Elucidation of the anti-colon cancer mechanism of Phellinus baumii polyphenol by an integrative approach of network pharmacology and experimental verification

Colon cancer, a prevalent malignant tumor affecting the digestive system, presents a substantial risk to human health due to its high occurrence and mortality rates. Phellinus baumii polyphenol (PBP), a natural product derived from traditional Chinese medicine, has gained widespread popularity due to its low toxicity and minimal side effects, compared to radiation and chemotherapy. This study used an integrated approach of network pharmacology and experimental verification to elucidate the anti-colon cancer effects of PBP and its potential mechanisms. In network pharmacology, the identification of relevant targets involved a comprehensive search across multiple databases using keywords such as "active components of PBP" and "colon cancer". Venn diagram analysis was subsequently performed to ascertain the shared targets. To identify the key active components and core targets, we constructed a network of "Disease-Drug-Pathways-Targets" and a protein-protein interaction (PPI) network among the targets using Cytoscape 3.9.1. Furthermore, molecular docking was carried out to predict the binding affinity and conformation between the main active compounds (davallialactone and citrinin) of PBP and the core targets (TP53, STAT3, CASP3, CTNNB1, PARP1, MYC). To validate our findings, in vitro experiments were conducted. We verified that PBP exerted an anti-colon cancer effect on human colon cancer HCT116 cells by significantly inhibiting cell proliferation, promoting apoptosis and arresting the cell cycle in S phase by using Cell Counting Kit-8 (CCK-8) and flow cytometry. Finally, we determined the key regulatory proteins related to apoptosis and the cell cycle by western blot analysis, and proposed the potential mechanism by which PBP exerts an anti-colon cancer effect by inducing the caspase-dependent mitochondrial-mediated intrinsic apoptotic pathway and arresting the cell cycle in S phase in HCT116 cells. These results suggest that PBP possesses substantial potential for the treatment of colon cancer and may serve as a viable alternative therapeutic strategy in colon cancer treatment.