Quantitative analysis of saponins in a tea-leaf extract and their antihypercholesterolemic activity.
A novel simple method using liquid chromatography/time-of-flight mass spectrometry (LC/TOF-MS) and LC/UV was established for the quantification of saponins in an extract from green tea leaves. The amount of saponins in a fraction with high in vitro antihypercholesterolemic activity, Fr2-3, was determined to be 72%. An in vivo experiment showed that the addition of 0.5% Fr2-3 to a high-cholesterol diet suppressed the increase in serum cholesterol levels in rats. Fr2-3 induced a decrease in the liver cholesterol and triglyceride levels and an increase in the fecal excretion of cholesterol. These results indicate tea-leaf saponins to be the active components in Fr2-3 and that these saponins exhibited antihypercholesterolemic activity by inhibiting cholesterol absorption in the intestines.
Matsui
Yoko
Y
Functional Ingredient Department, Laboratory of Health Materials, Ogawa & Co, Ltd, Urayasu, Chiba, Japan. matsui.yoko.2000@ogawa.net
Kobayashi
Keiko
K
Masuda
Hideki
H
Kigoshi
Hideo
H
Akao
Makoto
M
Sakurai
Hidetoshi
H
Kumagai
Hitomi
H
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D028241:Camellia sinensis / Q000737:chemistry*; D002784:Cholesterol / Q000097:blood; D002853:Chromatography, Liquid; D004435:Eating / Q000187:drug effects; D006937:Hypercholesterolemia / Q000097:blood / Q000139:chemically induced / Q000503:physiopathology; D000960:Hypolipidemic Agents / Q000032:analysis / Q000302:isolation & purification / Q000494:pharmacology; D008297:Male; D013058:Mass Spectrometry; D009929:Organ Size / Q000187:drug effects; D010936:Plant Extracts / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry*; D051381:Rats; D017208:Rats, Wistar; D012503:Saponins / Q000032:analysis* / Q000302:isolation & purification / Q000494:pharmacology*; D013662:Tea / Q000737:chemistry*
D000960:Hypolipidemic Agents; D010936:Plant Extracts; D012503:Saponins; D013662:Tea; D002784:Cholesterol