title: In vitro inhibition activity of polyphenol-rich extracts from Syzygium aromaticum (L.) Merr. & Perry (Clove) buds against carbohydrate hydrolyzing enzymes linked to type 2 diabetes and Fe(2+)-induced lipid peroxidation in rat pancreas.
abstract: OBJECTIVE
  To investigate and compare the inhibitory properties of free and bound phenolic extracts of clove bud against carbohydrate hydrolyzing enzymes (alpha-amylase & alpha-glucosidase) and Fe(2+)-induced lipid peroxidation in rat pancreas in vitro.
  
  
  METHODS
  The free phenolics were extracted with 80% (v/v) acetone, while bound phenolics were extracted from the alkaline and acid hydrolyzed residue with ethyl acetate. Then, the interaction of the extracts with alpha-amylase and alpha-glucosidase was subsequently assessed. Thereafter, the total phenolic contents and antioxidant activities of the extracts were determined.
  
  
  RESULTS
  The result revealed that both extracts inhibited alpha-amylase and alpha-glucosidase in a dose-dependent manner. However, the alpha-glucosidase inhibitory activity of the extracts were significantly (P<0.05) higher than their alpha-amylase inhibitory activity. The free phenolics (31.67 mg/g) and flavonoid (17.28 mg/g) contents were significantly (P<0.05) higher than bound phenolic (23.52 mg/g) and flavonoid (13.70 mg/g) contents. Both extracts also exhibited high antioxidant activities as typified by their high reducing power, 1,1 diphenyl-2- picrylhydrazyl (DPPH) and 2, 2-azinobis-3-ethylbenzo-thiazoline-6-sulfonate (ABTS) radical scavenging abilities, as well as inhibition of Fe(2+)-induced lipid peroxidation in rat pancreas in vitro.
  
  
  CONCLUSIONS
  This study provides a biochemical rationale by which clove elicits therapeutic effect on type 2 diabetes.
authors.affiliation: Department of Biochemistry, Federal University of Technology, Akure, P.M.B. 704, Akure-340001, Nigeria.
authors.forename: Stephen Adeniyi
authors.initials: SA
authors.lastname: Adefegha
authors.forename: Ganiyu
authors.initials: G
authors.lastname: Oboh
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000737:chemistry; D050260:Carbohydrate Metabolism / Q000187:drug effects*; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology; D005296:Ferrous Compounds / Q000494:pharmacology; D005419:Flavonoids / Q000737:chemistry; D065089:Glycoside Hydrolase Inhibitors / Q000737:chemistry / Q000494:pharmacology; D020128:Inhibitory Concentration 50; D015227:Lipid Peroxidation / Q000187:drug effects*; D010179:Pancreas / Q000187:drug effects* / Q000378:metabolism*; D010636:Phenols / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D059808:Polyphenols / Q000737:chemistry / Q000494:pharmacology; D051381:Rats; D027842:Syzygium / Q000737:chemistry*; D000516:alpha-Amylases / Q000037:antagonists & inhibitors; D000520:alpha-Glucosidases
chemical_list: D000975:Antioxidants; D004791:Enzyme Inhibitors; D005296:Ferrous Compounds; D005419:Flavonoids; D065089:Glycoside Hydrolase Inhibitors; D010636:Phenols; D010936:Plant Extracts; D059808:Polyphenols; D000516:alpha-Amylases; D000520:alpha-Glucosidases
keywords: Alpha-amylase; Alpha-glucosidase; Antioxidant; Fe2+-induced lipid peroxidation Pancrea; Phenol