Abstract

UPLC-ESI-QTOF-MS/MS PREDICTION AND IN VITRO ANTIPLASMODIAL ACTIVITY OF ETHANOLIC EXTRACTS OF DIFFERENTS PARTS OF SPATHODEA CAMPANULATA P. BEAUV. (BIGNONIACEAE)

Jean Emmanuel Mbosso Teinkela*, Hassan Oumarou, Edwige Laure Nguemfo, Thierry Fokou Nzodjou, Noella Molisa Efange, Lawrence Ayong and Carole Else Eboumbou Moukoko

Abstract

Malaria remains the first medical concern and a public health problem in many countries of the world, including Cameroon, where almost the entire population is exposed to the risk of infection. Given the presence of Plasmodium strains resistant to artemisinin derivatives reported in Southeast Asia and its emergence in East Africa, new strategies oriented towards the discovery of new antimalarial molecules are necessary and particularly urgent in an unfavorable economic and social context. Apart from conventional molecules, pharmacopoeia and traditional Cameroonian medicine constitute frequent recourses in the management of malaria by families. The objective of this work was to study the antiplasmodial activity of different organs of the plant Spathodea campanulata P. Beauv., also called tulip tree of Gabon, a tree used in traditional medicine in the management of malaria. Phytochemical screening was carried out on the various ethanolic extracts obtained from the plant (flowers, leaves, branches, stem bark, roots) with the aim of identifying the various groups of secondary metabolites. Analysis by Ultra Performance Liquid Chromatography coupled with Mass Spectrometry (UPLC-MS) was carried out in order to identify the secondary metabolites present. The determination of the antiplasmodial activity of the extracts of Spathodea campanulata was carried out in vitro on the multiresistant strain Pf Dd2 by measuring the growth of the parasites in the microtiter plates based on the reading of DNA fluorescence at the SYBER Green 1. Artemisinin and chloroquine were chosen as the reference antiplasmodial. The phytochemical profile of the extracts of the different organs (flowers, leaves, branches, stem bark, roots) showed the presence of sterols, polyphenols, saponins, polyterpenes and flavonoids. UPLC-MS analysis enabled us to identify in the different parts of Spathodea campanulata, 10 compounds: cinnamic acid, β- sistosterol, quercetin, naringinin, catechin, loganic acid, β-sitosterol 3-O-β-Dglucopyranoside, syringic acid and n-hexadecanoic acid (palmitic acid). The study of the antiplasmodial activity showed that the ethanolic extract of the leaves and stem bark at 10 μg/ml reduced the viability of the Pf Dd2 strains with values of IC50 at 93.68 μg/ml and 79.68 μg/ml respectively. Chloroquine and artemisinin gave IC50s of 0.2953 and 0.02867 μg/ml respectively. It emerges from this study that only the leaves and stem bark of S. campanulata would present a weak activity on the PfDd2 strain, with the stem bark as the most active part. The abundance of polyphenolic compounds and the antiplasmodial activity of ethanolic extracts of leaves and stem bark of S. campanulata could confirm their good potential therapeutic properties attributed in the traditional pharmacopoeia to cure malaria.

Keywords: Spathodea campanulata, phytochemical screening, UPLC-MS/MS, antiplasmodial activity.