Effect of a short- and long-term treatment with Ginkgo biloba extract on amyloid precursor protein levels in a transgenic mouse model relevant to Alzheimer's disease.

Several clinical trials have reported beneficial effects of the Ginkgo biloba extract EGb761 in the prevention and therapy of cognitive disorders including Alzheimer's disease (AD). The aim of the present long-term feeding trial was to study the impact of dietary EGb761 on Amyloid precursor protein (APP) metabolism in mice transgenic for human APP (Tg2576). Tg2576 mice were fed diets with and without EGb761 (300 mg/kg diet) for 1 and 16 months, respectively. Long-term treatment (16 months) with EGb761 significantly lowered human APP protein levels by approximately 50% as compared to controls in the cortex but not in the hippocampus. However, APP levels were not affected by EGb761 in young mice. Current data indicate that APP seems to be an important molecular target of EGb761 in relation to the duration of the Ginkgo biloba treatment and/or the age of the animals. Potential neuroprotective properties of EGb761 may be, at least partly, related to its APP lowering activity.