ABSTRACT
Rooibos, Aspalathus linearis (Barm.f.) R. Dahlgren, is a South African endemic plant. Modern researches have shown that its leaves and branches are rich in polyphenols and specific flavonoids, aspalathin and nothofagin, which have many pharmacological effects on improving oxidative stress and inflammation, reducing blood sugar, protecting liver, resisting cancer and mutagenesis. In this paper, the research progress of Rooibos is summarized which could provide reference for further research and development.
ABSTRACT
The aim of the study is to investigate the effect of nardosinone (Nar) on neuronal injury induced by oxygen-glucose deprivation (OGD) in primary cortical cultures isolated from embryos at gestational day 14. MTT method was used to determine the dosage regimen of Nar in primary neuronal cultures and observe the influence of Nar on the neurons suffering OGD; Western blotting analysis was used to detect expressions of protein kinase A (PKA), Ras related protein 1 (Rap1), mitogen-activated protein kinase kinase 1 (MEK1) and phospho-extracellular signal-regulated kinase 1/2 (p-ERK1/2) of OGD-injured or uninjured primary cultured neurons after Nar treatment. Results showed that Nar (50 and 100 micromol x L(-1)) improved the cell viability during OGD damage (P < 0.01) and increased the expression of PKA, Rap1, MEK1 and p-ERK1/2 in injured neurons. Additionally, elevations of PKA, Rapl, MEK1 and p-ERK1/2 in uninjured neurons were caused by Nar (50, 100 and 200 micromol x L(-1)) with a dose-dependent tenclency as well (P < 0.01). In conclusion, Nar could protect against the neuronal injury exposed to OGD, which may be relevant to the promotion of PKA and ERK signaling pathway.
ABSTRACT
The aim of the study is to investigate the effect of salvianolic acid B (SalB) on blood-brain barrier (BBB) in rats after cerebral ischemia-reperfusion, and to illustrate its possible mechanisms. Cerebral ischemia-reperfusion was induced by middle cerebral artery occlusion in rats. The break-down of BBB was indicated by extravasations of immunoglobulin (IgG) monitored with immunohistochemistry. The expression of MMP-9 and NOS2 in the brain was determined by immunohistochemistry, and the expression of p-p38 and p-ERK1/2 was detected by Western blotting. It was shown that on day 2 after ischemia-reperfusion the IgG accumulated around the vascular boundary zone, suggesting the break-down of BBB, and the expression of MMP-9 and NOS2 up-regulated at the same time. The result of Western blotting suggested that the expression of p-p38 and p-ERK1/2 increased. On day 7 after ischemia-reperfusion the. expression of MMP-9 and NOS2 was about the same level as day 2, the expression of p-p38 was higher than that on day 2 and the expression of p-ERK1/2 was slightly lower than that on day 2. SalB (1 and 10 mg x kg(-1)) significantly alleviated the extravasations of immunoglobulin induced by cerebral ischemia-reperfusion (P < 0.05). On day 2 and day 7 SalB attenuated the expression of MMP-9 and NOS2 (P < 0.05). SalB (10 mg x kg(-1)) reduced the expression of p-p38 and p-ERK1/2 apparently on day 2 and 7 after ischemia-reperfusion (P < 0.05). SalB (1 mg x kg(-1)) inhibited the expression of p-p38 on day 7 after ischemia-reperfusion (P < 0.05). The results indicate that SalB protects blood-brain barrier in rats after cerebral ischemia-reperfusion by inhibiting the MAPK pathway.
ABSTRACT
Microglia cells are immune cells in the central nervous system.When the microenvironment of brain has changed,microglia will respond rapidly.ATP,UTP,or other nucleotide signals released by neurons from damaged site and their metabolites such as ADP,adenosine,UDP and so on will bind with the purinergic receptors on microglia to regulate the morphology and function of microglia,then the microglial cells activated by nucleotide signals are to regulate neural cells by phagocytosis or releasing cytokines.In this article,the function and corresponding mechanisms of nucleotide signals on chemotaxis,phagocytosis,and process retraction are reviewed.