Figure 5.

Role of metformin in controlling COVID-19 symptoms. Metformin has been shown to phosphorylate the ACE2 receptor and change its confirmation, leading to blockage of SARS viral binding. Metformin controls COVID-19-induced cytokine storm by preventing NF-κB-induced inflammatory response. and NLRP3-induced innate immune response in an AMPK-dependent manner. By activating the endosomal ATPases, metformin could cause viral maturation and assembly. Metformin protects from cardiopulmonary effects by increasing insulin sensitivity and endothelial function. AMPK: AMP-activated protein kinase; ACE2: angiotensin-converting enzyme 2; AKT: protein kinase B; COVID-19: coronavirus disease 2019; NF-κB: nuclear factor kappa binding protein; NLRP3: NLR family pyrin domain containing 3; PI3K: phosphatidylinositol 3-kinase; and SARS: severe acute respiratory syndrome.