Sweet elements of Siraitia grosvenori inhibit oxidative modification of low-density lipoprotein.
This study examined the ability of sweet elements extracted from Siraitia grosvenori (SG) to inhibit the oxidation of LDL. We monitored the formation of conjugated diene during copper-mediated LDL oxidation in the presence or absence of sweet elements of whole extract of SG (SG extract) or cucurbitane glycosides (CGs) purified from SG extract as sweet elements. CGs consist of Mogroside IV (Mog.IV), Mogroside V (Mog.V), 11-Oxo-mogroside V (11-Oxo-mog.V), and Siamenoside I (Sia.I). In addition, the effect of these elements on human umbilical vein endothelial cell (HUVEC)- mediated LDL oxidation was tested by measuring production of lipid peroxides. SG extract inhibited copper-mediated LDL oxidation in a dose-dependent fashion, but neither glucose nor erythritol suppressed the oxidation. Among CGs, 11-Oxo-mog.V significantly inhibited LDL oxidation, and prolongation of the lag time during LDL oxidation by 11-Oxo-mog.V was dose-dependent. The lag time (119.7 +/- 8.9 min) in the presence of 200 microM 11-Oxo-mog.V was significantly longer than that (76.8 +/- 5.5 min) of control (p < 0.01). In addition, SG extract and 11-Oxo-mog.V inhibited HUVEC-mediated LDL oxidation in a dose-dependent manner. These results demonstrate that SG extract can inhibit LDL oxidation and that 11-Oxo-mog.V, a sweet element of SG extract, provides the anti-oxidative property of SG which might reduce the atherogenic potential of LDL.
Takeo
Eiichiro
E
First Department of Internal Medicine, Hiroshima University School of Medicine, Japan.
Yoshida
Hiroshi
H
Tada
Norio
N
Shingu
Tetsuji
T
Matsuura
Hideo
H
Murata
Yuji
Y
Yoshikawa
Shinichi
S
Ishikawa
Toshitsugu
T
Nakamura
Haruo
H
Ohsuzu
Fumitaka
F
Kohda
Hiroshi
H
D002478:Cells, Cultured; D003300:Copper / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D016166:Free Radical Scavengers / Q000737:chemistry / Q000494:pharmacology; D005638:Fruit / Q000737:chemistry*; D006027:Glycosides / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects; D008077:Lipoproteins, LDL / Q000378:metabolism*; D008297:Male; D010084:Oxidation-Reduction / Q000187:drug effects; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D014315:Triterpenes / Q000737:chemistry / Q000494:pharmacology; D014471:Umbilical Veins / Q000166:cytology
D016166:Free Radical Scavengers; D006027:Glycosides; D008077:Lipoproteins, LDL; D010936:Plant Extracts; D014315:Triterpenes; D003300:Copper; C041740:mogroside V; C041741:mogroside IV