title: Flavonoids isolated from Lespedeza cuneata G. Don and their inhibitory effects on nitric oxide production in lipopolysaccharide-stimulated BV-2 microglia cells.
abstract: BACKGROUND
  Lespedeza cuneata (Dum. Cours.) G. Don, a perennial legume native to Eastern Asia, has been used therapeutically in traditional Asian medicine to protect the function of liver, kidneys and lungs. However, its effect on inflammatory nitric oxide (NO) production and the active constituents have not yet been explored.
  
  
  OBJECTIVE
  In this study, we investigated the phytochemical constituents of L. cuneata and evaluated their effect on NO production using lipopolysaccharide (LPS)-stimulated BV2 cells.
  
  
  METHODS
  The 80% methanol extract of the aerial part of L. cuneata were used for the isolation of flavonoids. The isolated compounds were elucidated by various spectroscopic methods including nuclear magnetic resonance and mass spectrometry spectrometry. To evaluate the effect on inflammatory NO production, LPS-stimulated murine microglia BV-2 cells were used as a screening system.
  
  
  RESULTS
  Nine flavonoids were isolated from the aerial parts of L. cuneata. Among the isolated flavonoids, compounds 4, 5, 7 and 9 are reported from the genus Lespedeza for the first time. Moreover, compounds 1 and 6 showed significant inhibitory effects on NO production in LPS-stimulated BV2 cells without cell toxicity.
  
  
  CONCLUSIONS
  In this study, nine flavonoids were isolated from L. cuneata. Among the compounds, only 1 and 6, which have free hydroxyl groups at both C3 and C7 showed significant inhibitory activity on NO production in LPS-stimulated BV2 cells. These results suggested L. cuneata and its flavonoid constituents as possible candidate for the treatment of various inflammatory diseases.
authors.affiliation: College of Pharmacy, Yonsei Institute of Pharmaceutical Science, Yonsei University, Incheon 406-840, Republic of Korea.
authors.forename: Guijae
authors.initials: G
authors.lastname: Yoo
authors.affiliation: College of Pharmacy, Yonsei Institute of Pharmaceutical Science, Yonsei University, Incheon 406-840, Republic of Korea.
authors.forename: Seon Ju
authors.initials: SJ
authors.lastname: Park
authors.affiliation: College of Pharmacy, Yonsei Institute of Pharmaceutical Science, Yonsei University, Incheon 406-840, Republic of Korea.
authors.forename: Taek Hwan
authors.initials: TH
authors.lastname: Lee
authors.affiliation: College of Pharmacy, Kangwon National University, Chuncheon 200-701, Republic of Korea.
authors.forename: Heejung
authors.initials: H
authors.lastname: Yang
authors.affiliation: Department of Oriental Medicinal and Processing, Graduate School of Biotechnology, Kyung Hee University, Gyeonggi 446-701, Republic of Korea.
authors.forename: Yoon-Su
authors.initials: YS
authors.lastname: Baek
authors.affiliation: College of Pharmacy, Yonsei Institute of Pharmaceutical Science, Yonsei University, Incheon 406-840, Republic of Korea.
authors.forename: Nanyoung
authors.initials: N
authors.lastname: Kim
authors.affiliation: College of Pharmacy, Yonsei Institute of Pharmaceutical Science, Yonsei University, Incheon 406-840, Republic of Korea.
authors.forename: Yoon Jae
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: College of Pharmacy, Yonsei Institute of Pharmaceutical Science, Yonsei University, Incheon 406-840, Republic of Korea.
authors.forename: Seung Hyun
authors.initials: SH
authors.lastname: Kim
keywords: BV2 microglia; Lespedeza cuneata; flavonoids; nitric oxide