1 Tahrcountry Musings: Biodiversity loss and its implications

Friday, April 25, 2008

Biodiversity loss and its implications

The Earth's biodiversity is disappearing at an alarming rate. For people concerned about biodiversity here is something that is going to interest you. The new book, ‘Sustaining Life” is a great eye opener. It deals with biodiversity and fills a major gap in the arguments made to conserve nature. Sustaining Life is the first book to examine the full range of potential threats that diminishing biodiversity poses to human health. At the heart of the book is a chapter dedicated to exploring seven threatened groups of organisms valuable to medicine, including amphibians, bears, cone snails, sharks, nonhuman primates, gymnosperms, and horseshoe crabs that underscore what may be lost to human health when species go extinct.

The story of southern gastric brooding frog (Rheobatrachus), which was discovered in undisturbed rainforests of Australia in the 1980, makes interesting reading. The frogs raise their young in the female’s stomach where they would, in other animals, be digested by enzymes and acid. The baby frogs produced a substance, or perhaps a variety of substances, that inhibited acid and enzyme secretions and prevented the mother from emptying her stomach into her intestines while the young were developing. The authors point out that the research on gastric brooding frogs could have led to new insights into preventing and treating human peptic ulcers which affect some 25 million people in the United States alone. The bad news is that the frogs have become extinct

Other interesting stories include.

Pumiliotoxins, like those made by the Panamanian Poison Frog that may lead to medicines that strengthen the contractions of the heart and thus prove useful in treating heart disease.

Alkaloids made by species like the Ecuadorian Poison Frog, which could be the source of a new and novel generation of painkillers.

Bradykinins and maximakinins, made in the skin glands of species like the Chinese Large-Webbed Bell Toad; Mexican Leaf Frog, and North American Pickerel Frog that dilate the smooth muscle of blood vessels in mammals and therefore offer promising avenues for treating high blood pressure.

Several medical benefits have already arisen from the study of bears, including the development of rsodeoxycholic acid, found in the gall bladders of some bear species such as polar and black bears, into a medicine.

Some bear species, known as “denning” bears because they enter into a largely dormant state when food is scarce, are of tremendous value to medicine as they are able to recycle a wide variety of their body’s substances.

Bears appear to produce a substance that inhibits cells that break down bone and promote substances that encourage bone and cartilage-making cells. Currently, 740,000 deaths a year are the result of hip fractures worldwide, a large number of which are caused by osteoporosis. By 2050 there will be an estimated six million osteoporosis-linked hip fractures globally.

Several pharmaceuticals, including decongestants and the anti-cancer drug taxol, have already been isolated from gymnosperms. The researchers believe many more are yet to be discovered and may be lost if species of Gymnosperms become extinct.

Substances from one Gymnosperm, the Ginkgo tree may reduce the production of receptors in the human nervous system linked with memory loss. Thus they may play a role in countering Alzheimer’s disease. They may also help in the treatment of epilepsy and depression.

One compound, known as ziconotide extracted from snails is thought to be 1000 times more potent than morphine and has been shown in clinical trials to provide significant pain relief for advanced cancer and AIDS patients. Another cone snail compound has been shown in animal models to protect brain cells from death during times of inadequate blood flow.

‘Sustaining Life: How Human Health Depends on Biodiversity’ is published by Oxford University Press priced $34.95

ISBN13: 9780195175097ISBN10: 0195175093 hardback, 568 pages

About the Author(s)

Eric Chivian , M.D., is the Director of the Center for Health and the Global Environment at Harvard Medical School. He shared the 1985 Nobel Peace Prize. He is the lead editor and author of Last Aid: The Medical Dimensions of Nuclear War and Critical Condition: Human Health and the Environment .
Aaron Bernstein , M.D., is a Research Associate at the Center for Health and the Global Environment at Harvard Medical School, and Resident, Boston Combined Residency in Pediatrics, Harvard Medical School/Boston University School of Medicine.

Posted with inputs from IUCN

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