Retinoic acid is a translation inhibitor against chikungunya virus both in vitro and invivo.

Chikungunya virus (CHIKV), a mosquito-borne alphavirus, causes debilitating febrile and arthritic disease and remains a persistent public health threat in tropical and subtropical regions, with no clinically approved antiviral drugs currently available, which underscores the urgent need for targeted and effective therapeutic interventions. Through high-throughput screening of an FDA-approved compound library, we identified retinoic acid (RA) as a broad-spectrum inhibitor of multiple arboviruses, exhibiting potent activity against CHIKV. Time-of-addition experiments, together with assays on viral binding, endocytosis, membrane fusion, replication and translation, were performed to determine the specific lifecycle stages inhibited by RA. Notably, RA exerts anti-CHIKV effects by selectively targeting eukaryotic translation initiation factor 4B (EIF4B), thereby disrupting the viral translation, as revealed by limited proteolysis-mass spectrometry (LiP-MS). And, our results demonstrated that RA administration exerted potent protective effects against CHIKV infection in vivo. Specifically, RA significantly reduced cerebral pathological damage, relieved clinical manifestations, and enhanced survival in a murine model of CHIKV-induced encephalitis, while also markedly attenuating footpad swelling and joint pathological alterations in a CHIKV-induced arthritis mouse model. Collectively, our findings highlight RA as a promising anti-CHIKV candidate targeting EIF4B, supporting its further development as a therapeutic agent against CHIKV infection.