Peonidin Suppresses the Malignant Characteristics in Colon Cancer Cells by Regulating Erk/NF-κB/COX-2 Axis

Peonidin is a compound derived from cyanidin, belonging to the anthocyanin group, which imparts a purplish-red color to flowers and fruits. It exhibits antioxidant, anti-inflammatory, and antiproliferative properties. This study investigated the anticancer properties of peonidin in human colon cancer cell lines. Normal and colon cancer cells were exposed to different doses of peonidin for different durations. Cell-based assays and Western blotting were performed to investigate the mechanisms driving peonidin activity. Peonidin exhibited cytotoxic effects on colon cancer cells in a dose- and time-dependent manner while sparing normal colon epithelial cells. Furthermore, peonidin triggered autophagy, as evidenced by the increase in autophagosomes in colon cancer cells. Western blot analysis revealed that peonidin elevated the levels of autophagy-related 4B, microtubule-associated protein 1 light chain 3-I/II, and sequestosome-1 (SQSTM/p62). Conversely, peonidin reduced cell invasion and the expression of matrix metalloproteinase-9, Snail, Slug, and vimentin. From a mechanistic standpoint, Western blotting indicated that peonidin might inhibit the extracellular signal-regulated kinase/nuclear factor-κB/cyclooxygenase-2 pathways, leading to autophagy induction and inhibition of cell invasion in colon cancer cells. These results provide preliminary evidence supporting the use of peonidin as a new potent candidate for colorectal cancer chemotherapy.