Effects of xiaoyu tablet on endothelin-1, nitric oxide, and apoptotic cells of atherosclerotic vessel wall in rabbits.

AIM: To investigate the mechanism of xiaoyu tablet on reduction of smooth muscle
cells (SMC) in atherosclerotic vessel wall.
METHODS: The atherosclerotic model was performed in male New Zealand rabbits that
were given high fat diet and abrasion of the abdominal aorta endothelial cells.
The rabbits were then administered with xiaoyu tablet 0.16-0.32 g x kg(-1) x
d(-1) for 16 weeks. Changes in morphology, endothelin (ET)-1, nitric oxide (NO),
and apoptotic cells of atherosclerotic vessel wall were determined by the
microscopy, radioimmunoassay, colorimetric method, the techniques of DNA in situ
end labeling, and image pattern analysis, respectively.
RESULTS: After 16 weeks of xiaoyu tablet treatment, intimal thickness and SMC in
atherosclerotic vessel wall were diminished, ET-1 was decreased by 8.2 %-42.6 %,
NO was increased by 7.5 %-54.2 %, and labeled apoptotic nuclei were markedly
decreased, the area and integral optical density of positive granule were
(846+/-308) microm2 and 3425+/-1374 in atherosclerotic group and (225+/-60)
microm2 and 1445+/-606 in xiaoyu tablet 0.32 g/kg group, respectively.
CONCLUSION: Xiaoyu tablet not only inhibited proliferation of SMC through
reducing ET-1 in atherosclerotic vessel wall, but also induced apoptosis of SMC
by increasing NO in vessel wall.