The lab that goes to the root of the problem
1/14/09

Around 20 % of the 750,000 plants counted on the surface of the planet, are in danger of disappearing over the next thirty years. In southern countries, this accelerated erosion of biodiversity could have a dramatic and brutal impact, involving the disappearance of numerous potential medicines, and the traditional know-how associated with them. Together with local partners (universities and NGOs), the pharmacognosy department of the University of Liège is attempting to tap into this cultural and biological heritage, for the benefit of local communities. Its main objective is the fight against malaria (paludism).

Cinchona pubescens ENSome well-known drugs, occurring naturally, are Taxol, and its derivatives which are extracted from the yew tree, used in the treatment of cancer, quinine, extracted from the cinchona, and still used in the treatment of malaria, or morphine, extracted from the poppy, and which is the most widely used analgesic drug in the world. Lesser known examples are the extracts from the perforated St. John’s wort, used in treatment of various forms of depression, vincristine and vinblastine, obtained from the Madagascar periwinkle, and used particularly in the treatment of certain forms of leukaemia, and artemisinin, extracted from the Chinese plant Artemisia annua, and now recommended by the WHO as a front-line treatment for malaria. But at some point in the future, if the results of research at the University of Liège are confirmed, the therapeutic value of other little-known plants such as Dicoma tomentosa, Fagara chalybea, and Strychnos usambarensis, will also be acknowledged in the fight against malaria.

The pharmacognosy unit of the pharmacology department of the University of Liège takes a keen interest in natural substances, medicinal plants, and the ancestral traditions associated with them. «In the eighties and nineties, the pharmaceutical companies diverted their attention away from this discipline. The formidable progress made possible by combinatorial chemistry in particular, seemed to create the belief that an in-depth knowledge of plants was no longer needed. Today there has been something of a u-turn in this respect. It is widely accepted that this ‘oversight’ only served to diminish therapeutic options. The chemical structures found in nature cannot always be replicated by chemical synthesis», explains Michel Frédérich, senior research fellow at the FNRS.

Malaria kills a child every 30 seconds

It is no accident that the researchers from Liège have turned their attention to malaria. The condition known as «plasmodium», named after the parasite transmitted by bites from certain kinds of mosquitoes (of the Anopheles genus), kills a million people in the world every year. Young children are the principal victims. So great is the problem, that malaria kills three times more children than the AIDS virus (HIV). Because of the poverty of the victims, this sickness is far from being a priority for the pharmaceutical companies. Indeed, the multinational companies have only a moderate interest in medicines from the plant kingdom, as, strictly speaking, they are forbidden to patent them.

The process set in motion by the University of Liège is essentially an ethno-pharmacological one. It involves contact with «tradi-practitioners» in regions where malaria is rife, and who, because they are at the heart of life in the towns, and particularly the countryside, know how to use plants for therapeutic ends. «Working with a local partner is indispensable, we Europeans can not hope to naively enter the African market and demand that these ‘witch doctors’ yield up their secret formulas. We need to make them aware, via our Southern partners, of the benefits they can get from our analyses. This could take the form of information about the toxicity of certain plants, or information about side effects, or the variable effectiveness of plant extracts, in relation to the part of the plant used, or the period when they are harvested», continues Michel Frédérich.

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