Hepatoprotective diastereomeric lignans from Saururus chinensis herbs

Two new diastereomeric sauchinones (2, 3), along with the known sauchinone (1), a phenylpropanoid (sarisan), and two known lignans (galbacin and saucernetin), were isolated from the n-hexane fraction of Saururus chinensis using reversed-phase HPLC. The stereostructures of the lignans, sauchinone A (2) and 1'-epi-sauchinone (3), were established by analysis of spectroscopic data. Incubation of cultured rat hepatocytes intentionally injured by CCl(4) with each of the compounds 1, 2, and 3 significantly reduced the levels of glutamic pyruvic transaminase released by the damaged hepatocytes.

SSA/RO52gene and expressed sequence tags in an 85 kb region of chromosome segment 11p15.5

Frequent allelic loss in lung cancer has been described in a region on chromosome segment 11p15.5 (LOH11A). The region is approximately 650 kb in size and flanked by the markers D11S988 centromeric and D11S860 telomeric. Clinical and cell biological studies suggest that it contains a gene associated with metastatic tumor spread. One of the genes identified within this region is SSA/Ro52, which has a RING finger domain and may be involved in gene regulation. We studied this gene for mutations using SSCP analysis and for expression using RT-PCR and Western blotting on lung cancer cell lines and tumor-normal tissue pairs. No mutations and no differences in mRNA or protein expression between tumor tissue and normal tissue pairs were identified. We discovered a novel polymorphic site (SSA44C/T) within exon 1 of this gene. Among 141 primary lung cancers, allelic loss was observed in 16% of informative cases. Our analyses excluded SSA/Ro52 as a tumor-suppressor gene in lung cancer and newly defined the centromeric border of the LOH11A region from D11S988 previously to SSA44C/T. This reduced the region of the putative suppressor gene to 460 to 485 kb. A significant difference (p = 0.01) in the frequency of alleles for this polymorphism between Caucasians and African-Americans was observed. The "T" allele frequency was 0.12 in Caucasians and 0.23 in African-Americans. A genomic EcoRI map over 85 kb surrounding the SSA/Ro52 gene was constructed, and 4 expressed sequence tags were identified by sequencing and studied.

The ethanol-soluble part of a hot-water extract from Artemisia iwayomogi inhibits liver fibrosis induced by carbon tetrachloride in rats

This study was carried out to investigate the protective effects of the hot-water extract from Artemisia iwayomogi (Compositae) on carbon tetrachloride-induced liver fibrosis in rats. Liver injury was induced by oral administration of carbon tetrachloride (1 mL kg(-1)) twice a week during 4 weeks of A. iwayomogi treatment. Extracts from A. iwayomogi were prepared and administered to rats orally (2 g kg(-1) as A. iwayomogi for 4 weeks) as follows: group 1, hot-water extract; group 2, ethanol-soluble part of hot-water extract; group 3, ethanol-insoluble part of hot-water extract; and group 4, methanol extract. In rats treated with the ethanol-soluble part of the hot-water extract, liver hydroxyproline content was reduced to 74% that of carbon tetrachloride control rats (P < 0.05). Protein expression of alpha smooth muscle cell like actin was also decreased in rats treated with the ethanol-soluble part of the hot-water extract, which indicates inhibition of hepatic stellate cell activation. Liver malondialdehyde levels were significantly lowered in rats treated with the ethanol-soluble part of hot-water extract (P < 0.05). Serum cholesterol levels in rats treated with hot-water extract, ethanol-soluble or -insoluble parts of hot-water extract or methanol extract were significantly reduced when compared with those of carbon tetrachloride control rats (P < 0.05). The ethanol-soluble part of the hot-water extract from A. iwayomogi inhibited fibrosis and lipid peroxidation in rats with liver fibrosis induced by carbon tetrachloride. Both hot-water extract (either ethanol-soluble or -insoluble) and methanol extract of A. iwayomogi also lowered serum cholesterol levels in fibrotic rats.

Sedative activity of two flavonol glycosides isolated from the flowers of Albizzia julibrissin Durazz

The flowers of Albizzia julibrissin are used as a sedative in oriental traditional medicine. The phytochemical study of this plant allowed the isolation of two flavonol glycosides, quercitrin (1) and isoquercitrin (2). The sedative activity of these compounds was evaluated, and both compounds 1 and 2 increased pentobarbital-induced sleeping time in dose-dependent manner in mice. These results support the use of the flowers of this plant as a sedative agent.

Repression of hspA2 messenger RNA in human testes with abnormal spermatogenesis

OBJECTIVE

To evaluate the messenger RNA (mRNA) expression of hspA2 in testes of infertile men with azoospermia.

DESIGN

Prospective study.

SETTING

Center for Reproduction and Genetics, Pundang Je-Saeng General Hospital, Dae-Jin Medical Center, Korea.

PATIENT(S)

Azoospermic patients (n = 15) undergoing testicular biopsy for pathologic evaluation were selected.

INTERVENTION(S)

After pathologic evaluation, testicular biopsy specimens were subdivided into three groups: group 1, normal spermatogenesis (n = 5); group 2, spermatocyte arrest (n = 5); and group 3, Sertoli cell-only syndrome (n = 5). The levels of hspA2 mRNA expression were compared in testes of group 1, group 2, and group 3 with the use of a competitive reverse transcription polymerase chain reaction (RT-PCR) technique.

MAIN OUTCOME MEASURE(S)

Comparison of hspA2 mRNA levels in testes.

RESULT(S)

On competitive RT-PCR analyses for hspA2 mRNA, significant hspA2 expression was observed in group 1, whereas a very low level of hspA2 was expressed in groups 2 and 3.

CONCLUSION(S)

This study demonstrates that hspA2 gene expression is down-regulated in human testes with abnormal spermatogenesis, which in turn suggests that the hspA2 gene might play a specific role during meiosis in human testes.

Vascular endothelial growth factor in malignant and tuberculous pleural effusions

The purpose of this study is to assess the usefulness of soluble vascular endothelial growth factor (VEGF) in the effusions of patients with malignant and tuberculous diseases. Using a sandwich enzyme-linked immunoadsorbent assay, VEGF concentration was measured in malignant (n=17) and tuberculous (n=11) pleural effusions. Pleural biopsy, cytology or microbiological methods were used to make final diagnoses. Adenosine deaminase (ADA) levels in tuberculous pleural effusions were significantly higher than those in malignant pleural effusions. The median level of VEGF in patients with malignant effusions (median, 2418 pg/mL; range, 97-62103 pg/mL) was significantly higher than tuberculous effusions (median, 994 pg/mL; range, 44-3552 pg/mL). There were no significant differences in pleural VEGF levels in patients with different histological types of lung cancer. The VEGF level was not correlated with ADA, lactate dehydrogenase and total protein levels of pleural fluid. In conclusion, pleural VEGF levels in patients with malignant effusions were significantly higher than tuberculous effusions, and the measurement of pleural VEGF is helpful in discriminating between malignant and tuberculous effusions. Further studies are needed to determine the clinical value of VEGF as a tumor marker and a prognostic factor.

Neuroprotective phenylpropanoid esters of rhamnose isolated from roots of Scrophularia buergeriana

Four phenylpropanoid esters of rhamnose, buergerisides A1, B1, B2 and C1 were isolated from roots of Scrophularia huergeriana MIQ. (Scrophulariaceae), and were characterized as 2-O-acetyl-3,4-di-O-(E)-p-methoxycinnamoyl-alpha-L-rhamnopyranosid e, 2-O-acetyl-3-O-(E)-p-methoxycinnamoyl-alpha-L-rhamnopyranoside, 2-O-acetvl-3-O-(Z)-p-methoxycinnamoyl-alpha-L-rhamnopyranosi de and 4-O-(E)-p-methoxycinnamoyl-alpha-L-rhamnopyranoside, respectively. In addition, six known phenylpropanoids were authenticated as: (E)-cinnamic acid, (E)-p-methoxycinnamic acid, (E)-p-methoxycinnamic acid methyl ester, (E)-p-coumaric acid, (E)-caffeic acid, (E)-ferulic acid and a phenylalcohol, 2-(3-hydroxy-4-methoxyphenyl)ethanol. These ten phenylpropanoids all attenuated glutamate-induced neurotoxicity when added to primary cultures of rat cortical cells in a dose-dependent manner. These results demonstrate that phenylpropanoids isolated from S. buergeriana may exert significant protective effects against glutamate-induced neurodegeneration in primary cultures of cortical neurons.

Rotundines A-C, three novel sesquiterpene alkaloids from Cyperus rotundus

Rotundines A (1), B (2), and C (3), three novel sesquiterpene alkaloids with an unprecedented carbon skeleton, were isolated from the rhizomes of Cyperus rotundus. The structures of 1-3 were elucidated by spectral and chemical methods.

Cytotoxic lavandulyl flavanones from Sophora flavescens

Two new lavandulylated flavanones, (2S)-2'-methoxykurarinone (1) and (-)-kurarinone (2), were isolated from the root of Sophora flavescens, together with two known lavandulyl flavanones, sophoraflavanone G (3) and leachianone A (4), and two known isoflavonoids, formononetin and l-maakiain. The structures of 1 and 2 were determined on the basis of optical rotation and spectral evidence and by comparison with known compounds. Compounds 1-4 exhibited cytotoxic activity against human myeloid leukemia HL-60 cells.

Functional characterization of Caenorhabditis elegans DNA topoisomerase IIIalpha

To investigate the function of a DNA topoisomerase III enzyme in Caenorhabditis elegans, the full-length cDNA of C.elegans DNA topoisomerase IIIalpha was cloned. The deduced amino acid sequence exhibited identities of 48 and 39% with those of human DNA topoisomerase IIIalpha and Saccharomyces cerevisiae DNA topoisomerase III, respectively. The overexpressed polypeptide showed an optimal activity for removing negative DNA supercoils at a relatively high temperature of 52-57 degrees C, which is similar to the optimum temperatures of other eukaryotic DNA topoisomerase III enzymes. When topoisomerase IIIalpha expression was interfered with by a cognate double-stranded RNA injection, pleiotropic phenotypes with abnormalities in germ cell proliferation, oogenesis and embryo-genesis appeared. These phenotypes were well correlated with mRNA expression localized in the meiotic cells of gonad and early embryonic cells.

Sauchinone, a lignan from Saururus chinensis, attenuates CCl4-induced toxicity in primary cultures of rat hepatocytes

We used primary cultures of rat hepatocytes injured by the hepatotoxin, carbon tetrachloride (CCl4), as a test system to screen for hepatoprotective compounds from natural products. Sauchinone was isolated from the aerial parts of Saururus chinensis (Saururaceae) by this method. At a concentration of 50 microM, sauchinone significantly reduced the release into the culture medium of glutamic pyruvic transaminase from CCl4-damaged cultures of rat hepatocytes. It has been determined that glutathione, superoxide dismutase and glutathione peroxidase all play important roles in the cellular defense against oxidative stress. Sauchinone appeared to protect primary cultured rat hepatocytes exposed to CCl4 from significant drops in the levels of each of these three specific markers, respectively. Sauchinone also seemed to ameliorate lipid peroxidation as demonstrated by a reduction in the production of the oxidized lipid byproduct, malondialdehyde. These results suggest that sauchinone may exert hepatoprotective activity through antioxidant activity.

Antiproliferative effects of alkaloids from Sedum sarmentosum on murine and human hepatoma cell lines

The whole plant of Sedum sarmentosum (SS) has been traditionally used for the treatment of chronic viral hepatitis in China and South Korea. Certain hepatitis virus causes acute and chronic hepatitis and induces hepatocellular carcinoma (HC). In the present study, we examined whether the crude alkaloid fraction (CAF) of SS had any anticancer effects on hepatoma cell lines. Murine hepatoma (BNL CL. 2) and human hepatoma (HepG2) cell lines were cultured in the presence of CAF of SS at various doses (50-150 microg/ml) for 24 or 48 h. CAF caused a dose-dependent inhibition of cell proliferation without necrosis or apoptosis. Antiproliferative effects of CAF of SS were associated with an increase in the number of cells in the G1 phase of cell cycle. This study suggests that SS may improve survival of hepatoma patients via the inhibition of excessive growth of tumor cells.

Characterization and expression of the pseudomonas putida bacterioferritin alpha subunit gene

The root-colonizing pseudomonad Pseudomonas putida (Pp) appears to produce two subunits, alpha and beta, of the iron-binding protein, bacterioferritin. A gene encoding the alpha-bacterioferritin subunit was located adjacent to the major catalase in Pp. The deduced protein sequence of the Pp bfralpha gene had a very high identity with other alpha-subunits, possessing conserved amino acids responsible for ferroxidase activity. The gene also lacked a deduced methionine at residue 52, associated with heme binding in beta-subunits. An antibody generated toward the Escherichia coli (E. coli) multifunctional single subunit bacterioferritin recognized two proteins in the Pp extract, a 22 kDa protein likely to be a beta-subunit and, to a lesser extent, a 23 kDa band. The 23 kDa band was absent in a Pp mutant in which the bfralpha gene was disrupted. Loss of alpha-bacterioferritin stimulated production of fluorescent siderophore. Growth on media and on root surfaces was not impaired by deletion of the alpha-bacterioferritin. Transcription of bfralpha was independent of the catalase gene and was dependent on iron. The transcript levels from bfralpha decreased in iron deficiency experienced during stationary-phase or upon treatment during growth with an iron chelator.

Design and synthesis of anticonvulsive agents as gamma-vinyl GABA-based potential dual acting prodrugs and their biological activities

For the development of new anticonvulsive agents, gamma-vinyl GABA (vigabatrin) and GABA mimetics derivatives were covalently coupled as potential dual acting prodrugs and evaluated for their anticonvulsive activities. Among the prepared compounds, 11 showed the most potent anticonvulsive activity, a shorter onset time and a broader spectrum compared to vigabatrin.

Superoxide dismutase activity in Pseudomonas putida affects utilization of sugars and growth on root surfaces

To investigate the role of superoxide dismutases (SOD) in root colonization and oxidative stress, mutants of Pseudomonas putida lacking manganese-superoxide dismutase (MnSOD) (sodA), iron-superoxide dismutase (FeSOD) (sodB), or both were generated. The sodA sodB mutant did not grow on components washed from bean root surfaces or glucose in minimal medium. The sodB and sodA sodB mutants were more sensitive than wild type to oxidative stress generated within the cell by paraquat treatment. In single inoculation of SOD mutants on bean, only the sodA sodB double mutant was impaired in growth on root surfaces. In mixed inoculations with wild type, populations of the sodA mutant were equal to those of the wild type, but levels of the sodB mutant and, to a great extent, the sodA sodB mutant, were reduced. Confocal microscopy of young bean roots inoculated with green fluorescent protein-tagged cells showed that wild type and SOD single mutants colonized well predominantly at the root tip but that the sodA sodB double mutant grew poorly at the tip. Our results indicate that FeSOD in P. putida is more important than MnSOD in aerobic metabolism and oxidative stress. Inhibition of key metabolic enzymes by increased levels of superoxide anion may cause the impaired growth of SOD mutants in vitro and in planta.

Protective effects of bergenin, the major constituent of Mallotus japonicus, on D-galactosamine-intoxicated rat hepatocytes

This study was designed to investigate the effects of bergenin against D-galactosamine-induced injury in primary cultured rat hepatocytes. Bergenin (100 microM) decreased the release of glutamic pyruvic transaminase and sorbitol dehydrogenase by 62 and 50%, respectively, into hepatocyte medium incubated for 14 h with 1.5 mM galactosamine. Decreased RNA synthesis by 1.5 mM galactosamine was recovered 2.5 times compared with that of control hepatocytes at 100 microM bergenin. Therefore, the present results suggest that bergenin show hepatoprotective effects against galactosamine-intoxicated rat hepatocytes by inhibiting the release of glutamic pyruvic transaminase and sorbitol dehydrogenase as well as by increasing RNA synthesis.

Cloning and characterization of the UDP-sugar hydrolase gene (ushA) of Enterobacter aerogenes IFO 12010

A bacterial alkaline phosphatase (BAP, the phoA gene product) is primarily responsible for the hydrolysis of the substrates 5-bromo-4-chloro-3-indolylphosphate-p-toluidine (XP) and p-nitrophenyl phosphate (pNPP). Using these substrates and an E. coli phoA mutant, we have cloned Enterobacter aerogenes genes conferring an XP(+) phenotype. Two types of clones were identified based on phenotypic tests and DNA sequences. One of them is a E. aerogenes phoA gene (XP(+), pNPP(+)) as expected; surprisingly the other one was found to be a ushA gene (XP(+), pNPP(-)), which encodes an UDP (uridine 5'-diphosphate)-sugar hydrolase. The E. aerogenes ushA gene shares high sequence identity with ushA of E. coli and the mutationally silent ushA0 gene of Salmonella typhimurium at both the nucleotide (over 79%) and amino acid (over 93%) levels. Expression of the E. aerogenes ushA gene in E. coli produced high level of UDP-sugar hydrolase, as confirmed by TLC (thin layer chromatography) analysis together with a presence of a strong band due to a XP hydrolysis on a polyacrylamide gel.

Protection of rat hepatocytes exposed to CCl4 in-vitro by cynandione A, a biacetophenone from Cynanchum wilfordii

To identify hepatoprotective agents from plant sources we use primary cultures of rat hepatocytes injured by CCl4. The hepatoprotective agents are the compounds that mitigate the injury caused by CCl4. Using this system we have investigated the biochemical mechanisms involved in the hepatoprotective activity of cynandione A, a biacetopherone, isolated from the roots of Cynanchum wilfordii Hemsley (Asclepiadaceae). Cynandione A (50 microM) significantly reduced (approximately 50%) the release into the culture medium of glutamic pyruvic transaminase and sorbitol dehydrogenase from the primary cultures of rat hepatocytes exposed to CCl4. Glutathione, superoxide dismutase, catalase and glutathione reductase play important roles in the cellular defence against oxidative stress. Cynandione A appeared to protect primary cultured rat hepatocytes exposed to CCl4 from significant drops in the levels of each of these four specific markers. Cynandione A also ameliorated lipid peroxidation by up to 50% as demonstrated by a reduction in the production of malondialdehyde. These results suggest that cynandione A protected the hepatocytes from CCl4-injury by maintaining the level of glutathione and by inhibiting the production of malondialdehyde, due to its radical scavenging properties.

Activation of the A3 adenosine receptor affects cell cycle progression and cell growth

The A3 adenosine receptor has been implicated in modulation of cell growth. As a first step to the characterization of the underlying mechanisms, we exposed Chinese hamster ovary (CHO) cells transfected with the human A3 receptor (A3R-CHO) to selective A3 receptor ligands. At micromolar concentrations, the A3 agonists N6-(3-iodobenzyl)-adenosine-5'-N-methyluronamide (IB-MECA) and its 2-chloro derivative Cl-IB-MECA reduced cell number, with no effects on either parental CHO cells (not expressing any adenosine receptor), or CHO cells transfected with the human A1 receptor. Cl-IB-MECA also reduced cell number in the human HEK293 cell line transfected with the human A3 receptor cDNA as opposed to the respective untransfected wild-type cells. In A3R-CHO, agonist-induced effects were antagonized by nanomolar concentrations of A3 antagonists, including the triazoloquinazoline derivative MRS 1220, the dihydropyridine derivative MRS 1191, and the triazolonaphthyridine derivative L-249,313. A3 agonist-induced effects were not due to modulation of cell adhesion, nor to necrosis or apoptosis. Growth curves revealed highly impeded growth, and flow-cytometric analysis showed markedly reduced bromodeoxyuridine incorporation into nuclei. The effect on cell cycle was completely antagonized by MRS1191. Hence, activation of the human A3 receptor in A3R-CHO results in markedly impaired cell cycle progression, suggesting an important role for this adenosine receptor subtype in cell cycle regulation and cell growth.

Hyaluronidase inhibitory active 6H-dibenzo[b,d]pyran-6-ones from the feces of Trogopterus xanthipes

Bioassay-guided fractionation of the MeOH extract of Pteropi faeces (the feces of Trogopterus xanthipes Milne-Edwards) furnished three hyaluronidase inhibitory active 6H-dibenzo[b,d]-pyran-6-ones (1-3), together with a new compound, 3,8,10-trihydroxy-6H-dibenzo[b,d]pyran-6-one (4). Their structures were established on the basis of the spectroscopic methods.

Baicalein: an in vitro antigenotoxic compound from Scutellaria baicalensis

Bioassay-guided fractionation of an H2O extract of the root of Scutellaria baicalensis has furnished an in vitro antigenotoxic flavonoid, baicalein (1) and 2',5,5',7-tetrahydroxy-6',8-dimethoxyflavone (2). Compound 1 exhibited a dose-dependent inhibition of aflatoxin B1 (AFB1) and N-methyl-N'-nitro-N-nitrosoguanidine mutagenicity in the Salmonella typhimurium bacterial mutation assay. In the chromosome aberration assay, compound 1, at a concentration of 5 microM, reduced the frequency of chromosome aberration induced by AFB1 but increased the clastogenic effect of AFB1 at a concentration of 50 microM.

Cyclic adenosine monophosphate inhibits ursolic acid-induced apoptosis via activation of protein kinase A in human leukaemic HL-60 cells

This study was designed to investigate the effect of cAMP on ursolic acid-induced apoptosis of HL-60 cells. Ursolic acid decreased the viability of the cells in a dose-dependent manner, which was revealed as an apototic process characterized by ladder-pattern DNA fragmentation in agarose gel electrophoresis and segmented nuclei in DAPI-sulpharhodamin 101 staining. Ursolic acid-induced apoptosis of the cells was markedly inhibited by the addition of cAMP-elevating agents including DB-cAMP, CPT-cAMP, 8-Br-cAMP and forskolin. These results were further evidenced by the fact that inhibitors of cAMP-dependent protein kinase including H89 and KT5720 completely inhibited the cAMP-mediated rescue of HL-60 cells from ursolic acid-induced apoptosis. In addition, differentiating agents of the cells such as dimethyl sulfoxide and retinoic acid did not affect the ursolic acid-induced apoptosis of HL-60 cells. These results suggest that signaling pathway of cAMP-dependent activation of protein kinase A may affect the responsiveness of tumor cells upon ursolic acid.

Cynandione A from Cynanchum wilfordii protects cultured cortical neurons from toxicity induced by H2O2, L-glutamate, and kainate

Oxidative stress has been implicated as a primary cause of neuronal death in certain neurodegenerative disorders and in aging brains. Natural products have been used in Asian societies for centuries for treating such neurodegenerative disorders as senile dementia. In an effort to identify active neuroprotective compounds from these products, we have employed cultures of rat cortical neurons as our screening system. A methanolic extract from dried roots of Cynanchum wilfordii Hemsley (Asclepiadaceae) significantly mitigated the neurotoxicity induced by H2O2 in this screening system. Activity-guided fractionation using several chromatographic techniques resulted in the isolation of the neuroprotective compound, cynandione A, a biacetophenone. At a concentration of 50 microM, cynandione A significantly reduced neurotoxicity induced by H2O2. Cynandione A significantly attenuated decreases in levels of glutathione, superoxide dismutase, and other enzymes that participate in the cellular defense against oxidative stress. Furthermore, cynandione A alleviated neurotoxicity induced by the excitotoxic neurotransmitter, L-glutamate, the neurotoxicity induced by kainate, but not that mediated by N-methyl-D-aspartate. Cynandione A was demonstrated to be a natural antioxidant as it facilitated the breakdown of hydrogen peroxide in vitro; however, no mechanism was uncovered to explain its neuroprotectant effects against glutamate and kainate. Therefore, cynandione A may be efficacious in protecting neurons from oxidative stress mediated via activation of alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate/kainate receptors since it exerted significant neuroprotective effects on cultured cortical neurons.

Antihepatotoxic activity of bergenin, the major constituent of Mallotus japonicus, on carbon tetrachloride-intoxicated hepatocytes

To determine the antihepatotoxic activity of bergenin from Mallotus japonicus, carbon tetrachloride (CCl4)-induced cytotoxicity in primary cultured rat hepatocytes has been adopted as an assay system. Bergenin significantly reduced the activities of glutamic pyruvic transaminase and sorbitol dehydrogenase released from the CCl4-intoxicated hepatocytes. The antihepatotoxicity of bergenin was also evidenced by elevating the activities of glutathione S-transferase and glutathione reductase, and content of glutathione in the CCl4-intoxicated hepatocytes. From these results, it is assumed that bergenin exerted antihepatotoxicity against CCl4-induced cytotoxicity through glutathione-mediated detoxification as well as free radical suppressing activity.