Proliferative Activity and Neuroprotective Effect of Ligustrazene Derivative by Irritation of Vascular Endothelial Growth Factor Expression in Middle Cerebral Artery Occlusion Rats

Purpose: To investigate the proliferative activity and neuroprotective effect of a newly identified ligustrazine derivative (4-((3,5,6-trimethylpyrazine-2-yl)methoxyl)-3-methox-ybenzoic acid-3,5,6- trimethylpyrazin- 2-methyl ester, T-VA) and the possible mechanism related to vascular endothelial growth factor (VEGF) in cerebral ischemic injury.
Methods: The pharmacological activity of T-VA was evaluated using MTT ((3-(4,5-dimethylthiazolyl2- yl)-2,5-diphenyltetrazolium bromide)) assay, while cellular morphology was observed with hematoxylin and eosin (HE) staining. Chick chorioallantoic membrane (CAM) model, immuno-histochemical analysis, and enzyme-linked immunosorbent assay (ELISA) were used to determine the expression of VEGF. Middle cerebral artery occlusion (MCAO) model was used to investigate both VEGF expression and the survival rate after treatment with T-VA.
Results: T-VA promoted neuron activity, and the doses of 15 and 30 μM showed more significant effect (p < 0.05). The viability of PC12 cells increased significantly in T-VA (30 and 60 μM) groups (p < 0.05) and increased in a dose-dependent manner. Immunohistochemical analysis showed stimulated VEGF expression, and CAM model results showed that T-VA (20 mg/egg) significantly promoted microangiogenesis (p < 0.01). Moreover, in MCAO model, the survival rate of T-VA (60 mg/kg) group reached 86.7 % while for the ischemia group it was 60.0 %. In addition, ELISA results showed that T-VA promoted the expression of VEGF (p < 0.05).
Conclusion: These findings indicate that T-VA helps to prevent ischemic injury by increasing VEGF expression.

Keywords
Ligustrazine; Neuron; PC12 cell; Chick Chorioallantoic Membrane; Middle Cerebral Artery Occlusion; Vascular Endothelial Growth Factor