From ethnopharmacology to laboratory results: does discrepancy mean irrelevancy?

Résumé 0

Since 1992, our research team (a combination of bolivian and french researchers) is working on the problematic of the evaluation of the biological activity of plants used traditionally in different Bolivian ethnias (Chacobo, Mosetene, Alteños, Tacana). Species retained have been screened against malaria, in vitro and on the animal. More than 200 different species have been evaluated, and only a weak percentage did show a strong correlation between uses and biological results. These discrepancies can be explained by different considerations:Firstly, the difficulties related with the interpretation of the traditional use of plants, generally presented as usefull for aleviate different symptoms, more or less related with a malarial attack. The criterium to select the plant has to be discussed. Also, different successive treatments are administered to the patient until he cures. Synergism effects could be responsible for the antimalarial activity and the method to study this type of effect has to be invented.Then, the traditional way of using medicinal plant (preparation, administration) cannot always be taken into account in the screening test performed in the laboratory: therefore the in vivo inactivity of extracts may be correlated with the way of administration, having a strong perturbating effect on the absorption rate, delivery process, metabolisation process. The laboratory tests have difficulties to mesure the part of acquired human immunity, etc. The validity and accuracy of the antimalarial screening test aimed to evidenciate antimalarial agents from plant extract will be discussed.