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Background: Morbidity and mortality rates associated with acute lung injury/acute respiratory distress syndrome (ALI/ARDS) are high (30–40%). Nuclear factor-kappa B (NF-κB) is a transcription factor, associated with transcription of numerous cytokines leading to cytokine storm, and thereby, plays a major role in ALI/ARDS and in advanced COVID-19 syndrome. Methods: Considering the role of NF-κB in ALI, cost-effective in silico approaches were utilized in the study to identify potential NF-κB inhibitor based on the docking and pharmacokinetic results. The identified compound was then pharmacologically validated in lipopolysaccharide (LPS) rodent model of acute lung injury. LPS induces ALI by altering alveolar membrane permeability, recruiting activated neutrophils and macrophages to the lungs, and compromising the alveolar membrane integrity and ultimately impairs the gaseous exchange. Furthermore, LPS exposure is associated with exaggerated production of various proinflammatory cytokines in lungs. Results: Based on in silico studies Olopatadine Hydrochloride (Olo), an FDA–approved drug was found as a potential NF-κB inhibitor which has been reported for the first time, and considered further for the pharmacological validation. Intraperitoneal LPS administration resulted in ALI/ARDS by fulfilling 3 out of the 4 criteria described by ATS committee (2011) published workshop report. However, treatment with Olo attenuated LPS-induced elevation of proinflammatory markers (IL-6 and NF-κB), oxidative stress, neutrophil infiltration, edema, and damage in lungs. Histopathological studies also revealed that Olo treatment significantly ameliorated LPS-induced lung injury, thus conferring improvement in survival. Especially, the effects produced by Olo medium dose (1 mg/kg) were comparable to dexamethasone standard. Conclusion: In nutshell, inhibition of NF-κB pathway by Olo resulted in protection and reduced mortality in LPS- induced ALI and thus has potential to be used clinically to arrest disease progression in ALI/ARDS, since the drug is already in the market. However, the findings warrant further extensive studies, and also future studies can be planned to elucidate its role in COVID-19-associated ARDS or cytokine storm. [ABSTRACT FROM AUTHOR]

The first cases of COVID-19 were identified in China in 2019, and the disease subsequently spread rapidly around the world, leading it to be declared a pandemic. The disease affects the lungs through the upper and lower respiratory tracts, and with the development of pneumonia, a clinical picture leading to respiratory failure referred to as cytokine storm occurs as a result of excessive cytokine production associated with an excessive inflammatory immune response. The increase in inflammatory markers is related to acute respiratory distress syndrome, disseminated intravascular coagulation and hypercoagulation. We present here an explanation of cytokine storm and the associated immune damage mechanisms. [ABSTRACT FROM AUTHOR]

COVID-19 has posed unprecedented challenges to global public health since its outbreak. The Qing-Fei-Pai-Du decoction (QFPDD), a Chinese herbal formula, is widely used in China to treat COVID-19. It exerts an impressive therapeutic effect by inhibiting the progression from mild to critical disease in the clinic. However, the underlying mechanisms remain obscure. Both SARS-CoV-2 and influenza viruses elicit similar pathological processes. Their severe manifestations, such as acute respiratory distress syndrome (ARDS), multiple organ failure (MOF), and viral sepsis, are correlated with the cytokine storm. During flu infection, QFPDD reduced the lung indexes and downregulated the expressions of MCP-1, TNF- α , IL-6, and IL-1 β in broncho-alveolar lavage fluid (BALF), lungs, or serum samples. The infiltration of neutrophils and inflammatory monocytes in lungs was decreased dramatically, and lung injury was ameliorated in QFPDD-treated flu mice. In addition, QFPDD also inhibited the polarization of M1 macrophages and downregulated the expressions of IL-6, TNF- α , MIP-2, MCP-1, and IP-10, while also upregulating the IL-10 expression. The phosphorylated TAK1, IKK α / β , and I κ B α and the subsequent translocation of phosphorylated p65 into the nuclei were decreased by QFPDD. These findings indicated that QFPDD reduces the intensity of the cytokine storm by inhibiting the NF- κ B signaling pathway during severe viral infections, thereby providing theoretical and experimental support for its clinical application in respiratory viral infections. [ABSTRACT FROM AUTHOR]

BACKGROUND: Corona Virus Disease 2019 (COVID-19) is a highly contagious, rapidly variable, and dangerous infectious disease. However, no specific and effective treatment for COVID-19 is available until now. The safety and efficacy of mesenchymal stem cells and their exosomes have been well verified in numerous clinical trials. Their immunomodulatory and tissue regeneration capabilities may support them as a prospective therapy for COVID-19 application in the clinic. OBJECTIVE: To focus on the development, pathogenesis and the current treatment status of COVID-19, efficacy and possible immunomodulatory mechanisms of mesenchymal stem cells and their exosomes for COVID-19 so as to provide new insights into the clinical treatment for the disease in the future. METHODS: Articles were searched on PubMed and CNKI with the key words of “SARS-CoV-2, COVID-19, cytokine storm, acute respiratory distress syndrome, mesenchymal stem cells, exosomes, immune regulation, tissue repair” in Chinese and English. Finally, 64 articles were collected for this review. RESULTS AND CONCLUSION: Acute respiratory distress syndrome and acute lung injury caused by cytokine storm are the primary precipitating factors of death in individuals with COVID-19. Mesenchymal stem cells and their exosomes can effectively treat the symptoms of acute respiratory distress syndrome and repair the damaged lung tissue in COVID-19 patients by reducing the cytokine storm and promoting the regeneration of alveolar epithelial cells through the interaction with immune cells and their paracrine effects. All of these investigations confirmed that mesenchymal stem cells and their exosomes can fight the COVID-19 infection, and this might be a promising, safe and effective strategy. However, more preclinical studies and randomized, controlled clinical trials are needed to conduct the biodistribution, metabolic fate, and the potential treatment risks of mesenchymal stem cells and their derived exosomes in vivo to fully exploit their clinical efficacy. [ABSTRACT FROM AUTHOR]

A cytokine storm is one of the leading causes of acute respiratory distress syndrome (ARDS) and sepsis‐associated multiple organ failure in many respiratory viral infections, including severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2). The coronavirus disease 2019 (COVID‐19) pandemic has caused millions of deaths worldwide, resulting in an urgent need for effective therapeutic interventions. Repurposing immunosuppressive drugs that target cytokines with immunomodulatory properties is a promising approach to counteract SARS‐CoV‐2‐induced ARDS at the infective and post‐infective stages. In this minireview, we examine drugs targeting IL‐1β, IL‐4/IL‐13, IL‐6 and TNF‐α tested in COVID‐19 patients. [ABSTRACT FROM AUTHOR]

Considering the high impact that severe Coronavirus disease 2019 (COVID-19) cases still pose on public health and their complex pharmacological management, the search for new therapeutic alternatives is essential. Mesenchymal stromal cells (MSCs) could be promising candidates as they present important immunomodulatory and anti-inflammatory properties that can combat the acute severe respiratory distress syndrome (ARDS) and the cytokine storm occurring in COVID-19, two processes that are mainly driven by an immunological misbalance. In this review, we provide a comprehensive overview of the intricate inflammatory process derived from the immune dysregulation that occurs in COVID-19, discussing the potential that the cytokines and growth factors that constitute the MSC-derived secretome present to treat the disease. Moreover, we revise the latest clinical progress made in the field, discussing the most important findings of the clinical trials conducted to date, which follow 2 different approaches: MSC-based cell therapy or the administration of the secretome by itself, as a cell-free therapy. • Provide a comprehensive overview of the intricate inflammatory process derived from the immune dysregulation in COVID-19. • Discuss the potential of the cytokines and growth factors that constitute MSC-derived secretome to treat the disease. • Revise the latest clinical progress made in the field, discussing the most important findings conducted to date. [ABSTRACT FROM AUTHOR]

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) represent a significant global burden of morbidity and mortality, with lung injury being the primary cause of death in affected patients. The pathogenesis of lung injury, however, remains a complex issue. In recent years, the role of the immune system in lung injury has attracted extensive attention worldwide. Despite advancements in our understanding of various lung injury subtypes, significant limitations persist in both prevention and treatment. This review investigates the immunopathogenesis of ALI/ARDS, aiming to elucidate the pathological processes of lung injury mediated by dendritic cells (DCs), natural killer (NK) cells, phagocytes, and neutrophils. Furthermore, the article expounds on the critical contributions of gut microbiota, inflammatory pathways, and cytokine storms in the development of ALI/ARDS. [Display omitted] • Damage to lung tissue caused by immune cell dysfunction. • The ecological stability of intestinal flora is important in protecting lung tissue. • The inflammatory pathway plays a crucial role in regulating and mediating lung injury. • The impact of cytokine storm on lung injury is severe. [ABSTRACT FROM AUTHOR]

COVID-19 is an infectious disease caused by the SARS-CoV-2 virus. The clinical presentations of the SARS-CoV-2 infection are widely variable and treatment strategies for COVID-19 are dependent on the infection phase. Timing the right treatment for the right phase of this disease is paramount, with correlations detected between the phase of the infection and the type of drug used to treat. The immune system activation following COVID-19 infection can further develop to a fulminant cytokine storm which can progress to acute respiratory distress syndrome. The inflammatory phase, or the hyperinflammation phase, is a later stage when patients develop acute respiratory distress syndrome (ARDS), sepsis, and kidney and other organ failure. In this stage, the virus is probably not necessary and all the damage is due to the immune system's cytokine storm. Immunosuppressive or immunomodulatory agent administration is the major strategy in treating COVID-19 patients at this stage. On the other hand, immunodeficient patients who are treated with immunomodulator agents have attenuated immune systems that do not produce enough cytokines. Current data do not show an increased risk of severe COVID-19 in patients taking biologic therapies or targeted disease-modifying antirheumatic drugs. However, more comprehensive studies are needed to assess the effect of these medications, and whether they may actually be protective of the severe type of disease. Although medications for COVID-19 and for the cytokine storm are important, the main breakthrough in slowing down the pandemic was developing effective vaccines. These vaccines showed a dramatic result in reducing morbidity and mortality up to the Delta variant's spread. However, the emergence of the new variant, Omicron, influenced the successful results we had before. This variant is more contagious but less dangerous than Delta. The aim now is to develop vaccines based on the Omicron and Delta immunogens in the future for broad protection against different variants. [ABSTRACT FROM AUTHOR]

Background: A cytokine storm is an abnormal host immune system response and a principal responsibility for the incidence of acute respiratory distress syndrome. The existence of the virus-induced cytokine has been linked to mortality in patients with COVID-19. This study aimed to review the gene's role in cytokine storm as a therapeutic target in patients with COVID-19. We demonstrated the role of pro-inflammatory cytokines in conditions that are often associated with COVID-19. Hyperproduction of mostly pro-inflammatory cytokines such as IFN-γ, IL-6, IL-1, TNF-α, and Chemokines, which target lung tissue preferentially, can significantly worsen the prognosis in almost all cases. The cytokines' data in this disease will support the development of more useful COVID-19 patient management strategies. In managing COVID-19 patients, targeting cytokines can decrease mortality and increase survival rates. [ABSTRACT FROM AUTHOR]

COVID-19 is a viral disease that commonly presents with mild symptoms with predominant respiratory system involvement. However, it can cause serious complications such as acute respiratory disease, multi-organ dysfunction, especially in patients with comorbidities. As it is a new disease, the full picture of the disease and its complications are not yet fully understood. Moreover, the patients at risk of complications are not well identified, and the data about the biphasic pattern of cytokine storm syndrome are limited. Here, we report the case of a 64-year-old male having diabetes mellitus, hypertension, ischemic heart disease with triple-vessel coronary artery disease tested positive for severe acute respiratory syndrome coronavirus 2, then complicated with acute respiratory distress syndrome and two waves of cytokine storm in 28 days. [ABSTRACT FROM AUTHOR]

The coronavirus disease-19 (COVID-19), at first, was reported in Wuhan, China, and then rapidly became pandemic throughout the world. Cytokine storm syndrome (CSS) in COVID-19 patients is associated with high levels of cytokines and chemokines that cause multiple organ failure, systemic inflammation, and hemodynamic instabilities. Acute respiratory distress syndrome (ARDS), a common complication of COVID-19, is a consequence of cytokine storm. In this regard, several drugs have been being investigated to suppress this inflammatory condition. Purinergic signaling receptors comprising of P1 adenosine and P2 purinoceptors play a critical role in inflammation. Therefore, activation or inhibition of some subtypes of these kinds of receptors is most likely to be beneficial to attenuate cytokine storm. This article summarizes suggested therapeutic drugs with potential anti-inflammatory effects through purinergic receptors. [ABSTRACT FROM AUTHOR]

Background: The cause of end-organ damage and acute respiratory distress syndrome (ARDS) in coronavirus disease 2019 (COVID-19) patients is postulated to be connected to the uncontrolled increase of pro-inflammatory cytokines. The upregulation of many cytokines is dependent on signaling through the Janus kinase 1 (JAK-1) and JAK-2 pathways. Ruxolitinib, a JAK-1 and JAK-2 inhibitor, is documented to have potent anti-inflammatory activity by targeting several cytokines and growth factors with proposed efficacy in the cytokine storm observed in severe COVID-19 patients; therefore, this study examines the efficacy and tolerability of ruxolitinib for adult COVID-19 patients. Materials and Methods: This review was conducted using preferred reporting items for aystematic reviews and meta-analyses (PRISMA) methodology. Six reviewers analyzed 1,120 results. Seven studies were selected and validated. A quantitative meta-analysis was further performed to evaluate clinical improvement at day 28, mortality at day 28, and oxygen requirements comparing treatment and standard of care groups. Results: 168 individuals were involved in the studies selected: 122 in cohort studies, 4 in case reports, and 41 in randomized controlled studies. The ruxolitinib group had a higher likelihood of clinical improvement by the 28th day of treatment when assessed with the standard of care (SOC) group (odds ratio [OR]: 1.48; 95% confidence interval [CI]: 0.53 - 4.16; P = 0.45; I² = 0%). The SOC group was at a higher risk of experiencing serious adverse events (OR: 0.17; 95% CI: 0.03 - 1.13; P = 0.07). Notably the SOC group had a higher likelihood of death (OR: 0.51; 95% CI: 0.11-2.29; P = 0.07; I² = 0%). Conclusion: Prior studies on ruxolitinib have demonstrated it is able to decrease inflammatory markers. In recent studies on COVID-19, treatment with ruxolitinib decreased the time on mechanical ventilation, hospitalization time, and the need for vasopressor support. Additionally, ruxolitinib showed decreased mortality and demonstrated improvement in lung congestion as evidenced by computerized tomography imaging. These findings warrant further clinical investigation into Ruxolitinib as a potential treatment approach for severe COVID-19. [ABSTRACT FROM AUTHOR]

The coronavirus disease 2019 is a disease caused by severe acute respiratory syndrome coronavirus 2 and continues to pose a global threat resulting in thousands of deaths. In the absence of effective therapeutics, implementation of non-pharmaceutical interventions still remains an important prevention strategy, while various vaccine candidates are either approved or in clinical trials, several drugs are also being tested in pre-clinical studies for their potential for repurposing to treat the coronavirus disease 2019. The mechanistic details underlying disease pathogenesis and therapeutic efficacy of various drugs are rapidly emerging, which will be useful for fast-tracking pharmaceutical leads to clinical utility. The current review details the mechanistic understanding of viral pathogenesis including host cell interactions, viral replication, altered host cell processes, cytokine release syndrome and the role of coagulation pathway, renin angiotensin system and kallikrein-bradykinin pathways in acute respiratory distress syndrome. Further, a detailed overview of therapeutic candidates including antibodies, targeted enzyme inhibitors, drugs that showed clinical efficacy and drugs with anti-severe acute respiratory syndrome coronavirus 2 activities in pre-clinical models are discussed. Additionally, the approval and availability of various vaccines and their mechanism of action are also detailed. Importantly, emerging clinical evidence regarding immune biomarkers that help in patient stratification into moderate or severe cases are highlighted that may aid in reducing mortality by choosing appropriate treatment strategies. Taken together, the report gives up to date mechanistic information on disease pathogenesis and potential therapeutics. [ABSTRACT FROM AUTHOR]

Novel coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus-2. The virus causes an exaggerated immune response, resulting in a cytokine storm and acute respiratory distress syndrome, the leading cause of COVID-19-related mortality and morbidity. So far, no therapies have succeeded in circumventing the exacerbated immune response or cytokine storm associated with COVID-19. Mesenchymal stem cells (MSCs), through their immunomodulatory and regenerative activities, mostly mediated by their paracrine effect and extracellular vesicle production, have therapeutic potential in many autoimmune, inflammatory, and degenerative diseases. In this paper, we review clinical studies on the use of MSCs for COVID-19 treatment, including the salutary effects of MSCs on the pathophysiology of COVID-19 and the immunomodulation of the cytokine storm. Ongoing clinical trial designs, cell sources, dose and administration, and populations are summarized, and the paracrine mode of benefit is discussed. We also offer suggestions for optimizing MSC-based therapies, including genetic engineering, strategies for cell surface modification, nanotechnology applications, and combination therapies. [ABSTRACT FROM AUTHOR]

• LDRT shows clinical response for COVID-19-induced pneumonia and ARDS via Nrf-2. • Nrf2-activation creates optimal redox environment for anti-inflammatory phenotype. • Nrf2-mediated response suppresses cytokine storm preventing COVID-19 deaths. • Activation of Nrf2 is highly dose dependent and conforms to a hormetic response. • LDRT can be regarded as safe and effective for use at any stage of COVID-19. Novel mechanistic insights are discussed herein that link a single, nontoxic, low-dose radiotherapy (LDRT) treatment (0.5–1.0 Gy) to (1) beneficial subcellular effects mediated by the activation of nuclear factor erythroid 2-related transcription factor (Nrf2) and to (2) favorable clinical outcomes for COVID-19 pneumonia patients displaying symptoms of acute respiratory distress syndrome (ARDS). We posit that the favorable clinical outcomes following LDRT result from potent Nrf2-mediated antioxidant responses that rebalance the oxidatively skewed redox states of immunological cells, driving them toward anti-inflammatory phenotypes. Activation of Nrf2 by ionizing radiation is highly dose dependent and conforms to the features of a biphasic (hormetic) dose–response. At the cellular and subcellular levels, hormetic doses of <1.0 Gy induce polarization shifts in the predominant population of lung macrophages, from an M1 pro-inflammatory to an M2 anti-inflammatory phenotype. Together, the Nrf2-mediated antioxidant responses and the subsequent shifts to anti-inflammatory phenotypes have the capacity to suppress cytokine storms, resolve inflammation, promote tissue repair, and prevent COVID-19-related mortality. Given these mechanistic considerations—and the historical clinical success of LDRT early in the 20th century—we opine that LDRT should be regarded as safe and effective for use at almost any stage of COVID-19 infection. In theory, however, optimal life-saving potential is thought to occur when LDRT is applied prior to the cytokine storms and before the patients are placed on mechanical oxygen ventilators. The administration of LDRT either as an intervention of last resort or too early in the disease progression may be far less effective in saving the lives of ARDS patients. [ABSTRACT FROM AUTHOR]

Coronavirus disease 2019 (COVID-19) pandemic is still a world-class challenge. Inflammation, especially its severe form with excess release of pro-inflammatory cytokines (cytokine storm) which is a life-threatening condition, is among the most important suspects involved in COVID-19 pathogenesis. It has been shown that cytokine storm could cause notable morbidities such as acute respiratory distress syndrome (ARDS) which leads to hypoxia which is significantly associated with mortality of patients with COVID-19. Hypoxia-inducible factor 1α (HIF-1α) which activates following ARDS-induced hypoxia plays a crucial role in pathogenesis of cytokine storm. The expression of tumor necrosis factor α (TNF-α), interleukin 1 β (IL-1β), and IL-6 which are key elements of cytokine storm are by nuclear factor κβ (NFκB). Interestingly, during the hypoxia, HIF-1α activates NFκB to induce expression of pro-angiogenic and pro-inflammatory factors. These released factors starts a autocrine/paracrine loop and causes deterioration of their etiological pathways of expression: cytokine storm and ARDS. To sum up, it seems HIF-1α is an important target to hit to ameliorate the mentioned pathways. Herein, we suggest perfluorocarbons (PFCs) which are among the organofluorine compounds as a possible co-treatment to reduce hypoxemia and then hypoxia. These substances are known for their high gas solving potential that make them able to be used as a synthetic artificial blood product. Due to the potential of PFCs to affect the fountain of important physiopathological pathway such as inflammation a hypoxia through affecting NFκB, they could be considered as multi-target co-treatment for ARD individuals with COVID-19. It is highly suggested to evaluate this hypothesis in following researches. [ABSTRACT FROM AUTHOR]

[Display omitted] • SARS-CoV-2 mediated cytokine storm is associated with the mortality and morbidity of COVID-19 patients. The key cytokines implicated in the onset of disease severity include TNF-α, IFN-γ, IL-6, IL-1β, GM-CSF, and G-CSF. • This review emphasizes the role of GM-CSF and G-CSF in COVID-19. • Emerging therapeutic interventions involve antibodies against TNF-α and IFN-γ, blocking IL-1 production, anti-IL-6 receptor antagonists, JAK-STAT inhibitors, and employment of mesenchymal stem cells and therapeutic plasma exchange. COVID-19 has claimed millions of lives during the last 3 years since initial cases were reported in Wuhan, China, in 2019. Patients with COVID-19 suffer from severe pneumonia, high fever, acute respiratory distress syndrome (ARDS), and multiple-organ dysfunction, which may also result in fatality in extreme cases. Cytokine storm (CS) is hyperactivation of the immune system, wherein the dysregulated production of proinflammatory cytokines could result in excessive immune cell infiltrations in the pulmonary tissues, resulting in tissue damage. The immune cell infiltration could also occur in other tissues and organs and result in multiple organs' dysfunction. The key cytokines implicated in the onset of disease severity include TNF-α, IFN-γ, IL-6, IL-1β, GM-CSF, and G-CSF. Controlling the CS is critical in treating COVID-19 disease. Therefore, different strategies are employed to mitigate the effects of CS. These include using monoclonal antibodies directed against soluble cytokines or the cytokine receptors, combination therapies, mesenchymal stem cell therapy, therapeutic plasma exchange, and some non-conventional treatment methods to improve patient immunity. The current review describes the role/s of critical cytokines in COVID-19-mediated CS and the respective treatment modalities. [ABSTRACT FROM AUTHOR]

[Display omitted] Fatal "cytokine storms (CS)" observed in critically ill COVID-19 patients are consequences of dysregulated host immune system and over-exuberant inflammatory response. Acute respiratory distress syndrome (ARDS), multi-system organ failure, and eventual death are distinctive symptoms, attributed to higher morbidity and mortality rates among these patients. Consequent efforts to save critical COVID-19 patients via the usage of several novel therapeutic options are put in force. Strategically, drugs being used in such patients are dexamethasone, remdesivir, hydroxychloroquine, etc. along with the approved vaccines. Moreover, it is certain that activation of the resolution process is important for the prevention of chronic diseases. Until recently Inflammation resolution was considered a passive process, rather it's an active biochemical process that can be achieved by the use of specialized pro-resolving mediators (SPMs). These endogenous mediators are an array of atypical lipid metabolites that include Resolvins, lipoxins, maresins, protectins, considered as immunoresolvents, but their role in COVID-19 is ambiguous. Recent evidence from studies such as the randomized clinical trial, in which omega 3 fatty acid was used as supplement to resolve inflammation in COVID-19, suggests that direct supplementation of SPMs or the use of synthetic SPM mimetics (which are still being explored) could enhance the process of resolution by regulating the aberrant inflammatory process and can be useful in pain relief and tissue remodeling. Here we discussed the biosynthesis of SPMs, & their mechanistic pathways contributing to inflammation resolution along with sequence of events leading to CS in COVID-19, with a focus on therapeutic potential of SPMs. [ABSTRACT FROM AUTHOR]

The emergence of Coronavirus disease 2019 (Covid-19) is a global problem nowadays, causing health difficulty with increasing mortality rates, which doesn't have a verified treatment. SARS-CoV-2 infection has various pathological and epidemiological characteristics, one of them is increased amounts of cytokine production, which in order activate an abnormal unrestricted response called "cytokine storm". This event contributes to severe acute respiratory distress syndrome (ARDS), which results in respiratory failure and pneumonia and is the great cause of death associated with Covid-19. Endotoxemia and the release of bacterial lipopolysaccharides (endotoxins) from the lumen into the bloodstream enhance proinflammatory cytokines. SARS-CoV-2 can straightly interplay with endotoxins via its S protein, leading to the extremely elevating release of cytokines and consequently increase the harshness of Covid-19. In this review, we will discuss the possible role of viral-bacterial interaction that occurs through the transfer of bacterial products such as lipopolysaccharide (LPS) from the intestine into the bloodstream, exacerbating the severity of Covid-19 and cytokine storms. • SARS-CoV-2 infection can increased amounts of cytokine production. • Interaction between viral and bacterial can be transfer bacterial products into the bloodstream. • SARS-CoV-2 infection can be activated an abnormal unrestricted response called "cytokine storm. [ABSTRACT FROM AUTHOR]

The outburst of inflammatory response and hypercoagulability are among the factors contributing to increased mortality in severe COVID-19 cases. Pentoxifylline (PTX), a xanthine-derived drug registered for the treatment of vascular claudication, has been reported to display broad-spectrum anti-inflammatory and immunomodulatory properties via adenosine A2A receptor (A2AR)-related mechanisms, in parallel to its rheological actions. Prior studies have indicated the efficacy of PTX in the treatment of various pulmonary diseases, including the management of acute respiratory distress syndrome of infectious causes. Therefore, PTX has been proposed to have potential benefits in the treatment of SARS-CoV-2 symptoms, as well as its complications. The aim of this review is to discuss available knowledge regarding the role of PTX as a complementary therapeutic in SARS-CoV-2. [ABSTRACT FROM AUTHOR]