title: In vitro antiviral activity of plant extracts from Asteraceae medicinal plants.
abstract: BACKGROUND
  Due to the high prevalence of viral infections having no specific treatment and the constant appearance of resistant viral strains, the development of novel antiviral agents is essential. The aim of this study was to evaluate the antiviral activity against bovine viral diarrhea virus, herpes simplex virus type 1 (HSV-1), poliovirus type 2 (PV-2) and vesicular stomatitis virus of organic (OE) and aqueous extracts (AE) from: Baccharis gaudichaudiana, B. spicata, Bidens subalternans, Pluchea sagittalis, Tagetes minuta and Tessaria absinthioides. A characterization of the antiviral activity of B. gaudichaudiana OE and AE and the bioassay-guided fractionation of the former and isolation of one active compound is also reported.
  
  
  METHODS
  The antiviral activity of the OE and AE of the selected plants was evaluated by reduction of the viral cytopathic effect. Active extracts were then assessed by plaque reduction assays. The antiviral activity of the most active extracts was characterized by evaluating their effect on the pretreatment, the virucidal activity and the effect on the adsorption or post-adsorption period of the viral cycle. The bioassay-guided fractionation of B. gaudichaudiana OE was carried out by column chromatography followed by semipreparative high performance liquid chromatography fractionation of the most active fraction and isolation of an active compound. The antiviral activity of this compound was also evaluated by plaque assay.
  
  
  RESULTS
  B. gaudichaudiana and B. spicata OE were active against PV-2 and VSV. T. absinthioides OE was only active against PV-2. The corresponding three AE were active against HSV-1. B. gaudichaudiana extracts (OE and AE) were the most selective ones with selectivity index (SI) values of 10.9 (PV-2) and > 117 (HSV-1). For this reason, both extracts of B. gaudichaudiana were selected to characterize their antiviral effects. Further bioassay-guided fractionation of B. gaudichaudiana OE led to an active fraction, FC (EC50 = 3.1 μg/ml; SI = 37.9), which showed antiviral activity during the first 4 h of the viral replication cycle of PV-2 and from which the flavonoid apigenin (EC50 = 12.2 ± 3.3 μM) was isolated as a major compound.
  
  
  CONCLUSIONS
  The results showed that, among the species studied, B. gaudichaudiana seemed to be the most promising species as a source of antiviral agents.
authors.affiliation: Cátedra de Virología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956, 4ºP, Ciudad de Buenos Aires, 1113, Argentina.
authors.forename: María F
authors.initials: MF
authors.lastname: Visintini Jaime
authors.forename: Flavia
authors.initials: F
authors.lastname: Redko
authors.forename: Liliana V
authors.initials: LV
authors.lastname: Muschietti
authors.forename: Rodolfo H
authors.initials: RH
authors.lastname: Campos
authors.forename: Virginia S
authors.initials: VS
authors.lastname: Martino
authors.forename: Lucia V
authors.initials: LV
authors.lastname: Cavallaro
mesh_terms: D000998:Antiviral Agents / Q000302:isolation & purification / Q000494:pharmacology*; D019659:Asteraceae / Q000737:chemistry*; D002853:Chromatography, Liquid; D003588:Cytopathogenic Effect, Viral / Q000187:drug effects; D004267:DNA Viruses / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D010946:Plants, Medicinal / Q000737:chemistry*; D012328:RNA Viruses / Q000187:drug effects*; D010948:Viral Plaque Assay
chemical_list: D000998:Antiviral Agents; D010936:Plant Extracts
references.citation: Science. 2006 Mar 17;311(5767):1539
references.pmid: 16543427
references.citation: Drug Discov Ther. 2007 Aug;1(1):14-22
references.pmid: 22504360
references.citation: Phytother Res. 1999 Mar;13(2):142-6
references.pmid: 10190189
references.citation: Gen Pharmacol. 1999 Apr;32(4):499-503
references.pmid: 10323492
references.citation: Biol Pharm Bull. 2002 Sep;25(9):1147-50
references.pmid: 12230106
references.citation: Clin Exp Pharmacol Physiol. 2005 Oct;32(10):811-6
references.pmid: 16173941
references.citation: Planta Med. 2002 Mar;68(3):209-12
references.pmid: 11914955
references.citation: J Nat Prod. 1994 Jun;57(6):801-7
references.pmid: 7931367
references.citation: J Pharm Biomed Anal. 2003 Sep 19;33(2):303-8
references.pmid: 12972095
references.citation: J Gen Virol. 1999 Jan;80 ( Pt 1):157-167
references.pmid: 9934698
references.citation: Nat Prod Commun. 2011 Jul;6(7):993-4
references.pmid: 21834241
references.citation: Antiviral Res. 2003 Sep;60(1):1-15
references.pmid: 14516916
references.citation: Antiviral Res. 2013 Jan;97(1):41-8
references.pmid: 23098745
references.citation: Antimicrob Agents Chemother. 2011 Feb;55(2):459-72
references.pmid: 21078929
references.citation: Eur J Med Chem. 2008 Aug;43(8):1767-73
references.pmid: 18063227
references.citation: J Ethnopharmacol. 2004 Jan;90(1):135-43
references.pmid: 14698521
references.citation: Br J Pharmacol. 2006 Jan;147(1):1-11
references.pmid: 16284630
references.citation: Phytother Res. 2003 Nov;17(9):1073-5
references.pmid: 14595590
references.citation: Rev Med Virol. 2013 May;23(3):194-208
references.pmid: 23440920
references.citation: J Ethnopharmacol. 2012 Dec 18;144(3):545-54
references.pmid: 23026306
references.citation: AIDS Res Hum Retroviruses. 1996 Jan 1;12(1):39-46
references.pmid: 8825617
references.citation: J Ethnopharmacol. 1997 May;56(3):227-32
references.pmid: 9201613
references.citation: Chem Pharm Bull (Tokyo). 2003 Feb;51(2):197-9
references.pmid: 12576656