Lung cancer is a leading cause of cancer-related deaths globally, with current treatments having significant limitations, including drug resistance, metastasis, and tumor heterogeneity. This study investigated the anticancer potential of isalpinin, a flavonoid isolated from Paphiopedilum dianthum, against non-small cell lung cancer (NSCLC) cell lines A549, H23, and H460. Isalpinin significantly inhibited NSCLC cell viability in a dose- and time-dependent manner; H23 and H460 cells showed greater sensitivity (IC₅₀ a ~ 44 μM at 48 h) compared to A549 cells (IC₅₀ 82 μM). Isalpinin suppressed proliferation, migration, and anchorage-independent growth, particularly in H23/H460 cells. Mechanistically, it induced apoptosis via increased ROS production and Bcl-2 downregulation, particularly in H23 and H460 cells. In a molecular docking analysis, isalpinin was found to directly bind to the ATP-binding pocket of AKT1, as confirmed by reduced Akt/GSK3β phosphorylation. These results suggest that isalpinin showed a potent multi-target natural compound against NSCLC that disrupts the key hallmarks of malignancy and pro-survival signaling. However, its subtype-specific efficacy warrants further in vivo studies and an investigation of combinatorial therapeutic approaches to elucidate its clinical potential.

Lung cancer remains a major clinical challenge, with therapy resistance in non-small-cell lung cancer (NSCLC) driving the search for novel selective agents. This study demonstrates that 2,3′-dihydroxy-5′-methoxystilbene exhibits significant anticancer activity in NSCLC cell lines (A549, H23, and H460) while displaying substantially lower toxicity toward normal NIH/3T3 fibroblasts. The compound reduced the viability of H23 and H460 cells after 48 h. (IC50: 23.39 ± 3.27 μM and 24.20 ± 2.61 μM, respectively), with NIH/3T3 cells remaining comparatively resistant (IC50 > 100 μM). At 25 μM, it suppressed proliferation by approximately 40% in H23, 30% in H460, and 20% in A549 cells, and dose-dependently impaired colony formation and migration, leading to near-complete migration arrest in H460 cells. Apoptosis induction peaked at 19% in H23, 17% in H460, and 8% in A549 cells at 25 μM. Mechanistic studies and molecular modeling revealed AKT-dependent activity, with decreased p-AKT and p-GSK3β levels (0.70 and 0.75 in H23; 0.65 and 0.70 in H460 at 25 μM), without changes in total protein expression. Combination treatment with cisplatin yielded synergistic effects in A549 (CI = 0.83) and H460 (CI = 0.94) cells, but antagonistic effects in H23 cells (CI = 1.32). These findings identify 2,3′-dihydroxy-5′-methoxystilbene as a selective AKT-targeting stilbene with promising anticancer potential and context-dependent chemosensitizing activity in NSCLC cells.