Anticoronavirus activity of rhizome of Dryopteris crassirhizoma via multistage targeting of virus entry and viral proteases, Mpro and PLpro

• Published in: Journal of ethnopharmacology 2024-10, Vol.333, p.118490, Article 118490
• Main Authors: Habib, Mobashira, Jin, Young-Hee, Kim, Yeonhwa, Min, Jung Sun, Ha, In Jin, Lee, Sang-Myeong, Kwon, Sunoh
• Format: Article
• Language: English
• Subjects: Animals; Antiviral Agents - isolation & purification; Antiviral Agents - pharmacology; Chlorocebus aethiops; Coronavirus 3C Proteases - antagonists & inhibitors; Coronavirus 3C Proteases - metabolism; Coronavirus OC43, Human - drug effects; Dryocrassin ABBA; Dryopteris - chemistry; Dryopteris crassirhizoma; Filixic acid ABA; HCoV-OC43; Humans; Plant Extracts - pharmacology; Protease; Rhizome; SARS-CoV-2; SARS-CoV-2 - drug effects; Vero Cells; Virus Internalization - drug effects
• ISSN: 0378-8741; 1872-7573; 1872-7573
• DOI: 10.1016/j.jep.2024.118490

The rhizome of Dryopteris crassirhizoma Nakai (Dryopteridaceae, RDC), a traditional East Asian herbal medicine, possesses a broad spectrum of medicinal properties, including anti-inflammatory, anticancer, antibacterial, and antiviral activities. This study investigates the 30% ethanolic extract of RDC's antiviral potential against human coronavirus OC43 (HCoV-OC43), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and its variants infections. A 30% ethanolic extract of RDC or its components, filixic acid ABA (PubChem CID: 15081408) and dryocrassin ABBA (PubChem CID: 3082025) were treated with Human Coronavirus infection (HCoV-OC43, SARS-CoV-2 and its variants). The base peak chromatogram of RDC was evaluated using UPLC-Q/TOF Mass to identify the RDC, and the quantitative analysis of RDC compounds was performed using LC-MS/MS. A cytopathic effect (CPE) reduction assay, Western blot, immunofluorescence staining of viral protein expression, and qRT-PCR were performed to quantify the viral RNA copy numbers and determine the antiviral activity. The time-of-addition assay, the virus attachment, penetration, and virucidal assays, and SARS-CoV-2 Mpro and PLpro activity assay were used to elucidate the mode of action. RDC exhibited dose-dependent inhibition of HCoV-OC43–induced cytopathic effects, reducing viral RNA copy numbers and viral protein levels. Time-of-addition assays indicated that RDC targets the early stages of the HCoV-OC43 life cycle, inhibiting virion attachment and penetration with virucidal activity. Notably, filixic acid ABA and dryocrassin ABBA, constituents of RDC, reduced HCoV-OC43 viral RNA loads. Furthermore, RDC effectively blocked viral entry in pseudotyped lentivirus assays, involving spike proteins of SARS-CoV-2 Delta plus and South Africa variants, as well as control lentiviral particles expressing vesicular stomatitis virus glycoprotein G. Additionally, RDC demonstrated inhibition of SARS-CoV-2 infection and its variants by targeting viral proteases, namely main protease (Mpro) and papain-like protease (PLpro). These findings underscore RDC's multistage approach to targeting viral infections by impeding virus entry and inhibiting viral protease activity. Therefore, RDC holds promise as a potent, broad-spectrum anticoronaviral therapeutic agent. [Display omitted] •The rhizome of Dryopteris crassirhizoma (RDC) inhibits HCoV-OC43 and SARS-CoV2 VOCs.•RDC targets the virion attachment and penetration with virucidal activity.•RD