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Nutraceuticals 2019
July 15-16, 2019
Volume 2
Journal of Food and Clinical Nutrition
Advanced Nutraceuticals and Functional Foods
July 15-16, 2019 | London, UK
World Congress on
J Food Clin Nutr, Volume 2
Green tea epigallocatechingallate regulates the growthandautophagyprotein expression
in white fat cells
Yung-Hsi Kao, Batubara, Siao AC, Lin
and
YY, Kuo YC
National Central University, Taiwan
Statement of the Problem:
Green tea catechins, particularly (-)-epigallocatechin gallate (EGCG), have been reported to
regulate obesity and white fat cell activity. This study investigated the effects of EGCG on the expression of autophagy
pathway proteins in 3T3-L1 white preadipocytes.
Methodology & Theoretical Orientation:
3T3-L1 preadipocytes were treated with EGCG and then cell number and
autophagy pathway proteins were measured by the dye exclusion method and Western blot analysis, respectively.
Findings:
EGCG was found to inhibit preadipocyte growth in a dose- and time-dependent manner, as indicated by
decreased cell number. Pretreatment with the respectively early staged and late-staged autophagy inhibitors, such as
3-methyladenine (3-MA) and chloroquine (CQ), suppressed preadipocyte growth and enhanced further EGCG-decreased
cell number. This suggests that a functional process of autophagy is necessary for preadipocytes to grow and that EGCG
may act differently from 3- MA and CQ in regulating levels of autophagy pathway proteins. Indeed, EGCG was found to
time- and dose-dependently reduce the expression of autophagy pathway proteins, such as Beclin-1, ATG3, ATG5, ATG7,
ATG16L1, and ERK proteins, while it increased the level of late-staged autophagy proteins, p62 and LC3β-II. Interestingly,
3-MA tended to increase levels of Beclin-1, ATG3, ATG5, ATG7, ATG16L1, p62, LC3β-II, and ERK proteins, while CQ
significantly increased levels of Beclin-1, ATG3, ATG16L1, p62, LC3β-II, and ERK proteins, decreased ATG5, and
unaltered ATG7. Pretreatment with 3-MA generally reversed EGCG-induced changes in levels of autophagy proteins.
Moreover, pretreatment with CQ enhanced the EGCG-increased levels of p62 and LC3β-II proteins.
Conclusion & Significance:
These data suggest that EGCG exerts its anti-growth action on preadipocytes via regulation
of multiple autophagy proteins and its effects may act differently from autophagy inhibitors 3-MA and CQ. Results of this
study possibly support that EGCG can be a therapeutic agent to regulate obesity by autophagy mechanism.
Biography
Kao, PhD (1997) in Zoology at North Dakota State University in US, Postdoc Research Associate (1997-2000) at University of Chicago,
and a distinguished professor of the National Central University in Taiwan, has his expertise in functional green tea catechin in improving
the health. His used animal and cell systems based on responsive body weight changes, fat cell function, and prostate cancer activity
discover signalling pathways of epigallocatechin gallate for improving obesity and prostate cancer. He has discovered the results after
years of experience in research, evaluation, teaching and administration both in research and education institutions.
ykao@cc.ncu.edu.tw