WHO eyes medicinal plants
2004-02-18 13:23
Geneva - Devil's claw is a medicinal plant grown in southern Africa that is considered a cure-all - used in treating sores, fever, arthritis, muscularpain, high cholesterol and many other ills - and is now in the sights of the World Health Organisation.
Also getting a close look is the African pygeum tree, which grows wild in the mountain forests of Africa and Madagascar. Its bark is used by European men, particularly in Spain, to treat prostate problems.
These two species are a tiny part of an extensive inventory of medicinal plants that in the past two decades have been gaining universal acceptance and popularity - a phenomenon that has pushed both the devil's claw and the pygeum to the verge of extinction.
The current world market for herbal medicines is worth $50bn to $60bn a year, says Hans Hogerzeil, acting director of the WHO's essential drugs and medicines division.
Some health insurance providers have begun to reimburse patients for their expenditures on herbal remedies, which are only a part of the broader concept of traditional medicine, he said.
The rapid rise of herbal medicines has obligated the WHO to look at setting guidelines to ensure that these products are effective and harmless, according to Xiaroui Zhang, traditional medicine co-ordinator for this United Nations agency.
Herbal remedies
The WHO has received numerous reports of individuals who have suffered adverse reactions to herbal remedies, said Xiaroui.
In response the WHO this week issued guidelines for best practices in growing and collecting medicinal plants to help national governments to ensure the quality, sustainable production and safety of these products.
The aim of the WHO is to "make sure that essential medicines are available, that they are good quality and that they are being used in a rational way by the doctor and by the patient," said Hogerzeil.
By extension, the same principles apply to traditional medicine in general, and to herbal remedies in particular, he said.
As the use of medicinal plants expands, so does the potential for negative side effects. Such reports become "more frequent and also get published," noted Hogerzeil.
For example, a person might end up taking the wrong drug. The leaf of one plant might look like another, but have entirely different effects on the human body, and may even be toxic, he said.
According to a WHO report, in the United States in 1997, there were several reports of serious heart arrhythmia. They were found to be the result of accidental substitution of plantain, used as a dietary supplement, with Digitalis lanata, used in treating heart conditions.
Wild ginseng
Shipments of what was thought to be plantain, but was really Digitalis lanata, were sent to 150 manufacturers, distributors and retailers over two years.
A similar situation occurred in Hong Kong, where 14 people were poisoned with Podophyllum root, believing they were taking Gentiana or Clematis, known for their antiviral properties. In this case, the similar appearance of the roots of these species caused the error.
The effort of the WHO goes beyond the medicinal aims of the herbal remedies to concern about the environment, particularly the potential extinction of certain plant species that are in high demand.
Wild ginseng, for example, is widely popular for treating digestive problems caused by nervous disorders. This family of plant species is now endangered due to overexploitation.
The African pygeum tree (Prunus africana) faces a similar fate.
Livelihood
"While the bark can be harvested sustainably, harvesters either cut too much, which results in the death of the trees, or they fell whole trees," states the WHO.
The International Centre for Research in Agroforestry and other groups are working with local populations to preserve the wild pygeum trees, but also to set up a breeding programme to select faster-maturing varieties.
As for devil's claw (Harpagophytum procumbens), there are between 10 000 and 15 000 people in Namibia who make their livelihood from this plant, which could become extinct in the wild because of unsustainable harvesting practices.
One effort to protect the species and the harvesters' source of income is a six-year-old project to sustainably produce the plant, certifying its organic production and guaranteeing the workers a fair price. The key now is to create a demand for the certified product over devil's claw harvested in the wild. -Inter Press Service