory route because of the postnatal contact with the mother rather than during the prenatal period. International organizations encourage breastfeeding regardless of the COVID-19 status of the mother or child as long as proper hygienic and safety measures are adhered to so as to minimize the chance of infant infection by droplets and direct contact with the infected mother. Pasteurized donor human milk or infant formula as supplemental feeding can be quite beneficial in the case of mother-infant separation till breastfeeding is safe.

The potential role of neopterin in Covid-19: a new perspective

Neopterin (NPT) is a member of pteridines group, synthesized by macrophages when stimulated by interferon gamma (INF-γ). NPT is regarded as a macrophage stimulation indicator, marker of cellular immune activation and T helper 1 (Th1) type 1 immune response. Here, we aimed to provide a view point on the NPT features and role in Covid-19. Serum NPT level is regarded as an independent prognostic factor for Covid-19 severity, with levels starting to increase from the 3rd day of SARS-CoV-2 infection, being associated with severe dyspnea, longer hospitalization period and complications. Also, early raise of NPT reflects monocytes/macrophages activation before antibody immune response, despite the NPT level may also remain high in Covid-19 patients or at the end of incubation period before the onset of clinical symptoms. On the other hand, NPT attenuates the activity of macrophage foam cells and is linked to endothelial inflammation through inhibition of adhesion molecules and monocytes migration. However, NPT also exerts anti-inflammatory and antioxidant effects by suppressing NF-κB signaling and NLRP3 inflammasomes. NPT can be viewed as a protective compensatory mechanism to counterpoise hyper-inflammation, oxidative stress, and associated organ damage.