title: Evaluation of hypoglycemic effects of polyphenols and extracts from Penthorum chinense.
abstract: BACKGROUND
  Penthorum chinense Pursh has a long history of use as a health food and folk medicine to alleviate "heat"-associated disorders, promote circulation and diuresis, and to treat liver problems, and to protect the spleen. In this study we provide experimental evidence for the clinical use of Penthorum chinense in the treatment of diabetes mellitus. The aim of the study was to investigate the hypoglycemic effects of extracts and active constituents from Penthorum chinense.
  
  
  METHODS
  High fat diet and STZ (35mg/kg) induced diabetic rats were administered with Penthorum chinense extract at graded oral doses (150 and 300mg/kg/day, ig.) for 2 weeks. A range of parameters, including blood glucose and lipid, serum insulin, glucose tolerance, were tested to evaluate its anti-hyperglycemic effects. Moreover, oral starch tolerance test (OSTT) was performed to test the level of postprandial glucose after administrating Penthorum chinense extract. In vitro study, the Penthorum chinense extracts and purified Penthorum chinense polyphenols were tested for α-amylase inhibitory activity. The polyphenols were determined by UPLC-Q-TOF mass spectrometry and NMR.
  
  
  RESULTS
  The Penthorum chinense extract possessed anti-hyperglycemic activities as shown by the decreased serum levels of glycosylated hemoglobulin A1C (HbA1c), triglyceride(TG), total cholesterol (TC), and low density lipoprotein-cholesterol (LDL-C), as well as increased serum levels of high density lipoprotein-cholesterol (HDL-C) and insulin. Penthorum chinense extract also improved the oral glucose tolerance test (OGTT) to a certain degree. Moreover, the OSTT study showed that in diabetic rats, the extract (600mg/kg) caused a significant hypoglycemic effect with a blood glucose reduction of 42% at 60min. To identify the active constituents, three polyphenols, pinocembrin-7-O-[4″,6″-hexahydroxydiphenoyl]-β-d-glucose (1), pinocembrin-7-O-[3″-O-galloyl-4″, 6″-hexahydroxydiphenoyl]-β- d-glucose (2), and thonningianin A (3) were isolated from Penthorum chinense. Compounds 1-3 moderately inhibited α-amylase activity, with IC50 values of 0.14, 0.03, and 0.08µmol/ml, respectively.
  
  
  CONCLUSIONS
  The folk medicinal plant, Penthorum chinense produced a moderated anti-hyperglycemic effect on STZ-induced diabetic rats and starch induced postprandial hyperglycemic mice.
authors.affiliation: Department of Identification of traditional Chinese Medicine, School of Pharmacy, Second Military Medical University, Shanghai 200433, PR China.
authors.forename: Doudou
authors.initials: D
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Science, University of Macau, Macau, PR China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Department of Pharmacy, Changzheng Hospital, Shanghai, PR China.
authors.forename: Wansheng
authors.initials: W
authors.lastname: Chen
authors.affiliation: Department of Identification of traditional Chinese Medicine, School of Pharmacy, Second Military Medical University, Shanghai 200433, PR China.
authors.forename: Fengyan
authors.initials: F
authors.lastname: Yao
authors.affiliation: Department of Identification of traditional Chinese Medicine, School of Pharmacy, Second Military Medical University, Shanghai 200433, PR China.
authors.forename: Guanghui
authors.initials: G
authors.lastname: Huang
authors.affiliation: Department of Identification of traditional Chinese Medicine, School of Pharmacy, Second Military Medical University, Shanghai 200433, PR China. Electronic address: sssnmr@163.com.
authors.forename: Lianna
authors.initials: L
authors.lastname: Sun
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000188:drug therapy*; D059305:Diet, High-Fat; D005260:Female; D005978:Glutathione / Q000097:blood; D006442:Glycated Hemoglobin / Q000032:analysis; D007004:Hypoglycemic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D007328:Insulin / Q000097:blood; D008315:Malondialdehyde / Q000097:blood; D008813:Mice, Inbred ICR; D008517:Phytotherapy; D035261:Plant Components, Aerial; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use*; D059808:Polyphenols / Q000494:pharmacology / Q000627:therapeutic use*; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000097:blood; D064028:Tracheophyta
chemical_list: D001786:Blood Glucose; D005978:Glutathione; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D007328:Insulin; D008315:Malondialdehyde; D010936:Plant Extracts; D059808:Polyphenols; D013482:Superoxide Dismutase
keywords: Diabetes; Hypoglycemic effect; Penthorum chinense; Polyphenols; Thonningianin A (PubChem CID: 10328286)