Synthesis and cytotoxic activities of some pyrazoline derivatives bearing phenyl pyridazine core as new apoptosis inducers.

The cyclization of chalcones 3a-3u with 3-hydrazinyl-6-phenylpyridazine 7 under basic condition led to the formation of new pyrazoline derivatives 8a-8u. All final compounds were characterized by spectral and elemental analyses. They were screened for their antiproliferative activities against A549 (lung), HepG-2 (liver), CaCo-2 (intestinal) and MCF-7 (breast) cancer cell lines. Some of the synthesized compounds exhibited promising antiproliferative activities especially compound 8k with IC50 values of 8.33, 1.67 and 10 μM against HepG-2, MCF-7 and CaCo-2 cancer cell lines, respectively. Moreover, their antiproliferative activity was due to apoptosis rather than necrosis induction except compound 8h which exhibited equal apoptotic and necrotic properties. Compound 8k showed 5 fold increase in caspase-3 activity indicating that the apoptosis proceeds via caspase-3 activation.