In vitro evaluation and phytochemical analysis of Curcuma aeruginosa Roxb. against human coronavirus OC43

Curcuma aeruginosa Roxb. is traditionally used across Southeast Asia in various cultural and medicinal practices. Its rhizome contains terpenes and has historically been employed to treat fever and gastrointestinal disorders-symptoms often associated with coronavirus infections. Large intestinal epithelial cells serve as potentially significant sites for viral replication, with pronounced susceptibility to human coronaviruses, and present promising targets for antiviral therapeutic interventions. This study investigated the phytochemicals in C. aeruginosa rhizome extracts using different extraction solvents and measured their inhibition against human coronavirus OC43 (HCoV-OC43) replication activities in the large intestine adenocarcinoma cell line (HCT-8). Extracts using hexane, ethyl acetate, ethanol, or methanol were quantified for curcumenol and furanodienone using HPLC, with GC-MS/MS utilized for phytochemical analysis. The inhibition of HCoV-OC43 replication was evaluated using in-cell ELISA. The crude hexane extract of C. aeruginosa rhizome demonstrated the highest inhibitory activity, with the greatest amounts of curcumenol and furanodienone (59.56 ± 1.56 and 5.70 ± 0.26 mg/g, respectively) compared to the other crude extracts from different solvents. In GC-MS/MS analysis, curcumenol was identified as the major component in C. aeruginosa rhizome crude extracts, serving as a potential active marker for this plant. The findings indicated that C. aeruginosa hexane extract showed significant therapeutic potential for future antiviral applications.