1Selected Tea and Tea Pomace Extracts Inhibit Intestinalalpha-Glucosidase Activity in Vitro and Postprandial Hyperglycemia inVivo

Collection with item attached
2015
Item details URL
http://open-repository.kisti.re.kr/cube/handle/open_repository/473408.do
DOI
10.3390/ijms16048811
Title
1Selected Tea and Tea Pomace Extracts Inhibit Intestinalalpha-Glucosidase Activity in Vitro and Postprandial Hyperglycemia inVivo
Description
This study was supported by a research grant from Hannam University in2014.
abstract
Type 2 diabetes mellitus (T2DM) is a metabolic disorder characterized by postprandial hyperglycemia, which is an early defect of T2DM and thus a primary target for anti-diabetic drugs. A therapeutic approach is to inhibit intestinal -glucosidase, the key enzyme for dietary carbohydrate digestion, resulting in delayed rate of glucose absorption. Although tea extracts have been reported to have anti-diabetic effects, the potential bioactivity of tea pomace, the main bio waste of tea beverage processing, is largely unknown. We evaluated the anti-diabetic effects of three selected tea water extracts (TWE) and tea pomace extracts (TPE) by determining the relative potency of extracts on rat intestinal -glucosidase activity in vitro as well as hypoglycemic effects in vivo. Green, oolong, and black tea bags were extracted in hot water and the remaining tea pomace were dried and further extracted in 70% ethanol. The extracts were determined for intestinal rat -glucosidases activity, radical scavenging activity, and total phenolic content. The postprandial glucose-lowering effects of TWE and TPE of green and black tea were assessed in male Sprague-Dawley (SD) rats and compared to acarbose, a known pharmacological -glucosidase inhibitor. The IC50 values of all three tea extracts against mammalian -glucosidase were lower or similar in TPE groups than those of TWE groups. TWE and TPE of green tea exhibited the highest inhibitory effects against -glucosidase activity with the IC50 of 2.04 +/- 0.31 and 1.95 +/- 0.37 mg/mL respectively. Among the specific enzymes tested, the IC50 values for TWE (0.16 +/- 0.01 mg/mL) and TPE (0.13 +/- 0.01 mg/mL) of green tea against sucrase activity were the lowest compared to those on maltase and glucoamylase activities. In the animal study, the blood glucose level at 30 min after oral intake (0.5 g/kg body wt) of TPE and TWE of both green and black tea was significantly reduced compared to the control in sucrose-loaded SD rats. The TPE of all thr
provenance
Made available in Cube on 2018-09-28T10:18:42Z (GMT). No. of bitstreams: 0
language
English
author
Oh, Jungbae
Jo, Sung-Hoon
Kim, Justin S.
Ha, Kyoung-Soo
Lee, Jung-Yun
Choi, Hwang-Yong
Yu, Seok-Yeong
Kwon, Young-In
Kim, Young-Cheul
accessioned
2018-09-28T10:18:42Z
available
2018-09-28T10:18:42Z
issued
2015
citation
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES(16): 4
issn
1422-0067
uri
http://open-repository.kisti.re.kr/cube/handle/open_repository/473408.do
Funder
교육부
Funding Program
BK21플러스사업
Project ID
1345244278
Jurisdiction
Rep.of Korea
Project Name
Studies on in vivo evaluation & mode of action of functional foods for senior healthcare
rights
openAccess
subject
-glucosidase
sucrase
inhibitor
postprandial hyperglycemia
pomace
green tea
oolong tea
black tea
diabetes
type
article


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