What is it about?
This study investigated silibinin, a flavonolignan from Silybum marianum, through a combined in silico–in vitro approach. Molecular docking analyses evaluated its predicted interaction with SARS‑CoV‑2 key proteins. Results indicated that silibinin forms stable complexes with the spike receptor‑binding domain (RBD) and shows favorable binding affinity for the main protease (Mpro), interacting with several active‑site residues. These data support the hypothesis that silibinin may interfere with viral entry and replication. Complementary in vitro experiments were performed in human umbilical vein endothelial cells (HUVECs) exposed to TNF‑α. Silibinin pretreatment reduced the expression of inflammatory cytokines (IL‑6, MCP‑1), as well as PAI‑1 and ET‑1, two markers linked to coagulopathy and vasoconstriction.
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Why is it important?
COVID‑19 involves not only viral infection but also endothelial inflammation, cytokine overproduction, and dysregulated coagulation. A molecule with potential interactions at multiple points of the SARS‑CoV‑2 lifecycle and simultaneous anti‑inflammatory, endothelial‑protective properties is of considerable interest. Silibinin already has a known pharmacokinetic and safety profile due to its long‑standing use in liver disease, which strengthens its suitability as a repurposing candidate. Its ability to downregulate endothelial inflammatory and pro‑coagulant signals aligns with pathways implicated in severe COVID‑19 outcomes.
Perspectives
The present findings rely on in silico predictions and in vitro data; therefore, further in vivo and clinical studies are needed to determine whether silibinin can effectively modulate viral dynamics and endothelial dysfunction in physiological settings. Additional research should explore its relevance for individuals with pre‑existing endothelial impairment—such as patients with hypertension, obesity, diabetes, or cardiovascular disease—who are at increased risk of severe COVID‑19. Future studies must also assess dose‑response relationships, metabolic considerations, and potential interactions with established therapies for COVID‑19. These preliminary results support the hypothesis that silibinin could be considered within multitarget approaches, combining antiviral potential with vascular protection.
Prof. Antonio Speciale
University of Messina
Read the Original
This page is a summary of: Silibinin as potential tool against SARS‐Cov‐2: In silico spike receptor‐binding domain and main protease molecular docking analysis, and in vitro endothelial protective effects, Phytotherapy Research, April 2021, Wiley,
DOI: 10.1002/ptr.7107.
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