title: Antioxidant activity and anti-inflammatory activity of ethanol extract and fractions of Doenjang in LPS-stimulated RAW 264.7 macrophages.
abstract: OBJECTIVE
  Fermentation can increase functional compounds in fermented soybean products, thereby improving antioxidant and/or anti-inflammatory activities. We investigated the changes in the contents of phenolics and isoflavones, antioxidant activity and anti-inflammatory activity of Doenjang during fermentation and aging.
  
  
  METHODS
  Doenjang was made by inoculating Aspergillus oryzae and Bacillus licheniformis in soybeans, fermenting and aging for 1, 3, 6, 8, and 12 months (D1, D3, D6, D8, and D12). Doenjang was extracted using ethanol, and sequentially fractioned by hexane, dichloromethane (DM), ethylacetate (EA), n-butanol, and water. The contents of total phenolics, flavonoids and isoflavones, 2,2-diphenyl-1 picryl hydrazyl (DPPH) radical scavenging activity, and ferric reducing antioxidant power (FRAP) were measured. Anti-inflammatory effects in terms of nitric oxide (NO), prostaglandin (PG) E2 and pro-inflammatory cytokine production and inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 expressions were also measured using LPS-treated RAW 264.7 macrophages.
  
  
  RESULTS
  Total phenolic and flavonoid contents showed a gradual increase during fermentation and 6 months of aging and were sustained thereafter. DPPH radical scavenging activity and FRAP were increased by fermentation. FRAP was further increased by aging, but DPPH radical scavenging activity was not. Total isoflavone and glycoside contents decreased during fermentation and the aging process, while aglycone content and its proportion increased up to 3 or 6 months of aging and then showed a slow decrease. DM and EA fractions of Doenjang showed much higher total phenolic and flavonoid contents, and DPPH radical scavenging activity than the others. At 100 µg/mL, DM and EA fractions of D12 showed strongly suppressed NO production to 55.6% and 52.5% of control, respectively, and PGE2 production to 25.0% and 28.3% of control with inhibition of iNOS or COX-2 protein expression in macrophages.
  
  
  CONCLUSIONS
  Twelve month-aged Doenjang has potent antioxidant and anti-inflammatory activities with high levels of phenolics and isoflavone aglycones, and can be used as a beneficial food for human health.
authors.affiliation: Institute on Aging, Seoul National University, #304 Biomedical Science building, 103 Daehak-ro, Jongno-gu, Seoul 110-799, Korea.
authors.forename: Chung Shil
authors.initials: CS
authors.lastname: Kwak
authors.affiliation: Institute on Aging, Seoul National University, #304 Biomedical Science building, 103 Daehak-ro, Jongno-gu, Seoul 110-799, Korea.
authors.forename: Dahee
authors.initials: D
authors.lastname: Son
authors.affiliation: Department of Biotechnology, Hoseo University, Chungnam 336-795, Korea.
authors.forename: Young-Shin
authors.initials: YS
authors.lastname: Chung
authors.affiliation: Department of Food and Nutrition, Seoul National University, Seoul 151-742, Korea.
authors.forename: Young Hye
authors.initials: YH
authors.lastname: Kwon
keywords: Doenjang; RAW 264.7 macrophages; antioxidant; inflammation; isoflavone aglycone