A series of N'-((1-(substituted)-1H-indol-3-yl)methylene)hydrazides were synthesized and evaluated for their in vitro antiproliferative activities against various cancer cell lines. Formation of indole hydrazide-hydrazones was accomplished by the reaction of indole 3-carboxaldehyde with aryl/alkyl hydrazides in the presence of acetic acid. Out of synthesized twenty-two compounds, some of the analogs exhibited specificity toward breast (18b, 18d, 18f and 18j) and prostate (18t and 18v) cancer cells. Among the prepared derivatives, compounds 18b, 18d and 18j were most cytotoxic (IC50 = 0.9, 0.4 and 0.8 μM, respectively) against the screened cancer cell lines. Exposure of PC3 cells to either 18d or 18j resulted in increased levels of cleaved PARP1, indicating that indolyl hydrazide-hydrazones induce apoptosis in PC3 cells.
