Topical Area: Dietary Bioactive Components
Objectives : The objective of this study is to investigate the effects of high hydrostatic pressure (HHP) extract of mulberry fruit on the regulation of hepatic cholesterol metabolism in high-cholesterol diet fed rats.
Methods : Male Sprague-Dawley rats(6-week-old) were randomly divided into 5 groups, and fed with a normal diet (NOR), High cholesterol diet (HC), HC supplemented with 0.4% mulberry (ML) or 0.8% mulberry (MH) and HC treated with statin (ST) for 4 weeks.
Results : The HHP extract of mulberry fruit did not affect body weight gain and food intake and reduced the serum and liver lipids in the mulberry supplemented groups (ML, MH). In this study, we found that the HHP extract of mulberry fruit changed the level of genes involved in hepatic cholesterol metabolism. In the MH group, the mRNA levels of apolipoprotein A-1 (apoA-1), ATP-binding cassette transporter A1 (ABCA1) and lecithin-cholesterol acyltransferase (LCAT), which are involved in hepatic HDL biogenesis, were significantly increased by 1.80-, 1.77- and 2.65-fold, respectively, compared with the HC group. The MH group also significantly upregulated mRNA levels of cholesterol efflux related gene such as the liver X receptor α (LXRα), ATP-binding cassette protein G5 (ABCG5) and ATP-binding cassette protein G8 (ABCG8) compared to the HC group in the liver tissue. ABCG5 and ABCG8 expression levels of the MH group were also higher than those of the ST group. The mRNA level of cholesterol 7a-hydroxylase (CYP7A1), which is bile acid synthetic rate-limiting enzyme was higher in the MH group than that of the HC group. Furthermore, the immunohistochemical staining intensity became evident for CYP7A1 in liver of the MH group.
Conclusions : These results suggest at least partial involvement of HDL cholesterol synthesis, cholesterol efflux and bile acid synthesis in HHP extract of mulberry fruit mediated beneficial effects on hepatic cholesterol metabolism.
Funding Sources : None