Asian Journal
Of Traditional Medicines

Abstract: In our study, CHO and BRL cells were cultured and exposed to different concentrations of protocatechualdehyde , ursolic acid or quercetin
for 24h. The inhibition of cholesterol biosynthesis was determined by the MTT method using an amphotercin B CHO cell model. The
expression of cholesterol 7α-hydroxylase mRNA was examined by RT-PCR in BRL cells. The results showed that protocatechualdehyde,
50 to 400μg/mL, and quercetin, 25 to 200μg/mL, clearly increased the OD and cell viability in this amphotercin B cell model.
Protocatechualdehyde, 50 to 400μg/mL, and ursolic acid, 1.25 to 10μg/mL, up-regulated cholesterol 7α-hydroxylase mRNA expression
in BRL cells. However, quercetin had no effect on cholesterol 7α-hydroxylase mRNA expression and ursolic acid did not affect CHO cell
viability. These results suggest that the reduction in cellular cholesterol biosynthesis by protocatechualdehyde or quercetin and the increase
in conversion of cholesterol into bile acid by protocatechualdehyde or ursolic acid could lead to a reduction in cholesterol and low density
lipoprotein-cholesterol levels in the circulation, and these effects may be synergistic.

Key words: protocatechualdehyde, ursolic acid, quercetin, cholesterol biosynthesis, cholesterol 7α-hydroxylase