Abstract
Green tea extracts enriched in catechins decrease plasma cholesterol in hamsters,
mice and rats. The aims of this study were to determine whether a catechin-enriched
extract of green tea could lower plasma cholesterol in the cholesterol-fed rabbit
and to determine the mechanism of action. Four groups of six New Zealand White rabbits
were initially made hypercholesterolaemic by feeding a 0.25% (w/w) cholesterol diet
for 2 weeks before the diet was supplemented with a catechin extract from green tea
at 0, 0.5, 1 or 2% (w/w) for 4 weeks. Administration of the crude catechin extract
from green tea significantly (p < 0.05) lowered cholesterol in plasma (−60%), VLDL + IDL (−70%), LDL (−80%), liver (total by −25% and unesterified by −15%) and aorta (−25%)
compared to control. There was a significant reduction in the cholesterol synthesis
index (−60%) and a significant increase in hepatic LDL receptor activity (+80%) and
protein (+70%) but there was no change in the intrinsic capacity to absorb cholesterol
from the intestines. These results suggest that green tea catechins lowered plasma,
liver and aortic cholesterol in the cholesterol-fed rabbit by lowering cholesterol
synthesis and upregulating the hepatic LDL receptor.
Keywords
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Article info
Publication history
Published online: September 29, 2006
Accepted:
August 14,
2006
Received in revised form:
August 2,
2006
Received:
June 5,
2006
Identification
Copyright
© 2006 Elsevier Ireland Ltd. Published by Elsevier Inc. All rights reserved.
