title: The inhibitory activities of the edible green alga Capsosiphon fulvescens on rat lens aldose reductase and advanced glycation end products formation.
abstract: OBJECTIVE
  Accumulating evidence suggests that inhibitors of aldose reductase (AR) may prevent hyperglycemia-induced long-term complications in diabetes mellitus. In the present study, we evaluated the AR inhibitory potential of ethanolic (EtOH) extracts from 22 seaweed species.
  
  
  METHODS
  AR inhibitory activities of the selected seaweed species were evaluated using the rat lens aldose reductase (RLAR) inhibitory assay.
  
  
  RESULTS
  All extracts exhibited RLAR inhibitory activity, which ranged from 5.87 to 92.71 % at a concentration of 50 μg/mL. Since Capsosiphon fulvescens exhibited significant inhibitory potential and is a frequently used foodstuff, it was selected for a detailed investigation using RLAR and advanced glycation end products (AGE) formation inhibitory assays. Among the different solvent-soluble fractions, the CH2Cl2, EtOAc, and n-BuOH fractions showed promising RLAR and AGE formation inhibitory activities. Considering the AR inhibitory potential, CH2Cl2 and EtOAc fractions were selected for chromatographic separation and yielded 11 compounds in which capsofulvesin A, capsofulvesin B, and chalinasterol showed potential RLAR inhibitory activity with the respective IC50 values of 52.53, 101.92, and 345.27 μM. Kinetic studies revealed that capsofulvesin A and chalinasterol exhibited mixed type inhibition, while capsofulvesin B exhibited noncompetitive inhibition. To our knowledge, this is the first report of AR inhibitory activity of the glycolipids capsofulvesin A and capsofulvesin B.
  
  
  CONCLUSIONS
  Our results clearly indicate the potential RLAR and AGE formation inhibitory activities of C. fulvescens as well as its isolated constituents, which could be further explored to develop therapeutic modalities for the treatment of diabetes and related complications.
authors.affiliation: Department of Food Science and Nutrition, Pukyong National University, Busan, 608-737, Republic of Korea.
authors.forename: Md Nurul
authors.initials: MN
authors.lastname: Islam
authors.forename: Sung Hwa
authors.initials: SH
authors.lastname: Choi
authors.forename: Hye Eun
authors.initials: HE
authors.lastname: Moon
authors.forename: Jin Ju
authors.initials: JJ
authors.lastname: Park
authors.forename: Hyun Ah
authors.initials: HA
authors.lastname: Jung
authors.forename: Mi Hee
authors.initials: MH
authors.lastname: Woo
authors.forename: Hee Chul
authors.initials: HC
authors.lastname: Woo
authors.forename: Jae Sue
authors.initials: JS
authors.lastname: Choi
mesh_terms: D000449:Aldehyde Reductase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000818:Animals; D000460:Chlorophyta / Q000737:chemistry*; D003920:Diabetes Mellitus / Q000517:prevention & control; D004791:Enzyme Inhibitors / Q000494:pharmacology; D017127:Glycation End Products, Advanced / Q000037:antagonists & inhibitors / Q000378:metabolism*; D007908:Lens, Crystalline / Q000187:drug effects* / Q000201:enzymology*; D010936:Plant Extracts / Q000494:pharmacology*; D051381:Rats
chemical_list: D004791:Enzyme Inhibitors; D017127:Glycation End Products, Advanced; D010936:Plant Extracts; D000449:Aldehyde Reductase