Combination Therapy With Isotretinoin and Tamoxifen Expected to Provide Complete Protection Against Severe Acute Respiratory Syndrome Coronavirus

Combination Therapy with Isotretinoin and Tamoxifen expected to provide Complete Protection against Severe Acute Respiratory Syndrome Coronavirus

Abstract:

The COVID-19 pandemic caused by SARS-COV-2 has infected over 2,000,000 people causing over 150,000 deaths.Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 and for which there are currently no approved treatments.The principal investigator reported according to previous research data that combination therapy with Isotretinoin and tamoxifen expected to provide Complete Protection against Severe Acute Respiratory Syndrome Coronavirus, 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. A study demonestrated 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, 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) Moreover, another study 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. As Investigators discussed before in their previous clinical trial (NCT04353180) that Isotretinoin is the strongest down-regulator of ACE2. and the principal investigator expects that Isotretinoin can inhibit or downrgulat ACE2 by direct interaction and binding with the transmembrane ACE2, Suggesting its therapeutic potential in preventing the entry of COVID 2019 to the host cell. The second combined drug is tamoxifen, A study demonstrated that tamoxifen causes redistribution of weak base chemotherapeutics from acidic organelles to the nucleus in drug-resistant cells. Agents that disrupt organelle acidification (e.g., monensin, bafilomycin A1) cause a similar redistribution. Measurement of cellular pH in several cell lines reveals that tamoxifen inhibits acidification of endosomes and lysosomes without affecting cytoplasmic pH, Tamoxifen decreased the rate of vesicular transport though the recycling and secretory pathways. Organellar acidification is required for many cellular functions, and its disruption could account for many of the side effects of tamoxifen. A sudy demonstrated that the phagocytosis is inhabited by tamoxifen and chloroquine in retinal epithelial cells and Also, a study demonstrated that Tamoxifen have weak base property and increase endolysosomal pH and alter endosomal dynamics. Importantly, TAM treatment enhanced survival of mice injected with a lethal dose of STx1 or STx2, TAM allowed TAM to increase endolysosomal pH and alter endosomal dynamics. A study demonstrated that Tamoxifen have antimalarial effect via treating mice infected with P. berghei, which show lower levels of parasitaemia and do not develop signs of cerebral malaria, Tamoxifen is found to prevent lung fibrosis and reduce serum TGFβ-1 levels. A study Reported that Tamoxifen have endosomal and lysosomal cysteine proteases inhibitory effect better than chloroquine , Cathepsins are endosomal and lysosomal cysteine proteases that play important roles in protein degradation in various cellular processes including both the endocytic pathway and autophagy. The role of cathepsins in viral infection was first identified by Huang et al and they found that one cysteine proteases inhibitor E64d and a specific cathepsin L inhibitor Z-FY(t-Bu)-DMK are able to block the SARS-CoV infection. A study demonestrated that Cathepsin D was more sensitive to tamoxifen than to chloroquine. Tamoxifen exposures decreased the cathepsin D activity at less than 10 pM concentrations. The effect of chloroquine started at concentration of 15 pM, Finally, the principal investigator expects strong inhibition of COVID-19 by this combination therapy.

In addition, Tamoxifen has anti estrogenic effect Therefore the principal investigator expects that Tamoxifen will protect patients with cancer against COVID-19 infection.

Keywords: COVID 2019 , Isotretinoin , Tamoxofin, ACE2,.Endosomal and Lysosomal pH.