Purpose: To investigate the effect
and the potential mechanisms of ginsenoside Rb1 on
nitric oxide (NO) production in chondrocytes.
Methods: SW1353 chondrosarcoma
cells were stimulated with interleukin-1β (IL-1β) in the
presence of 20, 40, 80 µM ginsenoside Rb1. NO
concentration was assessed by the Griess reaction.
Expression of inducible nitric oxide synthase (iNOS),
content of inhibitor of NF-κB (IκB)α and nuclear level
of nuclear factor (NF)-κB p65 were determined by Western
blot. DNA binding activity of NF-κB was evaluated with
Trans AM™ kit for NF-κB p65.
Results: Ginsenoside Rb1 (40 and
80 µM) significantly decreased NO level by 24 (p < 0.05)
and 46 % (p < 0.01), as well as iNOS protein expression
by 40 and 55 % (p < 0.01), respectively, in
IL-1β-stimulated SW1353 cells. Ginsenoside Rb1 (40 and
80 µM) also markedly elevated IκBα protein content by
200 and 260 % (p < 0.01), reduced the nuclear level of
p65 protein by 30 and 40 % (p < 0.01), as well as
decreased the DNA binding activity of NF-κB by 40 and 50
% (both p < 0.01), respectively, in IL-1β-stimulated
SW1353 cells.
Conclusion: These results suggest that
ginsenoside Rb1 inhibits IL-1β-induced NO production
through downregulation of NF-κB-dependent iNOS
expression in chondrocytes, and also underlines the
potential mechanisms of ginseng activity in OA treatment
of TCM.
Keywords: Ginsenoside Rb1, Nitric
oxide, Nuclear factor-κB, Chondrocytes, Osteoarthritis
