title: Kidney tubular-cell secretion of osteoblast growth factor is increased by kaempferol: a scientific basis for "the kidney controlling the bone" theory of Chinese medicine.
abstract: OBJECTIVE
  To study, at the cytological level, the basic concept of Chinese medicine that "the Kidney (Shen) controls the bone".
  
  
  METHODS
  Kaempferol was isolated form Rhizoma Drynariae (Gu Sui Bu, GSB) and at several concentrations was incubated with opossum kidney (OK) cells, osteoblasts (MC3T3 E1) and human fibroblasts (HF) at cell concentrations of 2×10(4)/mL. Opossum kidney cell-conditioned culture media with kaempferol at 70 nmol/L (70kaeOKM) and without kaempferol (0OKM) were used to stimulate MC3T3 E1 and HF proliferation. The bone morphological protein receptors I and II (BMPR I and II) in OK cells were identified by immune-fluorescence staining and Western blot analysis.
  
  
  RESULTS
  Kaempferol was found to increase OK cell growth (P<0.05), but alone did not promote MC3T3 E1 or HF cell proliferation. However, although OKM by itself increased MC3T3 E1 growth by 198% (P<0.01), the 70kaeOKM further increased the growth of these cells by an additional 127% (P<0.01). It indicates that the kidney cell generates a previously unknown osteoblast growth factor (OGF) and kaempferol increases kidney cell secretion of OGF. Neither of these media had any significant effect on HF growth. Kaempferol also was found to increase the level of the BMPR II in OK cells.
  
  
  CONCLUSIONS
  This lends strong support to the original idea that the Kidney has a significant influence over bone-formation, as suggested by some long-standing Chinese medical beliefs, kaempferol may also serve to stimulate kidney repair and indirectly stimulate bone formation.
authors.affiliation: Department of Complementary and Alternative Medicine, University of Hawai'i at Manoa. John A, Burns School of Medicine, Honolulu, 96813, USA, mlong48@hotmail.com.
authors.forename: Mian
authors.initials: M
authors.lastname: Long
authors.forename: Shun-xiang
authors.initials: SX
authors.lastname: Li
authors.forename: Jiang-feng
authors.initials: JF
authors.lastname: Xiao
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.forename: Scott
authors.initials: S
authors.lastname: Lozanoff
authors.forename: Zhi-guang
authors.initials: ZG
authors.lastname: Zhang
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Luft
authors.forename: Francis
authors.initials: F
authors.lastname: Johnson
mesh_terms: D016475:3T3 Cells; D000818:Animals; D002460:Cell Line; D017077:Culture Media, Conditioned; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D044949:Kaempferols / Q000494:pharmacology; D007684:Kidney Tubules / Q000378:metabolism* / Q000502:physiology; D008516:Medicine, Chinese Traditional; D051379:Mice; D009893:Opossums; D010006:Osteoblasts / Q000737:chemistry*
chemical_list: D017077:Culture Media, Conditioned; D036341:Intercellular Signaling Peptides and Proteins; D044949:Kaempferols; C006552:kaempferol