Antimalarial, antiplasmodial and analgesic activities of root extract of Alchornea laxiflora.
BACKGROUND
Alchornea laxiflora (Benth.) Pax. & Hoffman (Euphorbiaceae) root decoctions are traditionally used in the treatment of malaria and pain in Nigeria.


OBJECTIVE
To assess the antimalarial, antiplasmodial and analgesic potentials of root extract and fractions against malarial infections and chemically-induced pains.


METHODS
The root extract and fractions of Alchornea laxiflora were investigated for antimalarial activity against Plasmodium berghei infection in mice, antiplasmodial activity against chloroquine sensitive (Pf 3D7) and resistant (Pf INDO) strains of Plasmodium falciparum using SYBR green assay method and analgesic activity against experimentally-induced pain models. Acute toxicity study of the extract, cytotoxic activity against HeLa cells and GCMS analysis of the active fraction were carried out.


RESULTS
The root extract (75-225 mg/kg, p.o.) with LD50of 748.33 mg/kg exerted significant (p < 0.05-0.001) antimalarial activity against P. berghei infection in suppressive, prophylactive and curative tests. The root extract and fractions also exerted moderate activity against chloroquine sensitive (Pf 3D7) and resistant (Pf INDO) strains of P. falciparum with the ethyl acetate fraction exerting the highest activity with IC50value of 38.44 ± 0.89 μg/mL (Pf 3D7) and 40.17 ± 0.78 μg/mL (Pf INDO). The crude extract was not cytotoxic to HeLa cells with LC50value >100 μg/mL. The crude extract and ethyl acetate fraction exerted significant (p < 0.05-0.001) analgesic activity in all pain models used.


CONCLUSIONS
These results suggest that the root extract/fractions of A. laxiflora possess antimalarial, antiplasmodial and analgesic potentials and these justify its use in ethnomedicine to treat malaria and pain.
a Department of Pharmacology and Toxicology, Faculty of Pharmacy , University of Uyo , Uyo , Nigeria.|b Malaria Research Laboratory, International Centre for Genetic Engineering and Biotechnology , Aruna Asaf Ali Marg , New Delhi , India.
Jude E
JE
Okokon
a Department of Pharmacology and Toxicology, Faculty of Pharmacy , University of Uyo , Uyo , Nigeria.
Nkemnele Bensella
NB
Augustine
b Malaria Research Laboratory, International Centre for Genetic Engineering and Biotechnology , Aruna Asaf Ali Marg , New Delhi , India.
Dinesh
D
Mohanakrishnan
D000700:Analgesics / Q000494:pharmacology*; D000818:Animals; D000962:Antimalarials / Q000494:pharmacology*; D019665:Euphorbiaceae / Q000737:chemistry; D005260:Female; D008297:Male; D051379:Mice; D010936:Plant Extracts / Q000494:pharmacology*; D018517:Plant Roots / Q000737:chemistry; D010962:Plasmodium berghei / Q000187:drug effects*; D010963:Plasmodium falciparum / Q000187:drug effects*
D000700:Analgesics; D000962:Antimalarials; D010936:Plant Extracts
Antinociceptive; P. berghei; Plasmodium falciparum; malaria