Effect of glycyrrhizic acid on phospholipid membranes in media with different pH

Glycyrrhizic acid (GA) is the active ingredient in licorice root, which exhibits a wide range of biological activities, including anti-inflammatory and antiviral activities. In particular, the virus-inhibiting effect of GA on SARS-associated coronavirus was demonstrated. In addition, GA was found to be capable of increasing bioaccessibility of other drugs when used together. All these effects can be based on the ability of GA to incorporate into cell membranes and change their physical and functional properties. One of the possible mechanisms of the antiviral action of GA against COVID-19 is also considered to be the prevention of fusion of the virus envelope with the plasma membrane of the host cell. The interaction of GA with model lipid membranes was studied by the NMR method. Different factors influencing the incorporation of the GA molecule into the lipid bilayer (phospholipid structure, pH of the medium) were examined.