Anti-plasmodial activity of Norcaesalpin D and extracts of four medicinal plants used traditionally for treatment of malaria.
BACKGROUND
Malaria is an old life-threatening parasitic disease that is still affecting many people, mainly children living in sub-Saharan Africa. Availability of effective antimalarial drugs played a significant role in the treatment and control of malaria. However, recent information on the emergence of P. falciparum parasites resistant to one of the artemisinin-based combination therapies suggests the need for discovery of new drug molecules. Therefore, this study aimed to evaluate the antiplasmodial activity of extracts, fractions and isolated compound from medicinal plants traditionally used in the treatment of malaria in Tanzania.


METHODS
Dry powdered plant materials were extracted by cold macerations using different solvents. Norcaesalpin D was isolated by column chromatography from dichloromethane root extract of Caesalpinia bonducella and its structure was assigned based on the spectral data. Crude extracts, fractions and isolated compound were evaluated for antiplasmodial activity against chloroquine-sensitive P. falciparum (3D7), chloroquine-resistant P. falciparum (Dd2, K1) and artemisinin-resistant P. falciparum (IPC 5202 Battambang, IPC 4912 Mondolkiri) strains using the parasite lactate dehydrogenase assay.


RESULTS
The results indicated that extracts of Erythrina schliebenii, Holarrhena pubescens, Dissotis melleri and C. bonducella exhibited antiplasmodial activity against Dd2 parasites. Ethanolic root extract of E. schliebenii had an IC50of 1.87 μg/mL while methanolic and ethanolic root extracts of H. pubescens exhibited an IC50= 2.05 μg/mL and IC50= 2.43 μg/mL, respectively. Fractions from H. pubescens and C. bonducella roots were found to be highly active against K1, Dd2 and artemisinin-resistant parasites. Norcaesalpin D from C. bonducella root extract was active with IC50of 0.98, 1.85 and 2.13 μg/mL against 3D7, Dd2 and IPC 4912-Mondolkiri parasites, respectively.


CONCLUSIONS
Antiplasmodial activity of norcaesalpin D and extracts of E. schliebenii, H. pubescens, D. melleri and C. bonducella reported in this study requires further attention for the discovery of antimalarial lead compounds for future drug development.
Department of Biological and Pre-Clinical Studies, Institute of Traditional Medicine, Muhimbili University of Health and Allied Sciences, P.O.Box 65001, Dar es Salaam, Tanzania. rnondo@muhas.ac.tz.
Ramadhani Selemani Omari
RS
Nondo
Department of Biological and Pre-Clinical Studies, Institute of Traditional Medicine, Muhimbili University of Health and Allied Sciences, P.O.Box 65001, Dar es Salaam, Tanzania.
Mainen Julius
MJ
Moshi
National Institute for Medical Research, P.O.Box 9653, Dar es Salaam, Tanzania.
Paul
P
Erasto
Department of Biological and Pre-Clinical Studies, Institute of Traditional Medicine, Muhimbili University of Health and Allied Sciences, P.O.Box 65001, Dar es Salaam, Tanzania.
Pax Jessey
PJ
Masimba
Department of Natural Products Development and Formulation, Institute of Traditional Medicine, Muhimbili University of Health and Allied Sciences, P.O.Box 65001, Dar es Salaam, Tanzania.
Francis
F
Machumi
Department of Natural Products Development and Formulation, Institute of Traditional Medicine, Muhimbili University of Health and Allied Sciences, P.O.Box 65001, Dar es Salaam, Tanzania.
Abdul Waziri
AW
Kidukuli
Institut für Chemie, Universität Potsdam, Karl-Liebknecht, Str. 24-25, 14476, Golm, Germany.
Matthias
M
Heydenreich
Biotechnology Unit, University of Buea, P.O.Box 63, Buea, South West Region, Cameroon.
Denis
D
Zofou
D000962:Antimalarials / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D006801:Humans; D008288:Malaria / Q000188:drug therapy / Q000469:parasitology*; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D010946:Plants, Medicinal / Q000737:chemistry*; D010963:Plasmodium falciparum / Q000187:drug effects / Q000502:physiology; D013636:Tanzania
D000962:Antimalarials; D004224:Diterpenes; D010936:Plant Extracts; C000617631:norcaesalpin D
Antiplasmodial; C. bonducella; D. melleri; E. schliebenii; H. pubescens; norcaesalpin D