Anti-herpes simplex virus effect of an aqueous extract of propolis.
BACKGROUND
Propolis, a natural product from beehives, comprises a complex of chemicals, the most important group being flavinoids, which play a role in antiviral protection.


OBJECTIVE
To test the inhibitory effect of propolis extract against herpes simplex viruses in vitro and in vivo.


METHODS
In vitro: propolis was added to Vero cells at various times and concentrations before, at or after infection with HSV-1. In vivo: the effect of propolis was tested in newborn rats infected s.c. or i.p. and on rabbit come as infected with HSV-1.


RESULTS
In vitro: 0.5% propolis extract caused 50% inhibition of HSV infection. There was indirect evidence for a strong interaction between the propolis extract and the surface of the Vero cells, but there was no direct interaction with HSV-1 particles. Administration of propolis before or at the time of infection yielded the most significant inhibitory effect, but even when 10% propolis extract was added 2 hours post-infection it gave 80-85% protection. In vivo: as little as 5% propolis prevented the appearance and development of symptoms of local and i.p. HSV-1 infection in rats and of corneal HSV-1 infection in rabbits. There were no cytotoxic effects at a concentration of 10% in vitro or 20% in vivo.


CONCLUSIONS
The potent antiviral activity of propolis against HSV-1 infection in vitro and In vivo is probably due to prevention of virus absorption into the host cells and/or inhibition of an internal step(s) during the viral replication cycle.
Huleihel
Mahmoud
M
Institute for Applied Biosciences, Ben-Gurion University of the Negev, Beer Sheva, Israel. mahmoudh@bgumail.bgu.ac.il
Isanu
Vladimir
V
D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D004195:Disease Models, Animal; D004353:Drug Evaluation, Preclinical; D005419:Flavonoids / Q000494:pharmacology / Q000627:therapeutic use; D006561:Herpes Simplex / Q000188:drug therapy*; D008297:Male; D008517:Phytotherapy / Q000379:methods*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D011429:Propolis / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D011817:Rabbits; D051381:Rats; D018139:Simplexvirus / Q000187:drug effects*; D013997:Time Factors; D016662:Virus Integration / Q000187:drug effects; D014779:Virus Replication / Q000187:drug effects
D000890:Anti-Infective Agents; D005419:Flavonoids; D010936:Plant Extracts; D011429:Propolis