The Effect of the Volatile Oil from Ginger Rhizomes (Zingiber officinale), its Fractions and Isolated Compounds on the 5-HT3 Receptor Complex and the Serotoninergic System of the Rat Ileum

A contribution of the volatile oil from ginger rhizomes (Zingiber officinale Roscoe) on inhibiting the 5-HT3 receptor complex had been shown. In the present study a possible interaction of some compounds of the volatile oil with the 5-HT3 receptor system expressed in N1E-115 cells and with the serotoninergic system of the rat ileum was investigated. The volatile oil was obtained by steam distillation and fractionated using a silica gel column resulting in five fractions. Compounds of the fractions were identified by GC-MS. The influence of the volatile oil, its fractions and pure components on serotonin-induced [14 C]guanidinium influx into N1E-115 cells was measured indicating the inhibitory interaction with the 5-HT3 receptor channel system. Most potent inhibitors of cation influx were the volatile oil, fraction 4, β-pinene, terpinolene, α-copaene and α-phellandrene. The volatile oil and fractions 1 and 4 were not able to significantly influence either serotonin (10 μM)-induced maximum contraction of the rat ileum or the second phase of the biphasic contraction 2.5 min after serotonin addition. However, β-pinene, terpinolene and α-phellandrene reduced both contractions. In conclusion, the volatile oil and distinct compounds such as terpinolene, β-pinene and α-phellandrene interact with 5-HT3 receptor channel system and possess an antispasmodic effect at the rat ileum.