Echinacea purpurea polysaccharide reduces the latency rate in herpes simplex virus type-1 infections

Intervirology. 2009;52(1):29-34. doi: 10.1159/000212988. Epub 2009 Apr 17.


Objective: During the latency period of herpes simplex virus type-1 (HSV-1), the virus can occasionally reactivate, travel back to the eye and cause recurrent ocular disease. As this condition arises from the ability of HSV-1 to produce a dormant infection, effective medication to prevent the virus enter a latent state should prevent it. In this study, we applied Echinacea polysaccharide (EP) fraction as prophylactic mediator for latency prevention.

Methods: In order to investigate the protective properties of EP, we evaluated its immunostimulatory functions on different immune aspects that play important roles in latency prevention (particularly IFN-gamma as one of the main indicators of cellular immunity and latency). Finally, we assessed establishment of latency by detection of thymidine kinase gene in trigeminal ganglia of BALB/c mice.

Results: We demonstrated that EP promotes immune response, leading to a reduced latency rate, and it has a promising effect on latency prevention.

Conclusion: EP was able to exert an antiviral action on the development of recurrent HSV-1 disease when supplied prior to infection.

MeSH terms

  • Animals
  • Corneal Diseases / drug therapy
  • Corneal Diseases / virology
  • DNA, Viral / isolation & purification
  • Echinacea*
  • Female
  • Herpes Simplex / drug therapy*
  • Herpes Simplex / immunology
  • Herpes Simplex / virology
  • Herpesvirus 1, Human / drug effects*
  • Herpesvirus 1, Human / physiology
  • Humans
  • Interferon-gamma / metabolism
  • Lymphocyte Activation / drug effects
  • Mice
  • Phytotherapy*
  • Plant Extracts / therapeutic use*
  • T-Lymphocytes / drug effects
  • T-Lymphocytes / immunology
  • T-Lymphocytes / metabolism
  • Thymidine Kinase / genetics
  • Trigeminal Nerve / virology
  • Virus Latency / drug effects*


  • DNA, Viral
  • Plant Extracts
  • Interferon-gamma
  • Thymidine Kinase