Dietary fenugreek and onion attenuate cholesterol gallstone formation in lithogenic diet–fed mice.

An animal study was conducted to evaluate the antilithogenic effect of a combination
of dietary fenugreek seeds and onion. Lithogenic conditions were induced in
mice by feeding them a high (0.5%) cholesterol diet (HCD) for 10 weeks. Fenugreek
(12%) and onion (2%) were included individually and in combination in this HCD.
Fenugreek, onion and their combination reduced the incidence of cholesterol gallstones
by 75%, 27% and 76%, respectively, with attendant reduction in total cholesterol
content by 38–42%, 50–72% and 61–80% in serum, liver and bile
respectively. Consequently, the cholesterol ⁄ phospholipid ratio was reduced significantly
in serum, liver and bile. The cholesterol saturation index of bile was reduced
from 4.14 to 1.38 by the combination of fenugreek and onion and to 2.33 by onion
alone. The phospholipid and bile acid contents of the bile were also increased.
Changes in the hepatic enzyme activities (3-hydroxy-3-methylglutaryl Coenzyme A
reductase, cholesterol-7a-hydroxylase and cholesterol-27-hydroxylase) induced by
HCD were countered by fenugreek, onion and their combination. Hepatic lipid peroxides
were reduced by 19–22% and 39–45% with fenugreek, onion and their combination
included in the diet along with the HCD. Increased accumulation of fat in
the liver and inflammation of the gallbladder membrane produced by HCD were
reduced by fenugreek, onion and their combination. The antilithogenic influence was
highest with fenugreek alone, and the presence of onion along with it did not further
increase this effect. There was also no additive effect of the two spices in the recovery
of antioxidant molecules or in the antioxidant enzyme activities.