In vitro antiplasmodial activity and cytotoxicity of ethnobotanically selected South African plants

135

Ethanol extracts of eight plant species used traditionally in South Africa for the treatment of oral diseases were investigated for in vitro antimicrobial activity against oral pathogens namely Actinobacillus actinomycetemcomitans, Actinomyces naeslundii, Actinomyces israelii, Candida albicans, Porphyromonus gingivalis, Privotella intermedia and Streptococcus mutans using the disk diffusion method. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of ethanol extracts were determined against these microorganisms using micro dilution. The cytotoxicity and therapeutic index (TI) of selected active extracts were also determined. Out of eight plants, six (Annona senegalensis, Englerophytum magalismontanum, Dicerocarym senecioides, Euclea divinorum, Euclea natalensis, Solanum panduriforme and Parinari curatellifolia) exhibited MIC values ranging from 25.0 mg/ml to 0.8 mg/ml. Gram negative bacteria were found to be more resistant to the plant extracts than Gram positive bacteria, except for Euclea natalensis which inhibited all three Gram negative bacteria tested in this study. All plant extracts showed moderate cytotoxicity on the Vero cell line. The fifty percent inhibitory concentration (IC50) of all plants tested range from 92.3 to 285.1 g/ml.

Section: Resultsmentioning

confidence: 93%

Antimicrobial activity of medicinal plants against oral microorganisms

Tshikalange

Lall

et al. 2008

135

“…emetica subsp. suberosa) was active (El Tahir et al, 1999;Traore-Keita et al, 2000;Prozesky et al, 2001). Our studies analysed for the first time the in vitro activity of P. laxiflora and C. sieberiana on trypanosomes, leishmania and mammalian cells.…”

Section: Discussionmentioning

confidence: 91%

In vitro antitrypanosomal activity of ethnopharmacologically selected Beninese plants

Hoet

Opperdoes

Brun

et al. 2004

The in vitro antitrypanosomal activity of methylene chloride, methanol and aqueous extracts of the leaves and twigs of five plant species traditionally used in Benin for the treatment of sleeping sickness were evaluated on Trypanosoma brucei brucei and their selectivity was analysed on Leishmania mexicana mexicana and J774 macrophage-like murine cells. The results showed that the four most active extracts had MIC values ≤19 g/ml (Hymenocardia acida twig and leaf, Strychnos spinosa leaf, Trichilia emetica leaf methylene chloride extracts).All these extracts had a lower activity on L. m. mexicana and J774 cells. Determination of the IC 50 values of the methylene chloride leaf extracts on two strains of trypanosomes (T. b. brucei and T. b. rhodesiense) and two mammalian cell lines (L6 and J774 cells) showed that all extracts possessed some antitrypanosomal activity with IC 50 's ranging from 1.5 to 39 g/ml. All were also toxic to the mammalian cells, but usually with higher IC 50 's. The only exception was the S. spinosa methylene chloride leaf extract which had no toxicity on J774 cells. Although tannins have been identified in most of the species studied, they could not be detected in the most active extracts, just as alkaloids. The presence of flavonoids and quinones may at least in part explain the observed activities of some of the active extracts.

“…americanum (Lamiaceae) (Vieira et al, 2003), there are no reports on their antiplasmodial activity. Several representatives Croton pseudopulchellus Pax has shown in vitro activity (Prozesky et al, 2001) Croton menyhartii 1.7…”

Section: Resultsmentioning

confidence: 99%

“…Croton (Euphorbiaceae) (Prozesky et al, 2001), Acacia (Fabaceae) (El Tahir et al, 1999b), Hypericum (Clusiaceae) (Decosterd et al, 1991;Gu et al, 1988), Triumfetta (Tiliaceae) (Muñoz et al, 2000) and Vernonia (Asteraceae) (Abosi and Raseroka, 2003;Kraft et al, 2003;Oketch-Rabah et al, 1998;Alves et al, 1997)) have previously been shown to have antiplasmodial activity. In addition to identifying further species within these genera that display activity, our findings are substantiated by earlier reported antiplasmodial activity elsewhere in the genera.…”

Section: Vernonia Myrianthamentioning

confidence: 99%

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

CLARKSON¹

2004

107

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 ≤ 10 g/ml), while 17% were found to be highly active (IC 50 ≤ 5 g/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.