2. Academic Validation
  3. Calceolarioside B inhibits SARS-CoV-2 Omicron BA.2 variant cell entry and modulates immune response

Calceolarioside B inhibits SARS-CoV-2 Omicron BA.2 variant cell entry and modulates immune response

  • Virol J. 2024 Dec 21;21(1):329. doi: 10.1186/s12985-024-02566-w.
Xiao-Bin Lin # 1,  Yu-Zhi Yao # 1 2,  Qi-Rong Wen 3,  Fu-Bin Liu 4,  Yuan-Xuan Cai 1,  Rui-Hong Chen 5,  Jin Han 6
Affiliations

Affiliations

  • 1 Department of Thyroid and Breast Surgery, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, 510623, Guangdong Province, China.
  • 2 Department of Paediatric Surgery Clinic, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, 510623, Guangdong Province, China.
  • 3 Department of Gynecologic Oncology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, 510623, Guangdong Province, China.
  • 4 The Third Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, 510006, Guangdong Province, China.
  • 5 Department of Clinical Immunology, Institute of Clinical Laboratory Medicine, Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, Guangdong Medical University, Dongguan, 523000, Guangdong Province, China. guisitong2@hotmail.com.
  • 6 Prenatal Diagnosis Center, Guangzhou Women and Children's Medical Center,, Guangzhou Medical University, Guangzhou, 510623, Guangdong Province, China. hanjin1123@163.com.
  • # Contributed equally.
PMID: 39707427 DOI: 10.1186/s12985-024-02566-w
Abstract

This study evaluated the inhibitory effects of calceolarioside B, extracted from the traditional Chinese herb Mutong (Akebia quinata Thumb), on the SARS-CoV-2 Omicron BA.2 variant. Molecular docking and molecular dynamics simulations predicted the binding sites and interactions between calceolarioside B and the Omicron BA.2 spike (S) protein. Biolayer interferometry (BLI) and immunofluorescence assays validated its high-affinity binding. Pseudovirus entry assays assessed the inhibitory effects of calceolarioside B on viral entry into host cells, while enzyme-linked immunosorbent assay (ELISA) measured inflammatory cytokine levels. Flow cytometry was used to analyze its effects on macrophage phenotype switching. Results demonstrated that calceolarioside B could bind to the Omicron BA.2 S protein with high affinity, and significantly inhibited viral entry into host cells by interfering with the binding of angiotensin-converting enzyme 2 (ACE2) receptor and S protein. Additionally, calceolarioside B reduced IL(interleukin)-6 expression levels and promoted the switch of macrophages from the pro-inflammatory M1 phenotype to the anti-inflammatory M2 phenotype. These findings suggest that calceolarioside B possesses Antiviral and immunomodulatory effects, making it a potential dual-function inhibitor for the treatment of COVID-19.

Keywords

Calceolarioside B; Immunomodulation; Molecular docking; SARS-CoV-2 Omicron BA.2; Viral inhibition.

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