Hypoglycemic effect and antimicrobial activity of proanthocyanidin oligomers from peanut skin

2015 Fiscal Year Final Research Report

• Project/Area Number: 26750027
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Eating habits
• Research Institution: Tokyo University of Agriculture
• Principal Investigator: Tamura Tomoko 東京農業大学, 応用生物科学部, 准教授 (60451845)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: ラッカセイ / グルコース吸収 / 抗菌活性 / プロシアニジン / DNAマイクロアレイ / Bacillus cereus / ポリフェノール

Outline of Final Research Achievements

The skin of peanut, Arachis hypogaea L., is a rich source of polyphenols. We identified Procyanidin A1 as a dimer and epicatechin-(4β→6)-epicatechin-(2β→O→7, 4β→8)-catechin (EEC) as a procyanidin trimer from the skin of peanut. EEC showed strong inhibitory activities of alfa-amylase, maltase, sucrase. EEC also decreased the absorption of glucose from the intestine by inhibition of glucose transport.
On the other hands, EEC has antimicrobial activity, in particular food-borne gram-positive bacteria, Bacillus cereus. DNA microarray analysis of B. cereus treated with EEC was carried out, with a finding that 597 genes were significantly up-regulated. Analysis of the up-regulated genes suggested that EEC disrupted the normal condition of the cell membrane and wall of B. cereus and alter its usual nutritional metabolism. Moreover, treatment of B. cereus with EEC inhibited glucose uptake, suggesting that EEC affects the cell-surface adsorption.

Free Research Field

食品分子機能学