Antimalarial activity of 20 crude extracts from nine African medicinal plants used in Kinshasa, Congo.

Twenty extracts including ten EtOH and ten CH2Cl2 from different parts of nine African medicinal plants used in Congolese traditional medicine for the treatment of malaria, were submitted to a pharmacological test in order to evaluate their effect on P. falciparum growth in vitro. Of these plant species, 14 (70%) extracts including EtOH and CH2Cl2 from Cassia occidentalis leaves, Cryptolepis sanguinolenta root bark, Euphorbia hirta whole plant, Garcinia kola stem bark and seeds, Morinda lucida leaves and Phyllanthus niruri whole plant produced more than 60% inhibition of the parasite growth in vitro at a test concentration of 6 microg/ml. Extracts from E. hirta, C. sanguinolenta and M. morindoides showed a significant chemosuppression of parasitaemia in mice infected with P. berghei berghei at orally given doses of 100-400 mg/kg per day.

[New antimalarial sustained-release formulations based on bioresorbable polymers: therapeutic evaluation using the Plasmodium berghei model]. / Nouvelles formulations antipaludiques à action prolongée à base de polymères biorésorbables: évaluation thérapeutique sur le modèle de plasmodium berghei.

Chemotherapy keeps an important place in malaria control programme. The development of schizonticidal formulations, which may maintain their efficacy for at least one month after single administration, becomes needful. These formulations should allow to assure a suitable patient compliance and to avoid the disadvantages of high plasmatic peaks. The aim of this study is to evaluate the therapeutic efficacy of implantable bioresorbable reservoir-forms. The use of these polymers allow to avoid the surgical extraction of implanted preparations. Two drug delivery systems were prepared: microspheres and rods. Pyrimethamine, as a drug model was incorporated. Therapeutic activity of these preparations was evaluated on a TB mice-Plasmodium berghei model. Polycaprolactone and polylactide 100 microspheres are not suitable for long-term treatment. In contrast, implantable subdermic rods allowed to fulfil the long-term coverage requirements. Their activity depend on the administered dose and the drug content in implants. Polycaprolactone, polylactide 100 and polylactide 50 implants containing respectively 21.5%, 19-40% of pyrimethamine have protected animals for at least three months.

[In vitro study of the adsorption of chloroquine by an antidiarrheal remedy traditionally used in Africa]. / Etude in vitro de l'adsorption de la chloroquine par un remède antidiarrhéique employé traditionnellement en Afrique.

Mouboumou is a traditional medicine prepared from the inner part of termitarium and is used in traditional medicine in Zaire. In tropical diseases, antimalarial drugs are often used simultaneously with antidiarrheal absorbent drugs, which might, by their adsorbent properties, compromise the efficacy of the antimalarial treatment. The present in vitro study has allowed to determine the adsorption characteristics of chloroquine on Mouboumou; kaopectate was used a reference adsorbent. The adsorption of chloroquine by these two adsorbents is very important (from 30 to 60%) and fits quite well in with the Langmuir's relation. A decrease of bioavailability of chloroquine, due to the adsorption phenomena, might be observed in vivo and could contraindicate the concomitant administration of these drugs.