A substance found in the saliva of a venomous lizard could provide a treatment for Alzheimer's disease, scientists believe.
Alzheimer's research seeks out lizards
An experimental drug has been developed from the Gila monster's saliva to improve memory and learning.
The New York-based biotechnology company Axonyx Inc., which has developed the drug, Gilatide, hopes to use it in human trials later this year.
The Gila monster's bite can be deadly, but its saliva contains a chemical which acts on a previously unknown receptor pathway in the brain that affects memory.
The animal is native to the southwest United States and Mexico.
The society's director of research, Richard Harvey, said: "It's good to be imaginative and inventive when looking for new treatments.
"But more than 95% of drugs initially developed in this way fall by the wayside.
"So we shouldn't get too excited about it, but it is an example of the amount of enthusiasm and effort needed to discover effective treatments for all sorts of diseases, but especially Alzheimer's."
A growing number of companies are looking at how the human memory works, hoping to find drugs that can help offset memory loss in patients with diseases ranging from Alzheimer's to depression, schizophrenia, stroke, Parkinson's and Aids.
New developments It is a lucrative market, which pharmaceuticals' companies are eager to capture.
One of the leaders in developing memory-enhancing drugs is Memory Pharmaceuticals, a privately-held US company.
Its founder, Eric Kandel, who won the Nobel Prize for Medicine in 2000, began his experiments into memory with the Aplysia sea slug.
Memory Pharmaceuticals has discovered several compounds which show promise in counteracting memory loss in animals and is hoping to start testing at least one in humans within a year.
The company's chief executive, Tony Scullion, said: "What we have are a broader range of drugs that would work in different diseases."
Cortex Pharmaceuticals Inc. in the US, is working on a class of compounds shown to increase the production in the brain of nerotrophin BDNF (brain derived neurotrophic factor), a substance apparently deficient in Alzheimer's patients.
The company is enrolling patients with mild cognitive impairment, who have memory difficulties, in a study to test its Ampakine compound.
As many as 80% of patients with cognitive impairment go on to develop Alzheimer's over a five-year period.
About 700,000 people in the UK have dementia, and of these, 500,000 have Alzheimer's disease.
A variety of drug treatments have been shown to benefit Alzheimer's patients.
- antioxidants such as selegiline designed to limit the impact of free radicals
- cholinesterase Inhibitors including tacrine (Cognex) and donepezil (Aricept)
- the female sex hormone oestrogen
- nonsteroidal Anti-Inflammatory Drugs (NSAIDS)
Viagra for the brain?
Growing new brain cells
Exercise and neurogenesis
Smart drugs and aging brains
Mood and cognitive performance
Antidepressants and new brain cells
The Good Drug Guide
SMART DRUGS 2: REVIEW