Abstract
In this study, we investigated the neuroprotective effect of oxysophoridine
on ischemia and ischemia-like insults. Protection by oxysophoridine was
studied at the in vivo level using a model of middle cerebral artery
occlusion in mice and at the in vitro level using primary rat
hippocampal neuronal cultures exposed to oxygen-glucose deprivation, a model
of ischemia-like injury. The behavioral test was performed by using the
neurological scores. The infarction volume of brain was assessed in the
brain slices stained with 2,3,5-triphenyl tetrazolium chloride. The neuron
apoptosis was evaluated by Hoechst 33342 staining. The morphological change
in the neurons was examined using a Transmission Electron Microscope (TEM or
EM). To evaluate neuron apoptosis, caspase-3, -9, and − 8 activities were
measured using assay kits with an ELISA reader. The Western blotting assay
was used to evaluate the release of cytochrome c and expression of
caspase-3, Bcl-2, and Bax proteins. The quantitative real-time PCR assay was
used to evaluate the release of cytochrome c and the expression of caspase-3
mRNA. Oxysophoridine-treated groups (62.5, 125, 250 mg/kg) markedly reduced
neurological deficit scores and infarct volumes. Treatment with
oxysophoridine (5, 20, 80 µmol/L) significantly attenuated neuronal damage,
with evidence of decreased cell apoptosis and decreased cell morphologic
impairment. Furthermore, treatment with oxysophoridine could effectively
downregulate the expression of cytochrome c and caspase-3 in both mRNA and
protein levels, and Bax in the protein level, and induce an increase of
Bcl-2 in the protein level. The caspase-3, -9, and -8 activities were also
inhibited. These findings suggested that oxysophoridine may be a potential
neuroprotective agent for cerebral ischemia injury.
Key words
oxysophoridine - cerebral ischemia - middle cerebral artery occlusion - oxygen-glucose deprivation - apoptosis - neuroprotection -
Siphocampylus verticillatus
- Campanulaceae
