Molecular Mechanisms Responsible for Neuron-Derived Conditioned Medium (NCM)-Mediated Protection of Ischemic Brain.

The protective value of neuron-derived conditioned medium (NCM) in cerebral ischemia and the underlying mechanism(s) responsible for NCM-mediated brain protection against cerebral ischemia were investigated in the study. NCM was first collected from the neuronal culture growing under the in vitro ischemic condition (glucose-, oxygen- and serum-deprivation or GOSD) for 2, 4 or 6 h. Through the focal cerebral ischemia (bilateral CCAO/unilateral MCAO) animal model, we discovered that ischemia/reperfusion (I/R)-induced brain infarction was significantly reduced by NCM, given directly into the cistern magna at the end of 90 min of CCAO/MCAO. Immunoblocking and chemical blocking strategies were applied in the in vitro ischemic studies to show that NCM supplement could protect microglia, astrocytes and neurons from GOSD-induced cell death, in a growth factor (TGFß1, NT-3 and GDNF) and p-ERK dependent manner. Brain injection with TGFß1, NT3, GDNF and ERK agonist (DADS) alone or in combination, therefore also significantly decreased the infarct volume of ischemic brain. Moreover, NCM could inhibit ROS but stimulate IL-1ß release from GOSD-treated microglia and limit the infiltration of IL-ß-positive microglia into the core area of ischemic brain, revealing the anti-oxidant and anti-inflammatory activities of NCM. In overall, NCM-mediated brain protection against cerebral ischemia has been demonstrated for the first time in S.D. rats, due to its anti-apoptotic, anti-oxidant and potentially anti-glutamate activities (NCM-induced IL-1ß can inhibit the glutamate-mediated neurotoxicity) and restriction upon the infiltration of inflammatory microglia into the core area of ischemic brain. The therapeutic potentials of NCM, TGFß1, GDNF, NT-3 and DADS in the control of cerebral ischemia in human therefore have been suggested and require further investigation.

Therapeutic Effect of Yi-Chi-Tsung-Ming-Tang on Amyloid ß-Induced Alzheimer's Disease-Like Phenotype via an Increase of Acetylcholine and Decrease of Amyloid ß.

Alzheimer's disease (AD) is an irreversible neurodegenerative disorder characterized by amyloid accumulation, neuronal death, and cognitive impairments. Yi-Chi-Tsung-Ming-Tang (YCTMT) is a traditional Chinese medicine and has never been used to enhance cognitive function and treat neurodegenerative disorders such as senile dementia. Whether YCTMT has a beneficial role in improving learning and memory in AD patients remains unclear. The present study showed that oral administration of YCTMT ameliorated amyloid-ß- (Aß(1-40)) injection-induced learning and memory impairments in rats, examined using passive avoidance and Morris water-maze tests. Immunostaining and Western Blot results showed that continuous Aß(1-40) infusion caused amyloid accumulation and decreased acetylcholine level in hippocampus. Oral administration of medium and high dose of YCTMT 7 days after the Aß(1-40) infusion decreased amyloid accumulation area and reversed acetylcholine decline in the Aß(1-40)-injected hippocampus, suggesting that YCTMT might inhibit Aß plague accumulation and rescue reduced acetylcholine expression. This study has provided evidence on the beneficial role of YCTMT in ameliorating amyloid-induced AD-like symptom, indicating that YCTMT may offer an alternative strategy for treating AD.

Ethanol extract of Graptopetalum paraguayense upregulates paraoxonase 1 gene expression via an AKT/NF-κB-dependent pathway.

Human serum paraoxonase 1 (PON1), a calcium-dependent ester hydrolase, protects against the oxidative modification of low-density lipoprotein (LDL) and is a major anti-atherosclerotic component of high-density lipoprotein (HDL). Graptopetalum paraguayense, a folk herbal medicine commonly used in Taiwan, has antioxidative, anti-inflammatory, anti-hypertensive, and anti-atherogenic properties. The effects of G. paraguayense on the activity and/or expression of PON1 were examined using various extracts of the plant; extracts were made in water (GPWE), 50% ethanol (GP50E), and 95% ethanol (GP95E). Of these extracts, GP50E was found to be the most effective at increasing the function and expression of PON1 in a human hepatoma HepG2 cell line. Data from electrophoretic mobility shift assays and promoter-reporter luciferase analyses demonstrated that the DNA binding activity and transactivation ability of NF-κB were enhanced by GP50E. Treatment with NF-κB inhibitors, pyrrolidine dithiocarbamate, and BAY 11-7082 significantly attenuated GP50E-induced PON1 production and NF-κB transactivation activity. In addition, GP50E increased the levels of phosphorylated protein kinase B (PKB/AKT). Pharmacological inhibition of AKT by LY294002 effectively suppressed NF-κB activation and PON1 gene expression, suggesting that AKT was an upstream regulator of GP50E-mediated biological events. Overall, the results show that GP50E up-regulated PON1 gene expression via an AKT/NF-κB-dependent signaling pathway in human hepatoma HepG2 cells. This observation led to the conclusion that the anti-atherogenic characteristics of G. paraguayense are modulated, at least in part, via the up-regulation of hepatocyte PON1 gene expression.