A Green Tea Catechin Extract Upregulates the Hepatic Low-Density Lipoprotein Receptor in Rats
| dc.contributor.author | Bursill, Christina Anne | en |
| dc.contributor.author | Roach, Paul D. | en |
| dc.contributor.school | School of Earth and Environmental Sciences | en |
| dc.date.issued | 2007 | en |
| dc.description.abstract | Green tea extracts have hypocholesterolaemic properties in epidemiological and animal intervention studies. Upregulation of the low-density lipoprotein (LDL) receptor may be one mechanism to explain this as it is the main way cholesterol is removed from the circulation. This study aimed to determine if a green tea extract could upregulate the hepatic LDL receptor in vivo in the rat. A green tea extract (GTE) enriched in its anti-oxidant constituents, the catechins, was fed to rats (n = 6) at concentrations of either 0, 0.5, 1.0 or 2.0% (w/w) mixed in with their normal chow along with 0.25% (w/w) cholesterol for 12 days. Administration of the GTE had no effect on plasma total or LDL cholesterol concentrations but high-density lipoprotein significantly increased (41%; p < 0.05). Interestingly, there was a significant increase in LDL receptor binding activity (2.7-fold) and LDL receptor protein (3.4-fold) in the 2% (w/w) treatment group compared to controls. There were also significant reductions in liver total and unesterified cholesterol (40%). Administration of the GTE significantly reduced cholesterol absorption (24%) but did not affect cholesterol synthesis. These results show that, despite no effect on plasma cholesterol, the GTE upregulated the LDL receptor in vivo. This appears to be via a reduction in liver cholesterol concentration and suggests that the green tea extract was able to increase the efflux of cholesterol from liver cells. | en |
| dc.identifier.citation | Lipids, 2007; 42 (7):621-627 | en |
| dc.identifier.doi | 10.1007/s11745-007-3077-x | en |
| dc.identifier.issn | 0024-4201 | en |
| dc.identifier.uri | http://hdl.handle.net/2440/45731 | |
| dc.language.iso | en | en |
| dc.publisher | Amer Oil Chemists Soc A O C S Press | en |
| dc.subject | Green tea; LDL receptor; Cholesterol synthesis; Cholesterol absorption; Lathosterol; Phytosterols | en |
| dc.title | A Green Tea Catechin Extract Upregulates the Hepatic Low-Density Lipoprotein Receptor in Rats | en |
| dc.type | Journal article | en |