Prophylactic and Therapeutic Administration of Leutragin Increases the Survival Rate of Animals in a Model of Fatal Acute Respiratory Distress Syndrome

Abstract

This study aims to investigate effects of leutragin, an opioid peptide analogue of endogenous dynorphin 1-6, on animal survival in an experimental model of “cytokine storm” and fatal acute respiratory distress syndrome (ARDS) in C57Bl/6Y mice under different administration regimens. The aforementioned factors cause a severe course of COVID-19, which explains the current interest in seeking new treatments for ARDS. It was shown that both the prophylactic (before ARDS induction) and therapeutic (after ARDS induction) administration of leutragin in a combined mode — intramuscular injection plus inhalation leads to a statistically significant increase in the survival rate of animals. Compared to the control, leutragin significantly reduced the risk of death in animals with ARDS. The discovered prophylactic effect of leutragin deserves special attention due to its potential in preventing the onset of the disease and impeding the development of severe lung damage, thus reducing the risk of ARDS and fatal outcomes. Thus, the use of leutragin can be seen as a new effective approach to the treatment and prevention of respiratory diseases associated with a “cytokine storm” and ARDS, including the coronavirus infection COVID-19.