A casein diet added isoflavone-enriched soy protein favorably affects biomarkers of steatohepatitis in obese Zucker rats.
OBJECTIVE
Dietary supplementation of a soy protein enriched with isoflavones (HDI) has been shown to improve fatty liver in obese rats. The main objective of this study was to investigate whether HDI would influence the inflammatory status in livers of obese rats with fatty liver.


METHODS
Male obese Zucker fa/fa rats were fed casein (controls) or casein supplemented with HDI (containing 4.00 g of genistein and 4.50 g of daidzein per kilogram of diet) for 6 wk.


RESULTS
The HDI-fed rats had a markedly lower hepatic concentration of triacylglycerol when compared with controls. The decreased aspartate transaminase/alanine transaminase ratio in plasma, together with lower circulating levels of alkaline phosphatase and bile acids after HDI feeding, implied an improved hepatitis. This was supported by decreased plasma and hepatic mRNA levels of tumor necrosis factor-alpha, lower plasma levels of interleukin-1beta and monocyte chemoattractant protein-1, and an increased anti-inflammatory fatty acid index in plasma. HDI also seemed to protect the rats from oxidative damage, because the level of lipid peroxides in triacylglycerol-rich lipoproteins after in vitro copper oxidation was lower for HDI-fed rats when compared with controls.


CONCLUSIONS
These results show that isoflavone-enriched soy protein favorably affects biomarkers of hepatic inflammation in obese Zucker fa/fa rats with fatty liver. Thus, dietary soy proteins enriched in isoflavones may be a promising agent to improve steatohepatitis in patients.
Gudbrandsen
Oddrun Anita
OA
The Lipid Research Group, Institute of Medicine, University of Bergen, Haukeland University Hospital, Bergen, Norway. nkjgu@uib.no
Wergedahl
Hege
H
Berge
Rolf Kristian
RK
D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002364:Caseins / Q000008:administration & dosage / Q000494:pharmacology; D004195:Disease Models, Animal; D005234:Fatty Liver / Q000178:diet therapy* / Q000378:metabolism; D006505:Hepatitis / Q000378:metabolism / Q000517:prevention & control*; D007529:Isoflavones / Q000008:administration & dosage / Q000494:pharmacology*; D050356:Lipid Metabolism / Q000187:drug effects*; D008099:Liver / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D008297:Male; D009765:Obesity / Q000150:complications / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011897:Random Allocation; D051381:Rats; D011924:Rats, Zucker; D030262:Soybean Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D014280:Triglycerides / Q000378:metabolism
D015415:Biomarkers; D002364:Caseins; D007529:Isoflavones; D012333:RNA, Messenger; D030262:Soybean Proteins; D014280:Triglycerides