title: Synergism of Alkaline Extract of the Leaves of Sasa senanensis Rehder and Antiviral Agents.
abstract: BACKGROUND
  Previous studies have shown a much greater antiviral activity of alkaline extract of the leaves of Sasa senanensis Rehder (SE) against human immunodeficiency virus (HIV), compared to lignin precursors, tannins and flavonoids, suggesting its possible application to oral diseases. Systematic comparative study with herpes simplex virus (HSV) has been limited compared to that with HIV. In the present study, we investigated whether combination of SE with other popular antiviral agents further enhances their individual activity.
  
  
  METHODS
  Cell viability of mock-infected, HIV-infected and HSV-infected cells was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. The antiviral activity was evaluated by the selectivity index, defined as the ratio of 50% cytotoxic concentration to 50% effective concentration. Synergy between SE and antiviral agents was evaluated by MacSynerg and CompuSyn software.
  
  
  RESULTS
  SE showed potent anti-HIV activity, although its activity was two-orders lower than that of azidothymidine, 2',3'-dideoxycytidine dextran sulfate and curdlan sulfate. Combination of SE with these antiviral agents produced synergistic effects. Using a newly established MTT assay system for anti-HSV activity, SE and acyclovir were found to have synergistic anti-HSV activity.
  
  
  CONCLUSIONS
  The present study suggests the possible efficacy of the clinical application of SE combined with antiviral agents.
authors.affiliation: Division of Pharmacology, Meikai University School of Dentistry, Sakado, Japan sakagami@dent.meikai.ac.jp takaakio@daiwaseibutsu.co.jp.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sakagami
authors.affiliation: Graduate School, Showa University, Tokyo, Japan.
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Fukuchi
authors.affiliation: St. Marianna University School of Medicine, Kanagawa, Japan.
authors.forename: Taisei
authors.initials: T
authors.lastname: Kanamoto
authors.affiliation: St. Marianna University School of Medicine, Kanagawa, Japan.
authors.forename: Shigemi
authors.initials: S
authors.lastname: Terakubo
authors.affiliation: St. Marianna University School of Medicine, Kanagawa, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Nakashima
authors.affiliation: Daiwa Biological Research Institute Co., Ltd., Kanagawa, Japan.
authors.forename: Takenori
authors.initials: T
authors.lastname: Natori
authors.affiliation: Daiwa Biological Research Institute Co., Ltd., Kanagawa, Japan.
authors.forename: Madoka
authors.initials: M
authors.lastname: Suguro-Kitajima
authors.affiliation: Daiwa Biological Research Institute Co., Ltd., Kanagawa, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Oizumi
authors.affiliation: Division of Pharmacology, Meikai University School of Dentistry, Sakado, Japan.
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Yasui
authors.affiliation: Daiwa Biological Research Institute Co., Ltd., Kanagawa, Japan sakagami@dent.meikai.ac.jp takaakio@daiwaseibutsu.co.jp.
authors.forename: Takaaki
authors.initials: T
authors.lastname: Oizumi
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D002522:Chlorocebus aethiops; D004357:Drug Synergism; D004359:Drug Therapy, Combination; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology; D015497:HIV-1 / Q000187:drug effects; D006561:Herpes Simplex / Q000188:drug therapy* / Q000821:virology; D006801:Humans; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry*; D031787:Sasa / Q000737:chemistry*; D018139:Simplexvirus / Q000187:drug effects; D014709:Vero Cells
chemical_list: D000998:Antiviral Agents; D010936:Plant Extracts
keywords: HIV; HSV; MTT assay; Sasa senanensis Rehder leaf; alkaline extract; combination