Computational studies of drug repurposing and synergism of lopinavir, oseltamivir and ritonavir binding with SARS-CoV-2 Protease against COVID-19

A novel coronavirus (SARS-CoV-2) has caused a major outbreak in humans all over the world, and it is the latest pandemic in the series of other infectious diseases. The concept of drug repurposing has been used successfully for many years for known diseases. Considering the emergency and urgency, drug repurposing concept is being explored for coronavirus disease (COVID-19) as well. Recently, the combination of three known drugs, lopinavir, oseltamivir and ritonavir has been proposed to control the virulence to a great extent in COVID-19 affected patients within 48 hours. Hence, we tried to understand the effect of synergism of these drugs against the SARS-CoV-2 protease using sequential docking studies. As a result, combination of three drugs showed a better binding energy than that of individual drugs. Further, the complex was subjected to molecular dynamics simulations to get insights into the stability of the complex, considering the simultaneous interactions between three drugs and the protein. The protein complexed with three drugs remained stable during the simulations. Hence, these drugs can be explored further for drug repurposing against the successful inhibition of COVID-19.