They have found evidence that ginsenoside Rb1 one of the principal active components of ginseng can cause abnormalities in rat embryos.
Their research is published today (Thursday 25 September) in Europe's leading reproductive medicine journal Human Reproduction.
Dr Louis Chan and colleagues at the Chinese University of Hong Kong Prince of Wales Hospital, Hong Kong, tested ginsenoside Rb1 in various concentrations on 9-day old rat embryos.
They found that embryos exposed to more than 30 micrograms per millilitre of ginsenoside Rb1 had significantly lower morphological scores. Morphological scores are a way of assessing the development of the important organs of embryos: the higher the score, the more normal is the development of the embryo.
At 30 micrograms the total morphological scores were significantly lower than the scores of the control group, which had not been exposed to gensinoside 35 as opposed to 45 and they had lower scores for heart, limbs, eye development and flexion. At the highest dose of 50 micrograms the total score fell to 28 and the embryos were also significantly shorter in body length and had fewer somites (muscle pre-cursor cells).
"Our study has demonstrated that ginsenoside exerts a direct teratogenic effect on rat embryos: that is to say it is capable of causing malformations in rat embryos," said Dr Chan.
"Although there are numerous reports in the literature concerning the potential benefit of ginseng, much less is know about the potential toxicity and there are no data about its potential effect on the developing human foetus. Yet a survey published in 2001 showed that over 9% of pregnant women report using herbal supplements, and in Asia up to 10% have taken ginseng during pregnancy," he said.
Dr Chan said th
Contact: Margaret Willson
European Society for Human Reproduction and Embryology