title: Anti-malarial activity of some xanthones isolated from the roots of Andrographis paniculata.
abstract: Four xanthones were isolated from the roots of Andrographis paniculata using a combination of column and thin-layer chromatographic methods. They were characterized as (i) 1,8-di-hydroxy-3,7-dimethoxy-xanthone, (ii) 4,8-dihydroxy-2,7-dimethoxy-xanthone, (iii) 1,2-dihydroxy-6,8-dimethoxy-xanthone and (iv) 3,7,8-trimethoxy-1-hydroxy xanthone by IR, MS and NMR spectroscopic methods. In vitro study revealed that compound 1,2-dihydroxy-6,8-dimethoxy-xanthone possessed substantial anti-plasmodial activity against Plasmodium falciparum with its IC(50) value of 4 microg ml(-1). Xanthones bearing hydroxyl group at 2 position demonstrated most potent activity while xanthones with hydroxyl group at 1,4 or 8 position possessed very low activity. In vivo anti-malarial sensitivity test of this compound on Swiss Albino mice with Plasmodium berghei infection using Peters' 4-day test gave substantial reduction (62%) in parasitaemia after treating the mice with 30 mg kg(-1) dose. In vitro cytotoxicity against mammalian cells revealed that 1,2-dihydroxy-6,8-dimethoxy-xanthone is non-cytotoxic with its IC(50) > 32 microg ml(-1).
authors.affiliation: Malaria Research Centre, Sector III, BHEL, Hardwar 249 403, India. virendradua@hotmail.com
authors.forename: V K
authors.initials: VK
authors.lastname: Dua
authors.forename: V P
authors.initials: VP
authors.lastname: Ojha
authors.forename: R
authors.initials: R
authors.lastname: Roy
authors.forename: B C
authors.initials: BC
authors.lastname: Joshi
authors.forename: N
authors.initials: N
authors.lastname: Valecha
authors.forename: C Usha
authors.initials: CU
authors.lastname: Devi
authors.forename: M C
authors.initials: MC
authors.lastname: Bhatnagar
authors.forename: V P
authors.initials: VP
authors.lastname: Sharma
authors.forename: S K
authors.initials: SK
authors.lastname: Subbarao
mesh_terms: D035685:Andrographis; D000818:Animals; D000962:Antimalarials / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D006801:Humans; D051379:Mice; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D018517:Plant Roots; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000502:physiology; D044004:Xanthones / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D000962:Antimalarials; D010936:Plant Extracts; D044004:Xanthones