In vitro antiplasmodial activity of medicinal plants native to or naturalised in South Africa

Abstract

The increasing prevalence and distribution of malaria has been attributed to a number of factors, one of them being the emergence and spread of drug resistant parasites. Efforts are now being directed towards the discovery and development of new chemically diverse antimalarial agents. The present study reports on the in vitro antiplasmodial activity of 134 plant taxa native to or naturalised in South Africa, representing 54 families, which were selected semi-quantitatively using weighted criteria. The plant extracts were tested for in vitro activity against a Plasmodium falciparum strain D10 using the parasite lactate dehydrogenase (pLDH) assay. Of the 134 species assayed, 49% showed promising antiplasmodial activity (IC(50)< or = 10 microg/ml), while 17% were found to be highly active (IC(50)< or = 5 microg/ml). Several plant species and genera were shown for the first time to possess in vitro antiplasmodial activity. These results support a rational rather than random approach to the selection of antiplasmodial screening candidates, and identify a number of promising taxa for further investigation as plant-based antimalarial agents.

In vitro antiplasmodial screening of ethnopharmacologically selected South African plant species used for the treatment of malaria

“…An ethanol leaf extract from D. cinerea showed no activity at the highest concentration (5 μg/ml) tested (Atindehou, 2004). Results from the current study do not support the relatively low antiplasmodial activity (IC50 ≥ 10 μg/ml) reported previously for R. caffra (Clarkson et al, 2004). Boyom et al (2011) reported on the potency of methanol leaf and stem extracts of X. parviflora from Cameroon.…”

“…Chloroquine-sensitive strain of Although Albizia species are well documented for their strong in vitro as well as in vivo antimalarial activities (Samoylenko et al, 2009), reports on A. versicolor are lacking. Clarkson et al (2004) detected a weak antiplasmodial activity (IC50 = 38 μg/ml) in the dichloromethane root extract C. tomentosa, which is relatively low compared to the results (IC50 = 2.19 μg/ml) found in this study. An ethanol leaf extract from D. cinerea showed no activity at the highest concentration (5 μg/ml) tested (Atindehou, 2004).…”

“…The genus Cussonia has been extensively studied for its antiplasmodial properties, and the polar bark extracts of C. spicata were reported to have a relatively weak activity (De Villiers et al, 2010). Results obtained in this study are consistent with those reported for other members of the same family, when extracted with non-polar solvent (Clarkson et al, 2004). Although most of the investigated plant species have been previously tested against P. falciparum, data on the compounds attributable to their respective antiplasmodial activity is very limited.…”

In vitro inhibition of Plasmodium falciparum early and late stage gametocyte viability by extracts from eight traditionally used South African plant species

“…The subset of eight plant species investigated in this study was selected as follows: Plants were first and foremost chosen for being used traditionally for either malaria or fever treatment as documented in ethnobotanical studies (Alam et al, 2012;Clarkson et al, 2004;Van Wyk, 2008; Table 1). From the ethnobotanical set, plants were selected based on two parallel criteria: 1) previous reports of either good or moderate activity against the intraerythrocytic asexual parasites of P. falciparum parasites (IC 50 ≤10 µg/ml -good;…”

“…The three plant species investigated namely, L. leonurus, L. leonurus ex Hort and Olea europaea (Oleaceae) were selected based on previously reported activity against the intraerythrocytic asexual parasites of P. falciparum (Table 1) (Clarkson et al, 2004). Khaya anthotheca (Meliaceae) was selected as the Meliaceae family, has been shown to produce limonoids that are potent against gametocytes (Jones et al, 1994;Lucantoni et al, 2010;Yerbanga et al, 2014).…”