OBJECTIVE: To observe regulatory effect of Naoluoxintong formula (脑络欣通方, NLXT) and its split prescriptions on vascular regeneration of rats suffering from cerebral ischemia-reperfusion (IR) syndrome of Qi deficiency with blood stasis (QDBS).
METHODS: NLXT is the representative prescription of Yiqi Huoxue Tongluo decoction (益气活血通络方), and NLXT is divided into Yiqi herbs (益气药) and Huoxue Tongluo herbs (活血通络药) according to their efficacies. One hundred and eight specific-pathogen-free, clean-grade, Sprague-Dawley male rats were selected to prepare the classical rat model with QDBS due to middle artery ischemia-reperfusion using the multi-factor compound simulation approach. The animals were classified into sham operation (S), model (M), Nimodping (NMDP), NLXT, YQ and HXTL groups, each having 18 rats. Cerebral ischemia was reperfused after 2 h, and 24 h later, they were administered traditional Chinese medicine treatment for 14 d twice a day. Angiogenesis changes after NLXT administration to middle cerebral artery occlusion-reperfusion (MCAO/R) rats with QDBS were analyzed using the neurological deficit score and hematoxylin-eosin staining. Cerebral infarct area by 2,3,5-Triphenyltetrazolium chloride was detected, and the ultrastructure of the blood vessel in the ischemic frontoparietal cortex was observed by transmission electron microscopy. Angiopoietin 1 (Ang1), angiopoietin 2 (Ang2), vascular endothelial growth factor A (VEGFA), vascular endothelial growth factor receptor 2 (VEGFR2), platelet endothelial cell adhesion molecule-1 (CD31), angiopoietin receptor 2 (Tie2), and P38 mitogen-activated protein kinase (MAPK) protein levels in the frontal and parietal cortex were quantified by immunofluorescence, reverse transcription-polymerase chain reaction, and Western blotting assays.
RESULTS: Relative to the S group, VEGFA and VEGFR2 levels in the frontal and parietal cortex of group M were increased, and Ang1, Ang2, Tie2, CD31, and p38 MAPK levels remarkably increased (P < 0.05); cerebral infarct area was significant and pathological morphology and ultrastructure damage was obvious. Relative to the group M, VEGFA, VEGFR2, CD31, Ang1, Ang2, and Tie2 expression of group NLXT and NMDP remarkably elevated (P < 0.05) and infarct focus, pathological morphology and ultrastructure were significantly improved; VEGFA and VEGFR2 levels in the groups YQ and HXTL increased, and Ang1, Ang2, CD31, and Tie2 levels remarkably increased (P < 0.05); p38 MAPK levels in the three treatment groups decreased (P < 0.05). Relative to the group NLXT, the expression levels of p38 MAPK in group YQ and group HXTL were significantly increased, and the expression levels of other indicators were significantly decreased (P < 0.05).
CONCLUSION: NLXT can promote the angiogenesis of the rat model of MCAO/R with QDBS by activating VEGFA and inhibiting P38 MAPK, and the effect is better than that of split prescription groups.