The Effect of Compound Sophora on Fluorouracil and Oxaliplatin Resistance in Colorectal Cancer Cells

Fluorouracil (5-FU) and oxaliplatin (L-OHP) are the most commonly used chemotherapy drugs for colorectal cancer, though resistance is common. Compound Sophora injection is a traditional Chinese medicine that can protect the liver against oxidation, improve immunity, and enhance sensitivity to chemotherapy; it may have an effect of reversing resistance in 5-FU- and L-OHP-resistant gastric cancer cells (5-FU/SW480 and L-OHP/SW480, respectively). A concentration gradient experiment was performed to identify a nontoxic dose of compound Sophora injection. 5-FU/SW480 and L-OHP/SW480 cells were treated with the nontoxic dose of compound radix Sophorae injection for 48 h, and changes in drug resistance to 5-FU and L-OHP were detected. Alterations in apoptosis and the cell cycle were assessed, as were the mRNA and protein levels of permeability glycoprotein (P-gp), annexin A1 (ANXA1), and ATP-binding cassette superfamily G member 2 (ABCG2). Flow cytometry showed a reduction in the number of cells in the G1 phase and an increase of cells in the S phase (P < 0.05). mRNA and protein expression of P-gp and ABCG2 was significantly higher in 5-FU/SW480 and L-OHP/SW480 cell lines, and ANXA1 expression decreased significantly (P < 0.05). Compound Sophora injection can reverse the drug resistance of 5-FU/SW480 and L-OHP/SW480 cell lines to 5-FU and L-OHP, respectively, possibly through a mechanism involving reduced expression of P-gp and ABCG2 but enhanced expression of ANXA1, which is the basis for the identification of clinical drug resistance in colorectal cancer.