The study, by researchers from Taiwan's China Medical University, suggests that if confirmed by further studies, the findings could lead to an inexpensive, easy-to-obtain alternative to drug therapy for the condition.
Diarrhoea is a common condition that causes an average of 2.4 million doctor's visits in the US each year.
Children younger than the age of five and the elderly can develop severe health problems if their condition leads to dehydration.
The researchers considered the effects of ginger and its bioactive components for their ability to inhibit the binding of a toxin from the bacteria E. coli (heat-labile enterotoxin, LT) to specific receptors on cells in a mouse intestine (GM1 receptors) that initiate a cascade of events resulting in diarrhoea.
"In this study, we demonstrated for the first time that, in addition to an antiemetic effect [effective against nausea), ginger extracts exhibit anti-diarrheal activities by blocking the binding of LTB to GM1," wrote the authors, led by Jaw-Chyun Chen, in the Journal of Agricultural and Food Chemistry .
"Because LT and cholera toxin share an 83 per cent amino acid sequence homology… and the fact that LT causes cholera-like diarrhea), our findings suggest that ginger extract could be used as an herbal supplement to prevent cholera-like diarrhea in developing countries," they added.
The rhizome of the ginger plant (Zingiber officinale) is a rich source of antioxidants, including gingerols, shogaols, zingerones and other ketone derivatives.
It has long been used as a remedy for nausea, especially associated with morning sickness.
The researchers used laboratory mice to show that a ginger extract was effective at blocking the toxin from E. coli , with the compound zingerone identified as most likely bioactive component responsible for the effect.
"In this study, we demonstrated that ginger, the commonly used herb and spice, was effective in inhibiting cholera-like diarrhea in mice via the abolishment of toxin-receptor interaction.
By biological-activity-guided searching for active components of ginger, zingerone was identified as the likely active constituent responsible for the observed antidiarrheal activity of ginger," stated the researchers.
"The U.S. Food and Drug Administration classifies ginger as "Generally Recognized as Safe," and the German Commission E Monographs report that ginger has no known side effects and no known drug/herb interactions.
Therefore, our observations suggest that ginger may be an effective candidate [against] diarrhea, " they concluded.
The researchers called for additional studies to determine the effective doses of ginger needed and whether it is safe for infants, who may experience unexpected side effects from large doses.
Source: Journal of Agricultural and Food Chemistry Published on-line ahead of print, (ASAP article), doi: 10.1021/jf071460f "Ginger and Its Bioactive Component Inhibit Enterotoxigenic Escherichia coli Heat-Labile Enterotoxin-Induced Diarrhea in Mice" Authors: Jaw-Chyun Chen, L.-J. Huang, S.-L. Wu, S.-C. Kuo, T.-Y. Ho, and C.-Y. Hsiang