Salmon Protamine Decreases Serum and Liver Lipid Contents by Inhibiting Lipid Absorption in an In Vitro Gastrointestinal Digestion Model and in Rats.
Protamine has been used as an antiheparin drug and a natural preservative in various food products. However, limited studies have evaluated the physicochemical and functional properties of protamine. Hence, we assessed the mechanisms underlying the inhibition of lipid absorption following salmon protamine intake in in vitro and in vivo studies. In initial experiments, a salmon protamine hydrolyzate (PH) was prepared using in vitro simulated gastrointestinal digestion suppressed pancreatic lipase activity and micellar cholesterol solubility. This PH had higher bile acid-binding capacity and emulsion breakdown activity than casein hydrolyzate and l-arginine. However, the hypolipidemic functions of protamine were dramatically reduced by pancreatin digestion. In further experiments, groups of male Wistar rats were fed an AIN-93G diet containing 5% (wt/wt) salmon protamine or a protamine amino acid mixture. After 4 wk of feeding with experimental diets, reductions in serum and liver triacylglycerol (TAG) and cholesterol contents were observed in the presence of protamine, reflecting inhibition of TAG, cholesterol, and bile acid absorption. These data suggest that the formation of insoluble PH-bile acid complexes is critical before the bile acid-binding capacity is reduced. Therefore, dietary salmon protamine may ameliorate lifestyle-related diseases such as hyperlipidemia and obesity.
Lab. of Food and Nutritional Sciences, Faculty of Chemistry, Materials, and Bioengineering, Kansai Univ, Suita, Osaka, 564-8680, Japan.
Ryota
R
Hosomi
Lab. of Food and Nutritional Sciences, Faculty of Chemistry, Materials, and Bioengineering, Kansai Univ, Suita, Osaka, 564-8680, Japan.
Kazumasa
K
Miyauchi
Lab. of Food and Nutritional Sciences, Faculty of Chemistry, Materials, and Bioengineering, Kansai Univ, Suita, Osaka, 564-8680, Japan.
Daiki
D
Yamamoto
Dept. of Biotechnology and Environmental Chemistry, Kitami Inst. of Technology, Kitami, Hokkaido, 090-8507, Japan.
Hirofumi
H
Arai
Dept. of Public Health, Kansai Medical Univ., Hirakata, Osaka, 573-1010, Japan.
Toshimasa
T
Nishiyama
Lab. of Food and Nutritional Sciences, Faculty of Chemistry, Materials, and Bioengineering, Kansai Univ, Suita, Osaka, 564-8680, Japan.
Munehiro
M
Yoshida
Lab. of Food and Nutritional Sciences, Faculty of Chemistry, Materials, and Bioengineering, Kansai Univ, Suita, Osaka, 564-8680, Japan.
Kenji
K
Fukunaga
D000818:Animals; D001120:Arginine / Q000494:pharmacology; D001647:Bile Acids and Salts / Q000378:metabolism; D002364:Caseins / Q000494:pharmacology; D002784:Cholesterol / Q000097:blood / Q000378:metabolism; D004032:Diet; D004063:Digestion; D000960:Hypolipidemic Agents / Q000494:pharmacology*; D066298:In Vitro Techniques; D007408:Intestinal Absorption / Q000187:drug effects*; D050356:Lipid Metabolism / Q000187:drug effects*; D008099:Liver / Q000378:metabolism*; D008297:Male; D010194:Pancreatin / Q000378:metabolism; D011479:Protamines / Q000494:pharmacology*; D011492:Protein Hydrolysates / Q000494:pharmacology*; D017208:Rats, Wistar; D012474:Salmon; D014280:Triglycerides / Q000097:blood / Q000378:metabolism
D001647:Bile Acids and Salts; D002364:Caseins; D000960:Hypolipidemic Agents; D011479:Protamines; D011492:Protein Hydrolysates; D014280:Triglycerides; C475729:casein hydrolysate; D010194:Pancreatin; D001120:Arginine; D002784:Cholesterol
bile acid; cholesterol; hydrolyzate; lipid absorption; protamine