Malaria N° 9 - Subject N° 15

MEDICINAL PLANTS AND TRADITIONAL MEDICINES: CAN THEY CONTRIBUTE IN THE MALARIA CONTROL?
H.A. Oketch-Rabah & J.W. Mwangi

SUMMARY
Malaria is currently one of the world's most serious health problems especially in Africa, Asia and Latin America with 300-500 Million people infected (WHO, 1997). In the WHO report on Practical Chemotherapy of Malaria of 1990, deaths due to malaria infections was estimated at one Million annually (WHO, 1990). However, presently deaths due to malaria infection in children alone is estimated at over two Million yearly (Watkins et al., 1997). Of the four species of Plasmodium that infect man Plasmodium falciparum causes the most severe form of infection and is becoming increasingly difficult to control due to the development of drug resistance (Olliaro et al., 1996).

Most of the available drugs were developed through synthesis and screening an approach which has proved inefficient and very costly. Out of 250,000 compounds synthesised since the 1970's only mefloquin and halofantrine were eventually developed into antimalarial drug at the cost of over 150 Million $US (Salako, 1985). There being no vaccine in the immediate horizon, chemotherapy and chemoprophylaxis remain the major method of controlling this disease. However with the increase in cases of drug resistance and failure there is an urgent need for new drugs with novel modes of action.

Herbal medicines are considered as a potential source of new drugs or templates for developing new drugs. Some of the most important antimalarial drugs known today were originally obtained from plants. Quinine is obtained from Cinchona species (Phillipson and Wright, 1991; Phillipson, 1994) while the most recent drug to the Western Pharmacopoeia, artemisinin, comes from Artemisia annua; a Chinese traditional febrifuge that has been in use for 2000 years (Klayman et al, 1984; 1985; Trigg, 1985). Recent studies have also revealed a diverse range of plant secondary metabolites with varied levels of antimalarial activity (Nkunya, 1992). Traditional Medicines seem to have offered something in the past. What about today?