Transcriptome signature for host directed antiviral reprogramming by Nimba & Triphala in macrophage Dengue virus infection models.

Dengue virus (DENV) is responsible for hundreds of millions of infections per year, but no clinically approved antiviral therapy exists, and direct-acting candidates are limited by toxicity and viral genetic diversity. Traditional medicinal preparations such as Nimba/Neem (Azadirachta indica) and polyherbal Ayurvedic preparation Triphala (a combination of Terminalia chebula, Terminalia bellirica and Phyllanthus emblica) contain multiple metabolites with antiviral and antioxidant properties but their mechanisms of action are not fully characterised. Here, we combined cell-based antiviral assays with transcriptome profiling to compare how Nimba and Triphala shape host responses during DENV infection in RAW264.7 macrophages, a key innate immune target. Nimba and Triphala demonstrated low cytotoxicity in the concentrations of our assays, which supports a favourable therapeutic window. The RNA-seq analysis showed that Nimba induced broader transcriptional reprogramming in DENV-infected macrophages than Triphala, with 4,182 differentially expressed genes in the NB + DV versus DV comparison, indicating a stronger host transcriptional impact during infection. It increased interferon-stimulated gene (Isg15) programs and attenuated inflammatory signalling (e.g., Cxcl10), oxidative stress (Txnip, Aox4, Phlda3), and endoplasmic reticulum stress pathways (Trib3) upon infection. Triphala, in contrast, caused relatively restrained baseline transcriptional reprogramming and a more selective infection-context response. Docking analysis suggested that Triphala-associated metabolites may engage multiple DENV proteins. In line with this, molecular docking of nine proteins of DENV indicated multi-target binding of Triphala metabolites, with corilagin showing favorable predicted binding affinities (ΔG -13.9 kcal/mol), in certain proteins, superior to that of reference compounds (Remdesivir and NITD008). Together, these data support broader host-response modulation by Nimba and a more selective host response with a possible virus-directed contribution for Triphala during DENV infection and lay the foundational research for synthesis of anti-viral herbal formulations using Nimba and Triphala ingredients.