Soyasaponins lowered plasma cholesterol and increased fecal bile acids in female golden Syrian hamsters.
A study was conducted in hamsters to determine if group B soyasaponins improve plasma cholesterol status by increasing the excretion of fecal bile acids and neutral sterols, to identify group B soyasaponin metabolites, and to investigate the relationship between a fecal group B soyasaponin metabolite and plasma lipids. Twenty female golden Syrian hamsters, 11-12 weeks old and 85-125 g, were randomly assigned to a control diet or a similar diet containing group B soyasaponins (containing no isoflavones), 2.2 mmol/kg, for 4 weeks. Hamsters fed group B soyasaponins had significantly lower plasma total cholesterol (by 20%), non-high-density lipoprotein (HDL) cholesterol (by 33%), and triglycerides (by 18%) compared with those fed casein (P < 0.05). The ratio of total cholesterol to HDL cholesterol was significantly lower (by 13%) in hamsters fed group B soyasaponins than in those fed casein (P < 0.05). The excretion of fecal bile acids and neutral sterols was significantly greater (by 105% and 85%, respectively) in soyasaponin-fed hamsters compared with those fed casein (P < 0.05). Compared with casein, group B soyasaponins lowered plasma total cholesterol levels and non-HDL cholesterol levels by a mechanism involving greater excretion of fecal bile acids and neutral sterols. Hamsters fed group B soyasaponins statistically clustered into two fecal soyasaponin metabolite-excretion phenotypes: high excreters (n = 3) and low excreters (n = 7). When high and low producers of this soyasaponin metabolite were compared for plasma cholesterol status, the high producers showed a significantly lower total-cholesterol-to-HDL-cholesterol ratio compared with the low producers (1.38 +/- 0.7 vs. 1.59 +/- 0.13; P < 0.03). Greater production of group B soyasaponin metabolite in hamsters was associated with better plasma cholesterol status, suggesting that gut microbial variation in soyasaponin metabolism may influence the health effects of group B soyasaponins.
Food Science and Human Nutrition, 124 MacKay Hall, Iowa State University, Ames, IA 50011, USA.
Sun-Ok
SO
Lee
Andrean L
AL
Simons
Patricia A
PA
Murphy
Suzanne
S
Hendrich
D000818:Animals; D000924:Anticholesteremic Agents / Q000494:pharmacology*; D001647:Bile Acids and Salts / Q000032:analysis / Q000378:metabolism*; D002784:Cholesterol / Q000097:blood*; D006224:Cricetinae; D005243:Feces / Q000737:chemistry; D005260:Female; D008647:Mesocricetus; D009828:Oleanolic Acid / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000494:pharmacology*; D012503:Saponins / Q000493:pharmacokinetics / Q000494:pharmacology*; D013025:Glycine max / Q000737:chemistry; D013261:Sterols / Q000032:analysis / Q000378:metabolism
D000924:Anticholesteremic Agents; D001647:Bile Acids and Salts; D012503:Saponins; D013261:Sterols; C407096:soyasapogenol B; D009828:Oleanolic Acid; D002784:Cholesterol