Ethyl benzoate bearing pyrrolizine/indolizine moieties: Design, synthesis and biological evaluation of anti-inflammatory and cytotoxic activities.

Two new series of ethyl benzoate bearing pyrrolizine and indolizine moieties 8-11 were synthesized and evaluated for their anti-inflammatory and anticancer activities. Among these derivatives, compounds 9a, 10b and 11b displayed in vivo anti-inflammatory and analgesic activity comparable to ibuprofen. The acute ulcerogenicity and histopathological studies revealed better GIT safety profile than ibuprofen. Mechanistic study of these compounds revealed inhibitory activity against COX-1/2 with preferential inhibition of COX-2. Evaluation of cytotoxic activity of the new compounds using MTT assay revealed potent to moderate activity against three human (MCF-7, A2780 and HT29) cancer cell lines (IC50 = 0.02-23.35 µM). Compounds 9a, 10a,b and 11a,b exhibited high cytotoxic selectivity against MCF-7 cells (SI = 4-84). Although the indolizine bearing derivatives 8-11b exhibited higher selectivity to COX-2 than their corresponding pyrrolizine analogs 8-11a, but they were less active and selective against MCF-7 cells. Cell cycle analysis and annexin V-FITC/PI assay revealed G1 cell cycle arrest and induction of apoptosis in MCF-7 cells by compound 9a. The docking study revealed nice fitting of the new compounds into the active site of COX-1/2 with higher affinity to COX-2. Compounds 8-11 displayed drug-likeness score in the range of 0.67-1.56 compared to 1.06 for licofelone. These results suggested that compounds 9a, 10b and 11b could be promising agents in future research as anti-inflammatory and anticancer agents.