Effect of the active fraction of Huanglian-Jiedu Decoction on white matter injury in rats with cerebral ischemia by inhibiting NogoA/NgR expression / 国际中医中药杂志

ABSTRACT

Objective:To study the effect of Huanglian-Jiedu Decoction on the white matter lesion of rats with focal cerebral ischemia and to explore the regulative role of the active fraction of Huanglian-Jiedu Decoction on NogoA/NgR. Methods:Male SD rats were randomly divided into sham operation group, model group, total alkaloid group, total flavonoid group, and total iridoid group. Except for the sham operation group, the rats in the other groups were used to establish the middle cerebral artery occlusion rat model by the suture method. 2 hours after modeling, rats in the total alkaloid group were given intragastric administration with 44 mg/kg total alkaloids; rats in the total flavonoid group were given intragastric administration 50 mg/kg total flavonoids; rats in the total iridoid group were given intragastric administration 80 mg/kg total iridoids, the sham operation group and the model group were intragastrically given equal volume of normal saline, once a day, for 7 consecutive days. The pathological changes of rat white matter were observed by HE staining, the pathological changes of rat myelin sheath were observed by Luxol fast blue (LFB) staining, and the expression of Amyloid precursor protein (APP), NogoA, and NgR in the internal and external capsule areas of the brain was detected by immunohistochemical staining. Real-time fluorescence quantitative PCR was used to detect the expression of NogoA and NgR in the tissues surrounding the ischemic infarct.Results:Compared with the model group, the total alkaloid group, total flavonoid group, and total iridoid group had lower pathological damage scores in the internal and external capsule areas of rats ( P<0.05 or P<0.01), increased integral optical density value of LFB staining ( P<0.01), decreased expression of APP and NogoA; the expression of NgR in the internal and external capsules of rats in the total alkaloid group and the total iridoid group decreased ( P<0.05 or P<0.01), and the expression of NgR in the inner capsule of rats in the total flavonoid group decreased ( P<0.01); the expression of NogoA (1.20 ± 0.17, 1.55 ± 0.30, 1.19 ± 0.38 vs. 2.22 ± 0.58) and NgR (1.98 ± 0.55, 1.48 ± 0.31, 1.58 ± 0.27 vs. 3.36 ± 0.41) genes in the tissues around the infarct focus of rats in the total alkaloid group, total flavonoid group and total iridoid group decreased ( P<0.01). Conclusion:The present study investigates the therapeutic effects of Huanglian-Jiedu Decoction, promoting white matter repair by decreasing the overexpression of NogoA and NgR in an experimental animal model of stroke.