Effects of GC7101, a Novel Prokinetic Agent on Gastric Motor Function: Ex Vivo Study

ABSTRACT

BACKGROUND/AIMS: GC7101, an extract of Lonicera Flos, is a novel developing drug for reflux esophagitis and functional dyspepsia. However, the drug's exact pharmacological mechanism of action remains unclear. This study assessed the effects of GC7101 on gastrointestinal (GI) motor function. METHODS: We used male guinea pigs to evaluate the effects of GC7101 on GI motility. The contraction of antral circular muscle in the presence of different doses of GC7101 was measured in a tissue bath. The prokinetic effects of GC7101 were tested using the charcoal transit assay from the pylorus to the most distal point of migration of charcoal mixture. To clarify the mechanism of action of GC7101, atropine, dopamine and the selective 5-hydroxytryptamine 4 receptor antagonist, GR113808 were used. RESULTS: The maximal amplitude of circular muscle contraction was induced by 5 mg mL(-1) GC7101. The area under the curve of contraction was significantly increased at 5 mg mL(-1) GC7101. Addition of 10(-6) M atropine, 10(-8) M dopamine or 10(-7) M GR 113808 to GC7101 5 mg mL(-1) decreased the amplitude and area under curve compared to GC7101 5 mg mL(-1) alone. GC7101 accelerated GI transit in a dose dependent manner except 100 mg kg(-1). Delayed GI transit caused by atropine, dopamine and GR 113808 was restored by GC7101 50 mg kg(-1). CONCLUSIONS: GC7101, an extract of Lonicera Flos, exerts a gastric prokinetic effect in guinea pig through cholinergic, antidopaminergic and serotonergic mechanisms. Therefore, GC7101 might be a novel drug for the treatment of functional dyspepsia.