Evaluation of antiplasmodial activity of extracts from endemicmedicinal plants used to treat malaria in Côte d'Ivoire

Plasmodium falciparum strains had been increasingly resistant to commonly used molecules including artemisinin. It is therefore urges to find new therapeutic alternatives.

In this study, the antiplasmodial activity of 21 extracts obtained from seven plants of the Anthocleista djalonensis, Cochlospermum planchonii, Harungana madagascariensis, Hoslundia opposita, Mangifera indica, Margaritaria discoidea and Pericopsis laxiflora of the Ivorian pharmacopoeia was evaluated on the chloroquine sensitive (NF54) and multi-resistant (K1) reference strains and on clinical isolates as well. The technique used was the microtiter method based on fluorescence reading with SYBR Green.

The aqueous extract of the bark of H. madagascariensis and methanolic extracts of P. laxiflora showed the best antiplasmodial activity with IC50 values of 6.16 μg/mL and 7.44 μg/mL, respectively. On the other hand, extracts of M. indica showed a very moderate activity with IC50 values between 15 μg/mL and 50 μg/mL (5<IC50<50 μg/mL) on the same strains of P. falciparum. Only the aqueous extract of A. djalonensis had IC50 values greater than 50 μg/mL. The phytochemical analysis showed a strong presence of polyphenols and alkaloids in extracts with a cumulative rate of 90.47% and 95.23%, respectively.

The results obtained were also justified by the composition of these plants, which have several secondary metabolites involved in the treatment of malaria. The antiplasmodial properties of these plants could partially justify their use in malaria treatment. Further studies on these extracts are needed to manufacture a stable galenic formulation for the development of an improved traditional medicine.