Anticancer effects of picrasidine I on oral squamous cell carcinoma

Picrasidine I is a dimeric alkaloid derived from a Southern Asian plant Picrasma quassioides and demonstrated to possess pharmacological activities, such as anti-inflammatory and anti-osteoclastogenic effects. However, its potential anticancer effect remains unclear. In the present study, anticancer activity of picrasidine I was assessed by treating oral squamous cell carcinoma cells with different concentrations of picrasidine I (20, 30, and 40 μM) for 24, 48, and 72 h. The findings revealed that picrasidine I reduced the cell viability in a dose-dependent manner. Picrasidine I exerted its cytotoxic effect through arresting cell cycle at G2/M phase by downregulating cyclin A, cyclin B, CDK4, and CDK6, and inducing apoptosis in oral cancer cells. The induction of apoptosis was evidenced by increasing expression of death receptors, disruption of mitochondrial membrane potential, increased activation of PARP and caspases 3, 8, and 9, enhanced expression of proapoptotic mediators (Bak and Bim L/S), and reduced expression of antiapoptotic mediators (Bcl-2 and Bcl-xL). Moreover, analysis of MAPK signaling pathway revealed that picrasidine I-mediated proapoptotic activities by downregulating JNK phosphorylation. Taken together, the study identifies picrasidine I as a potent anticancer agent that can be used as a therapeutic intervention against oral squamous cell carcinoma.