TLR4 as a therapeutic target for respiratory and neurological complications of SARS-CoV-2.

Introduction: The COVID-19 pandemic remains aglobal challenge. While there are mRNA agents on the horizon as apotential prevention, adefinitive drug therapy is an unmet medical need. The hyperinflammatory response, known as the 'cytokine storm', is chiefly responsible for complications and deaths. The binding of spike-glycoprotein of SARS-CoV-2 to TLR4 receptors has been documented in several studies and has been found to play arole in hyperinflammation; hence, there is an interest in TLR4 as apotential drug target.Areas covered: This review discusses the neurological and respiratory complications of SARS-CoV-2 infection and progresses to examine the role of the 'cytokine storm' and the involvement of TLR4 receptors in these complications. The possibility of using TLR4 modulators to curb the complications are considered and finally, ashort perspective on future potential drug treatments is offered. Various databases were searched including Pub-Med, Google Scholar, and Medline. The search mainly included research articles, meta-analysis, retrospective studies, reports, and systematic reviews.Expert opinion: TLR4 modulators are being investigated in clinical trials for COVID-19. Challenges in terms of structural diversity of the agents, their natural origin, and efficacy demand extensive research.

Divulging the Intricacies of Crosstalk Between NF-Kb and Nrf2-Keap1 Pathway in Neurological Complications of COVID-19.

The severity of COVID-19 infection is surging day by day. With the cases increasing daily, it is becoming more and more essential to understand the pathogenic mechanisms underlying the severity of the disease. It is now well known that the infection manifests itself primarily as respiratory, but the involvement of the other organ systems has now been documented in many studies. SARS-CoV-2 can invade the nervous system by a multitude of proposed mechanisms that have been discussed in this review. NF-κB and Nrf2 are transcription factors that regulate genes responsible for inflammatory and anti-oxidant response respectively. Specific focus in this review has been given to NF-κB and Nrf2 pathways that are involved in the cytokine storm and oxidative stress that are the hallmarks of COVID-19. As the immune injury is an important mechanism of neuro-invasion and neuroinflammation, there is the possible involvement of these two pathways in the neurological complications. The crosstalk mechanisms of these signaling pathways have also been discussed. Immuno-modulators both synthetic and natural are promising candidates in catering to the pathologies targeted in the aforementioned pathways.

Pharmacological insight into potential therapeutic agents for the deadly Covid-19 pandemic.

Coronaviruses are pleomorphic, enveloped, or spherical viruses, which have a size ranging from 80 to 120 nm. These viruses act on receptors that cause the triggering of fusion. Coronaviruses were first described after cultivation from patients with common colds by Tyrell and Bynoe in 1966. There are various subtypes of coronavirus, 7 out of these can cause infection in human beings. The Alpha subtype is responsible for mild infection showing symptoms or infection without any prevailing symptoms. On the other hand, the beta subtype is responsible for very serious diseases leading to fatality. The lineage of this novel SARS-CoV-2 falls under the beta lineage of the beta coronavirus which has been observed to have a relation to the MERS and SARS coronavirus. In the Huanan market selling seafood, the transition of this novel virus in humans from animals has occurred. It has the potential to be the cause of widespread fatality amongst the people of the globe. On August 16, 2020, the World Health Organisation had reported 2,1294,845 cases which are confirmed to date out of which 413,372 deaths have occurred. Currently, no targeted antiviral vaccines or drugs to fight against COVID-19 infection have been approved for use in humans. This pandemic is fast emerging and drug repurposing is the only ray of hope which can ensure quick availability. Vaccine development is progressing each day with various platforms such as DNA, Live Attenuated Virus, Non-Replicating Viral Vector, Protein Subunit, and RNA, being utilized for the development. COVID-19 attacks the immune system of the host & this can result in a cytokine storm. As a result, various herbal agents both acting as antivirals and immunomodulatory can also be used. Convalescent Plasma Therapy and Mesenchymal Stem Cell therapy are also being explored as a plausible therapeutic. There remains a considerable unmet need for therapeutics to be addressed. The development and availability of accessible and efficient therapy are essential for the treatment of patients. This review discusses the epidemiology, pathogenesis, the tale of origin, and transmission of COVID-19 or Sars-Cov2 virus and gives evidence of potential therapeutic agents that can be explored to cast away this pandemic.