Protopine Inhibits Cell Growth and Enhances Oxidative Stress and Caspase-mediated Apoptosis in Oral Cancer KB Cells
Ming Yin, Jing Ren, Hongyu DongBackground
Oral cancer remains a common malignancy with a high mortality rate, and current treatment options are often associated with recurrence, resistance, and adverse effects. This study investigated the anti-cancer activity of protopine in human oral cancer KB cells.
Purpose
To evaluate the effects of protopine on cell viability, oxidative stress, and apoptosis in KB cells.
Materials and Methods
KB cells were treated with protopine at concentrations of 5–50 µM. Cell viability was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Oxidative stress markers, including thiobarbituric acid reactive substances (TBARS) and antioxidant levels, were measured using commercially available assay kits. The activities of caspase-3, caspase-8, and caspase-9 were also determined.
Results
Protopine reduced KB cell viability in a concentration-dependent manner, with a half-maximal inhibitory concentration (IC 50 ) value of 25 µM. Treatment increased TBARS levels and reduced intracellular antioxidant levels compared with untreated cells. In addition, the activities of caspase-3, caspase-8, and caspase-9 were significantly increased following protopine exposure.
Conclusion
Protopine decreased the viability of KB cells and was associated with increased oxidative stress and activation of caspase-dependent apoptotic pathways. These findings indicate that protopine possesses anti-cancer activity against KB cells under