Different mechanisms of actions of genistein and quercetin on spontaneous contractions of rabbit duodenum

Diego S Fagundes, Laura Grasa, Sergio Gonzalo, Marta Sofia Valero, Marta Castro, Mª Pilar Arruebo, Miguel Angel Plaza, M. Divina Murillo López de Silanes
2015 Revista Espanola de Enfermedades Digestivas  
Flavonoids are known to relax precontracted intestinal smooth muscle and delay intestinal transit or intestinal peristalsis. The aim of this study was to determine the effects of genistein and quercetin on spontaneous contractions of rabbit duodenum in vitro in an organ bath. Genistein and quercetin (0.1-10 µM) reduced the amplitude of spontaneous contractions in the longitudinal and circular smooth muscle of rabbit duodenum, but they did not modify the frequency. Bay K8644 (L-type Ca 2+
more » ... L-type Ca 2+ channel activator), apamin, charybdotoxin, and tetraetylammonium (K + channel blockers) reverted the inhibition of amplitude of spontaneous contractions induced by genistein in longitudinal and circular smooth muscle. H-89 (protein kinase A inhibitor) antagonized the reduction of the amplitude of spontaneous contractions induced by quercetin in longitudinal and circular smooth muscle of duodenum, while 2,5-dideoxiadenosine (adenylyl cyclase inhibitor) reverted only the reduction of the amplitude in circular smooth muscle. In conclusion, genistein and quercetin reduce the spontaneous contractions in the duodenum by different mechanisms of actions. The effect of genistein would be mediated by Ca 2+ and K + channels, while the effect of quercetin would be mediated by cAMP and protein kinase A.
doi:10.17235/reed.2015.3695/2015 fatcat:k5c46in755h6hcqmhybvb5styy