Pharmacology of COVID-19.

The arrival of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in our lives and responsible for the COVID-19 pandemic has posed an enormous challenge for healthcare and researchers. This pandemic situation has represented the biggest global health problem in recent times and an enormous challenge for the search for effective therapies. Covid-19 can present itself in very different ways, from being asymptomatic to developing an upper respiratory tract infection, pneumonia, or a hyperinflammatory process [1]. In the most severe cases of the disease, there is a deregulation of the immune system characterized by an excess of inflammatory mediators, known as a cytokine storm, which can cause organ damage and increase the risk of mortality [2]. Because the symptomatology of COVID-19 is variable among patients, treatment must be tailored to address the specific presentation of symptoms, from prophylactic treatment with vaccines to treatment of early infection, the pulmonary phase, and finally the hyperinflammatory phase. It is clear that vaccines are the most effective way to prevent and eradicate COVID-19. Other strategies are based on the development of antivirals to prevent COVID-19 progression with different targets such as blocking the interaction between the SARS-CoV-2 spike protein and its ACE2 receptor or preventing virus replication after it has entered the host cell, among others [3]. Other approaches are based on the development and use of immune system enhancers, pulmonary supportive agents, immunosuppressants and anti-inflammatories. One of the main problems today is that the only therapies with published evidence of benefits over the course of the infection, such as inhaled interferon and monoclonal antibodies, are very expensive treatments and have limited availability. In this sense, much work remains to be done to find molecules that are effective and at the same time accessible to the majority of the world's population [4].

This especial issue focuses on the study of the interactions between chemicals and/or compounds of natural origin with elements related to Covid-19 to generate knowledge that contributes to the development of new treatments against Covid-19.