Baicalin improves inflammatory response of human microglia by regulating cAMP-PKA-NF-κB/CREB pathway / 中国中药杂志

This study aims to investigate the effects of baicalein(BAI) on lipopolysaccharide(LPS)-induced human microglial clone 3(HMC3) cells, with a focus on suppressing inflammatory responses and elucidating the potential mechanism underlying the therapeutic effects of BAI on ischemic stroke via modulating the cAMP-PKA-NF-κB/CREB pathway. The findings have significant implications for the application of traditional Chinese medicine in treating cerebral ischemic diseases. First, the safe dosage of BAI was screened, and then an inflammation model was established with HMC3 cells by induction with LPS for 24 h. The cells were assigned into a control group, a model group, and high-, medium-, and low-dose(5, 2.5, and 1.25 μmol·L~(-1), respectively) BAI groups. The levels of superoxide dismutase(SOD) and malondialdehyde(MDA) in cell extracts, as well as the levels of interleukin-1β(IL-1β), IL-6, tumor necrosis factor-α(TNF-α), and cyclic adenosine monophosphate(cAMP) in the cell supernatant, were measured. Western blot was performed to determine the expression of protein kinase A(PKA), phosphorylated cAMP-response element binding protein(p-CREB), and nuclear factor-kappa B p65(NF-κB p65). Hoechst 33342/PI staining was employed to assess cell apoptosis. High and low doses of BAI were used for treatment in the research on the mechanism. The results revealed that BAI at the concentrations of 10 μmol·L~(-1) and below had no impact on normally cultured HMC3 cells. LPS induction at 200 ng·mL~(-1) for 24 h reduced the SOD activity and increased the MDA content in HMC3 cells. However, 5, 2.5, and 1.25 μmol·L~(-1) BAI significantly increased the SOD activity and 5 μmol·L~(-1) BAI significantly decreased the MDA content. In addition, BAI ameliorated the M1 polarization of HMC3 cells induced by LPS, as indicated by cellular morphology. The results of ELISA demonstrated that BAI significantly lowered the levels of TNF-α, IL-1β, IL-6, and cAMP in the cell supernatant. Western blot revealed that BAI up-regulated the protein levels of PKA and p-CREB while down-regulating the expression of NF-κB p65. Hoechst 33342/PI staining results indicated that BAI mitigated the apoptosis of HMC3 cells. Overall, the results indicated that BAI had protective effects on the HMC3 cells induced by LPS, and could inhi-bit inflammatory response and improve cell apoptosis, which might be related to the regulation of the cAMP-PKA-NF-κB/CREB pathway.

Baicalin treats cerebral ischemia reperfusion-induced brain edema in rats by inhibiting TRPV4 and AQP4 of astrocytes / 中国中药杂志

This study aims to explore the pharmacodynamic effect of baicalin on rat brain edema induced by cerebral ischemia reperfusion injury and discuss the mechanism from the perspective of inhibiting astrocyte swelling, which is expected to serve as a refe-rence for the treatment of cerebral ischemia with Chinese medicine. To be specific, middle cerebral artery occlusion(suture method) was used to induce cerebral ischemia in rats. Rats were randomized into normal group, model group, high-dose baicalin(20 mg·kg~(-1)) group, and low-dose baicalin(10 mg·kg~(-1)) group. The neurobehavior, brain index, brain water content, and cerebral infarction area of rats were measured 6 h and 24 h after cerebral ischemia. Brain slices were stained with hematoxylin and eosin(HE) for the observation of pathological morphology of cerebral cortex after baicalin treatment. Enzyme-linked immunosorbent assay(ELISA) was employed to determine the content of total L-glutathione(GSH) and glutamic acid(Glu) in brain tissue, Western blot to measure the content of glial fibrillary acidic protein(GFAP), aquaporin-4(AQP4), and transient receptor potential vanilloid type 4(TRPV4), and immunohistochemical staining to observe the expression of GFAP. The low-dose baicalin was used for exploring the mechanism. The experimental results showed that the neurobehavioral scores(6 h and 24 h of cerebral ischemia), brain water content, and cerebral infarction area of the model group were increased, and both high-dose and low-dose baicalin can lower the above three indexes. The content of GSH dropped but the content of Glu raised in brain tissue of rats in the model group. Low-dose baicalin can elevate the content of GSH and lower the content of Glu. According to the immunohistochemical staining result, the model group demonstrated the increase in GFAP expression, and swelling and proliferation of astrocytes, and the low-dose baicalin can significantly improve this situation. The results of Western blot showed that the expression of GFAP, TRPV4, and AQP4 in the cerebral cortex of the model group increased, and the low-dose baicalin reduce their expression. The cerebral cortex of rats in the model group was severely damaged, and the low-dose baicalin can significantly alleviate the damage. The above results indicate that baicalin can effectively relieve the brain edema caused by cerebral ischemia reperfusion injury in rats, possibly by suppressing astrocyte swelling and TRPV4 and AQP4.

Effects of Buyang Huanwu Decoction on neurovascular units after cerebral ischemia: a review / 中国中药杂志

Buyang Huanwu Decoction, a representative prescription in traditional Chinese medicine(TCM) for tonifying Qi and activating blood, has been proved to be effective in preventing and treating acute cerebral infarction(ACI). It consists of Astragali Radix, Angelicae Sinensis Radix, Paeoniae Radix Rubra, Pheretima, Chuanxiong Rhizoma, Carthami Flos, and Persicae Semen, possessing multiple active ingredients. The neurovascular unit is a functionally and structurally interdependent multicellular complex composed of neurons-glial cells-blood vessels. It plays an important role in the pathological changes of cerebral ischemia and the permeability variation of the blood-brain barrier. In recent years, Buyang Huanwu Decoction has been found to protect the integrity of neurovascular units and improve the permeability of the blood-brain barrier, thereby alleviating stroke and other diseases caused by cerebral ischemia. This paper collated and summarized the protective effects of Buyang Huanwu Decoction on neurovascular units.

Effect of Yinxing Mihuan Oral Solutionon P2RX7/NLRP3 Signaling Pathway in Depression Model Rats Induced by Isolation Combined with Chronic Unpredictable Mild Stress / 中国实验方剂学杂志

Objective:To explore the antidepressant mechanism of Yinxing Mihuan oral solution （YMO） by investigating its effect on depression model rats. Method:The depression rats were induced by isolation combined with chronic unpredictable mild stress （CUMS） and then randomly divided into model group， fluoxetine group （10 mg·kg^-1） and high-dose （618 mg·kg^-1） and low-dose （309 mg·kg^-1） YMO groups. A blank control group was also set up and ten rats were included in each group. Modeling lasted for 21 consecutive days， and rats were administered the 8th day after stimulation at a dose of 10 mL·kg^-1 for 14 days， except those in the blank control and model groups which were given distilled water. Afterward， the sucrose preference test， open field test， tail suspension test were carried out. The pathological changes of hippocampus in depression rats were observed after hematoxylin-eosin （HE） staining. The content of interleukin-1<italic>β </italic>（IL-1<italic>β</italic>）， interleukin-6 （IL-6） and tumor necrosis factor-<italic>α </italic>（TNF-<italic>α</italic>） in the hippocampus of rats in each group and the expression of NOD-like receptor 3 （NLRP3） and other proteins in its related activation signaling pathways were detected with multi-factor detection （Luminex） and Western blot. Result:After 14 days of continuous administration， compared with the blank control group， the model group witnessed significantly reduced sugar water consumption rate and the times of rearing and significantly prolonged cumulative time of immobility during tail suspension （<italic>P</italic><0.05， <italic>P</italic><0.01）. Compared with the model group， the fluoxetine group and the high-dose YMO group saw increases in the times of rearing， times of crossing and sugar water consumption rate and a significant decrease in the cumulative time of immobility during tail suspension （<italic>P</italic><0.05， <italic>P</italic><0.01）. The results of HE staining showed that the neurons in the hippocampus of rats in the high-dose YMO group were arranged in order and slightly loosened， without obvious microglia infiltration observed. The levels of IL-1<italic>β</italic>， IL-6 and TNF-<italic>α</italic> in the hippocampus of the model group increased significantly as compared with the blank control group （<italic>P</italic><0.05， <italic>P</italic><0.01）， and their content in the high-dose YMO group was significantly lowered in the comparison with the model group （<italic>P</italic><0.05， <italic>P</italic><0.01）. Molecular biology experiments demonstrated that compared with the results of blank group， the expression of purinergic receptor P2X7 （P2RX7）， NLRP3， apoptosis-associated speck-like protein （ASC）， Caspase-1 and IL-1<italic>β</italic> remarkably increased in the model group （<italic>P</italic><0.05， <italic>P</italic><0.01）. Additionally， the expression of P2RX7， NLRP3， ASC， Caspase-1 and IL-1<italic>β </italic>was significantly inhibited in the fluoxetine group and the high-dose YMO group compared with the model group （<italic>P</italic><0.05， <italic>P</italic><0.01）. Conclusion:YMO can improve the depression-like behaviors of rats induced by isolation combined with CUMS， and its mechanism of action is related to the regulation of the P2RX7/NLRP3 signaling pathway.

Characterization and pathophysiological changes of cerebral infarction rat model with qi-deficiency and blood-stasis Syndrome / 中国中药杂志

This study aimed to observe the general state and changes in pathophysiological indexes of multiple cerebral infarction rat model with Qi-deficienty and Blood-stasis syndrome. Rats were randomly divided into 4 groups(with 30 in each group): the normal group, the sham group, the model group and the Yiqi Huoxue recipe group. Rats in the model group and Yiqi Huoxue group were provided with interruptable sleep deprivation for 7 days before the multiple cerebral infarction operation, and followed by another 4 weeks of sleep deprivation; rats in the Yiqi Huoxue group were intragastrically administrated with drug at a dose of 26 g·kg⁻¹, once a day for 4 weeks. The general state was observed, and the pathophysiological indexes were measured at 48 h, 2 weeks and 4 weeks after administration. The results showed that rats in the normal group and the sham group represented a good general state and behaviors, with a normal morphological structure of brain tissues; rats in the model group featured yellow fur, depression, accidie, loose stools and movement disorder, with obvious brain histomorphological damage, which became aggravated with the increase of modeling time; rats in the Yiqi Huoxue group showed release in the general state and above indexes. Compared with the sham group at three time points, rats in the model group showed decrease in body weight, exhaustive swimming time and RGB value of tongue surface image, and increase in whole blood viscosity of the shear rate under 5, 60 and 150 S⁻¹, reduction in cerebral cortex Na⁺-K⁺-ATPase, Ca²⁺-ATPase activity and contents of 5-HT, rise in TXB2 levels and decline in 6-keto-PGF1a in serum(<0.05, <0.01). Compared with the model group, rats in the Yiqi Huoxue group showed alleviations in the above indexes at 2 w and 4 w(<0.05, <0.01). The results showed that the characterization and pathophysiological indexes in the multiple cerebral infarction rat model with Qi-deficiency and blood-stasis syndrome were deteriorated; Yiqi Huoxue recipe could significantly alliviate the abnormal conditions, which suggested of the model was stable and reliable and the pathophysiologic evolutionary mechanism might be related to energy metabolism dysfunction, vasoactive substance abnormality and changes in neurotransmitters.

Analysis on microdialysis probe recovery of baicalin in vitro and in vivo based on LC-MS/MS / 中国中药杂志

To further study the brain behavior and the pharmacokinetics of baicalin in intercellular fluid of brain, and study the recovery rate and stability of brain and blood microdialysis probe of baicalin in vitro and in vivo. The concentration of baicalin in brain and blood microdialysates was determined by LC-MS/MS and the probe recovery for baicalin was calculated. The effects of different flow rates (0.50, 1.0, 1.5, 2.0，3.0 μL•min⁻¹) on recovery in vitro were determined by incremental method and decrement method. The effects of different drug concentrations (50.00, 200.0, 500.0, 1 000 μg•L⁻¹) and using times (0, 1, 2) on recovery in vitro were determined by incremental method. The probe recovery stability and effect of flow rate on recovery in vivo were determined by decrement method, and its results were compared with those in in vitro trial. The in vitro recovery of brain and blood probe of baicalin was decreased with the increase of flow rate under the same concentration; and at the same flow rate, different concentrations of baicalin had little influence on the recovery. The probe which had been used for 2 times showed no obvious change in probe recovery by syringe with 2% heparin sodium and ultrapure water successively. In vitro recovery rates obtained by incremental method and decrement method were approximately equal under the same condition, and the in vivo recovery determined by decrement method was similar with the in vitro results and they were showed a good stability within 10 h. The results showed that decrement method can be used for pharmacokinetic study of baicalin, and can be used to study probe recovery in vivo at the same time.

Effect of Sailuotong capsule on mitochondrial dynamics in focal cerebral ischemia/reperfusion rats / 中国中药杂志

To observe the protective effect and mechanism of Sailuotong capsule in focal cerebral ischemia/reperfusion. The 90 min middle cerebral artery occlusion (MCAO) reperfusion model was established. The expressions of dynamin-related protein 1 ( Drp1) and optic atrophy 1 (Opa1) were tested by Western blot. The transmission electron microscope was used to observe the changes in the mitochondrial ultra-structure. The pathological morphological changes were observed through the HE staining. The immunohistochemical method was used to test Drp1 and Opa1 expressions. Sailuotong capsule (33, 16.5 mg x kg(-1), ig) can inhibit the abnormal mitochondrial fission and fusion in the cortical area on the ischemia side and the mitochondrial fission gene expression and promote the mitochondrial fusion gene Opa1 expression, so as to alleviate the energy metabolism disorder caused by ischemia/reperfusion. Sailuotong capsule can inhibit the abnormal mitochondrial dynamics in peri-ischemic regions and maintain the normal morphology of mitochondria, which may be the mechanism of Sailuotong capsule in promoting the self-recovery function in the ischemic brain region.

Study on effect of weinaokang and bilobalide on autophagy and neurogenesis induced by focal cerebral ischemia reperfusion / 中国中药杂志

<p><b>OBJECTIVE</b>To observe the protective effect of the Weinaokang (WNK) and its active compound bilobalide on focal cerebral ischemia reperfusion, and their mechanisms.</p><p><b>METHOD</b>The 60-minute middle cerebral artery occlusion (MCAO) was adopted to establish the 24 h-14 d reperfusion model. The expression of Beclin-1 was detected by the Western blotting technique. The transmission electron microscopy was used to observe ultrastructural changes. Neurogenesis was detected by the immunofluorescence staining.</p><p><b>RESULT</b>WNK (20, 10 mg x kg(-1), ig) or its active compound bilobalide (10, 5 mg x kg(-1), ig) could promote the generation of mature neurons (BrdU(+) -MAP-2+) at the ischemic side, and inhibit expression of autophagy-related gene Beclin-1, so as to reduce the neuron injury induced by focal cerebral ischemia reperfusion.</p><p><b>CONCLUSION</b>WNK and its active compound bilobalide can inhibit neuron autophagy and improve neurogenesis in ischemic peripheral area, suggesting that neurogenesis may be the intervention target for WNK to promote self-repairing of ischemic area.</p>

Effect and mechanism of huatuo zaizao extractum on focal cerebral ischemia/reperfusion-induced blood-brain barrier injury in rats / 中国中药杂志

<p><b>OBJECTIVE</b>To observe the effect and mechanism of Huatuo Zaizao extractum (HTZZ) on focal ischemia/reperfusion (I/R) blood-brain barrier injury induced by middle cerebral artery occlusion.</p><p><b>METHOD</b>Sixty healthy male adult Sprague-Dawley rats was randomly divided into the sham operation group, the MCAO model group, the Tanakan (20 mg x kg(-1)) group, and high, middle and low-dose HTZZ groups (5, 2.5, 1.25 g x kg(-1)), with 10 in each group and single-dose duodenal administration. Middle cerebral artery occlusion was adopted to establish the rat focal I/R model. After ischemia for 90 min and reperfusion for 24 h, the pathological injury at the ischemia side was observed by HE staining. The blood-brain barrier structure was observed under transmission electron microscope. Expressions of G protein-coupled receptor kinases 2 (GRK2), matrix metalloproteinases 2 (MMP-2) and MMP-9 were detected by western blotting technique.</p><p><b>RESULT</b>After 90 min MCAO/24 h reperfusion, penumbra cerebral cortical micro-vessels showed edema, mitochondrial injury, vacuolation, membrane injury and reduction. Along with the changes, sub-cells of G protein-coupled receptor kinase 2 (GRK2) in cortical penumbra brain tissues transferred from cytoplasm to membrane, with increase in expressions of MMP-2 and MMP-9. HTZZ could effectively recover cerebral micro-vascular endothelial edemaand blood-brain barrier ultrastructure injury induced by I/R, reduce expression of functional (membrane coupling) GRK2, and inhibit expressions of MMP-2 and MMP-9.</p><p><b>CONCLUSION</b>Cell membrane coupling GRK2 may be the effective target of Huatuo Zaizao extractum.</p>

Effect of sailuotong capsule on intervening cognitive dysfunction of multi-infarct dementia in rats / 中国中药杂志

<p><b>OBJECTIVE</b>To study the effect of Sailuotong capsule (Sailuotong) on learning and memory functions of multi-infarct dementia (MID) rats and its mechanism.</p><p><b>METHOD</b>All SD rats were divided into five groups, namely the sham operation group, the model group, the positive group, the low dosage Sailuotong-treated group and the high dosage Sailuotong-treated group. The multi-infarct dementia model was established by injecting the micro-sphere vascular occlusive agent. On the 10th day after the successful operation, the rats were administered intragastrically with distilled water, memantine hydrochloride (20 mg x kg(-1)) and Sailuotong (16.5 mg x kg(-1) and 33.0 mg x kg(-1)) once a day for 60 days respectively, in order to detect the effect of Sailuotong in different doses on the latent period and route length in Morris water maze and the activities of choline acetyltransferase (ChAT) and acetylcholinesterase (AchE) in brain tissues.</p><p><b>RESULT</b>Compared with the sham operation rats, it had been observed that the latent period and route length of MID rats in Morris water maze were significantly increased (P < 0.05 or P < 0.01), and the activity of ChAT in brain tissues was significantly decreased (P < 0.05). After the intervention with Sailuotong for sixty days, the latent period and route length of MID rats in Morris water maze significantly shrank (P < 0.05 or P < 0.01). Additionally, Sailuotong decreased AchE activity, while increasing ChAT activity in brain tissues of MID rats (P < 0.05 or P < 0.01).</p><p><b>CONCLUSION</b>Sailuotong capsule can improve cognitive dysfunction of MID rats to some extent. Its mechanism may be related to its different regulation of activities of ChAT and AchE in brain tissues.</p>

Effect of sailuotong capsule on Glu and GABA levels as well as NMDA receptor subtypes expression in recovery period of rat multiple cerebral infarction / 药学学报

The rat model of multi-infarct was adopted in this study to elucidate the protective mechanism of Sailuotong capsule (Sailuotong) in recovery period of multiple cerebral infarction. The effects of Sailuotong on levels of Glu, GABA and the expression of NMDA receptor subtypes including NR1, NR2A and NR2B, were detected. The multi-infarct model rats were established by injecting embolizing microsphere via internal carotid artery, and were given Sailuotong treatment (16.5 and 33.0 mg x kg(-1)) for 60 days. The pathological changes in brain ultrastructure were observed by transmission electron microscope. The levels of Glu and GABA in brain tissue were measured with high performance liquid chromatography. The expression of NMDA receptors including NR1, NR2A and NR2B in neurons was evaluated by immunohistochemical staining. Compared with the sham rats, abnormal changes were observed in ultrastructures of neurons, neuroglia cells and synapses of model rat brains. Moreover, significant decrease of Glu and GABA, as well as the elevated expression of NR1, NR2A and NR2B were detected in brain tissues. Sailuotong (16.5 and 33.0 mg x kg(-1)) could improve ultrastructure of cerebral tissue, facilitate synthesis of Glu and GABA, and down-regulate expression of NR1, NR2A and NR2B in neurons. The results demonstrated that Sailuotong could exert neuroprotective effects to some extent in the recovery phase of multiple cerebral infarction by promoting expression of NMDA receptors and synthesis of Glu and GABA.