TY - JOUR
T1 - Ghrelin receptor is activated by naringin and naringenin, constituents of a prokinetic agent Poncirus fructus
AU - Jang, Yongwoo
AU - Kim, Su Won
AU - Oh, Jungeun
AU - Hong, Gyu Sang
AU - Seo, Eun Kyoung
AU - Oh, Uhtaek
AU - Shim, Won Sik
PY - 2013/7/9
Y1 - 2013/7/9
N2 - Ethnopharmacological relevance Poncirus fructus (PF), also known as a dried immature fruit of Poncirus trifoliata (L.) Raf. (Rutaceae), has long been traditionally used for the various gastrointestinal disorders in Eastern Asia. Aim of study The aqueous extract of PF (PF-W) has the strong prokinetic effect, yet the underlying mechanism is still elusive. The present study investigated whether PF-W has any effect on motilin receptor or ghrelin receptor, since these receptors enhance intestinal motility when activated. Materials and methods The effect of PF-W and its components on motilin or ghrelin receptor was determined by calcium imaging and whole-cell patch clamp methods. Results PF-W activates the ghrelin receptor, but not the motilin receptor, resulting in a transient increase of intracellular calcium levels. Furthermore, among various constituents of PF, only naringin and naringenin evoked the intracellular calcium augmentation via the ghrelin receptor. Moreover, cortistatin-8 - a ghrelin receptor inhibitor - specifically blocked naringin- and naringenin-induced calcium increases. In addition, naringin and naringenin induced inward currents in ghrelin receptor-expressing cells under whole-cell patch clamp configuration. Conclusion PF-W activates the ghrelin receptor, and naringin and naringenin are key constituents responsible for the activation of ghrelin receptor. Therefore, the present study suggests that the ghrelin receptor is a molecular entity responsible for the strong prokinetic activity of PF-W.
AB - Ethnopharmacological relevance Poncirus fructus (PF), also known as a dried immature fruit of Poncirus trifoliata (L.) Raf. (Rutaceae), has long been traditionally used for the various gastrointestinal disorders in Eastern Asia. Aim of study The aqueous extract of PF (PF-W) has the strong prokinetic effect, yet the underlying mechanism is still elusive. The present study investigated whether PF-W has any effect on motilin receptor or ghrelin receptor, since these receptors enhance intestinal motility when activated. Materials and methods The effect of PF-W and its components on motilin or ghrelin receptor was determined by calcium imaging and whole-cell patch clamp methods. Results PF-W activates the ghrelin receptor, but not the motilin receptor, resulting in a transient increase of intracellular calcium levels. Furthermore, among various constituents of PF, only naringin and naringenin evoked the intracellular calcium augmentation via the ghrelin receptor. Moreover, cortistatin-8 - a ghrelin receptor inhibitor - specifically blocked naringin- and naringenin-induced calcium increases. In addition, naringin and naringenin induced inward currents in ghrelin receptor-expressing cells under whole-cell patch clamp configuration. Conclusion PF-W activates the ghrelin receptor, and naringin and naringenin are key constituents responsible for the activation of ghrelin receptor. Therefore, the present study suggests that the ghrelin receptor is a molecular entity responsible for the strong prokinetic activity of PF-W.
KW - Poncirus fructus Naringin Naringenin Prokinetic Ghrelin receptor Motilin receptor
UR - http://www.scopus.com/inward/record.url?scp=84879414835&partnerID=8YFLogxK
U2 - 10.1016/j.jep.2013.04.039
DO - 10.1016/j.jep.2013.04.039
M3 - Article
C2 - 23639361
AN - SCOPUS:84879414835
SN - 0378-8741
VL - 148
SP - 459
EP - 465
JO - Journal of Ethnopharmacology
JF - Journal of Ethnopharmacology
IS - 2
ER -