TITLE:
Promotive Effects of Yokukansan, a Traditional Japanese Medicine, on Proliferation and Differentiation of Cultured Mouse Cortical Oligodendrocytes
AUTHORS:
Toshiyuki Ueki, Yasushi Ikarashi, Zenji Kawakami, Kazushige Mizoguchi, Yoshio Kase
KEYWORDS:
Yokukansan, Oligodendrocyte, Proliferation, Differentiation, Geissoschizine Methyl Ether
JOURNAL NAME:
Pharmacology & Pharmacy,
Vol.5 No.7,
June
17,
2014
ABSTRACT: Effects of yokukansan, a traditional Japanese medicine, on proliferation
and differentiation of oligodendrocytes were examined using purified mouse
cortical oligodendrocyte precursor cells (OPCs). OPCs were cultured for four
days, and proliferation was evaluated by counting A2B5 (a specific antibody to
OPC)-reactive cells on the second day of cell culture. Differentiation from OPC
to oligodendrocyte was evaluated by counting O4 (a specific antibody to detect
differentiated cells in various stages)-reactive cells on the fourth day of
culture. The effects of yokukansan (final concentration: 100 or 200 μg/ml) on
proliferation and differentiation were examined by adding it to the medium for
four days. Yokukansan increased not only the number of A2B5-positive cells on
the second day but also the number of O4-positive cells on the fourth day
compared to those in the corresponding controls. A WST-8 assay was used to
identify active components from seven components of Uncaria Hook (UH), one of
the constituent galenicals of yokukansan. Geissoschizine methyl ether (GM: 0.1
- 3.0 μM) was identified by this screening assay and increased the number of
A2B5-positive cells on the second day and O4-positive cells on the fourth day
as yokukansan did. These results suggest that yokukansan promotes the
proliferation and differentiation of oligodendrocytes, and also that GM
contained in UH is one of active components responsible for this effect of
yokukansan.