Antimalarial actions of Lawsonia inermis, Tithonia diversifolia and Chromolaena odorata in combination.
BACKGROUND
Chromolaena odorata, Tithonia diversifolia and Lawsonia inermis are medicinal plants used in treating malaria in traditional medicine system. Previous studies however showed that their dichloromethane, methanol (1:1) extracts were more active against Plasmodium parasite than the aqueous extracts.


OBJECTIVE
To determine the in vitro and in vivo antiplasmodial activity of dichloromethane, methanol (1:1) extracts of Chromolaena odorata, Tithonia diversifolia and Lawsonia inermis in combination and evaluate their safety using acute limit toxicity test.


METHODS
Dichloromethane, methanol (1:1) extracts of Chromolaena odorata, Tithonia diversifolia and Lawsonia inermis leaves were combined at ratios 1:1, 1:3, 3:1, 1:5 and 5:1 using in vitro semi-automated microdilution technique against P. falciparum Chloroquine sensitive (D6) and Chloroquine resistant (W2) strains, with chloroquine and artemisinin as controls. The in vivo antiplasmodial activity of the crude extracts was carried out singly, and in combination at the different combination ratios on Plasmodium berghei Anka infected Swiss albino mice using Peters' 4-day suppressive test. Acute toxicity test was done in mice at 5000mg/kg.


RESULTS
The in vitro combination of L. inermis and T. diversifolia (1:1) extracts against P. falciparum showed the highest synergy with IC50 of 0.43±0.02µg/mL and 2.55±0.19µg/mL against D6 and W2 respectively; while the combination of C. odorata with T. diversifolia and L. inermis were antagonistic. A synergy with chemosuppression of 83.6% against P. berghei infected mice was observed in L. inermis and T. diversifolia (1:1) treated animals. In contrast to the in vitro result, combination of C. odorata with T. diversifolia and L. inermis showed some degrees of synergy in vivo. Extracts were not toxic at the concentration tested.


CONCLUSIONS
These findings rationalized the use of these plants in combination as antimalarials in traditional medicine. However, the combination of Chromolaena odorata with other medicinal plants should be used with caution because of its possible antagonistic effect.
Department of Zoology, University of Ibadan, Ibadan, Nigeria; Centre for Traditional Medicine and Drugs Research, Kenya Medical Research Institute, (KEMRI), P.O. Box 54840 00200, Nairobi, Kenya. Electronic address: fidifede@gmail.com.
Funmilayo I D
FID
Afolayan
Department of Pharmaceutical Chemistry, University of Ibadan, Ibadan, Nigeria. Electronic address: duplag03@yahoo.com.
Olayemi M
OM
Adegbolagun
Centre for Traditional Medicine and Drugs Research, Kenya Medical Research Institute, (KEMRI), P.O. Box 54840 00200, Nairobi, Kenya. Electronic address: birungu@yahoo.com.
Beatrice
B
Irungu
Centre for Biotechnology and Research Development, Kenya Medical Research Institute, (KEMRI), P.O. Box 54840 00200, Nairobi, Kenya. Electronic address: lkangethe@gmail.com.
Lucy
L
Kangethe
Centre for Traditional Medicine and Drugs Research, Kenya Medical Research Institute, (KEMRI), P.O. Box 54840 00200, Nairobi, Kenya. Electronic address: JOrwa@kemri.org.
Jennifer
J
Orwa
Department of Zoology, University of Ibadan, Ibadan, Nigeria. Electronic address: cianumudu@yahoo.com.
Chiaka I
CI
Anumudu
D000818:Animals; D000962:Antimalarials / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D019659:Asteraceae / Q000737:chemistry* / Q000633:toxicity; D036604:Chromolaena / Q000737:chemistry* / Q000633:toxicity; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004351:Drug Resistance; D004357:Drug Synergism; D004359:Drug Therapy, Combination; D031564:Lawsonia Plant / Q000737:chemistry* / Q000633:toxicity; D008288:Malaria / Q000188:drug therapy* / Q000469:parasitology; D000432:Methanol / Q000737:chemistry; D008752:Methylene Chloride / Q000737:chemistry; D051379:Mice; D021261:Parasitic Sensitivity Tests; D008517:Phytotherapy; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D018515:Plant Leaves / Q000737:chemistry; D010946:Plants, Medicinal; D010962:Plasmodium berghei / Q000187:drug effects* / Q000254:growth & development; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000254:growth & development; D012997:Solvents / Q000737:chemistry; D013997:Time Factors
D000962:Antimalarials; D010936:Plant Extracts; D012997:Solvents; D008752:Methylene Chloride; D000432:Methanol
Antiplasmodial; Chromolaena odorata; Combination; Lawsonia inermis; Tithonia diversifolia