title: Chemical properties, mode of action, and in vivo anti-herpes activities of a lignin-carbohydrate complex from Prunella vulgaris.
abstract: The chemical nature, the mode of action, and the in vitro and in vivo anti-HSV activities of the polysaccharide from Prunella vulgaris were characterized. The polysaccharide was isolated by ethanol precipitation, dialysis, CTAB precipitation, and gel exclusion chromatography. The isolated compound (PPS-2b) was a lignin-carbohydrate complex with a molecular weight of 8500. The carbohydrate moiety was composed of glucose, galactose, mannose, galacturonic acid, rhamnose, xylose, and arabinose with glucose as the major sugar. In plaque reduction assay, PPS-2b showed activities against HSV-1 and HSV-2. The anti-HSV activity could be abolished by periodate oxidation. Mechanism studies showed that PPS-2b inactivated HSV-1 directly, blocked HSV-1 binding to Vero cells, and inhibited HSV-1 penetration into Vero cells. A similar inhibition was observed with a gC-deficient strain of HSV-1. The in vivo activities of a Prunella cream formulated with a semi-purified fraction was assessed in a HSV-1 skin lesion model in guinea pigs and a HSV-2 genital infection model in BALB/c mice. Guinea pigs that received the Prunella cream treatment showed a significant reduction (P<0.01) in skin lesions. Mice that received the Prunella cream treatment showed a significant reduction (P<0.01) in mortality. In conclusion, the anti-HSV compound from P. vulgaris is a lignin-polysaccharide complex with potent activity against HSV-1 and HSV-2. Its mode of action appears to be inhibiting viral binding and penetration into host cells.
authors.affiliation: Department of Biology and Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, PR China.
authors.forename: Yongwen
authors.initials: Y
authors.lastname: Zhang
authors.forename: Paul Pui-Hay
authors.initials: PP
authors.lastname: But
authors.forename: Vincent Eng-Choon
authors.initials: VE
authors.lastname: Ooi
authors.forename: Hong-Xi
authors.initials: HX
authors.lastname: Xu
authors.forename: Gillian D
authors.initials: GD
authors.lastname: Delaney
authors.forename: Spencer H S
authors.initials: SH
authors.lastname: Lee
authors.forename: Song F
authors.initials: SF
authors.lastname: Lee
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology / Q000627:therapeutic use* / Q000633:toxicity; D002522:Chlorocebus aethiops; D005260:Female; D006168:Guinea Pigs; D006558:Herpes Genitalis / Q000188:drug therapy; D006561:Herpes Simplex / Q000188:drug therapy*; D018259:Herpesvirus 1, Human / Q000187:drug effects*; D018258:Herpesvirus 2, Human / Q000187:drug effects*; D008031:Lignin / Q000494:pharmacology / Q000627:therapeutic use; D051379:Mice; D008807:Mice, Inbred BALB C; D008517:Phytotherapy; D010936:Plant Extracts / Q000627:therapeutic use; D011134:Polysaccharides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use*; D031347:Prunella; D014709:Vero Cells
chemical_list: D000998:Antiviral Agents; D010936:Plant Extracts; D011134:Polysaccharides; D008031:Lignin