Plant extinction threatens pharmaceutical industry

K. G. H. MUNIDASA

It is time we strove for the conservation of the wild plants. The general tendency at present is to think of conservation only in terms of wildlife, while ignoring the fact that plant species are also an integral part of the self same environment.

Broadly speaking the term “wildlife” encloses both the flora and fauna, since they are the products of a single environment and so to say largely interdependent. Thus, it would be clear that the conservation of the total environment is the best safeguard against extinction of the living species.

A list compiled by the International Union for the Conservation of Nature and Natural Resources (IUCN) estimates between 20,000 to 25,000 plants as facing extinction in the world today.

This alarming situation is due chiefly to human activity, i.e deforestation and Urbanization, Over-exploitation, Over-grazing by Domestic Animals, Competition from Introduced Plants and all types of pollution are the contributory factors.

Medicinal plants

The disappearance of plant species from the Earth is most damaging to the pharmaceutical industry, which annually spends vast amounts of funds and energy to discover plant-based drugs.

Though we live in an era of synthetics, our dependence on nature for medicinal properties has not diminished to any extent. It has been found that more than half of the prescriptions doled out by physicians the world over for various ailments contain properties derived from plants.

For example, the alkaloid called Ephedrine now used as a nasal decongestant or a nervous stimulant is a derivative of Ephedrine- a shrub known in China for more than 5,000 years. Ergotrine is an alkaloid widely administered today to contract uterine muscles during child-birth.

This is derived from Ergot, a poisonous substance found on a fungus of the Genus Claviceps, which affects rye and other serials. Dioxin (a heart stimulant) is a compound extracted from Spanish Fox-Glove, a common weed in Europe.

From very remote times the study of nature was chiefly concerned with the utilization of plants as sources of food and drugs. The relation between botany and pharmacology has been so close that out of ten books that Pliny (23-79 AD) wrote on Natural History, eight were on the subject of medicinal plants.

The folklore of native tribes in many parts of the world has been ever rich in knowledged about medicinal plants and floral pharmacopoeias are said to have been used by almost all ancient civilizations.

The World Health Organization (WHO) has now initiated action to pursue these invaluable documents, because the effectiveness of traditional medicines over the present-day pills is increasingly being proved.

The primitive man’s knowledge about various medicinal plants was so vast that the WHO has been able to computerize 3,000 plant species which have been used by him for population control alone.

To utilize these pharmaceutical data, it is felt that we should endeavour to preserve all the native plants. It is tragical therefore, to note that irresponsible forest clearing, chiefly in the Tropics, has endangered the survival of many of these species of plants.

Threatened species

Between 70-90 per cent of the plant species known to science are found in the tropical rain forests. Notwithstanding this, it is in these that the greatest damage is seen today, and species are becoming extinct even before they are discovered.

The rate of destruction of the tropical forests is estimated to be an incredible 20 hectares a minute. In Malaya 350,000 hectares of valuable forest cover are being indiscriminately cleared annually.

It is said that among the 25,000 species of flowering plants found in South-east Asia, there are thousands which are economically vital to agricultural improvements and as pest control or sources of new drugs.

A great percentage of the 50,000 plants species at present listed as endangered are those found on isolated island habitats. Generally, such plant and animal species having a very susceptible ecological balance in restricted habitats are the most commonly denuded by man’s inroads.

During the last 300 years or so man has almost annihilated such island species from existence. By the devastation of forest cover, and the introduction of alien plants and animals, he had brought about a complete “vegetative upheaval” in many areas of the world.

It has been recorded that about 80 percent of the plant species found in New Zealand are peculiar to that island and many of them restricted in distribution.

The population growth and the resultant alienation of land for settlement have reduced the available habitats for many of the others. However, conservation measures introduced by the New Zealand government have resurrected some of them from extinction.

But smaller Indian Ocean islands like Socotra, Aldabra and the Seychelles have not been so fortunate.

Of a total of 326 plant species on these island, 11 percent are now believed to be extinct, and another 24 percent are currently threatened. In St. Helena Island, for instance, destruction of the natural vegetation by goats has resulted in the extinction of 30 endemic species and the rest are fast disappearing.

Rare orchids

The Orchids and Cacti are two groups of plants which certainly suffer from horticulturists and plant collectors, owing to their specific selectivity and narrow adaptability.

Forty out of the fifty species of wild orchids in the U.K. has in recent times become rare due to the destruction of their habitats and indiscriminate collection. For example, the European Lady’s Slipper Orchid which once grew in 30 localities in Northern England is now reported only from one place.

The best way to encourage the survival potential of an endangered species is to protect it in its own natural habitat. But for many species this is not possible, since their habitats have been so much disturbed and altered.

In the modern world, botanical gardens and horticultural centres go a long way in fulfilling the requirements of displaced species. On the other hand, special reserves or plant sanctuaries would be helpful in this respect.

One cannot say for sure any one particular plant among those currently threatened species should be saved because it might one day prove of use to mankind.

Yet, among the mentioned 20,000 endangered species there will certainly be hundreds of potential plants for food, medicine, fodder, timber, fibre or oil.