Total flavonoids of litchi seed inhibit breast cancer metastasis by regulating the PI3K/AKT/mTOR and MAPKs signaling pathways.

Abstract

Context: Total flavonoids from Litchi chinensis Sonn. (Sapindaceae) seeds (TFLS) effectively attenuate stem cell-like properties in breast cancer cells. However, their pharmacological effects and mechanisms in suppressing breast cancer metastasis remain unclear.

Objective: This study aimed to elucidate the inhibitory effects and underlying mechanisms of TFLS on breast cancer metastasis.

Materials and methods: The antiproliferative, migratory, and invasive activities of breast cancer cells following TFLS treatment were evaluated using CCK-8, wound-healing, and transwell assays. The epithelial-mesenchymal transition (EMT) biomarkers were evaluated via Western blot analysis. The anti-metastatic effects of TFLS were further validated in vivo using zebrafish and mouse models. Network pharmacology methodology was utilized to predict potential targets and signaling pathways, which were subsequently corroborated by Western blot. Potential active compounds were identified through molecular docking, and the chemical constituents of TFLS were analyzed and characterized using UPLC-QTOF/MS.

Results: TFLS suppressed the proliferation of MDA-MB-231 and MDA-MB-468 cells, with IC₅₀ values of 44.47 μg/mL and 37.35 μg/mL at 72 h, respectively. It effectively suppressed breast cancer metastasis in vitro, demonstrated by a marked reduction in cellular motility and invasiveness, alongside the reversal of EMT. Consistent with pathway enrichment analysis, network pharmacology revealed that TFLS reduced the phosphorylation levels of PI3K, AKT, mTOR, JNK, ERK, and p38 in breast cancer cells. Molecular docking identified seven potential active ingredients, and UPLC-MS/MS confirmed the presence of key compounds, including procyanidin A2.

Discussion and conclusion: TFLS effectively inhibits breast cancer cell proliferation, migration, and invasion in vitro by reversing the EMT phenotype, while suppressing metastasis in vivo. These effects are likely mediated via the attenuation of the PI3K/AKT/mTOR and MAPK signaling pathways.