Role of edaravone in alleviating prognosis of rats following traumatic brain injury

Abstract

Objective To investigate the effects of edaravone on improving the prognosis of TBI rats. Methods A total of 150 SD male rats were divided into normal control group (10 rats), TBI group (70 rats) and edaravone group (70 rats). In the edaravone treatment group, the rats were injected intraperitoneally once a day continously for 2 weeks with the injection dose of 5.4 mg·kg-1·d-1. At 6 hours, 12 hours, 24 hours, 48 hours, 72 hours, 1 week and 2 weeks after injury, the neurobehavioral and motor function scores of rats were monitored respectively, with 10 rats monitored at each time point. Serum and cerebrospinal fluid samples were collected and the levels of β-endorphin and gonadotropin-releasing hormone (GnRH) were determined by radioimmunoassay (RIA). Results In the edaravone group, the neurobehavioral and motor function scores were higher than those of the TBI group at 6 hours, 12 hours, 24 hours, 48 hours, 72 hours, 1 week and 2 weeks after injury. At 48 hours after injury, the neurobehavioral scores of the TBI group and the edaravone treatment group were (8.2±0.9)points and (10.3±0.7)points, respectively (P<0.05), and the motor function scores were (5.9±1.0)points and (6.9±1.2)points respectively (P<0.05). Meanwhile, the contents of β-endorphin in blood and cerebrospinal fluid of the normal control group were (50.2±9.5)pg/ml and (16.2±2.8)pg/ml, and the contents of GnRH were (75.2±11.2)pg/ml and (36.2±10.8)pg/ml, respectively.The levels of β-endorphin and GnRH in serum and cerebrospinal fluid were significantly increased at 6 hours, 12 hours, 24 hours, 48 hours, 72 hours, 1 week and 2 weeks after injury. The levels of β-endorphin and GnRH in the edaravone group were lower than those of TBI group. At 72 hour after injury, the levels of β-endorph in serum in TBI group and edaravone group were (165.2±8.5) pg/ml and (109.5±6.3)pg/ml respectively (P< 0.05), and the levels of β-endorph in cerebrospinal fluid were (63.3±3.1)pg/ml and (38.2±2.3)pg/ml respectively (P<0.05). At 72 hour after injury, the levels of GnRH in serum in TBI group and edaravone group were (203.7±17.1)pg/ml and (110.4±19.2)pg/ml respectively (P<0.05), and the levels of GnRH in cerebrospinal fluid is (153.0±13.4)pg/ml and (93.2±10.5)pg/ml respectively (P<0.05). Conclusion During acute and recovery periods after TBI, continuous treatment with edaravone can obviously reduce the levels of β-endorphin and GnRH, which is beneficial to alleviate the secondary brain injury after TBI in rats, promote the recovery of nerve and function, and improve the prognosis. Key words: Brain injuries; β-Endorphin; Gonadotropin-releasing hormone; Edaravone