eugeniin and Herpes-Simplex

Traditional medicines contain various metabolites derived from nucleic acid, protein, and lipid metabolism. Some of these specific metabolites may recognize the differences between viral and host metabolism resulting in anti-viral activity; hence traditional medicines may be useful sources for new antiviral agents. Traditional medicines can be cheaply obtained and have been orally administered as hot-water extracts. Therefore, they may be used for the prophylactic and therapeutic treatment of viral infection by drinking them, such as coffee or tea. Here we describe how the antiviral activity of traditional medicines was screened in vitro and how their therapeutic antiviral activities were verified in vivo, to obtain traditional antiviral medicines that can be clinically used. Therefore, we have selected 12 herbal extracts, from more than 250 herbal medicines, that exhibit therapeutic activities against cutaneous herpes simplex virus (HSV) type 1 (HSV-1) infection in mice. Four of the 12 augmented the therapeutic efficacy of acyclovir (ACV) in mice and showed potent anti-HSV activity against infection with ACV-resistant HSV-1 mutants in mice. These herbal extracts selectively inhibited viral DNA synthesis and showed a different mode of anti-HSV-1 action from that of ACV. They were also effective against both recurrent HSV and cytomegalovirus infections, without toxicity. Such prophylactic and therapeutic antiviral activities of the traditional medicines were verified by the purification of major active compounds. We could show new indications of traditional medicines as antiviral agents. Thus, the drinking of the extracts, in a daily tea or coffee, may be used for prophylaxis and therapy of diseases caused by herpes virus infection and improve the quality of life.

Topics: Animals; Antiviral Agents; Cytomegalovirus Infections; DNA, Viral; Drug Evaluation, Preclinical; Drug Resistance, Microbial; Drugs, Chinese Herbal; Gallic Acid; Glucosides; Guinea Pigs; Herpes Simplex; Herpesvirus 1, Human; Immunocompromised Host; Mice; Recurrence

Eugeniin exhibits antiviral activity against acyclovir and phosphonoacetic acid (PAA)-resistant herpes simplex virus type 1 (HSV-1) as well as the wild-type HSV-1 in vitro. In this study, we characterized the biological activity of eugeniin in cutaneously HSV-1-infected mice and its interaction with HSV-1 DNA polymerase. The oral and intraperitoneal administrations of eugeniin at 0.3 mg/kg showed similar therapeutic efficacy in retarding the development of skin lesions of HSV-1-infected mice. The two routes of administration at 6 or 50 mg/kg significantly prolonged the mean survival times and/or reduced mortality without toxicity. The oral administration of eugeniin at 50 mg/kg reduced virus yields in the skin and brain of infected mice. Thus, the therapeutic efficacy of oral administration at the various doses of eugeniin was similar to that of intraperitoneal administration, suggesting that the oral bioavailability of eugeniin was high with respect to absorption. Furthermore, the anti-HSV-1 activity of eugeniin was characterized by isobolograms analyzing its combined effects with acyclovir or PAA in HSV-1-infected Vero cells. Eugeniin enhanced the anti-HSV-1 activity of acyclovir but was suggested to be antagonistic with PAA. The interaction of eugeniin and PAA on the activity of partially purified HSV-1 DNA polymerase suggested that eugeniin interacted with the polymerase in the vicinity of PAA-binding site. Thus, eugeniin showed different anti-HSV-1 action from acyclovir and PAA and therapeutic anti-HSV-1 activity in mice.

Topics: Acyclovir; Animals; Antiviral Agents; Brain; Female; Gallic Acid; Glucosides; Herpes Simplex; Herpesvirus 1, Human; Mice; Mice, Inbred BALB C; Nucleic Acid Synthesis Inhibitors; Phosphonoacetic Acid; Skin