Repurposing Camellia sinensis Roots and Ginkgo biloba Leaves for Multiple Myeloma via Wnt/β-Catenin-Dependent Cell Cycle Arrest and Apoptosis.

Multiple myeloma (MM) is a hematological malignancy with limited therapeutic options. Drug repurposing offers a pragmatic strategy to identify novel candidates, including those from Traditional Chinese Medicine (TCM). Here, a gene signature-guided repurposing approach was applied to transcriptomic data using Limma and weighted gene coexpression network analysis to define MM-associated hub genes, followed by diagnostic and prognostic evaluation. Coremine Medical screening identified Camellia sinensis root (CSR) and Ginkgo biloba leaves (GBL) as promising candidates. CSR and GBL extracts inhibited MM cell proliferation with IC50 values of 1.54 mg/mL and 1.79 mg/mL, respectively, and induced G2/M cell cycle arrest with cyclin B1 downregulation. Apoptosis assays showed increased cell death and Bcl-2/Bax modulation. Wnt/β-catenin signaling was suppressed, correlating with cell cycle arrest and apoptosis. HPLC analysis revealed that CSR is rich in amino acids and flavanols, including L-theanine and epicatechin, while GBL contains flavonol glycosides and terpene lactones, such as quercetin, kaempferol, isorhamnetin, ginkgolide A-C, and bilobalide. These results indicate that CSR and GBL exert selective anti-myeloma activity via Wnt/β-catenin-mediated cell cycle arrest and apoptosis, highlighting their potential as repurposing candidates for MM.