Carvacrol: A PL^pro Inhibitor of SARS-CoV-2 Is a Natural Weapon for COVID-19

Abstract

The outbreak of SARS-CoV-2 created the biggest crisis to human health and has adversely affected economic growth worldwide. Several vaccines emerged from manufacturers to combat COVID-19. Unfortunately, no therapeutic medication has yet been approved by the FDA for the treatment of this disease. Many researchers have performed in silico studies for the identification of potential SARS-CoV-2 inhibitors from the molecules present in Indian medicinal plants and spices. In this paper, we have performed a structure-based virtual screening (VS) of 120 compounds derived from Nigella sativa (NS) against Mpro, PLpro, and spike proteins of SARS-CoV-2. Strong binding interactions of Mpro occurred with hits NS-40 and NS-84, whereas hits NS-72D and NS-95D showed strong binding interactions with spike proteins. Interestingly, four promising hits (i.e., NS-21, NS-40, carvacrol (NS_08), and menthol) exhibited good binding interactions with both Mpro and spike proteins. Carvacrol, a monoterpenoid phenol possessing several biological activities, showed a favourable binding affinity towards the papain-like protease of SARS-CoV-2. This small molecule may be used as a natural weapon to combat COVID-19.

Keywords

• carvacrol
• black seed
• SARS-CoV-2
• COVID-19
• natural product