Protective effect of DL-3-n-Butylphthalide on radiation injury of rat brain tissue

Objective: To investigate the protective effect and its mechanism of DL-3-n-Butylphthalide on the brain damage in rats following whole brain irradiation. Methods: A total of 120 male Sprague Dawley rats were randomly divided into sham-irradiation group, irradiation group and DL-3-n-Butylphthalide group. The model of whole-brain irradiation was established by exposing rat brain to 4 MeV X-rays with a single-dose of 10 Gy. The rats were intraperitoneally injected with DL-3-n-Butylphthalide at the dosages of 0.3, 1.0, and 3.0 mg/kg once a day. The contents of malondialdehyde and super oxide dismutase activity were measured, while the expressions of apoptosis-associated genes and the ultrastructural changes in hippocampus were examined by immunohistochemistry staining and electron microscope, respectively. Results: After irradiation, the content of malondialdehyde and the expression of apoptosis gene bax in rat brain tissue increased while the activity of super oxide dismutase (SOD) and the expression of anti-apoptosis gene bcl-2 decreased. Apoptosis was also observed in the neurons of hippocampus CA1. Compared with irradiation group, the content of malondialdehyde and the expression of bax gene in the DL-3-n-Butylphthalide group wen significantly reduced (t=-3.89 - -1.96, 2.72-3.48, P<0.05), while the activity of SOD and bcl-2 gene were significantly elevated (t=2.94-3.76, -3.18 - -2.08, P<0.05), and the injury degree of neuron structure in the DL-3-n-Butylphthalide group was slighter than that in the irradiation group. Conclusions: DL-3-n-Butylphthalide executes protective effects in a dose-dependent manner against the radiation injury in rats brain by reducing the induction of malondialdehyde, raising the activity of SOD and inhibiting the generation of apoptosis. (authors)