title: In Vitro Inhibition of Cytopathic Effect of Influenza Virus and Human Immunodeficiency Virus by Bamboo Leaf Extract Solution and Sodium Copper Chlorophyllin.
abstract: BACKGROUND
  Although the link between oral and oropharyngeal health status and susceptibility to infection has long been recognized, there is a limit to the selection of antiseptics for oral care.
  
  
  METHODS
  Madin-Darby canine kidney (MDCK) cells were exposed to influenza virus and cultured in the presence or absence of test reagents: bamboo leaf extract solution and sodium copper chrolophyllin. MDCK cells were pre-incubated with the reagents to assess the inhibitory activity at adsorption (viral attachment). Similarly, anti-HIV activity and the inhibitory mechanism at adsorption were assessed by MT-2 cell culture system. Mixture of HIV and bamboo leaf extract solution was fixed and examined by transmission electron microscopy.
  
  
  RESULTS
  The 50% inhibitory concentration (IC50) of bamboo leaf extract solution against influenza virus and the 50% cytotoxic concentration (CC50) in MDCK cells of the solution lay between 0.0313-0.0625% and 0.5-1.0%. The solution inhibited the influenza virus adsorption at the concentration of 0.5% (P < 0.05). The values of IC50 and CC50 of sodium copper chlorophyllin lay between 50-100 µM and 200-400 µM, respectively. This inhibited the virus adsorption at 200 µM (P < 0.05). The bamboo leaf extract solution showed values of IC50 against HIV and CC50 in MT-2 cells at around 0.0313% and between 0.25-0.5%, respectively. This solution inhibited HIV adsorption at 1.25% (P < 0.05). The IC50 and CC50 of sodium copper chlorophyllin lay between 50-100 µM and 200-400 µM, respectively. Sodium copper chlorophyllin inhibited HIV adsorption at 2.5 mM (P < 0.05). HIV particles survived after the exposure to 0.5% bamboo leaf extract solution.
  
  
  CONCLUSIONS
  Sodium copper chlorophyllin exerted antiviral activities against influenza virus and HIV as the major ingredient of bamboo leaf extract solution by blocking adsorption. This mechanism of action is different completely from the one of povidone-iodine.
authors.affiliation: Division of Oral and Maxillofacial Biopathological Surgery, Department of Medicine of Sensory and Motor Organs, School of Medicine, Tottori University Faculty of Medicine, Yonago 683-8503, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Ito
authors.affiliation: †Division of Virology, Department of Microbiology and Immunology, School of Medicine, Tottori University Faculty of Medicine, Yonago 683-8503, Japan.
authors.forename: Akeno
authors.initials: A
authors.lastname: Tsuneki
authors.affiliation: Division of Oral and Maxillofacial Biopathological Surgery, Department of Medicine of Sensory and Motor Organs, School of Medicine, Tottori University Faculty of Medicine, Yonago 683-8503, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Yoshida
authors.affiliation: Division of Oral and Maxillofacial Biopathological Surgery, Department of Medicine of Sensory and Motor Organs, School of Medicine, Tottori University Faculty of Medicine, Yonago 683-8503, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Ryoke
authors.affiliation: ‡Department of Anatomy, Tottori University Faculty of Medicine, Yonago 683-8503, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Kaidoh
authors.affiliation: †Division of Virology, Department of Microbiology and Immunology, School of Medicine, Tottori University Faculty of Medicine, Yonago 683-8503, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Kageyama
keywords: HIV; adsorption; bamboo leaf extract solution; human; influenza; sodium copper chlorophyllin