| Objective: A collagenase-induced rat model of intracerebral hemorrhage(ICH)was used to investigate the neuroprotective effect and possible mechanism of oridonin on secondary brain injury of ICH.Methods: ICH model in rats was induced by collagenase injection on the right basal ganglia.All rats were randomly divided into SHAM group,ICH group,solvent group,5 mg/kg Ori low-dose group,15 mg/kg Ori medium-dose group,25 mg/kg Ori high-dose group and Nrf2 inhibitor(ICH + Ori + ML385)group.After 72 h of surgery or drug treatment,neurobehavioral tests were performed,and rats were sacrificed to extract brain tissue.Notably,brain tissue requiring staining experiments was perfused with 4% polyformaldehyde before death in rats.The brain tissue was divided into three parts: cerebellum,left brain and right brain,and then brain water content was measured by drywet weight method.FJC staining was used to detect neuronal damage.The protein expressions of Nrf2/HO-1 antioxidant protein,ABI3 and NF-κB inflammatory protein were detected by Western blot and immunofluorescence staining was used to detect the expression of Nrf2,HO-1 in the brain of experimental rats.Elisa was used to detect the expression of TNF-α,IL-1β and IL-6 in each group of brain tissues.Results: Neurobehavioral tests showed that the modified neurological severity score(mNSS)of each group in the Ori treatment group were lower than that in ICH group,and there was a significant difference between Ori medium-dose group and Ori high-dose group(P < 0.05).The brain water content test showed no difference between the cerebellum and the left brain,while brain water content of the right brain increased significantly after ICH modeling compared with the SHAM group(P < 0.05).however,after medium and high dose Ori treatment,the water content of the right brain tissue was significantly lower than that of the ICH group(P < 0.05).However,after medium-dose or high-dose of Ori treatment,brain water content of the right brain was significantly lower than that of the ICH group(P < 0.05).Subsequent Western blot tests showed that the protein expression of ABI3 increased at 6 h,12 h,24h,and 48 h after ICH,but decreased at 72 h,but remained higher than SHAM group(P < 0.05).In addition,the expression of Nrf2,HO-1,ABI3,and NF-κB in the ICH group increased compared with SHAM group,while the expression of ABI3 and NF-κB decreased and the expression of Nrf2 and HO-1 increased further after medium-dose or high-dose Ori treatment.In addition,these experimental results all showed that there was no significant difference in the above indicators between Ori medium-dose group and Ori high-dose group.Therefore,we chose the medium-dose(15 mg/kg)as the optimal dose for Ori treatment for follow-up experiments.The results of immunofluorescence staining showed that compared with ICH group,the expression of Nrf2 / HO-1 in Ori treatment group was significantly increased.ELISA assays revealed a significant increase in proinflammatory factors such as TNF-α,IL-1β,and IL-6 after ICH,but Ori treatment could significantly reduce the expression of that(P < 0.05).The number of degeneration neurons in Ori treatment group were significantly reduced compared with ICH group,but they were increased after using Nrf2 inhibitors,and the difference was significant(P < 0.05).Conclusion: 1.Ori plays a neuroprotective role in the early brain injury of ICH by reducing the damage of neurons and the degree of brain edema as well as promoting the recovery of nerve function.2.Ori may achieve neuroprotective effects in ICH by promoting the Nrf2 / HO-1 antioxidant pathway.3.Ori attenuates inflammatory injury after ICH by reducing the expression of proinflammatory factors such as TNF-α,IL-1β and IL-6,which may be related to inhibition of NF-κB inflammation pathway,and ABI3 protein may be involved in this antiinflammatory process. |
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