Bark of Hovenia dulcis Thunb. Suppresses Non-small Cell Lung Cancer Cells via PI3K–AKT–mTOR Pathway-mediated Apoptosis and Autophagy In vivo and In vitro

Background: Non-small cell lung cancer (NSCLC) is a leading cause of cancer-related death, and the treatments are often constrained by side effects and resistance. Hovenia dulcis Thunb. ( H. dulcis ), a traditional herb rich in triterpenoids, possesses antitumor potential, but its mechanisms of action in NSCLC have not been elucidated. Objective: This research aimed to assess the antitumor effects of H. dulcis bark total triterpenoid fraction (H-TP) in NSCLC and to determine the underlying molecular mechanisms via in vivo and in vitro studies. Materials and Methods: H-TP components were analyzed using ultra-performance liquid chromatography–tandem mass spectrometry. Antitumor activity was tested in a nude mouse xenograft model. Serum metabolites were profiled using ultra-performance liquid chromatography–quadrupole/time-of-flight mass spectrometry. Effects on A549 cells were evaluated using counting kit-8, colony formation, wound healing, and Transwell assays, as well as flow cytometry, Western blot, immunofluorescence, and transmission electron microscopic analysis. Results: A total of 27 compounds were identified in H-TP, which significantly inhibited NSCLC tumor growth, invasion, and metastasis and induced G1-phase arrest. Mechanistically, H-TP suppressed the phosphatidylinositol 3 kinase–protein kinase B–mammalian target of rapamycin (PI3K–AKT–mTOR) pathway while upregulating Bax, cleaved caspase-3/8, LC3-II, and ATG proteins and downregulating Bcl-2 and p62, thereby promoting apoptosis and autophagy. Conclusions: H-TP exerts potent anti-NSCLC effects by inducing both apoptosis and autophagy via PI3K–AKT–mTOR inhibition, confirming its promising potential as a natural therapeutic candidate.