Network Pharmacology and Experimental Validation to Explore the Potential Mechanism of Salvianolic Acid B in Reversing Oxaliplatin Resistance of Colorectal Cancer Cells.

Chemotherapy resistance of colorectal cancer (CRC) seriously affects the therapeutic effect. Salvianolic acid B (SalB) is a primary active compound found in the traditional Chinese medicine (TCM) Danshen, known for its antitumour properties and ability to reverse chemoresistance. However, the underlying mechanism remains to be elucidated. The present study aims to explore the chemoresistance-reversal effects of SalB on colon cancer cells and elucidate its potential mechanisms using both network pharmacology and experimental approaches. Accordingly, SalB- and disease-related targets were extracted from the public database. A protein-protein interaction (PPI) network was constructed to identify critical targets. Functional enrichment analyses, including Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, were conducted using the DAVID database. Validation experiments were carried out using CCK-8, colony-formation, EdU, flow cytometry (Fc), and Western blot (WB) assays. Ultimately, network pharmacology analysis identified 29 overlapping targets between SalB and CRC drug resistance (DR), with key proteins such as TP53, JUN, CASP3 and MMP9. Enrichment analysis revealed that SalB addresses CRC resistance through multiple targets and pathways, notably oxidative stress and apoptosis pathways. Further cellular experiments demonstrated that SalB significantly inhibited the proliferation of HCT116/L-OHP cells. A nontoxic dose of SalB enhanced the sensitivity of these cells to oxaliplatin, promoted apoptosis, upregulated the expression of apoptotic proteins cleaved caspase-3 and Bax and downregulated the expression of antiapoptotic protein Bcl-2. Additional studies indicated that SalB increased ROS levels induced by oxaliplatin. Pretreatment with NAC, a ROS inhibitor, markedly reduced the apoptosis induced by the combined treatment of SalB and oxaliplatin. In conclusion, SalB modulates CRC drug resistance through multiple targets and pathways. SalB potentially reverses oxaliplatin resistance in CRC cells by regulating the ROS-mediated apoptotic signalling pathway.