Anti-lung cancer targets of ellagic acid and biological interaction with a blood carrier protein

Ellagic acid (C14H6O8, 4,4′,5,5′6,6′-hexahydroxydiphenic acid 2,6,2′6′-dilactone) as a metabolite polyphenol compound has shown potential anticancer activities. However, its potential interaction affinity with plasma carrier proteins and antimetastatic activities are still unknown. Therefore, in this study, the anticancer and antimetastatic activities of ellagic acid in H358 metastatic lung cancer cells were assessed by MTT, qRT-PCR and western blotting. Then, the interaction of ellagic acid with human transferrin (HTf) as a drug carrier protein was measured. The results showed that ellagic acid-triggered cytotoxicity in H358 metastatic cells with an IC50 concentration of 7.18 µM. was mediated by overexpression of Bax/Bcl-2 ratio and caspase-3 mRNA as well as caspase-3 activity. Additionally, after being incubated with ellagic acid, the mRNA and protein expression levels of vascular endothelial growth factor (VEGF), a hallmark of angiogenesis, and the metastasis markers matrix metalloproteinase-2 (MMP-2) and MMP-9 were noticeably reduced. In protein–ligand interaction section, we found that one molecule of ellagic acid moderately (Kb = 104 M−1) binds to one molecule of HTf mediated by the involvement of hydrogen bonds and van der Waals forces, supported by molecular docking simulations. In conclusion, our novel data suggested that ellagic acid can show promising antimetastatic activity against H358 lung cancer cells as well as potential favorable binding to a drug carrier protein model.