Isotretinoin in Treatment of COVID-19

Contributors: Lamia Elgarhy, Sabah El-Gaeish 1, Eman Hamed 2 , Wagdy Fathy2 Department of Dermatology, Department of Pharmacology1 , Faculty of Medicine, Tanta University, Department of Chest, Faculty of Medicine, Suez Canal University2. Abstract: The COVID-19 pandemic caused by SARS-COV-2 has infected over 2,000,000 people causing over 150,000 deaths. A key host cellular protein required for the virus entry is angiotensin-converting enzyme 2 (ACE2) whose expression has been demonstrated in many tissues including alveolar epithelial type II cells in lungs, oral mucosa and intestine, heart, kidney, endothelium and skin. ACE2-expressing cells can act as home cells and are prone to SARS-CoV-2 infection as ACE2 receptor facilitates cellular viral entry and replication. (1) Fang et al. has suggested that patients with hypertension and diabetes mellitus may be at higher risk of SARS-CoV-2 infection, as these patients are often treated with ACE inhibitors (ACEIs) or angiotensin II type-I receptor blockers (ARBs), which have been previously suggested to increase ACE2 expression. (2) In another study by Sinha et al who analyzed a publicly available Connectivity Map (CMAP) dataset of pre/post transcriptomic profiles for drug treatment in cell lines for over 20,000 small molecules, isotretinoin was the strongest down-regulator of ACE 2 receptors. On the other hand, they found 6 drugs in CMAP that are currently being investigated in clinical trials for treating COVID-19 (chloroquine, thalidomide, methylprednisolone, losartan, lopinavir and ritonavir, from clinicaltrials.gov), none of which was found to significantly alter ACE2 expression (P\>0.1) (3) Moreover, Wu et al, demonstrated that isotretinoin is a Potential papain like protease (PLpro) inhibitors which is a protein encoded by SARS-CoV-2 genes and considered one of the proteins that should be targeted in COVID-19 treatment by performing target-based virtual ligand screening. (4) In addition, isotretinoin was reported