Potato pulps lowered the serum cholesterol and triglyceride levels in rats.
In our previous study, we demonstrated that retrograded starch, a kind of resistant starch, of beans reduced serum lipid levels in rats. In this study, we examined whether retrograded starch in potato pulps could reduce serum lipid concentrations. Rats were given diets containing 15 g of retrograded starch in potato pulps from the Benimaru potato (BM) or Hokkaikogane potato (HK) in a 100 g diet for 4 wk. At the 4th week, the total cholesterol level in the serum in the BM group and serum triglyceride (TG) level in the HK group were significantly lower than those in the control group. In the BM group, the contents of fecal bile acids were significantly higher than those in the control group. On the other hand, in the HK group, the hepatic mRNA level of fatty acid synthase (FAS) was significantly lower than that in the control group. The FAS mRNA level correlated with the mRNA level of sterol regulatory element-binding protein-1c (SREBP-1c), a regulator of expression of FAS, positively. These results suggested that BM pulp promoted the excretion of bile acids, which resulted in a low concentration of serum cholesterol. On the other hand, HK pulp inhibited the synthesis of fatty acids at the mRNA levels of FAS and SREBP-1c, which might lead to a reduction of the serum TG level.
Hashimoto
Naoto
N
Department of Animal Science, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan.
Ito
Yusaku
Y
Han
Kyu-Ho
KH
Shimada
Ken-ichiro
K
Sekikawa
Mitsuo
M
Topping
David L
DL
Bird
Anthony R
AR
Noda
Takahiro
T
Chiji
Hideyuki
H
Fukushima
Michihiro
M
D000818:Animals; D001647:Bile Acids and Salts / Q000378:metabolism; D001835:Body Weight / Q000187:drug effects; D004083:Cholestanol / Q000378:metabolism; D002784:Cholesterol / Q000097:blood*; D004032:Diet; D064429:Fatty Acid Synthases / Q000187:drug effects / Q000378:metabolism; D005243:Feces; D006863:Hydrogen-Ion Concentration; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D009929:Organ Size / Q000187:drug effects; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D011198:Solanum tuberosum; D013213:Starch / Q000008:administration & dosage / Q000494:pharmacology*; D051780:Sterol Regulatory Element Binding Protein 1 / Q000187:drug effects / Q000378:metabolism; D013997:Time Factors; D014280:Triglycerides / Q000097:blood*
D001647:Bile Acids and Salts; D012333:RNA, Messenger; D051780:Sterol Regulatory Element Binding Protein 1; D014280:Triglycerides; D004083:Cholestanol; D013213:Starch; D002784:Cholesterol; D064429:Fatty Acid Synthases