Chemical Compositions of Dill (Anethum graveolens L.) Water and Ethanol Extracts and Their Potential in Blocking the SARS-CoV-2 Entry into Cells and Free Radical Scavenging Capacities

Dill (Anethum graveolens L.) is a spice belonging to the Apiaceae family and is widely used in various dishes. This study aims to evaluate dill's potential in preventing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infiltration and alleviating coronavirus disease (COVID-19) symptoms when infected. Thus, chemical compositions, SARS-CoV-2's spike protein, and angiotensin-converting enzyme 2 (ACE2) receptor interaction along with ACE2 activity inhibition, total phenolic content, and free radical scavenging capacities of dill water and ethanol extracts (WE/EE) were evaluated. As a result, 10 compounds were tentatively identified, with quercetin glucuronide having the highest peak intensity. Dill WE33.3 and EE3.3 (33.3 and 3.3 mg of dry dill equivalents/mL, respectively) showed 66% and 79% SARS-CoV-2's spike protein and ACE2 receptor interaction inhibition, respectively. In ACE2 inhibition, 5.0 mg/mL WE and EE had 85 and 88% inhibition, respectively, whereas 0.5 mg/mL showed 33 and 11% inhibition, respectively. The Dill WE had a significantly greater total phenolic content (TPC), radical scavenging capacity (RDSC), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) values of 15.28 mg GAE/g, 595.21, 90.31, and 36.76 smol TE/g, respectively, compared to the dill EE (2.63 mg GAE/g, 248.20, 10.38, and 0.85 smol TE/g, respectively).