|
Journal of Lipid Research, Vol. 41, 1969-1979, December 2000
Copyright © 2000 by Lipid Research, Inc.
Modulation of hepatic lipoprotein synthesis and secretion by taxifolin, a plant flavonoid
Andre Theriaulta,
Qi Wanga,
Stephen C. Van Iderstineb,
Biao Chenb,
Adrian A. Frankec, and
Khosrow Adelib
a Division of Medical Technology, University of Hawaii, Honolulu, HI 96822
b Department of Laboratory Medicine, Hospital for Sick Children, Toronto, Canada
c Cancer Research Center of Hawaii, University of Hawaii, Honolulu, HI 96822
Correspondence to:
Andre Theriault
In the present study, the effects of taxifolin, a plant flavonoid, on lipid, apolipoprotein B (apoB), and apolipoprotein A-I (apoA-I) synthesis and secretion were determined in HepG2 cells. Pretreatment of cells with (±)-taxifolin led to an inhibition of cholesterol synthesis in a dose- and time-dependent manner, with an 86 ± 3% inhibition at 200 µM observed within 24 h. As to the mechanism underlying this inhibitory effect, taxifolin was shown to inhibit the activity of HMG-CoA reductase by 47 ± 7%. In addition, cellular cholesterol esterification, and triacylglycerol and phospholipid syntheses, were also significantly suppressed in the presence of taxifolin. ApoA-I and apoB synthesis and secretion were then studied by pulse-chase experiments. ApoA-I secretion was found to increase by 36 ± 10%. In contrast, an average reduction of 61 ± 8% in labeled apoB in the medium was apparent with taxifolin. This effect on secretion appeared not to be exerted at the transcriptional level. Rather, the effect on apoB secretion was found to be exerted in the early stages of apoB degradation and to be sensitive to dithiothreitol (DTT) and insensitive to N-acetyl-leucyl-leucyl-norleucinal, suggesting a proteolytic pathway involving a DTT-sensitive protease. Fractionation of secreted apoB revealed a slight shift in the distribution of secreted apoB-containing lipoproteins. Cholesteryl ester, rather than triacylglycerol, was shown to be the lipid that primarily regulated apoB secretion.
In summary, our data suggest that taxifolin decreases hepatic lipid synthesis with a concomitant decrease and increase in apoB and apoA-I secretion, respectively. Theriault, A., Q. Wang, S. C. Van Iderstine, B. Chen, A. A. Franke, and K. Adeli. Modulation of hepatic lipoprotein synthesis and secretion by taxifolin, a plant flavonoid. J. Lipid Res. 2000. 41: 1969;1979.
Supplementary key words:
apolipoprotein B, cholesterol, silymarin, silybin, HepG2

CiteULike Complore Connotea Del.icio.us Digg Reddit Technorati What's this?
This article has been cited by other articles:

|
 |

|
 |
 
G. K. Maiyoh, J. E. Kuh, A. Casaschi, and A. G. Theriault
Cruciferous Indole-3-Carbinol Inhibits Apolipoprotein B Secretion in HepG2 Cells
J. Nutr.,
October 1, 2007;
137(10):
2185 - 2189.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
A. Davalos, C. Fernandez-Hernando, F. Cerrato, J. Martinez-Botas, D. Gomez-Coronado, C. Gomez-Cordoves, and M. A. Lasuncion
Red Grape Juice Polyphenols Alter Cholesterol Homeostasis and Increase LDL-Receptor Activity in Human Cells In Vitro
J. Nutr.,
July 1, 2006;
136(7):
1766 - 1773.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
H Vanacker, L. Sandalio, A Jimenez, J. Palma, F. Corpas, V Meseguer, M Gomez, F Sevilla, M Leterrier, C. Foyer, et al.
Roles for redox regulation in leaf senescence of pea plants grown on different sources of nitrogen nutrition.
J. Exp. Bot.,
May 1, 2006;
57(8):
1735 - 1745.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
P. V. Nerurkar, L. Pearson, J. T. Efird, K. Adeli, A. G. Theriault, and V. R. Nerurkar
Microsomal Triglyceride Transfer Protein Gene Expression and ApoB Secretion Are Inhibited by Bitter Melon in HepG2 Cells
J. Nutr.,
April 1, 2005;
135(4):
702 - 706.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
R. Vidal, S. Hernandez-Vallejo, T. Pauquai, O. Texier, M. Rousset, J. Chambaz, S. Demignot, and J.-M. Lacorte
Apple procyanidins decrease cholesterol esterification and lipoprotein secretion in Caco-2/TC7 enterocytes
J. Lipid Res.,
February 1, 2005;
46(2):
258 - 268.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
A. Casaschi, G. K. Maiyoh, B. K. Rubio, R. W. Li, K. Adeli, and A. G. Theriault
The Chalcone Xanthohumol Inhibits Triglyceride and Apolipoprotein B Secretion in HepG2 Cells
J. Nutr.,
June 1, 2004;
134(6):
1340 - 1346.
[Abstract]
[Full Text]
[PDF]
|
 |
|
Copyright © 2000 by the American Society for Biochemistry and Molecular Biology.
|
Advertisement
Advertisement
|