morroniside and Brain-Ischemia

Preservation of cerebral microvascular functional integrity is crucial for protecting and repairing the brain after stroke. Our previous study demonstrated that morroniside promoted angiogenesis 7days after stroke. The current study aimed to further evaluate the long-term effects of morroniside on angiogenesis and to examine whether angiogenesis induced by morroniside could improve blood flow velocity. Sprague-Dawley rats were subjected to middle cerebral artery occlusion (MCAO), and morroniside was then administered once per day at a dose of 270mg/kg. New vessel formation and the expression of ephrinB2/VEGFR2 signaling pathway components were examined 14days after MCAO to examine angiogenesis and the associated mechanisms. The dynamics of regional cerebral blood flow (rCBF) and the number of vessels of the leptomeningeal anastomoses were analyzed to characterize microvascular circulation 3days after MCAO. We demonstrated that morroniside promoted angiogenesis by regulating the ephrinB2/VEGFR2 signaling pathway 14days post-ischemia. By 3days post-ischemia, morroniside improved rCBF and increased the number of vessels of the leptomeningeal anastomoses. Moreover, morroniside decreased the infarct volume and improved neurological function 14days after MCAO. Our findings suggest that morroniside promoted long-term angiogenesis, thereby improving microvascular circulation and neurological function. It suggested that the angiogenic mechanism of morroniside might be mediated by the ephrinB2/VEGFR2 signaling pathway.

Topics: Angiogenesis Inducing Agents; Animals; Brain; Brain Ischemia; Cerebrovascular Circulation; Disease Models, Animal; Ephrin-B2; Glycosides; Male; Microvessels; Neovascularization, Physiologic; Random Allocation; Rats, Sprague-Dawley; Reperfusion Injury; Stroke; Vascular Endothelial Growth Factor Receptor-2

Treating the vascular elements within the neurovascular unit is essential for protecting and repairing the brain after stroke. Acute injury on endothelial systems results in the disruption of blood-brain barrier (BBB), while post-ischemic angiogenesis plays an important role in delayed functional recovery. Here, we considered alterations in microvessel integrity to be targets for brain recovery, and tested the natural compound morroniside as a therapeutic approach to restore the vascular elements of injured tissue in a rat model of focal cerebral ischemia. Sprague-Dawley rats were subjected to middle cerebral artery occlusion (MCAO) model, and morroniside was then administered intragastrically once a day at doses of 30, 90, and 270 mg/kg. BBB integrity and associated factors were analyzed to identify cerebrovascular permeability 3 days after MCAO. The recruitment of endothelial progenitor cells (EPCs), the expression of angiogenic factors and the new vessel formation in the peri-infarct cortex of rats were examined 7 days after MCAO to identify the angiogenesis. We demonstrated that at 3 days post-ischemia, morroniside preserved neurovascular unit function by ameliorating BBB injury. By 7 days post-ischemia, morroniside amplified angiogenesis, in part by enhancing endothelial progenitor cell proliferation and expression of angiogenic factors. Morever, the increase in the amount of vWF+ vessels induced by ischemia could be extended to 28 days after administration of morroniside, indicating the crucial role of morroniside in angiogenesis during the chronic phase. Taken together, our findings suggested that morroniside might offer a novel therapeutic approach for promoting microvascular integrity recovery and provide a thoroughly new direction for stroke therapy.

Topics: Animals; Blood-Brain Barrier; Brain Ischemia; Capillary Permeability; Cell Proliferation; Cerebral Cortex; Endothelial Cells; Glycosides; Infarction, Middle Cerebral Artery; Inflammation; Male; Matrix Metalloproteinases; Microvessels; Models, Biological; Neovascularization, Physiologic; Rats, Sprague-Dawley; Receptor, TIE-2; von Willebrand Factor

Cornus officinalis Sieb. et Zucc., known as Shan-zhu-yu in Chinese, has been used to treat cerebrovascular disease and diabetes in Traditional Chinese Medicine for a long time and morroniside is the main component of Shan-zhu-yu. In this study, we examined whether morroniside could protect ischemia/reperfusion-induced brain injury by minimizing oxidative stress and anti-apoptosis. Morroniside was intragastrically administered to rats in doses of 30, 90 and 270mg/kg/day, starting 3h after the onset of middle cerebral artery occlusion. The behavioral test was performed by using the Zea-Longa scores, Prehensile Traction score and Ludmila Belayer score. Rats were sacrificed 3 days after ischemia occurred. The infarction volume of brain was assessed in the brain slices stained with 2,3,5-triphenyl tetrazolium chloride. Cortex tissues were also used for determination of malondialdehyde levels, glutathione levels and superoxide dismutase. The treatment with morroniside significantly improved Zea-Longa scores and Prehensile Traction score at the doses of 30, 90 and 270mg/kg, increased Ludmila Belayer score and reduced the infarction volume at the doses of 90 and 270mg/kg. Morroniside (30, 90 and 270mg/kg) treatment significantly decreased the level of malondialdehyde and caspase-3 activity by colorimetric analysis in ischemic cortex tissues. Morroniside (270mg/kg) treatment significantly increased the content of glutathione, enhanced the activity of superoxide dismutase, but decreased the caspase-3 expression by Western-blot analysis in ischemic cortex tissues. These findings demonstrated that morroniside could notably protect the brain from damage induced by focal cerebral ischemia which might be related to morroniside antioxidant and anti-apoptotic properties in the brain.

Topics: Animals; Behavior, Animal; Brain; Brain Ischemia; Caspase 3; Cornus; Drugs, Chinese Herbal; Glutathione; Glycosides; Humans; Male; Medicine, Chinese Traditional; Molecular Structure; Neuroprotective Agents; Rats; Rats, Wistar; Superoxide Dismutase