Tomatidine inhibits porcine epidemic diarrhea virus replication by targeting 3CL protease

Abstract

Porcine epidemic diarrhea virus (PEDV) causes lethal diarrhea in suckling piglets, leading to severe economic losses worldwide. There is an urgent need to find new therapeutic methods to prevent and control PEDV. Not only is there a shortage of commercial anti-PEDV drugs, but available commercial vaccines fail to protect against highly virulent PEDV variants. We screened an FDA-approved library of 911 natural products and found that tomatidine, a steroidal alkaloid extracted from the skin and leaves of tomatoes, demonstrates significant inhibition of PEDV replication in Vero and IPEC-J2 cells in vitro. Molecular docking and molecular dynamics analysis predicted interactions between tomatidine and the active pocket of PEDV 3CL protease, which were confirmed by fluorescence spectroscopy and isothermal titration calorimetry (ITC). The inhibiting effect of tomatidine on 3CL protease was determined using cleavage visualization and FRET assay. Tomatidine-mediated blocking of 3CL protease activity in PEDV-infected cells was examined by western blot detection of the viral polyprotein in PEDV-infected cells. It indicates that tomatidine inhibits PEDV replication mainly by targeting 3CL protease. In addition, tomatidine also has antiviral activity against transmissible gastroenteritis virus (TGEV), porcine reproductive and respiratory syndrome virus (PRRSV), encephalo myocarditis virus (EMCV) and seneca virus A (SVA) in vitro. These results may be helpful in developing a new prophylactic and therapeutic strategy against PEDV and other swine disease infections.

Construction of a Recombinant Porcine Epidemic Diarrhea Virus Encoding Nanoluciferase for High-Throughput Screening of Natural Antiviral Products

“…To search for new anti-PEDV agents, Deejai et al screened the FDA-approved drugs that could associate with the PEDV N protein using virtual screening and found that trichlormethiazide, D-(+) biotin and acetazolamide could inhibit PEDV replication in vitro [ 42 ]. Recently, based on the assessment of CPE and viral protein expression by IFA, Wang et al screened a natural product library and demonstrated that tomatidine could reduce PEDV proliferation in Vero cells [ 4 ].…”

“…Porcine epidemic diarrhea virus (PEDV), a member of swine enteric coronaviruses (CoVs), causes diarrhea, vomiting, anorexia, and dehydration in neonatal piglets [ 1 ]. After PEDV classical strains of the genogroup I (GI) were first reported in the UK in 1971 [ 2 ], it has spread throughout most European and Asian countries [ 3 , 4 ]. In 2010, highly pathogenic PEDV variants suddenly emerged in China, and they rapidly spread to North America, Europe, and other Asian countries in 2013 [ 5 , 6 , 7 ].…”

Tomatidine and Patchouli Alcohol as Inhibitors of SARS-CoV-2 Enzymes (3CLpro, PLpro and NSP15) by Molecular Docking and Molecular Dynamics Simulations

“…More recently, Troost and colleagues [ 27 ] reported that this akkaloid exhibited antiviral activity against chikungunya virus by decreasing the number of infected cells and acted at a post-entry step of the virus replication cycle. It has also been elucidated that tomatidine inhibits porcine epidemic diarrhea virus (PEDV) by blocking 3CL protease activity in infected cells, and consequently PEDV replication [ 32 ]. Additionally, this molecule is active against Sunnhemp Rossette virus and Tobacco mosaic, and do not affect the replication of herpes simplex virus, human respiratory syncytial and influenza virus [ 33 , 34 , 35 , 36 ].…”

Molecular docking studies of HIV TAT and sitagliptin nano-formula as potential therapeutic targeting SARS-CoV2 protease

“…The reaction was then started by adding 10 μL of substrate dissolved inside the buffer at volume of 50 μL final volume, before being incubated at room temperature for four hours. After sealing the plates, the measurement of fluorescence intensity was checked in a microtiter plate-reading fluorimeter with a 360 nm wavelength that could detect emissions at 460 nm wavelength [ 35 , 36 ] .…”