Zingiber officinale: Ayurvedic uses of the plant and in silico binding studies of selected phytochemicals with Mpro of SARS-CoV-2

Among the large number of plants that are part of the Ayurvedic system of medicine in India and Bangladesh, Zingiber officinale Roscoe (Zingiberaceae), or ginger in English, holds a special place and is often referred to as Mahaushadha(great medicine) and Vishvabhesaja(worldwide or universal herb) to signify its special status. The plant and particularly its rhizomes are used both in the raw and dry form for the relief of a multitude of disorders. Since a number of these disorders occur in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), it was of interest to perform in silico studies (molecular docking) to evaluate the binding affinities of a number of constituents of Zingiber officinale with the 3C-like protease or main protease (Mpro) of SARS-CoV-2, which plays an essential role in the cleavage of viral polyproteins and subsequent viral replication. Our studies indicated that 2 of the compounds present in ginger, namely, chlorogenic acid and hesperidin, had high binding affinities for Mpro with predicted binding energies of 7.5 and 8.3 kcal/mol. The two-dimensional and three-dimensional interactions also showed that, while chlorogenic acid interacts with one of the His41 amino acids of the catalytic dyad of Mpro, hesperidin interacts with the other amino acid Cys145, which can account for their predicted high binding energies and, therefore, possibly can inhibit Mpro activity. Taken together, our findings indicate that ginger, besides alleviating the symptoms induced by SARS-CoV-2, may also play a role in inhibiting the virus.