Ginger has been shown to have an anti-serotonin effect mediated by 5-HT3 receptors and to be effective against nausea and emesis (vomiting)

Effect on Gastrointestinal Tract (GIT)

In isolated guinea pig ileum, several compounds in ginger (e.g., 6-gingerol, 6-shogaol, and galanolactone) have been shown to have anti-serotonin (5-hydroxytryptamine) effects (Yamahara et al., 1989; Huang et al., 1991). This may possibly suggest that the anti-emetic action of either ginger or some of its constituents may be mediated centrally via 5-HT3 receptors, as these constituents have small molecular weights and could easily cross the blood brain barrier (Ali et al., 2008).  In Suncus murinus (the Asian house shrew), it has been shown that orally administered 6-gingerol completely prevented vomiting in response to clophosphamide, presumably via a central nervous system effect (Yamahara et al., 1989).

Cisplatin treatment causes nausea and vomiting in man and animals.  Acetone and 50% ethanolic extracts of ginger at oral doses of 25, 50, 100 and 200 mg/kg exhibited significant protection, while aqueous extract at these doses was ineffective against cisplatin emesis in dogs (Sharma et al., 1997), and rats (Sharma and Gupta, 1998).

It has been suggested that ginger exhibits effects on the gastrointestinal tract by increasing bile secretion, preventing the occurrence of gastric ulcers and enhancing pancreatic lipase, intestinal lipase, disaccharidases, sucrose and maltase activities in animal models (Yamahara et al., 1990, Huang, 1991, Sharma and Gupta, 1998).  An acetone extract of ginger and its constituents has been shown to enhance the gastric emptying of charcoal meal in mice (Yamahara et al., 1990).

Mahady et al. (2003) were the first to provide evidence that the active constituents of ginger (gingerols) are effective in vitro against Helicobacter pylori, the primary etiological factor associated with dyspepsia, peptic ulcer disease and development of gastric and colon cancer. This was further confirmed by Mahady et al. (2005) and Nostro et al. (2006).

References:

• Ali B, Blunden G, Tanira M and Nemmar A. (2008). Some phytochemical, pharmacological and toxicological properties of ginger (Zingiber officinale Roscoe): A review of recent research. Food and Chemical Toxicology. 46(2): 409-420.
• Huang Q, Iwamoto M, Aoki S, Tanaka N, Tajima K, Yamahara J, Takaishi Y, Yoshida M, Tomimatsu T and Tamai Y. (1991). Anti-5-hydroxytryptamine 3 effect of galanolactone, diterpenoid isolated from ginger. Chem. Pharm. Bull. (Tokyo). 39, 397–99.
• Mahady G, Pendland S, Yun G, Lu Z and Stoia A. (2003). Ginger (Zingiber officinale Roscoe) and the gingerols inhibit the growth of Cag A+ strains of Helicobacter pylori. Anticancer Res. 23, 3699–3702.
• Mahady G, Pendland S, Stoia A, Hamill F, Fabricant D, Dietz B, Chadwick L. (2005). In vitro susceptibility of Helicobacter pylori to botanical extracts used traditionally for the treatment of gastrointestinal disorders. Phytother. Res. 19, 988–991.
• Nostro A Cellini L, Di Bartolomeo S, Cannatelli M, Di Campli E, Procopio F, Grande R, Marzio L and Alonzo V. (2006). Effects of combining extracts (from propolis or Zingiber officinale) with clarithromycin on Helicobacter pylori. Phytother. Res. 20, 187–190.
• Sharma S, Kochupillai V, Gupta S, Seth S and Gupta Y. (1997). Antiemetic efficacy of ginger (Zingiber officinale) against cisplatin-induced emesis in dogs. J. Ethnopharmacol. 57, 93–96.
• Sharma S and Gupta Y. (1998). Reversal of cisplatin-induced delay in gastric emptying in rats by ginger (Zingiber officinale). J Ethnopharmacol 62(1): 49-55.
• Yamahara J, Rong H, Iwamoto M, Kobayashi G, Matsuda H and Fujimura H. (1989). Active components of ginger exhibiting antiserotinergic action. Phytother. Res. 3, 70–71.
• Yamahara J, Rong H, Naitoh Y, Kitani T and Fujimura H.  (1989). Inhibition of cytotoxic drug-induced vomiting in suncus by a ginger constituent. J. Ethnopharmacol. 27, 353–355.
• Yamahara J, Huang Q, Li Y, Xu L and Fujimura H. (1990). Gastrointestinal motility enhancing effect of ginger and its active constituents. Chem Pharm Bull (Tokyo). 38(2): 430-1.