In vitro alpha-glucosidase and alpha-amylase enzyme inhibitory effects of Andrographis paniculata extract and andrographolide.

Abstract

There has been an enormous interest in the development of alternative medicines for type 2 diabetes, specifically screening for phytochemicals with the ability to delay or prevent glucose absorption. The goal of the present study was to provide in vitro evidence for potential inhibition of alpha-glucosidase and alpha-amylase enzymes, followed by a confirmatory in vivo study on rats to generate a stronger biochemical rationale for further studies on the ethanolic extract of Andrographis paniculata and andrographolide. The extract showed appreciable alpha-glucosidase inhibitory effect in a concentration-dependent manner (IC(50)=17.2+/-0.15 mg/ml) and a weak alpha-amylase inhibitory activity (IC(50)=50.9+/-0.17 mg/ml). Andrographolide demonstrated a similar (IC(50)=11.0+/-0.28 mg/ml) alpha-glucosidase and alpha-amylase inhibitory activity (IC(50)=11.3+/-0.29 mg/ml). The positive in vitro enzyme inhibition tests paved way for confirmatory in vivo studies. The in vivo studies demonstrated that A. paniculata extract significantly (P<0.05) reduced peak blood glucose and area under curve in diabetic rats when challenged with oral administration of starch and sucrose. Further, andrographolide also caused a significant (P<0.05) reduction in peak blood glucose and area under the curve in diabetic rats. Hence alpha-glucosidase inhibition may possibly be one of the mechanisms for the A. paniculata extract to exert antidiabetic activity and indicates that AP extract can be considered as a potential candidate for the management of type 2 diabetes mellitus.

• Authors: Rammohan Subramanian, M Zaini Asmawi, Amirin Sadikun
• Journal: Acta biochimica Polonica (Acta Biochim Pol) Vol. 55 Issue 2 Pg. 391-8 ( 2008) ISSN: 0001-527X [Print] Poland
• PMID: 18511986 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Blood Glucose
• Diterpenes
• Enzyme Inhibitors
• Glycoside Hydrolase Inhibitors
• Hypoglycemic Agents
• Plant Extracts
• andrographolide
• Starch
• alpha-Amylases

Topics

• Andrographis (chemistry)
• Animals
• Blood Glucose (metabolism)
• Diabetes Mellitus, Experimental (blood, drug therapy)
• Diabetes Mellitus, Type 2 (drug therapy)
• Diterpenes (pharmacology)
• Drug Evaluation, Preclinical
• Enzyme Inhibitors (pharmacology)
• Female
• Glucose Tolerance Test
• Glycoside Hydrolase Inhibitors
• Hypoglycemic Agents (pharmacology)
• In Vitro Techniques
• Phytotherapy
• Plant Extracts (pharmacology)
• Rats
• Rats, Sprague-Dawley
• Starch (administration & dosage)
• alpha-Amylases (antagonists & inhibitors)