title: Piperaquine and Lumefantrine resistance in Plasmodium berghei ANKA associated with increased expression of Ca2+/H+ antiporter and glutathione associated enzymes.
abstract: We investigated the mechanisms of resistance of two antimalarial drugs piperaquine (PQ) and lumefantrine (LM) using the rodent parasite Plasmodium berghei as a surrogate of the human parasite, Plasmodium falciparum. We analyzed the whole coding sequence of Plasmodium berghei chloroquine resistance transporter (Pbcrt) and Plasmodium berghei multidrug resistance gene 1(Pbmdr-1) for polymorphisms. These genes are associated with quinoline resistance in Plasmodium falciparum. No polymorphic changes were detected in the coding sequences of Pbcrt and Pbmdr1 or in the mRNA transcript levels of Pbmdr1. However, our data demonstrated that PQ and LM resistance is achieved by multiple mechanisms that include elevated mRNA transcript levels of V-type H(+) pumping pyrophosphatase (vp2), Ca(2+)/H(+) antiporter (vcx1), gamma glutamylcysteine synthetase (ggcs) and glutathione-S-transferase (gst) genes, mechanisms also known to contribute to chloroquine resistance in P. falciparum and rodent malaria parasites. The increase in ggcs and gst transcript levels was accompanied by high glutathione (GSH) levels and elevated activity of glutathione-S-transferase (GST) enzyme. Taken together, these results demonstrate that Pbcrt and Pbmdr1 are not associated with PQ and LM resistance in P. berghei ANKA, while vp2, vcx1, ggcs and gst may mediate resistance directly or modulate functional mutations in other unknown genes.
authors.affiliation: Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000-00200, Nairobi, Kenya; KEMRI-Centre for Traditional Medicine and Drug Research, P.O. Box 54840-00200, Nairobi, Kenya. Electronic address: muthuikiboi@gmail.com.
authors.forename: Daniel
authors.initials: D
authors.lastname: Kiboi
authors.affiliation: KEMRI-Centre for Traditional Medicine and Drug Research, P.O. Box 54840-00200, Nairobi, Kenya.
authors.forename: Beatrice
authors.initials: B
authors.lastname: Irungu
authors.affiliation: KEMRI-Centre for Traditional Medicine and Drug Research, P.O. Box 54840-00200, Nairobi, Kenya.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Orwa
authors.affiliation: KEMRI-Centre for Biotechnology Research and Development, P.O. Box 54840-00200, Nairobi, Kenya.
authors.forename: Luna
authors.initials: L
authors.lastname: Kamau
authors.affiliation: KEMRI-Wellcome Trust Research Programme, P.O. Box 230-80108, Kilifi, Kenya.
authors.forename: Lynette Isabella
authors.initials: LI
authors.lastname: Ochola-Oyier
authors.affiliation: Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000-00200, Nairobi, Kenya.
authors.forename: Joseph
authors.initials: J
authors.lastname: Ngángá
authors.affiliation: Department of Chemistry, King Fahd University of Petroleum and Minerals, P.O. Box 468, Dharan 31261, Saudi Arabia.
authors.forename: Alexis
authors.initials: A
authors.lastname: Nzila
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000494:pharmacology*; D017920:Antiporters / Q000235:genetics / Q000378:metabolism*; D027682:Cation Transport Proteins / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D018432:Drug Resistance, Multiple / Q000502:physiology; D004983:Ethanolamines / Q000494:pharmacology*; D005449:Fluorenes / Q000494:pharmacology*; D015971:Gene Expression Regulation, Enzymologic; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D000078102:Lumefantrine; D008297:Male; D051379:Mice; D021261:Parasitic Sensitivity Tests; D010962:Plasmodium berghei / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D011804:Quinolines / Q000494:pharmacology*; D060888:Real-Time Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D010879:Piperazines
chemical_list: D000962:Antimalarials; D017920:Antiporters; D027682:Cation Transport Proteins; D016054:DNA, Protozoan; D004983:Ethanolamines; D005449:Fluorenes; D005978:Glutathione; D005979:Glutathione Peroxidase; D005980:Glutathione Reductase; D005982:Glutathione Transferase; D000078102:Lumefantrine; D011804:Quinolines; C027614:calcium-hydrogen antiporters; C034759:piperaquine; D010879:Piperazines
keywords: Lumefantrine; Malaria; Piperaquine; Plasmodium berghei; Resistance