Butylphthalide Inhibits TLR4/NF-κB Pathway by Upregulation of miR-21 to Have the Neuroprotective Effect

Abstract

Stroke is a disease with the highest incidence rate and the highest mortality rate in the world. The study aims to verify the neuroprotective effect of Butylphthalide. The mice were divided into sham group, MCAO group, and MCAO + Butylphthalide-treated group. The mice in MCAO + Butylphthalide-treated group were administered with 70 mg/kg Butylphthalide injection intraperitoneally after cerebral ischemia-reperfusion. The normal saline with the same volume was administered intraperitoneally for the mice in the MCAO group and sham group. The levels of miR-21 in brain tissue and cells were detected by qPCR. The OGD/R injury model of Neuro2A cells was used to simulate the hypoxic-ischemic environment of neurons in vitro. The proliferation rate of Neuro2A cells was detected with CCK-8. The production of ROS was detected with DCFH-DA. Compared with the mice in MCAO group, a decrease ( $P<0.01$ ) was observed in the functional neurologic impairment scoring, cerebral infarction volume, and brain loss volume in the mice treated with MCAO + Butylphthalide, but an increase ( $P<0.01$ ) was observed in the level of miR-21, which was positively correlated with functional neurologic impairment scoring (r = −0.8933, $P<0.001$ ). MTT assay showed that the cell viability of OGD/R + Butylphthalide group was significantly higher than that of other groups ( $P<0.001$ ), and the activity of ROS was significantly decreased ( $P<0.001$ ). The WB results showed that, compared with OGD/R + miR-NC and control groups, the ratio of Bcl-2/Bax in OGD/R + Butylphthalide group and OGD/R + miR-21 mimics group was significantly higher ( $P<0.05$ ), while the ratio of caspase-3/GAPDH was significantly lower ( $P<0.05$ ). In conclusion, Butylphthalide has neuroprotective effect on the mouse model of MCAO. It may upregulate the level of miR-21 to inhibit neuronal apoptosis and ROS production and improve the proliferation activity. The specific mechanism may lie in inhibiting TLR4/NF-κB pathway.