Antioxidant, Antidiabetic, and Antihypertensive Properties of Echinacea purpurea Flower Extract and Caffeic Acid Derivatives Using In Vitro Models

J Med Food. 2017 Feb;20(2):171-179. doi: 10.1089/jmf.2016.3790. Epub 2017 Jan 6.


The extraction yield, total phenols, caffeic acid derivatives (CAD), and antioxidant properties of 50% ethanolic Echinacea purpurea flower extract were determined. The in vitro inhibitory effects of 50% ethanolic extract and CAD on α-amylase, α-glucosidase, and angiotensin-converting enzyme (ACE) linked with type 2 diabetes were also investigated. The extraction yield, total phenols, and total CAD of the extract were 27.04%, 195.69 mg CAE/g and 78.42 mg/g, respectively. Cichoric acid (56.03 mg/g) was the predominant CAD compound in the extract. The extract exhibited good antioxidant properties. The extract and CAD inhibited α-amylase, α-glucosidase, and ACE activities in a concentration-dependent manner. Among the tested samples, chlorogenic acid, and caffeic acid (IC50 of 1.71-1.81 mg/mL) had the highest α-amylase inhibitory activity, cichoric acid (IC50 of 0.28 mg/mL) showed higher α-glucosidase inhibitory activity. Both chlorogenic acid and caffeic acid (IC50 of 0.11-0.14 mg/mL) demonstrated higher ACE-inhibitory activity. The in vitro results suggest that E. purpurea extract and CAD have good potential for managing hyperglycemia and hypertension. Overall, the data suggest it is a choice for developing antihyperglycemia and antihypertension compounds from field-grown E. purpurea.

Keywords: Echinacea purpurea; angiotensin-converting enzyme; antioxidant activity; caffeic acid derivatives; α-Amylase; α-glucosidase.

MeSH terms

  • Antihypertensive Agents / chemistry*
  • Antioxidants / chemistry*
  • Caffeic Acids / chemistry*
  • Echinacea / chemistry*
  • Enzyme Inhibitors / chemistry
  • Flowers / chemistry
  • Humans
  • Hypoglycemic Agents / chemistry*
  • Kinetics
  • Peptidyl-Dipeptidase A / chemistry
  • Phenols / chemistry
  • Plant Extracts / chemistry*
  • alpha-Amylases / antagonists & inhibitors
  • alpha-Amylases / chemistry
  • alpha-Glucosidases / chemistry


  • Antihypertensive Agents
  • Antioxidants
  • Caffeic Acids
  • Enzyme Inhibitors
  • Hypoglycemic Agents
  • Phenols
  • Plant Extracts
  • alpha-Amylases
  • alpha-Glucosidases
  • Peptidyl-Dipeptidase A