title: Antidiabetic and antihypertensive effect of a polyphenol-rich fraction of Thymelaea hirsuta L. in a model of neonatal streptozotocin-diabetic and N(G) -nitro-l-arginine methyl ester-hypertensive rats.
abstract: BACKGROUND
  The present study examined the effect of the polyphenol-rich fraction from Thymelaea hirsuta (PRF-Th) in a rat model of streptozotocin (STZ)-diabetes and nitric oxide (NO)-deficient hypertension.
  
  
  METHODS
  Diabetes was induced by a single dose of STZ (90 mg/kg, i.p.). To induce NO-deficient hypertension, rats were treated with the NO synthase inhibitor N(G) -nitro-l-arginine methyl ester; l-NAME; 30 mg/kg per day, p.o. for 3 weeks. The effects of 21 days treatment with 80 mg/kg per day PRF-Th in the drinking water were evaluated in diabetic-hypertensive (DH) rats. In all groups (n = 6 in each), glycemia and systolic blood pressure were determined weekly. At the end of the experiment, hepatic glycogen was determined.
  
  
  RESULTS
  Blood glucose levels decreased gradually from baseline until the end of the experiment in untreated DH rats (from 1.92 ± 0.09 to 1.3 ± 0.1 g/L; P < 0.05). Administration of PRF-Th concomitantly with l-NAME prevented the blood pressure increase in rats. After 21 days, blood pressure in PRF-Th + l-NAME- and l-NAME-treated rats was 132 ± 1 and 157 ± 1 mmHg, respectively (P < 0.001). Administration of 2 mL/kg per day PRF-Th to DH rats significantly increased hepatic glycogen levels compared with levels in untreated DH rats (13.65 ± 1.84 vs 6.34 ± 0.75 mg/g tissue, respectively; P < 0.01). Moreover, PRF-Th significantly reduced the amount of glucose absorbed in in situ perfused jejunum segments compared with control (by 33.6%; P <0.001). This effect of PRF-Th was comparable with that of acarbose, an α-glucosidase inhibitor.
  
  
  CONCLUSIONS
  The findings of the present study indicate that T. hirsuta has antidiabetic and antihypertensive activity in STZ-diabetic, NO-deficient hypertensive rats. This effect seems to be due to its rich polyphenol content. Therefore, T. hirsuta may be useful as a food supplement for the prevention of type 2 diabetes and hypertension.
authors.affiliation: Department of Biology, University Mohamed Ist, Oujda, Morocco. mbnouham@yahoo.fr
authors.forename: Mohamed
authors.initials: M
authors.lastname: Bnouham
authors.forename: Wafaa
authors.initials: W
authors.lastname: Benalla
authors.forename: Said
authors.initials: S
authors.lastname: Bellahcen
authors.forename: Zineb
authors.initials: Z
authors.lastname: Hakkou
authors.forename: Abderrahim
authors.initials: A
authors.lastname: Ziyyat
authors.forename: Hassane
authors.initials: H
authors.lastname: Mekhfi
authors.forename: Mohammed
authors.initials: M
authors.lastname: Aziz
authors.forename: Abdelkhaleq
authors.initials: A
authors.lastname: Legssyer
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000959:Antihypertensive Agents / Q000494:pharmacology*; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000139:chemically induced / Q000188:drug therapy*; D005260:Female; D005947:Glucose / Q000378:metabolism / Q000493:pharmacokinetics; D006973:Hypertension / Q000097:blood / Q000139:chemically induced / Q000188:drug therapy*; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D007583:Jejunum / Q000187:drug effects / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008112:Liver Glycogen / Q000378:metabolism; D008297:Male; D019331:NG-Nitroarginine Methyl Ester; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology; D059808:Polyphenols / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013311:Streptozocin; D029645:Thymelaeaceae / Q000737:chemistry*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000959:Antihypertensive Agents; D001786:Blood Glucose; D007004:Hypoglycemic Agents; D008112:Liver Glycogen; D010936:Plant Extracts; D059808:Polyphenols; D013311:Streptozocin; D005947:Glucose; D019331:NG-Nitroarginine Methyl Ester