While the authors have indicated that tests included in USP do not permit to detect adulteration of ginkgo extract
with flavonol aglycones, we feel compelled to bring to the readers' attention that a test similar to that described by Wohlmuth et al.
The authors undertook research to investigate the influence of a specific type of ginkgo extract
, EGb761[R] on embryofoetal development in mice during the critical period of organogenesis (6th to 15th day of pregnancy) by oral administration to the dams.
The ABC statement follows news of the publication of a report by the National Toxicology Program that showed that a special formulation of a Chinese ginkgo extract
produced cancers in certain strains of rats and mice in a series of animal toxicology studies performed over two years In the conclusion of the report, the authors wrote, "We conclude that Ginkgo biloba extract caused cancers of the thyroid gland in male and female rats and male mice and cancers of the liver in male and female mice.
Direct and indirect cholinergic activity has been reported with administration of ginkgo extract
in vitro (Das 2002, Nathan 2000).
In the French GuidAge study, groups of elderly people with memory complaints were randomly assigned 240 milligrams per day of ginkgo extract
, or a placebo, to be taken daily.
They were randomized either to twice-daily doses of placebo or 120 mg of ginkgo extract
And, regarding that higher dose, we see the need for a purer Ginkgo extract
containing terpene lactones at a much higher concentration.
They were randomized to twice-daily doses of either placebo or 120 mg of ginkgo extract
To determine effectiveness of ginkgo versus placebo in reducing the incidence of all-cause dementia and AD in elderly individuals with normal cognition and those with mild cognitive impairment (MCI), US Ginkgo Evaluation of Memory Study investigators randomised 3000 volunteers aged 75 years or older to receive twicedaily doses of 120mg ginkgo extract
or matching placebo.
In earlier lab tests, ginkgo extract
showed an ability to protect brain cells from the sort of problems that occur in Alzheimer's patients.
The Ginkgo extract
was given (on average) as two to three coated 40 mg tablets mixed in with the food once a day by the pet owners.
Another study looked at the bleeding time in older patients who were taking a ginkgo extract