Inhibition of CHIKV after the treatment with DOXY, RIBA and DOXY+RIBA.

<p><b>(A)</b> ELISA-like cell-based assay was used to evaluate the antiviral activity of the drugs. Viral antigen was detected by CHIKV antibody and anti-mouse IgG conjugated with alkaline phosphatase. The 50% effective concentration (EC₅₀) of the DOXY was calculated to be 10.95±2.12 μM and the RIBA drug was 15.51±1.62 μM, while DOXY+RIBA (1:1) showed an EC₅₀ of 4.52±1.42 μM. <b>(B)</b> Levels of viral proteins after the treatment with drugs were measured by ELISA-like cell-based assay of triplicates at 4, 8, 24, 48 and 72 h post infection. The OD values were measured by an ELISA reader at 490–650 nm. The result showed considerable improvement on performance when the test compound were administered together compared to individual treatment (Two way ANOVA, *P<0.05).