Effect of songling xuemaikang pretreatment on the expression of tmnor necrosis factor-α after cerebral ischemia-reperfusion in rats

Objective To investigate the effect of songling xuemaikang pretreatment on the expression of tumor necrosis factor-α （TNF-α after focal cerebral ischemia-reperfusion in rats. Methods Sixty male Sprague-Dawiey rats were randomly allocated into songling xuemaikang （SL-xmk） pretreatment, sham-operation, and control groups. The SL-xmk pretreatment group was treated with SL-xmk （937.5 mg/kg） suspension for preventive garage in rats for 2, 4, and 8 weeks （n = 12 in each group）; the sham-operation （n = 12） and control （n = 12） groups were treated with equal volume of saline for preventive garage. At the end of the pretreatment process, a model of middle cerebral artery occlusion （MCAO） in rats was induced by suture method. The effects of SL-xmk on neurological deficit score, brain water content, and volume of infarction of the MCAO rats at different time course for prevention were observed. Enzyme-linked immunosorbent assay （ELISA） was used to determine serum TNF-α concentration, and immunohistochemical staining was used to detect TNF-α immunoreactive positive cell in ischemic brain tissue. Results After the different time course of SL-xmk pretreatment, the neurological deficit scores of MCAO in rats were all decreased slightly. The numbers of TNF-α positive cells in brain tissue in the pretreatment 2-, 4-, and 8-week groups were 1.92 ± 0.42, 1.63 ± 0.43, and 1.17 ± 0.25, respectively, and they were significantly lower than 2.37 ± 0.38 （all P =0. 000）; The numbers of TNF-α positive cells in brain tissue in the pretreatment 2-,4-, and 8-week groups were 19.0 ± 2.19, 17.33 ± 2.07, and 13.17 ± 2.32/mm, respectively, and they significantly less than 24.67 ± 2.50/mm in the control group; and he numbers of TNF-α positive cells in brain tissue in the pretreatment 8-week group was significantly less than those in the pretreatment 2- and 4-week groups （all P 〈0.05）; the serum TNF-α levels at pretreatment 2, 4, and 8 weeks were 57.55 ± 3.27, 54. 10 ± 3.11, and 45.92 ±3.32 ng/ml, respectively, and they were significantly lower than 77.15 ± 6.19 ng/ml in the control group （all P =0. 000）; The ischemic brain water content in the pretreatment 2-, 4-, and 8-week groups were 77.67 ± 5.46%, 76.63 ± 5.31%, and 75.37 ± 5.25%, respectively, and they were significantly lower than 89.31 ± 7.65 % in the control group （P = 0.04, 0. 028 and 0. 018, respectively）; The percentage of infarct volume in the pretreatment 2-, 4-, and 8-week groups were 25.39 ± 2.28%, 24.73 ± 2.26%, and 21.38 ± 2.23%, respectively, and they were significantly lower than 29.52 ±2.98% in the control group （P = 0. 044, 0. 024, and 0.00 l, respectively）. Conclusions SL-xmk pretreatment may significantly inhibit the expression of TNF-α, alleviate neurological deficits, and reduce brain water content and infarct volume after cerebral ischemia-reperfusion in rats. Key words: Brain ischemia;  Reperfusion injury;  Tumor necrosis factory; Songling Xuemaikang;  Rats