English

Abstract

Coronavirus disease-19 (COVID-19) is the deadliest pandemic that the whole world is facing today. COVID-19 is different from normal flu by its two lethal manifestations which includes deadly pneumonia which may lead to acute respiratory distress syndrome (ARDS) due to hyper-inflammation of alveolar tissues and pulmonary intravascular coagulopathy (PIC).1,2 It is noteworthy here to mention that both these lethal manifestations of COVID-19 are due to abnormally high levels of pro-inflammatory cytokines like interleukin (IL) - 1β, IL - 6, and tumour necrosis factor (TNF) - α, termed as “cytokine storm.”3,4 There is a certain link between pro-inflammatory cytokines like IL - 1β, IL - 6, and TNF - α and its pro-coagulatory influence on coagulation pathway mediated by tissue factor that binds and activate factor VII, leading to formation of tissue factor – VII a complexes which results in the activation of clotting factor X and IX.4 Recently the researchers in China and some European countries have found raised level of pro-inflammatory cytokines particularly IL - 6 in severe cases of COVID-19. They also found raised D-dimer, fibrinogen levels and prothrombin time in moderate to severe COVID-19 cases.5,6 Both of these lethal manifestations of COVID-19 – ARDS and PIC are linked to raised levels of pro-inflammatory cytokines, particularly, IL - 6. It is not very clear that the pro-inflammatory action of cytokines is mediated through leukotrienes as the biochemical assay for leukotrienes are not widely available but possibility of this probable mechanism cannot be ruled out. Hence, development of any molecule with ability to inhibit pro-inflammatory cytokines, particularly IL-6 may be able to tame the lethal nature of COVID-19, and may ultimately reduce the mortality of this deadly pandemic. Montelukast sodium is such molecule which has capacity to inhibit proinflammatory cytokines such as IL - 1β, IL - 6, and TNF - α.7 Montelukast sodium is leukotriene receptor antagonist that inhibits the cysteinyl leukotriene type-1 receptor. Leukotrienes modulate the production of pro-inflammatory cytokines.8 Its antagonist action on leukotriene receptors can inhibit the production of these pro-inflammatory cytokines. Even recent in silico study by Jacobson at Oak Ridge National Lab, was found that excess bradykinin production may be responsible for pulmonary, cardiac, neurological and nephrological lethal manifestations of COVID-19.9 Crimi et al.10 already found that Montelukast is effective to control bradykinin induced bronchoconstriction. Thus, theoretically, montelukast seems to be best molecule to deal with deadly manifestation of COVID-19 even if we go by cytokine storm hypothesis or bradykinin hypothesis.