Study on the Material Basis of Guiqi Baizhu Prescription Inhibiting the Proliferation of Uveal Melanoma Cells Based on Traditional Chinese Medicine Chemical Bioinformatics

OBJECTIVE To utilize the pharmacophore model-molecular docking combined with the virtual screening strategy of free energy calculation and the chemical bioinformatics method of traditional Chinese medicine in cell biology experiments to investigate the components of Guiqi Baizhu prescription that target phosphatidylinositol 3-kinase(PI3K) and inhibit the proliferation of uveal melanoma(UM) cells.

METHODS The pharmacophore model of PI3K inhibitor was constructed, and the compounds of Guiqi Baizhu prescription were virtual screened. The components that fit the pharmacophore model were calculated by molecular docking and binding free energy, and the potential inhibitory components were selected for biological experimental evaluation. The effects of potential inhibitory components on UM cell proliferation were detected by CCK-8 and clonal formation assay. Flow cytometry was used to detect the cell cycle and apoptosis of UM cells. The mitochondrial membrane potential of UM cells was detected using JC-10 staining. The expressions of PI3K and downstream pathway proteins were detected by Western blotting.

RESULTS The pharmacophore model included 2 hydrogen bond receptors, 2 aromatic ring centers, and exclusion volumes. The results of the CCK-8 experiment showed that quercetin, tangerine, and nobiletin at concentrations of 10, 20, 40, 80 μmol·L⁻¹, and cyrtin at concentrations of 20, 40, 80 μmol·L⁻¹, were able to inhibit the proliferation of UM cells. The clonal formation experiment showed that quercetin, tangerine, nobiletin, and morusin, at different concentrations, could significantly inhibit the clonal proliferation of UM cells. Flow cytometry showed that UM cells were arrested in the G0/G1 phase by tangeretin and quercetin, while UM cells were arrested in the G2/M phase by nobiletin and morusin. The results of JC-10 staining showed that quercetin, nobiletin, tangeretin, and morusin could reduce the mitochondrial membrane potential of UM cells. Western blotting results showed that 4 compounds could target PI3K, but their downstream pathways were different.

CONCLUSION Based on the method of chemical bioinformatics in traditional Chinese medicine, this study explores the material basis for the inhibition of UM cell proliferation by the Guiqi Baizhu prescription. It also provides insights for the modern development of traditional Chinese medicine prescription.