1. Recently, we reported that
4-hydroxyderricin, one of the major
chalcones in Angelica keiskei extract (
ethyl acetate extract from the yellow liquid of stems), exerted hypotensive and
lipid regulatory actions in
stroke-prone spontaneously hypertensive rats (SHRSP). In the present study, we isolated
xanthoangelol, another major
chalcone in A. keiskei extract, and examined the effect of dietary
xanthoangelol on blood pressure and lipid metabolism in SHRSP. 2. Six-week-old male SHRSP were fed diets containing 0.02% or 0.1%
xanthoangelol (0.02 and 0.10 Xan, respectively) for 7 weeks, with free access to the diet and water. There were no significant changes in daily food intake, bodyweight or systolic blood pressure throughout the experimental period. Serum total
cholesterol levels tended to decrease in the two experimental groups (albeit not significantly), which was due to a dose-dependent decrease in the
cholesterol content of the
low-density lipoprotein (
LDL) fraction. These results suggest that dietary
xanthoangelol decreases serum
LDL levels. 3. In the liver, significant dose-dependent decreases in relative liver liver weight and total
triglyceride content were seen in the 0.02 and 0.10 Xan groups. In addition, a significant decrease in total
cholesterol content was found in the 0.10 Xan group, which may be due to an elevation of faecal
cholesterol excretion in addition to the decrease in liver weight. 4. Investigation of the hepatic
mRNA expression of
proteins involved in lipid metabolism indicated that there was a significant increase in
peroxisome proliferator-activated receptor (
PPAR) alpha mRNA expression associated with the tendency for increases in
acyl-coenzyme A (
CoA)
synthetase and
acyl-CoA oxidase mRNA expression in the 0.10 Xan group, which may be responsible, at least in part, for the decrease in hepatic
triglyceride content in the
xanthoangelol-treated rats. In addition, a significant increase in
LDL receptor mRNA expression in the 0.10 Xan group may be responsible, at least in part, for the decrease in serum
LDL levels in the
xanthoangelol-treated rats. 5. In conclusion, dietary
xanthoangelol results in a reduction of serum
LDL levels and decreases in total
cholesterol and
triglyceride contents in the liver of SHRSP. These beneficial effects are more effective following consumption of diet containing 0.10%
xanthoangelol.