Conditioned medium of bone marrow mesenchymal stem cells via intravenous injection to treat cerebral ischemia-reperfusion injury

Background: Large numbers of experimental data have confirmed that bone marrow mesenchymal stem cells have a positive therapeutic effect on cerebral ischemia-reperfusion injury, but there are few reports about intravenous administration of bone marrow mesenchymal stem cell conditioned medium in the treatment of stroke. Objective: To investigate the effects of the conditioned medium of rat bone marrow mesenchymal stem cells on the recovery of neurological function in rats after cerebral ischemia-reperfusion injury. Methods: The bone marrow mesenchymal stem cells were isolated from rat bone marrow. When cells at passage 2 or 3 reached 90% confluence, the original culture medium was removed. Then the cells were cultured in serum-free DMEM for 18 hours. After that, the culture solution was collected as the conditioned medium of rat bone marrow mesenchymal stem cells. Adult rats were subjected to 2 hours of right middle cerebral artery occlusion. Ischemia-reperfusion injury rats were randomly assigned to three groups: control group, simple culture medium group and conditioned medium group, and respectively given injection of normal saline, DMEM, conditioned medium (10 mL/kg) via the tail vein at 2, 24, 48 hours after operation. RESULTS AND CONCLUSION: There was no difference in the behavioral tests among the three groups at postoperative 2 hours (P > 0.05). Compared with the control and simple culture medium group, neurological impairment was significantly improved in the conditioned medium group at postoperative 1, 3, 5 days (P < 0.05), but there was no significant difference between the control and simple culture medium groups. At postoperative 5 days, brain edema was significantly eased in the conditioned medium group in comparison to the control and simple culture medium groups (P <0.05), and there was also no difference between the latter two groups (P > 0.05). These results suggest that rat bone marrow mesenchymal stem cells-conditioned medium via intravenous administration can significantly ease brain edema and improve the neurologic function after cerebral ischemia-reperfusion injury.