Abstract
Background/Objectives: COVID-19 was responsible for millions of deaths worldwide. This study aimed to identify substances with in vitro and in vivo effects against the SARS-CoV-2 virus. Methods: Compounds PQM-243 and PQM-249, two terpene-N-acyl-aryl-hydrazone analogues, were evaluated in vitro against SARS-CoV-2 to a antiviral activity and inhibitory effect against angiotensin converting enzyme 2 (ACE2). A possible inhibitory effect affecting the interaction between the receptor-binding domain (RBD) protein and/or ACE2 was evaluated using LUMMIT kit. A SARS-CoV-2-induced pulmonary pneumonia model was developed to evaluate the effects of the compounds after 3 days of treatment. Results: Compounds PQM-243 and PQM-249 exhibited IC(50) values of 0.0648 ± 0.041 µM and 0.2860 ± 0.057 µM against SARS-CoV-2 with a selective index of >1543.21 and 349.65, respectively, and IC(50) values of 12.1 nM and 13.3 nM, respectively, against ACE2. All concentrations used significantly reduced interactions between ACE2 and RBD. Computational studies suggest that these new compounds are potent direct anti-SARS-CoV-2 agents, capable of reducing both virus viability and its invasive ability in the host cells by reducing the interaction between RBD and ACE2. It was also demonstrated that even when administered by the oral route, both compounds reduced SARS-CoV-2-induced lung inflammation. Our data suggests that both compounds can act as potent direct anti-SARS-CoV-2 agents, reducing both viral viability and host cell entry. In addition, they exhibited a significant multi-target-directed pharmacological profile, also reducing SARS-CoV-2-induced lung inflammation when administered orally. Conclusions: Overall, these findings support further investigation of PQM-243 and PQM-249 as promising antiviral and anti-inflammatory multi-target prototypes for the development of innovative drug candidates targeting SARS-CoV-2 and other virus-related respiratory diseases.