Hypoglycemic effect of basil (Ocimum basilicum) aqueous extract is mediated through inhibition of α-glucosidase and α-amylase activities: an in vitro study

Toxicol Ind Health. 2012 Feb;28(1):42-50. doi: 10.1177/0748233711403193. Epub 2011 Jun 2.

Abstract

The present study investigated the in vitro hypoglycemic activity of basil (Ocimum basilicum) aqueous extract. Preliminary phytochemical screening of the extract revealed the presence of reducing sugars, cardiac glycosides, tannins, saponins, glycosides, flavonoids and steroids. The total polyphenols content (TPC), flavonoids content (FC), percentage diphenylpicrylhydrazyl (DPPH( · )) radical inhibition and total antioxidant status (TAS) were estimated. The FC was 41 ± 2.2 rutin/g dry extract, the TPC was 146 ± 5.26 mg catechin/g dry extract and the TAS was 5.12 ± 0.7 mmol/L. The %DPPH( · ) free radical inhibition was 60%, 54%, 49% and 43%, respectively, for different extract concentrations; 20, 18.2, 16.3 and 14.5 mg/ml, respectively. The extract elicited significant dose-dependent pattern against rat intestinal sucrase (RIS; IC(50) = 36.72 mg/ml), rat intestinal maltase (RIM; IC(50) = 21.31 mg/ml) and porcine pancreatic α-amylase (PPA; IC(50) = 42.50 mg/ml) inhibitory activities. The inhibition was greater against maltase compared with sucrase. These effects may be attributed to the high TPC and FC levels. The linear regression analysis revealed strong significant positive correlations between %DPPH( · ) radical inhibition and each of %RIS, %RIM and %PPA inhibiting activity. Also, strong significant positive correlations between %RIS and either %RIM or %PPA inhibition activity were observed. We concluded therefore that basil aqueous extract via antioxidant and possibly α-glucosidase and α-amylase inhibiting activities, offered positive benefits to control diabetes.

MeSH terms

  • Analysis of Variance
  • Animals
  • Antioxidants / analysis
  • Biphenyl Compounds / antagonists & inhibitors
  • Enzyme Inhibitors / chemistry
  • Enzyme Inhibitors / pharmacology*
  • Flavonoids / analysis
  • Glycoside Hydrolase Inhibitors*
  • Hypoglycemic Agents / chemistry
  • Hypoglycemic Agents / pharmacology*
  • Linear Models
  • Ocimum basilicum / chemistry*
  • Picrates / antagonists & inhibitors
  • Plant Extracts / chemistry
  • Plant Extracts / pharmacology*
  • Plant Leaves / chemistry
  • Polyphenols / analysis
  • Rats
  • Sucrase / antagonists & inhibitors
  • Sucrase / metabolism
  • Swine
  • alpha-Amylases / antagonists & inhibitors*
  • alpha-Amylases / metabolism
  • alpha-Glucosidases / metabolism

Substances

  • Antioxidants
  • Biphenyl Compounds
  • Enzyme Inhibitors
  • Flavonoids
  • Glycoside Hydrolase Inhibitors
  • Hypoglycemic Agents
  • Picrates
  • Plant Extracts
  • Polyphenols
  • 1,1-diphenyl-2-picrylhydrazyl
  • alpha-Amylases
  • alpha-Glucosidases
  • Sucrase