Targeting CoV-2 Spike RBD and ACE-2 Interaction with Flavonoids of Anatolian Propolis by in silico and in vitro Studies in terms of possible COVID-19 therapeutics

Guler, Halil Ibrahim; Ay Sal, Fulya; Can, Zehra; Kara, Yakup; Yildiz, Oktay; Belduz, Ali Osman; Çanakci, Sabriye; Kolayli, Sevgi

Propolis is a multi-functional bee product with a rich in polyphenols. In this study, the inhibition effect of Anatolian propolis against SARS coronavirus-2 (SARS CoV-2) was investigated as in vitro and in silico. Raw and commercial of propolis samples were used in the study and it was found that both of were rich in caffeic acid, p-coumaric acid, ferulic acid, t-cinnamic acid, hesperetin, chrysin, pinocembrin and caffeic acid phenethyl ester (CAPE) by HPLC-UV analysis. The ethanolic propolis extracts (EPE) were used in the screening ELISA test against the spike S1 protein (SARS Cov-2): ACE-2 inhibition KIT for in vitro study. Binding energy constants of these polyphenols to the CoV-2 Spike S1 RBD and ACE-2proteinwere calculated separately as molecular docking study using AutoDock 4.2 molecular docking software. In addition, pharmacokinetics and drug-likeness properties of these eight polyphenols were calculated according to the SwissADME tool. Binding energy constant of pinocembrin was the highest for both of the receptors, followed by chrysin, CAPE and hesperetin. In silico ADME behavior of the eight polyphenols were found potential ability to work effectively as novel drugs. The findings of both studies showed that propolis has a high inhibitory potential against Covid-19 virus. However, further studies are needed.