[Ginsenoside Rg1 protects rat hippocampal neurons from radiation injury by regulating NOS activity].

OBJECTIVE: To study the protective effect of ginsenoside Rg1 on cultured rat hippocampal neurons against radiation injury and explore new therapies for preventing radiation encephalopathy. METHODS: Rat hippocampal neurons cultured for 12 days were subjected to a single-dose X-ray exposure of 30 Gy. 4',6-diamidino-2-phenylindole (DAPI) staining was used to detect the neuronal apoptosis and NOS activity kit utilized to evaluate NOS activity in the cells after the exposure. RESULTS: Nuclear condensation was detected in (25.3-/+3.57)% of the neurons 24 h after 30 Gy X-ray exposure, a rate significantly higher than that in the control cells [(1.95-/+0.78)%, P<0.01]. In the neurons pretreated with ginsenoside Rg1, only (7.43-/+1.51)% of the cells presented with nuclear condensation after the exposure, significantly different from the rates in the control cultures and the exposed cultures (P<0.01). The NOS activity of exposed cultures was 6.46-/+0.95 U/ml, significantly higher than that in the control cultures (3.20-/+0.70 U/ml, P<0.01). The NOS activity of the neurons pretreated with ginsenoside Rg1 was 3.85-/+0.69 U/ml, significantly different from that in the control cultures (P<0.05) and the exposed cultures (P<0.01). CONCLUSION: Ginsenoside Rg1 offers significant protective effect on rat hippocampal neurons from radiation-induced apoptosis by reducing the activity of NOS.