EGb 761 research studies, ginkgo extract, benefit for Alzheimer's disease

EGB 761 is an extract from ginkgo biloba. It was first used in Europe.

Alzheimer's disease therapy
Ginkgo biloba extract EGb 761, donepezil or both combined in the treatment of Alzheimer's disease with neuropsychiatric features: a randomised, double-blind, exploratory trial.
Aging Ment Health. 2009; Yancheva S, Ihl R, Nikolova G, Panayotov P; GINDON Study Group. Hospital St. Naum, Sofia, Bulgaria.
This randomised, double-blind exploratory trial was undertaken to compare treatment effects and tolerability of EGb 761, donepezil and combined treatment in patients with AD and neuropsychiatric features. EGb 761 240 mg per day, donepezil (initially 5 mg, after 4 weeks 10 mg per day) or EGb 761 and donepezil combined (same doses) were administered for 22 weeks. Changes from baseline to week 22 and response rates were similar for all three treatment groups . An apparent tendency in favour of combination treatment warrants further scrutiny. Compared to donepezil mono-therapy, the adverse event rate was lower under EGb 761 treatment and even under the combination treatment. These exploratory findings helped to develop three hypotheses that will have to be proven in further studies: (1) there is no significant difference in the efficiency between EGb 761 and donepezil, (2) a combination therapy will be superior to a mono-therapy with one of both substances and (3) there will be less side effects under a combination therapy than under mono-therapy with donepezil.

Bone health
Effects of Egb 761 on bone mineral density, bone microstructure, and osteoblast function: Possible roles of quercetin and kaempferol.
Mol Cell Endocrinol. 20090; Trivedi R, Kumar A, Gupta V, Romero JR, Dwivedi AK, Chattopadhyay N. Division of Endocrinology, Central Drug Research Institute (Council of Scientific and Industrial Research), Chattar Manzil, Lucknow, India.
The effects of standardized and concentrated extract of Ginkgo biloba, Egb 761, were studied on estrogen deficiency-induced bone loss in ovariectomized (OVx) rats rendered osteopenic. Upon osteopenia development, Egb 761 was administered at a dose of 100mgkg day by oral gavage to OVx rats whereas control group received vehicle. Following 5 weeks of treatment, the OVx + Egb 761 group of rats exhibited significantly higher whole body BMD and lower bone turnover markers (serum alkaline phosphatase and osteocalcin) than OVx rats that were given vehicle. Egb 761 did not exhibit estrogen agonistic activity at the uterine level. OVx + Egb 761 group had higher femoral mRNA levels of osterix, type I collagen and osteocalcin compared with OVx+vehicle group. Determination of levels of three flavonoids of Egb 761, that are known to have bone conserving property, in serum and bone marrow suggests that kaempferol and quercetin, and not rutin, likely mediate the beneficial actions observed with Egb 761 treatment. These results show for the first time that oral administration of Egb 761 restores bone mass in aged OVx rats.