In silico study of the inhibition of SARS-COV-2 viral cell entry by neem tree extracts

The outbreak of COVID-19, caused by SARS-COV-2, is responsible for higher mortality and morbidity rates across the globe. Until now, there is no specific treatment of the disease and hospitalized patients are treated according to the symptoms they develop. Efforts to identify drugs and/or vaccines are ongoing processes. Natural products have shown great promise in the treatment of many viral related diseases. In this work, using in silico methods, bioactive compounds from the neem tree were investigated for their ability to block viral cell entry as spike RBD-ACE2 inhibitors. Azadirachtin H, quentin and margocin were identified as potential compounds that demonstrated viral cell entry inhibition properties. The structural re-orientation of azadirachtin H was observed as the mechanism for viral cell entry inhibition. These compounds possessed good pharmacodynamic properties. The proposed molecules can serve as a starting point towards developing effective anti-SARS-COV-2 drugs targeting the inhibition of viral cell entry upon further in vitro and in vivo validation.