Combination drug therapy using edaravone and Daio-Orengedoku-to after transient focal ischemia in rats.

In this study, we investigated the effect of Daio-Orengedoku-to (DOT) on ischemic brain damage in a rat model of focal ischemia-reperfusion and attempted to identify synergistic effects for the combination of edaravone and DOT against ischemic insult. Ischemia was induced by intraluminal occlusion of the right middle cerebral artery for 2 h and reperfusion followed for 22 h. To determine the neuroprotective effect of DOT, it was administered orally just before reperfusion and then 2 h after reperfusion. To examine the effects of combination therapy on survival, rats were divided into groups treated with edaravone, DOT, and edaravone and DOT. Microglial activation, neutrophil infiltration and brain-derived neurotrophic factor (BDNF) expression were examined in surviving animals. Infarct volume was significantly reduced by DOT (100, 200 and 400 mg/kg; P < 0.05), and edaravone plus DOT markedly improved the survival rate after transient ischemia (P = 0.0133). Microglial activation was reduced by edaravone and DOT and their combination (P < 0.05), and neutrophil infiltration was lowered in these groups (P < 0.05). BDNF-positive cells were increased in the combination edaravone and DOT group (P < 0.05). It appears that the neuroprotective mechanisms of combined therapy involve inhibition of microglial activation, reduction of invading neutrophils and enhancement of BDNF expression.

Effects of uwhangchungsimwon on cell viability, proliferation, and gene expression of human neuronal cell line IMR32.

Uwhangchungsimwon (pill, UC) is one of the traditional Korean medical prescriptions that has been most frequently used for stroke. To characterize the effects of UC on human neuronal cells, the human neuroblastoma cell line IMR32 was treated with UC, and cell viability, cell proliferation, apoptosis, and gene expression were analyzed. The effect of UC on recovery of cell viability was analyzed following stress induction by nutrient depletion or cold shock. Flow cytometric analysis of the cell cycle showed that UC inhibits cell cycle progression of IMR32 in a dose- and time-dependent manner. UC was also identified to increase cell viability and suppress apoptosis induction by a DNA-damaging agent, etoposide. Quantitative RT-PCR analysis revealed that expressions of the p53 tumor suppressor gene and its downstream effect, Waf1, are stimulated whereas expressions of positive cell cycle regulators, c-Myc, c-Fos, and Cyclin D1 were repressed by UC treatment. Moreover, while expression levels of apoptosis inhibitors, Bcl-2 and Bcl-XL were increased following UC treatment, that of an apoptosis promoter, Bax, was decreased. In addition, expression of BMP-7, which has been recently demonstrated to improve the motor neuron recovery from stroke, was induced by UC while it was not detected in untreated cells. Taken together, our data suggest that the pharmacoclinical effects of UC might be derived in part from its negative regulation of cell proliferation and apoptosis through the transcriptional control of related genes.

Inhibition of human smooth muscle cell proliferation by gamigeonsim-tang through the transcriptional regulation of cell cycle-controlling genes.

The effects of gamigeonsim-tang (GGT) on cellular proliferation and expression of cell cycle-related genes were investigated in human smooth muscle cell HISM. HISM cells were treated with an aqueous extract of GGT. Cellular proliferation was investigated by an immunocytometric analysis of PCNA expression and a flow cytometric analysis of the cell cycle progression. Reduced expression of PCNA and a significant accumulation of G1 phase cells were observed following treatment, indicating that GGT inhibits cellular proliferation of human smooth muscle cells. To explore whether GGT affects the transcription of cell cycle-regulating genes, we evaluated mRNA expression of p53, p21Waf1 PCNA, Cyclin D1, Cdc2, Histone H3, c-Myc, and c-Fos using a quantitative RT-PCR analysis. While increased expressions of two negative cell cycle regulators, p53 and p21Waf1 were found, reduced expressions of cell cycle stimulators, PCNA, c-Fos, and c-Myc, were identified following treatment. Taken together, our study demonstrates that GGT inhibits cellular proliferation of human smooth muscle cell through the up- and down-regulation of growth-inhibiting and growth-promoting genes, respectively.

Activation of caspase cascades in Korean mistletoe (Viscum album var. coloratum) lectin-II-induced apoptosis of human myeloleukemic U937 cells.

Mistletoe lectins are of high biological activity and exert cytotoxic effects. We have previously shown that Korean mistletoe, Viscum album var. coloratum, lectin-II specifically induces apoptotic cell death in cancer cells, not normal lymphocytes. The destructive mechanism by mistletoe lectins on tumor cells was mediated by activation of c-JUN N-terminal kinase (JNK)/stress-activated protein kinase. Herein, we investigated the involvement of caspase cascade and its proteolytic cleavage effects on biosubstrates of human myeloleukemic U937 cells by D-galactoside and N-acetyl-galactosamine-specific Korean mistletoe lectin-II. Mistletoe lectin-II induced ladder pattern DNA fragmentation and activation of caspase-3, -8, and -9 of U937 cells, but not caspase-1 protease, in a time- and dose-dependent manner. Consistent with catalytic activation of protease, both poly(ADP-ribose) polymerase (PARP) and protein kinase C-delta (PKC-delta) are also cleaved in mistletoe lectin-II-treated U937 cells. An inhibitor of caspase-3-like protease, DEVD-CHO peptide, significantly inhibited mistletoe lectin-II-induced apoptosis, PARP cleavage, and fragmentation of DNA. These results provide the evidence that Korean mistletoe lectin-II induces apoptotic death of U937 cells via activation of caspase cascades.

Hwansodan protects PC12 cells against serum-deprivation-induced apoptosis via a mechanism involving Ras and mitogen-activated protein (MAP) kinase pathway.

Hwansodan has been used as a prescription for senile and vascular dementia in Oriental medicine. We investigated the neuroprotective effects of Hwansodan water extract on the apoptotic death of PC12 cells by serum deprivation. Hwansodan significantly rescued PC12 cells from apoptotic death by serum deprivation in a dose-dependent manner. The nuclear staining of PC12 cells clearly showed that Hwansodan attenuated nuclear condensation and fragmentation, which represents typical neuronal apoptotic characteristics. Hwansodan also prevents DNA fragmentation and caspase-3-like protease activation in serum-deprived PC12 cells and induces the tyrosine phosphorylation of proteins around 44 kDa, which was identified as ERK1 with electrophoretic gel mobility shift by Western blot. In addition, MEK inhibitor PD98059 and Ras inactivator, alpha-hydroxyfarnesylphosphonic acid and mevastatin, attenuated the neuroprotective effects of Hwansodan in serum-deprived PC12 cells. These results indicate that Ras/MEK/ERK signaling pathway plays a role in neuroprotective effects of Hwansodan in serum-deprived PC12 cells.