title: Ethnopharmacology guided screening of traditional Indian herbs for selective inhibition of Plasmodium specific lactate dehydrogenase.
abstract: BACKGROUND
  Medicinal plants traditionally used to treat malaria can provide quality leads towards identifying novel anti-malarial drugs. Here we combined this approach with target based drug discovery and explored Plasmodium specific lactate dehydrogenase (LDH) inhibitory activity of 8 Indian plants which are ethnically used to treat malaria.
  
  
  METHODS
  LDH from Indian Plasmodium falciparum and Plasmodium vivax strains, were cloned and expressed in Escherichia coli, followed by purification of recombinant enzymes (rPfLDH and rPvLDH respectively). Extracts of 8 plants in different organic and aqueous solvents, were screened for their inhibitory activity on rPfLDH, rPvLDH and mammalian LDHs. Phyllanthus amarus aqueous extract was further tested for in vitro parasiticidal activity.
  
  
  RESULTS
  Aqueous extract of Phyllanthus amarus Schum. and Thonn. and chloroform extract of Murraya koenigii (L.) Spreng. exhibited profound and exclusive inhibitory effect on Plasmodium falciparum LDH (IC(50)=11.2 μg/ml ± 0.4) and Plasmodium vivax LDH (IC(50)=6.0 μg/ml ± 0.6) respectively. Moreover, Phyllanthus amarus aqueous extract also demonstrated antiplasmodial activity in vitro, on Chloroquine sensitive and resistant strains of Plasmodium falciparum (IC(50)=7.1 μg/ml ± 0.5 and 6.9 μg/ml ± 0.7 respectively).
  
  
  CONCLUSIONS
  Target specific screening of traditional herbs used in malaria treatment has proffered Phyllanthus amarus and Murraya koenigii extracts as hits which can optimistically provide novel antimalarial drugs.
authors.affiliation: Department of Microbiology and Biotechnology Centre, Faculty of Science, M. S. University of Baroda, Vadodara 390002, India.
authors.forename: Priyadarshan
authors.initials: P
authors.lastname: Keluskar
authors.forename: Sanjay
authors.initials: S
authors.lastname: Ingle
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000494:pharmacology*; D002417:Cattle; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007194:India; D007770:L-Lactate Dehydrogenase / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D008519:Medicine, Traditional; D032101:Murraya; D009132:Muscles / Q000201:enzymology; D029803:Phyllanthus; D035261:Plant Components, Aerial; D010936:Plant Extracts / Q000494:pharmacology*; D010946:Plants, Medicinal; D010963:Plasmodium falciparum / Q000201:enzymology; D010966:Plasmodium vivax / Q000201:enzymology; D015800:Protozoan Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D000962:Antimalarials; D004791:Enzyme Inhibitors; D010936:Plant Extracts; D015800:Protozoan Proteins; D011994:Recombinant Proteins; D007770:L-Lactate Dehydrogenase