Chemical properties, mode of action, and in vivo anti-herpes activities of a lignin-carbohydrate complex from Prunella vulgaris

Antiviral Res. 2007 Sep;75(3):242-9. doi: 10.1016/j.antiviral.2007.03.010. Epub 2007 Apr 17.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antiviral Agents / pharmacology
  • Antiviral Agents / therapeutic use*
  • Antiviral Agents / toxicity
  • Chlorocebus aethiops
  • Female
  • Guinea Pigs
  • Herpes Genitalis / drug therapy
  • Herpes Simplex / drug therapy*
  • Herpesvirus 1, Human / drug effects*
  • Herpesvirus 2, Human / drug effects*
  • Lignin / pharmacology
  • Lignin / therapeutic use
  • Mice
  • Mice, Inbred BALB C
  • Phytotherapy
  • Plant Extracts / therapeutic use
  • Polysaccharides / chemistry
  • Polysaccharides / isolation & purification
  • Polysaccharides / pharmacology
  • Polysaccharides / therapeutic use*
  • Prunella*
  • Vero Cells

Substances

  • Antiviral Agents
  • Plant Extracts
  • Polysaccharides
  • Lignin