Panax ginseng protects against global ischemia injury in rat hippocampus.

Based on the use of Panax ginseng C.A. Meyer (Family Araliaceae) for the treatment of stroke in traditional Korean medicine, the present study was carried out to evaluate neuroprotective effects of P. ginseng after transient global cerebral ischemia using the four-vessel occlusion rat model. Nissl staining, lipid peroxidation (malondialdehyde [MDA] formation), and activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx) of rat brain were assessed. Ethanolic P. ginseng extract (200 mg/kg, i.p.) significantly protected CA1 neurons against 10 minutes of transient forebrain ischemia as demonstrated by measuring the density of neuronal cells. P. ginseng also significantly decreased the level of MDA and increased the expression of GPx and SOD. These results suggest that P. ginseng might be neuroprotective against cerebral ischemia-induced injury in rat brain by decreasing lipid peroxides and increasing the expression of GPx and SOD.

Enhanced production of asiaticoside from hairy root cultures of Centella asiatica (L.) Urban elicited by methyl jasmonate.

Transformed root ("hairy root") cultures have been shown to be a good model for the study of many secondary metabolites. However, economically important compounds such as asiaticoside and madecassoside are produced in insignificant amounts in the root of Centella asiatica (L.) Urban. To overcome this problem, C. asiatica was transformed using Agrobacterium rhizogenes strain R1000 that harbors pCAMBIA1302 encoding the hygromycin phosphotransferase (hpt) and green fluorescence protein (mgfp5) genes and the hairy culture was coupled with elicitation technique. Hairy roots were obtained at a frequency of up to 14.1% from a tissue junction between the leaf and petiole. Abundant hairy roots were observed when co-cultivation of the plant with A. rhizogenes was done for 7 days (36.1%). Transformation was confirmed by PCR and Southern blot analyses. Five weeks after inoculation, no asiaticoside was detected in the hairy root samples. However, when 0.1 mM methyl jasmonate (MJ) was applied as an elicitor to the culture medium for 3 weeks, a large quantity of asiaticoside was generated (7.12 mg/g, dry wt). In the case of gene expression, 12 h after MJ treatment the expression of the CabAS (C. asiatica putative beta-amyrin synthase) gene in the hairy roots is significantly different from that of the control and this level of transcripts was maintained for 14 days. Our results showed that production of C. asiatica hairy roots could be optimized and the resulting cultures could be elicited with MJ treatment for enhanced production of asiaticoside.

ProteoChip-based library screening of integrin alpha5beta1 antagonists from Korean medicinal plant extracts.

Integrins consist of transmembrane glycoproteins noncovalently associated to form alphabeta heterodimers. Various alpha/beta associations determine binding specieficities for cell surface molecules of the immunoglobulin superfamily as well as for extracellular matrix components. Through their cytoplasmic domains, integrins are responsible for the transmission of signals between the intracellular and the extracellular environment. We immobilized an integrin alpha5beta1 microarray on a ProteoChip to screen Korean medicinal plant extracts for binding activity. The microarray preserved the integrin alpha5beta1-fibronectin interaction, and was suppressed by the synthetic RGD peptide. We identified ten extracts with high integrin affinity using a high-throughput, competitive inhibition assay. We also demonstrate the biological function of these extracts in HUVECs.

Fingerprinting analysis of fresh ginseng roots of different ages using 1H-NMR spectroscopy and principal components analysis.

Fingerprinting analysis of fresh ginseng according to root age was performed using 1H-NMR spectroscopy and multivariate analysis techniques. Various peaks were detected in the aliphatic (0-3 ppm), sugar (3-6 ppm), and aromatic (6-9 ppm) regions of the 1H-NMR spectra of the water extracts of fresh ginseng root. The use of principal components (PCs) analysis (PCA) for metabolomic profiling allowed the large 1H-NMR data set obtained for various metabolites to be reduced to PC1, PC2, and PC3. Two dimensional score plots showed clear separations with these three components at different roots ages, and explained 89.6% of the total variance. Canonical discriminant analysis identified the ginseng roots at various ages from the NMR results with over 89.9% discrimination accuracy. These results indicate that the combination of 1H-NMR and PCA provides a very promising tool for the authentication and quality control of fresh ginseng roots at different ages.

Transient ischemia-induced expression and changes of tyrosine kinase A in the hippocampal dentate gyrus of the gerbil.

The present study examined ischemia-related changes in tyrosine kinase A (trkA) immunoreactivity and its protein content in the dentate gyrus after 5 min of transient forebrain ischemia in gerbils. One day after ischemic insult, cresyl violet-positive polymorphic cells showed ischemic degeneration. The ischemia-induced changes in trkA immunoreactivity were found in the polymorphic layer (PL) and granule cell layer (GCL) of the dentate gyrus. In the sham-operated group, trkA immunoreactivity in the dentate gyrus was very weak. From 30 min after ischemia, trkA immunoreactivity was increased in the dentate gyrus and peaked in the dentate gyrus at 12 h after ischemia-reperfusion. Thereafter, trkA immunoreactivity was decreased time-dependently after ischemia-reperfusion. Four days after ischemic insult, trkA immunoreactivity was similar to that of the sham-operated group. In addition, it was found that ischemia-related changes in trkA protein content were similar to the immunohistochemical changes. These results suggest that the chronological changes of trkA in the dentate gyrus after transient forebrain ischemia may be associated with ischemic damage in polymorphic cells of the dentate gyrus.

Cytotoxic steroidal saponins from the rhizomes of Asparagus oligoclonos.

Two new steroidal saponins, aspaoligonins A (2) and B (3), were isolated from the methanolic extract of the rhizomes of Asparagus oligoclonos together with a known spirostanol saponin, asparanin A (1). Aspaoligonins A and B were characterized as (25S*)-5beta-spirostan-3beta,17alpha-diol 3-O-beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranoside and (25S*)-5beta-spirostan-3beta,17alpha-diol 3-O-alpha-L-rhamnopyanosyl (1-->4)-[beta-D-xylopyranosyl-(1-->2)]-beta-D-glucopyranoside, respectively, by spectrometric analyses including HRFABMS and 2D NMR. Compounds 1-3 were cytotoxic against five human tumor cell lines with IC50 values of 2.05-2.84 microg/mL.

Ischemia-related changes in galanin expression in the dentate hilar region after transient forebrain ischemia in gerbils.

Although galanin (GAL) protects hippocampal neurons from ischemic damage, no study has examined ischemia-related changes in endogenous GAL in the hippocampal dentate gyrus. We investigated the chronological changes of GAL, well-known as the potassium channel opener, expression in the dentate gyrus at various times after 5 min of transient forebrain ischemia in gerbils. A few GAL-immunoreactive (IR) neurons were found in the polymorphic layer of the sham-operated group. Three hours after ischemia-reperfusion, the pattern of GAL immunoreactivity was similar to that of the sham-operated group and the number of GAL-IR neurons and immunoreactivity were highest 12 h after ischemic insult. At this time, GAL-IR neurons in the polymorphic layer showed strong GAL immunoreactivity. Thereafter, GAL-IR neurons and immunoreactivity significantly decreased in the dentate hilar region. Four days after ischemic insult, GAL-IR neurons were not detectable. In addition, the results of a Western blot study showed a pattern of GAL expression similar to the immunohistochemical changes. GAL protein content also was highest 12 h after ischemia. In conclusion, the increased expression of endogenous GAL in the dentate gyrus after ischemia is related to response to the ischemic damage.

Polygalae radix extract protects cultured rat granule cells against damage induced by NMDA.

Polygalae Radix (PR) from Polygala tenuifolia (Polygalaceae) is traditionally used in China and Korea, as this herb has a sedative, anti-inflammatory and antibacterial agent. To extend our understanding of the pharmacological actions of PR in the CNS on the basis of its CNS inhibitory effect, the present study examined whether PR has the neuroprotective action against N-methyl-D-aspartate (NMDA)-induced cell death in primarily cultured rat cerebellar granule neurons. PR, over a concentration range of 0.05 to 5 microg/ml, inhibited NMDA (1 mM)-induced neuronal cell death, which was measured by a trypan blue exclusion test and a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay. PR (0.5 microg/ml) inhibited glutamate release into medium induced by NMDA (1 mM), which was measured by HPLC. Pre-treatment of PR (0.5 microg/ml) inhibited NMDA (1 mM)-induced elevation of intracellular Ca2+ concentration ([Ca2+]i), which was measured by a fluorescent dye, Fura 2-AM, and generation of reactive oxygen species (ROS). These results suggest that PR prevents NMDA-induced neuronal cell damage in vitro.

Efficacy of dietary aloe vera supplementation on hepatic cholesterol and oxidative status in aged rats.

In the current study, we show the anti-oxidative and hypocholesterol effects of aloe vera in the liver. Male specific pathogen-free (SPF) Fischer 344 rats were randomly assigned to one of four groups: Group A (control) was fed test chow without aloe supplementation; Group B was fed a diet containing a 1% (per weight basis) freeze-dried aloe filet; Group C was fed a diet containing a 1% (per weight basis) charcoal-processed, freeze-dried aloe filet; and Group D was fed a diet containing a charcoal-processed freeze-dried, whole leaf aloe (0.02% per weight basis) in the drinking water. Our results show that a life-long intake of aloe had superior anti-oxidative action against lipid peroxidation in vivo, as indicated by reduced levels of hepatic phosphatidylcholine hydroperoxide. Additional anti-oxidative action was evidenced by enhanced superoxide dismutase (SOD) and catalase activity in groups B and C. Furthermore, our study revealed that hepatic cholesterol significantly increased in the control group during aging in contrast to the aloe-supplemented groups, which showed approximately 30% lower cholesterol levels, thereby an effective hypocholesteremic efficacy. In this report, we suggest that life-long dietary aloe supplementation suppresses free radical-induced oxidative damage and age-related increases in hepatic cholesterol.

Effect of the flavonoid components obtained from Scutellaria radix on the histamine, immunoglobulin E and lipid peroxidation of spleen lymphocytes of Sprague-Dawley rats.

The effect on the IgE content induced by concanavalin A in spleen lymphocytes of the presence wogonin, ganhuangenin, wogonoside and 3,5,7,2',6'-pentahydroxyl flavanone was investigated. These flavonoid components markedly inhibited the histamine released from cells stimulated with the calcium ionophore, A23187. However, the magnitude of the inhibitory effect on the degree of lipid peroxidation by ConA of these components was in order of PHF>GHG>WG>WGS. Interestingly, WG, GHG and WGS, with a methoxyl group in the A and B rings, strongly inhibited histamine and IgE production, whereas PHF without a methoxyl group was much stronger than that for lipid peroxidation. We suggest that WG, GHG and WGS might block the pathway for the release of histamine, and that the IgE level in spleen lymphocytes is responsible for the lipid peroxidation.