A Novel Compound from the Mushroom Cryptoporus volvatus Inhibits Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) In Vitro

Porcine reproductive and respiratory syndrome (PRRS), caused by PRRS virus (PRRSV), is a serious contagious disease in the swine industry. At present, there are no effective control strategies against PRRSV. Thus, there is an urgent need for new treatment regimens that have efficacious antiviral activity to compensate for vaccines. The anti-infective effect of Cryptoporus volvatus has previously been demonstrated in Tradational Chinese Medicine. In this report, we expected to identify a new anti-PRRSV agent in the aqueous extract of C. volvatus, by employing a combination of modern chromatographic purification techniques and indirect immunofluorescence assay (IFA). Our results showed that C. volvatus extracts from every separation step differed in their inhibitory potency on PRRSV. One anti-PRRSV component designated as CM-H-L-5 was isolated from water-soluble fraction of C. volvatus. The inhibition induced by CM-H-L-5 occurred in a dose-dependent manner. CM-H-L-5 appeared to be a low-molecular-weight polyol fragment with amide groups and carboxylic acid groups. Collectively, our findings imply that CM-H-L-5 from the aqueous extract of C. volvatus has the potential to be used for anti-PRRSV therapy.

猪繁殖与呼吸综合征（Porcine reproductive and respiratory syndrome, PRRS）由PRRS病毒（PRRS virus, PRRSV）引发，是养猪产业中极具危害性的传染性疫病。目前尚无针对PRRSV的有效防控策略，因此亟需研发具备高效抗病毒活性的新型治疗方案，以弥补现有疫苗防控的不足。隐孔菌（Cryptoporus volvatus）的抗感染活性此前已在传统中医药领域得到验证。本研究通过联用现代色谱纯化技术与间接免疫荧光试验（indirect immunofluorescence assay, IFA），旨在从隐孔菌水提取物中筛选新型抗PRRSV活性物质。研究结果显示，隐孔菌提取物经各分离步骤所得的不同组分，其抗PRRSV活性存在显著差异。本研究从隐孔菌水溶性组分中分离得到一种命名为CM-H-L-5的抗PRRSV活性组分。CM-H-L-5的抗病毒抑制活性呈剂量依赖性特征。经鉴定，CM-H-L-5为一种带有酰胺基团与羧基基团的低分子量多元醇片段。综上，本研究结果表明，隐孔菌水提取物中的CM-H-L-5具备开发为抗PRRSV治疗药物的潜力。