Key Laboratory of Animal Disease Diagnostics and Immunology, Ministry of Agriculture, MOE International Joint Collaborative Research Laboratory for Animal Health & Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China.
Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China.
Vet Res. 2020 Nov 11;51(1):136. doi: 10.1186/s13567-020-00865-y.
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.
猪流行性腹泻病毒（PEDV）可引起仔猪致命性腹泻，导致全球范围内的严重经济损失。因此，急需寻找新的治疗方法来预防和控制 PEDV。不仅商业抗 PEDV 药物短缺，而且现有的商业疫苗也不能预防高致病性 PEDV 变异株。我们筛选了美国食品和药物管理局（FDA）批准的 911 种天然产物文库，发现番茄啶，一种从番茄的皮和叶中提取的甾体生物碱，在体外的 Vero 和 IPEC-J2 细胞中对 PEDV 的复制具有显著的抑制作用。分子对接和分子动力学分析预测了番茄啶与 PEDV 3CL 蛋白酶活性口袋的相互作用，这些预测通过荧光光谱和等温滴定量热法（ITC）得到了证实。通过切割可视化和 FRET 测定法确定了番茄啶对 3CL 蛋白酶的抑制作用。通过 Western blot 检测 PEDV 感染细胞中的病毒多蛋白，研究了番茄啶介导的 PEDV 感染细胞中 3CL 蛋白酶活性的阻断作用。这表明番茄啶主要通过靶向 3CL 蛋白酶抑制 PEDV 的复制。此外，番茄啶在体外还对传染性胃肠炎病毒（TGEV）、猪繁殖与呼吸综合征病毒（PRRSV）、脑心肌炎病毒（EMCV）和塞尼卡病毒 A（SVA）具有抗病毒活性。这些结果可能有助于开发针对 PEDV 和其他猪病感染的新的预防和治疗策略。
