Abstract:Eleutherine americana is a folk medicinal plant common in Southwest China. Issues of isolation, purification, and identification of chemical constituents of Eleutherine americana have limited an in-depth study of its pharmacology. In this study, based on the 39 known chemical components of Eleutherine americana described in the literature, the interaction between hyaluronidase (HAase) and the chemical constituents of Eleutherine americana was evaluated using the molecular docking simulation software AutoDock4.2, using the binding free energy in molecular docking as the standard. HAase inhibitors were selected, and the effects of Eleutherine americana extracts with different polarities on HAase activity were also determined with a modified Elson-Morgan method. Ten compounds that were predicted to have good binding with HAase were screened out. Among them, compounds 37 and 33 had the lowest binding free energies, at -7.73 and -7.72 kcal/mol, respectively, implying a good inhibitory effect on HAase activity. The experimental results showed that amino acid residues TYR75, ASN37, and GLU131 of HAase were critical reactive sites responsible for the formation of hydrogen bonds between compounds and HAase. The enzyme activity results also showed that extracts of Eleutherine americana with different polarities had different inhibitory effects on HAase. This study provides a reference basis for a further exploration of the effects of the chemical constituents in Eleutherine americana on HAase activity.
