title: Gigantol from Dendrobium chrysotoxum Lindl. binds and inhibits aldose reductase gene to exert its anti-cataract activity: An in vitro mechanistic study.
abstract: BACKGROUND
  Dendrobium. chrysotoxum Lindl is a commonly used species of medicinal Dendrobium which belongs to the family of Orchidaceae, locally known as "Shihu" or "Huangcao". D. chrysotoxum Lindl is widely known for medicinal values in traditional Chinese medicine as it possesses anti-inflammatory, anti-hyperglycemic induction, antitumor and antioxidant properties.
  
  
  OBJECTIVE
  To characterize the interaction between gigantol extracted from D. chrysotoxum Lindl and the AR gene, and determine gigantol's efficacy against cataractogenesis.
  
  
  METHODS
  Human lens epithelial cells (HLECs) were induced by glucose as the model group. Reverse transcription polymerase chain reaction (RT-PCR) was used to assess AR gene expression. Then, the mode of interaction of gigantol with the AR gene was evaluated by UV-visible spectroscopy, atomic force microscope (AFM) and surface-enhanced Raman spectroscopy (SERS). The binding constant was determined by UV-visible.
  
  
  RESULTS
  Gigantol depressed AR gene expression in HLECs. UV-visible spectra preliminarily indicated that interaction between the AR gene and gigantol may follow the groove mode, with a binding constant of 1.85×103L/mol. Atomic force microscope (AFM) data indicated that gigantol possibly bound to insert AR gene base pairs of the double helix. Surface-enhanced Raman spectroscopy (SERS) studies further supported these observations.
  
  
  CONCLUSIONS
  Gigantol extracted from D. chrysotoxum Lindl not only has inhibitory effects on aldose reductase, but also inhibits AR gene expression. These findings provide a more comprehensive theoretical basis for the use of Dendrobium for the treatment of diabetic cataract.
authors.affiliation: School of Basic Medical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Wu
authors.affiliation: School of Basic Medical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, China.
authors.forename: Xue
authors.initials: X
authors.lastname: Li
authors.affiliation: School of Basic Medical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, China.
authors.forename: Wencheng
authors.initials: W
authors.lastname: Wan
authors.affiliation: School of Basic Medical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, China.
authors.forename: Qiaohong
authors.initials: Q
authors.lastname: Yang
authors.affiliation: School of Basic Medical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, China.
authors.forename: Weifeng
authors.initials: W
authors.lastname: Ma
authors.affiliation: School of Basic Medical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, China.
authors.forename: Jiangmiao
authors.initials: J
authors.lastname: Hu
authors.affiliation: Antioxidants Research Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA.
authors.forename: C-Y Oliver
authors.initials: CO
authors.lastname: Chen
authors.affiliation: School of Basic Medical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, China; Antioxidants Research Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA. Electronic address: jidewowxy2@163.com.
authors.forename: Xiaoyong
authors.initials: X
authors.lastname: Wei
mesh_terms: D000449:Aldehyde Reductase / Q000235:genetics*; D001632:Bibenzyls / Q000302:isolation & purification / Q000494:pharmacology*; D002386:Cataract / Q000209:etiology / Q000517:prevention & control*; D002478:Cells, Cultured; D031667:Dendrobium / Q000737:chemistry*; D048909:Diabetes Complications / Q000517:prevention & control; D004847:Epithelial Cells / Q000187:drug effects / Q000201:enzymology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D005947:Glucose / Q000378:metabolism; D006139:Guaiacol / Q000031:analogs & derivatives* / Q000302:isolation & purification / Q000494:pharmacology; D006801:Humans; D007908:Lens, Crystalline / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013059:Spectrum Analysis, Raman
chemical_list: D001632:Bibenzyls; C478099:gigantol; D006139:Guaiacol; D000449:Aldehyde Reductase; D005947:Glucose
keywords: 3- Aminopropyl triethoxysilane (PubChem CID: 13521); Aldose reductase (AR) gene; Atomic force microscopy (AFM); D-Glucose (PubChem CID: 579); ETOAC, (PubChem CID: 8857); ETOH, (PubChem CID: 702); Gigantol; Gigantol (PubChem CID: 10221179); Interaction; MEOH, (PubChem CID: 887); Penicillin (PubChem CID: 5904); Streptomycin (PubChem CID: 19649); Surface-enhanced Raman spectroscopy (SERS); UV–visible spectroscopy