A new study to investigate how certain extract from leaves of the ancient eastern tree, Ginkgo biloba, can ease symptoms of memory loss in patients with Alzheimer's disease has been started by scientists at the University of Maryland School of Pharmacy.
The researchers say that understanding the biochemical workings of the ginkgo extract called Egb 761 may be helpful in expanding treatment options for other medical conditions.
Associate Professor Yuan Luo thinks that the combination of separate actions by the Ginkgo extract, common in herbal remedies, may be the key to its effectiveness.
The researcher says that ongoing research has thus far shown that the administration of the extract to mice with the human Alzheimer's gene improved the process of making new nerve cells in part of the brain much affected by the disease.
The study found evidence that the protective effect of the extract could also be due to decreasing senile plaques or the clumping of beta-amyloid in the brain tissues.
Luo, whose study has shown that the Ginkgo extract in the hippocampus enhances the making of nerve cells and decreased clumping in brain tissue, says that finding out how it works might help drug discovery researchers and doctors learn how other herbal and conventional drugs work on in multiple ways.
She says that when herbal medicines are effective, it is often because of a synergy of different biological effects.
She feels that drugs that target multiple sites would be most efficacious because Alzheimer's disease is caused by multiple factors, not just one thing that has gone wrong.
Luo says that her study provides a rationale for future medicinal chemistry, and for identifying other potentially efficacious compounds with desirable activity as potential therapeutic agents to prevent and/or treat Alzheimer's disease.
Her team is also analysing data from a five-year clinical trial to determine whether medicine made from Ginkgo biloba can prevent or delay changes in memory, thinking, and personality as people get older.
While disease prevention theories associated with herbal medicine have the potential to both increase quality of life and reduce health care costs, ways that extracts of herbs work in the body are still poorly understood, she says.