Loss of biodiversity

From Wikipedia

Farnsworth, for example, has found that 25% of all prescriptions dispensed from community pharmacies in the United States from 1969 to 1990 contained active ingredients extracted from higher plants. In some countries in Asia and Africa 80% of the population relies on traditional medicine (including herbal medicine) for primary health care. Constituents of substances used by traditional healers, have rarely been incorporated into modern medicine. Quinine, physostigmine, d-tubocurarine, pilocarpine and ephedrine, have been demonstrated to have active effect. Knowledge of traditional medicinal practices is fast disappearing, particularly in the Amazon, as native healers die out and are replaced by more modern medical practitioners. Botanists and pharmacologists are racing to learn these ancient practice, which, like the forest plants they employ, are also endangered.

An explanation for some species loss is habitat lost due to invasive species introduction. Herbalist David Winston has suggested that a high proportion of nonnative species seen as invasive (kudzu, Japanese knotweed, mimosa, lonicera, St. Johnswort and purple loosestrife) may be harvested for the domestic herbal medicine market.

Species extinction is not only due to habitat loss. Overharvesting of medicinal species of plants and animals also contributes to species loss. This is particularly notable in the matter of Traditional Chinese Medicine where crude drugs of plant and animal origin are used with increasing demand. People with a stake in TCM often seek chemical and biological alternatives to endangered species because they realize that plants and animals lost from the wild are also lost to medicine forever but different cultural attitudes bedevil conservation efforts. Still conservation is not a new idea: Chinese advice against overexploitation of natural medicinal species dates from at least Mencius, a philosopher living in the 4th century BC.

Cooperation between western conservationists and practitioners have been beset by cultural difficulties. Westerners may emphasise urgency in matters of conservation, while Chinese may wish for the products used in TCM to remain publicly available. One repeated fallacy is that rhinoceros horn is used as an aphrodisiac in TCM. It is, in fact, prescribed for fevers and convulsions by TCM practitioners. There are no peer-reviewed studies showing that this treatment is effective. In 1995 representatives of the oriental medicine communities in Asia met with conservationists at a symposium in Hong Kong, organized by TRAFFIC. The two groups established a clear willingness to cooperate through dialogue and mutual understanding. This has led to several meetings, including the 1997 First International Symposium on Endangered Species used in Traditional East Asian Medicine where China was among 136 nations to sign a formal resolution recognizing that the uncontrolled use of wild species in traditional medicine threatens their survival and the continuation of these medical practices. The resolution, drawn up by the UN Convention on International Trade in Endangered Species (CITES), aims to initiate new partnerships in conservation.

THEME X. AT THE CHEMIST’S

Дата добавления: 2014-11-18