Fig. 1

Infectivity and cytotoxicity of the curcumin compound at various concentrations. (a) The SARS-CoV-2 spike pseudotyped virus was treated with the compound at 37 °C for 1 h and infected into HEK293-hACE2 cells expressing TMPRSS-2. The virus treated with DMSO served as the control. After 48 h of incubation, viral infectivity was determined by measuring the activity of the luciferase reporter using the Bright-Glo Luciferase Assay System. The cytotoxicity of the compound was determined by the viability of treated cells without infection using the CCK-8 assay. The relative mean values ± SD (%DMSO) from 3–4 independent experiments (each performed in duplicate) are shown. (b) Data from (a) were fitted into dose-response curves using GraphPad Prism software, and the estimated CC₅₀, EC₅₀, and selectivity index are shown