title: Anti-UV activity of lignin-carbohydrate complex and related compounds.
abstract: BACKGROUND
  We recently reported that an alkaline extract of the leaves of Sasa senanensis Rehder (SE) and Lentinus edodes mycelia extract (LEM), exhibiting lignin-carbohydrate complex (LCC)-like activity, protected cells from UV-induced injury (referred to as anti-UV activity). We investigated whether LCC is the major active components responsible for anti-UV activity.
  
  
  METHODS
  Human oral squamous cell carcinoma HSC-2 cells were exposed to short UV irradiation in phosphate-buffered saline, containing different concentrations of LCC. After culturing for 48 h in fresh culture medium, the viable cell number was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. From the dose-response curve, the 50% cytotoxic concentration (CC(50)) and the concentration that increased the viability of the UV-irradiated cells to 50% of the control value (EC(50)) were determined. The selectivity index (SI) was determined by the following equation: SI=CC(50)/EC(50).
  
  
  RESULTS
  LCCs (Fr. VI) of pine cones and seed shell, and sulfated LCC exhibited relatively high anti-UV activity (SI=7.1-38), compared with that of SE and LEM. LCCs with lower lignin content (Fr. VII) exhibited anti-UV activity, approximately one half that of Fr. VI. However, polysaccharides (laminarin, pullulan, dextran) introduced with dimethylaminoethyl- or sulfate groups with different substitution ratios were totally inactive (SI<1). The introduction of a sulfate group to LCC did not enhance the anti-UV activity of LCC. Sodium ascorbate and vanillin were the most active (SI=65), whereas gallic acid (SI=5), epigallocatechin gallate (SI=2.6), ar-trumeron (SI<1), and turmeric extract (SI<1) were much less active.
  
  
  CONCLUSIONS
  The prominent anti-UV activity of SE and LEM seems to be generated by LCCs present in the extract.
authors.affiliation: Division of Oral Maxillofacial Surgery, Meikai University School of Dentistry, Sakado, Saitama 350-0283, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Nanbu
authors.forename: Jun
authors.initials: J
authors.lastname: Shimada
authors.forename: Masahiko
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Kumi
authors.initials: K
authors.lastname: Hirano
authors.forename: Teho
authors.initials: T
authors.lastname: Koh
authors.forename: Mamoru
authors.initials: M
authors.lastname: Machino
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Ohno
authors.forename: Masaji
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sakagami
mesh_terms: D001205:Ascorbic Acid / Q000737:chemistry / Q000494:pharmacology; D001547:Benzaldehydes / Q000737:chemistry / Q000494:pharmacology; D001688:Biological Products / Q000737:chemistry / Q000494:pharmacology; D002241:Carbohydrates / Q000737:chemistry / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008031:Lignin / Q000737:chemistry / Q000494:pharmacology*; D046911:Macromolecular Substances / Q000737:chemistry / Q000494:pharmacology; D025282:Mycelium / Q000737:chemistry; D028223:Pinus / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D011134:Polysaccharides / Q000737:chemistry / Q000494:pharmacology; D011837:Radiation-Protective Agents / Q000737:chemistry / Q000494:pharmacology*; D031787:Sasa / Q000737:chemistry; D012639:Seeds / Q000737:chemistry; D020942:Shiitake Mushrooms / Q000737:chemistry; D013431:Sulfates / Q000737:chemistry; D014466:Ultraviolet Rays
chemical_list: D001547:Benzaldehydes; D001688:Biological Products; D002241:Carbohydrates; D046911:Macromolecular Substances; D010936:Plant Extracts; D011134:Polysaccharides; D011837:Radiation-Protective Agents; D013431:Sulfates; D008031:Lignin; C100058:vanillin; D001205:Ascorbic Acid