Improvement in cerebral ischemia-reperfusion injury through the TLR4/NF-κB pathway after Kudiezi injection in rats.

OBJECTIVE

Kudiezi injection (KDZ) can improve the clinical outcomes of patients with stroke, but the mechanisms remain unclear. This study aimed to investigate whether KDZ could modulate the nuclear factor kappa B (NF-κB) pathways in rat models of transient middle cerebral artery occlusion (tMCAO).

METHODS

Male Sprague-Dawley rats were subjected to tMCAO and randomized to Sham (sham-operated), tMCAO (tMCAO+0.9% saline), and KDZ (tMCAO+7.2mL/kg KDZ) groups. The infarct volume, brain water content, and neurological deficit were assessed 72h after reperfusion. Immunofluorescence was used to detect the expression of cleaved caspase-3 and NF-κBp65. The expression of cleaved caspase-3, NF-κB p65, TLR4, MyD88, TRAF6, and p-IκBα/IκBα was determined using Western blotting. The expression levels of TNF-α, interleukin (IL)-1β, and IL-10 in the ischemic cortex were measured using the enzyme-linked immunosorbent assay. In vitro ischemic paradigm (oxygen-glucose deprivation) was performed in SH-SY5Y cells to evaluate the effects of KDZ.

RESULTS

Lower brain water content, smaller infarct volume, and better neurologic function were found in the KDZ group compared with the tMCAO group. The expression of activated caspase-3, TLR-4, TRAF6, NF-κBp65, and p-IκBα/IκBα reduced and the levels of TNF-α and IL-1β decreased in the KDZ group, with the increased IL-10 level. In SH-SY5Y cells, KDZ significantly reduced the expression of p-IκBα and IκBα, lowered the death ratio, and reversed the effects induced by caffeic acid phenethyl ester (a potent NF-κB inhibitor).

CONCLUSIONS

KDZ may function through downregulating the TLR-4-dependent NF-κB signaling pathway to protect the brain against ischemic injury.