In Vitro Regulation of Expression of the SARS-CoV-2 Receptor Angiotensin-Converting Enzyme (ACE2) in Lung Cancer Cells by Natural Products

Abstract

The COVID-19 pandemic continues infecting people causing deaths globally. Although various medicines have been tried to combat with COVID-19, there is no medicine or treatment that has been validated yet. People have been using natural products for centuries against bacterial and viral illnesses. This study aimed to test the effects of the biomolecule oleuropein, whey collected from industrial waste and soaproot extracts obtained from Gypsophila arrostii Guss. var. nebulosa Boiss. & Heldr. and Saponaria officinalis L. on the expression of the human ACE2 gene as SARS-CoV-2 receptor on the A549 adenocarcinoma cell-line by Real-Time Quantitative Polymerase Chain Reaction (qPCR). According to the cytotoxicity tests, G. arrostii var. nebulosa and S. officinalis extract treatments showed a dose dependent cytotoxic effect on the cells. The EC50 values of G. arrostii var. nebulosa and S. officinalis were found to be 54.3 μg/ml and 17.3 μg/ml, respectively. Oleuropein showed moderate cytotoxic effects with the EC50 value over 250 μg/ml. Whey (fermented and non-fermented) did not show any cytotoxic effect at the applied doses. The qPCR results showed that the ACE2 mRNA level decreased by 89.8% and 35.2% due to the fermented and non-fermented whey extracts, respectively. Similarly, G. arrostii var. nebulosa and S. officinalis downregulated ACE2 by 79.8% and 90.1%, respectively. In contrast, oleropein upregulated ACE2 (102.8%). Our results showed that the natural supporting products produced from soaproot extracts and fermented whey can be used against COVID-19 by both cancer patients and people in potential risk groups. © 2021 Hürkan, Arslan, Atalar, Aydın, Demirtaş, Mutlu, Tabar & Alma.