Antiviral Immunological Potential of Male Papaya (Carica papaya L.) Leaf Extract Through Activation of the Type I Interferon Pathway

Lisa Savitri, Kharisul Ihsan, Elfred Rinaldo Kasimo

Abstract


Viral infections remain a major global health challenge, highlighting the need for novel host-directed antiviral strategies. Activation of the type I interferon pathway represents a critical component of innate antiviral immunity. Male papaya (Carica papaya L.) leaves have been traditionally used to enhance immunity; however, their antiviral immunological mechanisms remain insufficiently characterized. This study aimed to investigate the antiviral immunologic potential of male papaya leaf extract by activating the type I interferon signaling pathway. Male papaya leaves were extracted using 70% ethanol, and phytochemical screening was performed. The immunomodulatory activity of the extract was evaluated in RAW 264.7 and THP-1 cells stimulated with polyinosinic-polycytidylic acid [poly(I:C)] as a viral mimic. Cytotoxicity was assessed using the MTT assay. Type I interferon production (IFN-alpha and IFN-beta) was quantified by ELISA, while activation of interferon signaling was evaluated by analysis of interferon-stimulated gene expression using quantitative real-time PCR and signaling protein activation by Western blot. The extract showed no significant cytotoxicity at concentrations up to 200 µg/mL. Treatment with male papaya leaf extract significantly enhanced IFN-alpha and IFN-beta production in poly(I:C)-stimulated cells in a dose-dependent manner. This increase was accompanied by activation of IRF3 and STAT1 signaling and robust upregulation of interferon-stimulated genes, including MX1, OAS1, and ISG15. These findings indicate that the extract enhances antiviral immune responses by amplifying type I interferon-mediated signaling. In conclusion, male papaya leaf extract exhibits significant antiviral immunological activity through activation of the type I interferon pathway. This host-directed immunomodulatory mechanism supports its potential development as a complementary therapeutic agent for viral infections.


Keywords


antiviral immunity; Carica papaya L.; immunomodulation; interferon-stimulated genes; type I interferon

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References


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DOI: https://doi.org/10.14421/biomedich.2026.151.1515-1521

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Copyright (c) 2026 Lisa Savitri, Kharisul Ihsan, Elfred Rinaldo Kasimo



Biology, Medicine, & Natural Product Chemistry
ISSN 2089-6514 (paper) - ISSN 2540-9328 (online)
Published by Sunan Kalijaga State Islamic University & Society for Indonesian Biodiversity.

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This work is licensed under a CC BY-NC