Cytotoxicity and electron microscopy of cell death induced by goniothalamin

The cytotoxicity of goniothalamin was found to be strong towards both cancerous (HGC-27, MCF-7, PANC-1, HeLa), and non-cancerous (3T3) cell lines, especially in cases of dividing cells. Drug exposure studies indicated that the cytotoxic action of In the cytotoxicity assay of subconfluent cultures, goniothalamin was highly cytotoxic to all the cell lines tested (Table 1). All the CD50 values of goniothalamin were below the cut-off point of 4 mu g/ml for pure compounds to be considered as significantly active (8). The significant cytotoxicity of goniothalamin on a non-cancerous cell line, 3T3, reflects a non-selective mode of action incapable of distinguishing between normal and neoplastic cells. Goniothalamin exhibited the highest cytotoxic activity against HGC-27, the fastest growing cell line among the cell lines tested, and was less cytotoxic against the slow growing PANC-1 cells. Contact inhibited confluent 3T3 cells (quiescent) incubated for 60 hours showed a significantly lower cytotoxicity in comparision to subconfluent 3T3 cells (P < 0.05, Student's t, test, Table 2). Therefore, the cytotoxicity of goniothalamin appears to be more effective towards dividing cells.