Stimulation of cytosolic and mitochondrial calcium mobilization by indomethacin in Caco-2 cells: Modulation by the polyphenols quercetin, resveratrol and rutin

Abstract

BackgroundThe effect of indomethacin (INDO) on Ca2+ mobilization, cytotoxicity, apoptosis and caspase activation and the potential protective effect of quercetin (QUE), resveratrol (RES) and rutin (RUT) were determined in Caco-2 cells. MethodsCaco-2 cells were incubated with INDO in the presence or absence of QUE, RES or RUT. The concentrations of Ca2+ in the cytosol (Fluo-3 AM) and mitochondria (Rhod-2 AM) were determined as well as the cytotoxicity (MTT reduction and LDH leakage), apoptosis (TUNEL) and caspase-3 and 9 activities. ResultsINDO promoted Ca2+ efflux from the endoplasmic reticulum (ER), resulting in an early, but transient, increment of cytosolic Ca2+ at 3.5min, followed by a subsequent increment of intra-mitochondrial Ca2+ at 24min. INDO also induced cytotoxicity, apoptosis, and increased caspase activities and cytochrome c release. All these alterations were prevented by the inhibitors of the IP3R and RyR receptors, 2-Aminoethoxydiphenyl borate (2-APB) and dantrolene. QUE was the most efficient polyphenol in preventing Ca2+ mobilization induced by INDO and all of its consequences including cytotoxicity and apoptosis. ConclusionsIn Caco-2 cells, INDO stimulates ER Ca2+ mobilization, probably through the activation of IP3R and RyR receptors, and the subsequent entry of Ca2+ into the mitochondria. Polyphenols protected the cells against the Ca2+ mobilization induced by INDO and its consequences on cytotoxicity and apoptosis. General significanceThese results confirm the possibility of using polyphenols and particularly QUE for the protection of the gastroduodenal mucosa in subjects consuming NSAIDs.