Synergistic effect of piperine combined with luteolin on anti-non-small cell lung cancer activity in vitro and in LLC tumour-bearing mice: Mechanistic insights from network pharmacology and molecular docking

Piperine had synergistic effects with other natural products in treating lung cancer. The synergistic effects of piperine combined with luteolin on anti-non-small cell lung cancer activity and their mechanism of action are studied using network pharmacology and molecular docking. Cell viability, wound-healing, colony-formation, cell-apoptosis, and cell-cycle tests on A549 cells were used to detect the in vitro synergistic effects. Tumour growth and hematoxylin and eosin (HE) staining were used to verify the synergistic effects in Lewis lung carcinoma (LLC) tumour-bearing mice. Their combination indexes ranged from 0.3 to 0.8 across different concentrations, and the combination of 175.3 µmol L^–1 piperine and 87.32 µmol L^–1 luteolin showed synergistic inhibition of A549 cell viability. Moreover, the combination induced a higher apoptosis rate (75.60 %) than luteolin (24.56 %) or piperine (17.53 %). It arrested more cells in the G0/G1 phase than luteolin or piperine did. The combination achieved a tumour inhibition rate of 75.28 %, with lower tumour density and more obvious apoptosis. Network pharmacology identified AKT1, EGFR, SRC, and MMP9 as core targets regulating the PI3K/AKT pathway. Multi-software molecular docking confirmed binding of both compounds to these targets, with MMP9 as the common primary target. In conclusion, piperine and luteolin acted synergistically against non-small cell lung cancer.