Houshiheisan compound prescription protects neurovascular units after cerebral ischemia

Houshiheisan is composed of wind-dispelling （chrysanthemun fower, divaricate saposhnikovia root, Manchurian wild ginger, cassia twig, Szechwan lovage rhizome, and platycodon root） and deficiency-nourishing （ginseng, Chinese angelica, large-head atractylodes rhizome, Indian bread, and zingiber） drugs. In this study, we assumed these drugs have protective effects against cerebral ischemia, on neurovascular units. Houshiheisan was intragastrically administered in a rat model of focal cerebral ischemia. Hematoxylin-eosin staining, transmission electron microscopy, immu- nofluorescence staining, and western blot assays showed that Houshiheisan reduced pathological injury to the ischemic penumbra, protected neurovascular units, visibly up-regtflated neuronal nuclear antigen expression, and down-regulated amyloid precursor protein and amyloid-[3 42 expression. Wind-dispelling and deficiency-nourishing drugs maintained NeuN expression to varying degrees, but did not affect amyloid precursor protein or amyloid-~ 42 expression in the ischemic penumbra. Our results suggest that the compound prescription Houshiheisan effectively suppresses abnormal amyloid precursor protein accumulation, reduces amyloid substance depo- sition, maintains stabilization of the internal environment of neurovascular units, and minimizes injury to neurovascular units in the ischemic penumbra.

低剂量甲氨蝶呤治疗大鼠脊髓挫伤对神经细胞凋亡的影响

目的：观察低剂量甲氨蝶呤对大鼠脊髓挫伤后神经细胞凋亡的影响，探讨其对神经细胞的保护机制。方法：采用PinPointTM精密皮质撞击器制备大鼠脊髓挫伤模型。伤后30min皮下注射（sc）甲氨蝶呤（0.3mg·kg^-1·BW），给药时间间隔为24h，持续2周。分别采用免疫组织化学染色和TUNEL染色方法检测损伤区域神经元核抗原（neuronalnuclei，NeuN）的表达和神经细胞凋亡。结果：伤后1d各解剖位置灰、白质结构排列整齐；神经元坏死仅见于损伤中心；灰质后角有大量TUNEL阳性细胞表达。伤后3～7d，TUNEL阳性细胞不仅数量快速地增长，而且向腹侧和损伤灶周边节段蔓延；同时从0mm处至±3mm处，NeuN免疫阳性神经元数量也逐渐减少（P〈0．05）。伤后14d在损伤中心已无法辨认灰质结构，但其它解剖位置TUNEL阳性细胞与NeuN免疫阳性神经元的变化均基本趋于平缓；甲氨蝶呤组NeuN免疫阳性神经元数量均高于模型组，且差异具有显著性（P〈0．05，P〈0．01）。结论：低剂量甲氨蝶呤可能通过其代谢产物抑制或减少神经细胞凋亡，对脊髓继发性损伤发挥保护作用。