Ischemic stroke leads to severe brain damage and high mortality. Chlorogenic acid is a phenolic compound known to have neuroprotective properties. Bcl-2 family protein plays an important role in the regulation of apoptosis. We investigated whether chlorogenic acid exerts neuroprotective effects against ischemic injury by modulating Bcl-2 and Bax proteins. Middle cerebral artery occlusion (MCAO) was performed to induce cerebral ischemia and rats were injected intraperitoneally with phosphate buffered saline or chlorogenic acid (30 mg/kg) for 2 h after MCAO. Cortical tissues were collected 24 h after MCAO injury and reverse transcription-quantitative real time polymerase chain reaction and Western blot analyses were performed to investigate the expression of Bcl-2 and Bax. The regulation of Bcl-2 and Bax proteins by chlorogenic acid during glutamateinduced cell damage were examined. Cells were collected at 24 h after administration of glutamate (5 mM) and chlorogenic acid (10, 30, 50 μM). These results showed a decrease in Bcl-2 expression and an increase in Bax expression in MCAO animals, but chlorogenic acid treatment alleviated these changes by MCAO damage. Glutamate significantly reduced cell viability, and chlorogenic acid treatment alleviated this reduction in a dose-dependent manner. Glutamate induced a decrease in Bcl-2 expression and an increase in Bax expression, but chlorogenic acid treatment alleviated these changes. We found that chlorogenic acid alleviates changes in the expression of Bcl-2 and Bax proteins induced by brain injury. Therefore, our findings provide an evidence that chlorogenic acid has neuroprotective effects against MCAO damage by modulating Bcl-2 and Bax proteins.

Curcumin plays a protective role in brain injury through its anti-oxidant and anti-inflammatory activities. Moreover, peroxiredoxin-5 exerts a protective effect against oxidative stress. The aim of this study was to investigate whether curcumin modulated the peroxiredoxin-5 expression in focal cerebral ischemic animal model. Middle cerebral artery occlusion(MCAO) was performed to induce cerebral ischemic injury in rats. Adult male rats were injected intraperitoneally with vehicle or curcumin(50㎎/㎏ B.W.) 1 h after MCAO and cerebral cortex tissues were collected 24 h after MCAO. Photographs of hematoxylin and eosin staining showed that MCAO induced necrotic changes with scalloped shrunken form and apoptotic changes with nuclear chromatin condensations. However, curcumin treatment attenuated MCAO-induced histopathological changes. Moreover, this study clearly showed that peroxiredoxin-5 expression was decreased in MCAO operated animal with vehicle using a proteomics approach. However, this decrease in peroxiredoxin-5 expression was attenuated by curcumin treatment. Reverse-transcription PCR and Western blot analyses confirmed that curcumin treatment alleviated the MCAO injury-induced decrease in peroxiredoxin-5 expression(p<0.05). These results demonstrated that curcumin regulates peroxiredoxin-5 expression in MCAO animal model. In conclusion, our findings suggest that curcumin exerts a neuroprotective effect in cerebral ischemia by attenuating the MCAO-induced decrease in peroxiredoxin-5 expression.

Calbindin-D28k is a calcium-binding protein that mediates intracellular calcium concentrations and exerts a neuroprotective effect against ischemic injury. Ferulic acid provides a neuroprotective effect against focal cerebral ischemia through its anti-oxidative and anti-inflammatory mechanisms. In this study, we investigated whether ferulic acid regulates calbindin-D28k expression during focal cerebral ischemia and glutamate treatment-induced neuronal cell death. Middle cerebral artery occlusion (MCAO) was performed to induce focal cerebral ischemia. Ferulic acid (100 mg/kg, i.v.) or vehicle was immediately administered after MCAO, and brain tissues were isolated 24 h after MCAO. RT-PCR and Western blot analyses showed a decrease in calbindin-D28k in MCAO-operated animals. We found that ferulic acid treatment prevented the MCAO-induced decrease in calbindin-D28k expression. Glutamate exposure elevated the intracellular calcium levels in cultured hippocampal cells, and ferulic acid prevented the glutamate exposure-induced increase in calcium levels. Moreover, ferulic acid also attenuated the glutamate toxicity-induced decrease in calbindin-D28k. Taken together, these in vivo and in vitro results demonstrate that ferulic acid regulates calbindin-D28k expression in neuronal cell injury. Therefore, these findings suggest that ferulic acid exerts a neuroprotective effect by modulating calbindin-D28k expression.

본 연구는 중간대뇌동맥을 폐쇄한 대뇌허혈성 손상모델에서 ferulic acid에 의해 조절되는 HO-1과 HO-2의 발현에 관하여 조사하였다. 흰쥐(Sprague-Dawley, 수컷)에 ferulic acid (100 mg/kg) 또는 vehicle을 중간대뇌동맥폐쇄술(MCAO) 후 정맥으로 주사하였고 중간대뇌동맥폐쇄술(MCAO)을 실시한 24시간 후 대뇌피질의 조직을 적출하였다. Hematoxylin과 eosin 염색을 통하여 MCAO로 유도된 뇌 손상시 ferulic acid의 보호효과를 확인하였다. MCAO을 시행한 대뇌피질에서는 응축된 핵과 신경세포의 괴사 소견을 보였으나, ferulic acid 투여군에서는 이들 신경세포의 병변을 현저히 완화시켰다. HO-1과 HO-2의 RNA와 단백질 발현의 변화를 reverse-transcription PCR과 Western blot으로 분석하였다. HO-1 발현은 MCAO 후 vehicle 투여군에서 현저히 감소하였으나, MCAO 후 ferulic acid를 투여한 실험군에서는 이들 감소의 완화를 보였으며, MCAO를 시행하지 않은 실험군의 수준으로 유지되었다. 그러나, HO-2의 발현은 MCAO 후 vehicle 투여군과 ferulic acid 투여군에서 유의적인 차이는 관찰되지 않았고 MCAO를 시행하지 않은 실험군의 수준으로 유지되었다. 따라서, 본 연구의 결과는 허혈성 뇌 손상시 ferulic acid는 HO-1 발현을 조절하였으나, HO-2의 발현에는 영향을 미치지 못함을 확인하였다. 결론적으로, 허혈성 뇌손상시 ferulic acid는 HO-1의 발현을 조절하여 신경세포를 보호하는 역할을 수행한다는 사실을 확인하였다.

Neurotrophic factors are essential to maintain and organize neurons functionally; thereby neurotrophic factor-like substances or their inducers are expected to be applied to the treatment of neurodegenerative diseases such as stroke. In the present study, we firstly examined the effects of ethanol extracts of Hericium erinaceus (HE, Yamabushitake), on nerve growth factor expression in neuronal cells. HE extract promoted NGF expression in a brain tissue. Here we assessed neuroprotective effects of HE with a transient global cerebral ischemia model. Global cerebral ischemia was induced by occluding both common carotid arteries. Treatment with HE was initiated after ischemia induction and given once a day for 7 consecutive days. Neuronal cell loss in CA1 of hippocampus was significantly decreased and the performance in the Morris water maze was significantly improved in rats administered HE. We conclude that treatment with HE attenuated learning and memory deficits, motor functional disability, and neuronal cell loss induced by global cerebral ischemia. These results suggest that HE may be a potential candidate for the treatment of vascular dementia.

In traditional Korean and Chinese medicine, safflower (Carthamus tinctorius L.) for the treatment of centralnervous system-related symptoms such as tremor, seizure, stroke and epilepsy. We investigated the effects of safflower couldinfluence cerebral ischemia-induced neuronal and cognitive impairments. Administration of safflower for 1 day(200㎎/㎏ body weight, p.o.) increased the survival of hippocampal CA1 pyramidal neurons after transient global brainischemia. And neurological functions measured as short term memory. Post-treatment with safflower for 2 times decreasedthe induction/reduction - induced production of neuronal cell loss from global cerebral ischemia. Safflower markedlydecreased neuronal cell death and also caused a decrease in the content of thiobarbituric acid-reacting substances(TBARS) (55.2±9.4µmol mg-¹) and significant improvement of activities of glutathione (GSH) (27.2±5.0µmol mg-¹) inhippocampus. We conclude that treatment with safflower attenuated learning and memory deficits, and neuronal cell lossinduced by global cerebral ischemia. These results suggest that safflower may be a potential candidate for the treatment ofvascular dementia.

A stroke is the major cause of death and can cause neurological damage. The striatum serves as an input gate of the basal ganglia in assisting motor behavior. The activity-dependent synaptic plasticity in the dorsal striatum (DS) is known to play a key role for recovery of motor control after brain injury. Exercise supports functional recovery from ischemic brain injury through brain-derived neurotrophic factor (BDNF) -induced synaptic plasticity. Exercise upregulate the levels of BDNF within both the hippocampus and cerebral cortes and might act as a gate that primes the brain to respond to environmental stimulation, while simultaneously increasing the ability of neurons to resist insult. However, little is known about the effects of exercise on neuroprotection in the DS. Therefore, in this study we attempted to investigate the effects of exercise on the neuronal cell population in the DS. Transient focal brain ischemia was induced by middle cerebral artery occlusion (MCAO) on male Sprague-Dawley rats (300±30). Animals were subjected to forced treadmill exercise group and sedentary group after MCAO. Exercise improved neurologic functions measured by modified neurological severity score. Exercise group showed reduced infarct volume measured by vital staining with 2,3,5-triphenyltetrazolium chloride. Immunohistochemical analysis was performed in the DS with antibodies of neuronal nuclei (NeuN) protein, glial fibrillary acidic protein (GFAP), a matured neuronal marker and an astrocyte marker respectively and BDNF. Ischemic injury decreased NeuN+ cell population but exercise attenuated this decrease while increase in GFAP+ cell population induced by MCAO was inhibited by exercise. These findings suggest that the neurological function recovery by exercise after ischemic brain injury may be mediated by alteration of neuronal cell population in the DS.

Objective The aim of this work was to ascertain whether the memory disturbance following scopolamine administration and the neuroprotective effect of could be evidenced in global cerebral ischemia by evaluating improved cognitive capacity in the rats. Materials and Methods Neuronal cell density was measured by counting viable cells in the left and right CA1 regions of three coronal sections of 30 um. Behavior test; Acquisition deficits after ischemia.. Use passive avoidance test. Results Neuroprotective effect of GB at 100mg/kg is 87.3%. Representative photomicrographs of cresyl violet-stained hippocampal regions of either sham-operated animals(A,B) or animals that had been subjected to 10 min ischemia followed by the treatment with either saline (C,D) or 100mg/kg of Ginkgo biloba (E,F). Boxed regions in A, C, and E are shown in B, D, and F, respectively. The 10 min ischemia caused selective and delayed neuronal cell loss in the hippocampal CA1 region (C,D). In contrast, GB treatment conferred neuroprotection by markedly reducing the number of damaged pyramidal cells in the CA1 subfield (E,F). Scale bar is 100 um. Effect of GB on scopolamine induced memory deficits in the passive avoidance test. At 30 min after trainining trials, scopolamine(1mg/kg i.p.) or the same volume of saline was administered to rats. At 30 min after scopolamine injection, the rats were treated with GB(100mg/kg). Acquisition trials were carried out 30 min after GB treatment. At 24 hr after acquisition trials, the test trials were carried out. Data represents mean ± SEM (n=6).