title: In vivo anti-fatigue activity of sufu with fortification of isoflavones.
abstract: BACKGROUND
  Sufu is a traditional Chinese fermented soybean food. Isoflavones are abundant in soybean and products incorporated with isoflavones exert many health benefits. The aim of this study was to investigate anti-fatigue effect of sufu fortified with isoflavones.
  
  
  METHODS
  In vivo anti-fatigue activity of sufu with fortification of isoflavones (IF) was investigated in this study via exhaustive swimming test using ICR mice and determination of biochemical parameters. Factors relating to fatigue, including hepatic glycogen, blood lactic acid (BLA), blood urea nitrogen (BUN) were determined. The isoflavone composition in the IF sufu was also determined to explore the anti-fatigue activity of isoflavones.
  
  
  RESULTS
  During fermentation, isoﬂavone glucosides were converted into aglycones and both sufu with and without fortification of IF prolonged the exhaustive swimming time of ICR mice. Intake of sufu also increased the hepatic glycogen content, while it decreased the levels of both the blood lactic acid (BLA) and blood urea nitrogen (BUN) content. A dose-response relationship was observed in both exhaustive swimming and BLA clearance test, with medium dose (1%) fortification of IF revealing the highest activity.
  
  
  CONCLUSIONS
  IF sufu could possess high anti-fatigue activity.
authors.affiliation: Beijing Key Laboratory of Functional Food from Plant Resources, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, P. R. China.
authors.forename: Yunxian
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Beijing Key Laboratory of Functional Food from Plant Resources, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, P. R. China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Japan International Research Center for Agricultural Sciences, Tsukuba, 305-8686, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Nirasawa
authors.affiliation: Japan International Research Center for Agricultural Sciences, Tsukuba, 305-8686, Japan.
authors.forename: Eizo
authors.initials: E
authors.lastname: Tatsumi
authors.affiliation: Beijing Key Laboratory of Functional Food from Plant Resources, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, P. R. China.
authors.forename: Yongqiang
authors.initials: Y
authors.lastname: Cheng
authors.affiliation: Beijing Key Laboratory of Functional Food from Plant Resources, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, P. R. China.
authors.forename: Lite
authors.initials: L
authors.lastname: Li
keywords: Anti-fatigue; exhaustive swimming test; isoflavone; sufu