Biomedical subjects

Xin-Sheng Yao

Publications and source records attributed to Xin-Sheng Yao.

17 recordsLinked to original sources

PubMed2004

Selective inhibition of the growth of cancer cells by diterpenes selected with embryonic cells of Xenopus.

We used Xenopus embryo cells with a cell cycle of 20-30 min to detect inhibitory effects on cell proliferation. Inhibition of proliferation was observed when isolated embryonic cells were incubated for 16 h in a simple salt solution containing the well-known anticancer drugs 5-fluorouracil and adriamycin. In addition, three diterpene compounds isolated from the anticancer herbal medicine kansui: kansuinin B, 20-OD-ingenol Z, and 20-OD-ingenol E specifically inhibited the proliferation of isolated embryonic cells. The inhibitory compounds selected using the embryonic cells also inhibited proliferation of certain mammalian cell types.

Animals↗

PubMed2004

Three new cyclopentanoid monoterpenes from Picrorhiza scrophulariiflora.

Three new cyclopentanoid monoterpenes, named piscrocins A , B and C, were isolated from the roots of Picrorhiza scrophulariiflora (Scrophulariaceae). The structures of these new compounds were established by 1D and 2D NMR spectroscopic techniques ( (1)H- (1)H COSY, HMQC, HMBC, and NOESY) in combination with X-ray crystallographic analysis.

Crystallography, X-Ray↗

PubMed2004

Diosgenin-3-O-alpha-L-rhamnopyranosyl-(1 --> 4)-beta-D-glucopyranoside obtained as a new anticancer agent from Dioscorea futschauensis induces apoptosis on human colon carcinoma HCT-15 cells via mitochondria-controlled apoptotic pathway.

Diosgenin-3-O-alpha-L-rhamnopyranosyl-(1 --> 4)-beta-D-glucopyranoside (DRG) is a well-known pentacyclic triterpene glycoside newly isolated from the rhizomes of Dioscorea futschauensis R. Kunth (Dioscoreaceae) by our group. In the present work, the inhibitory effect of DRG on the cell proliferation of human cancer cell lines was examined to reveal for the first time that DRG shows stronger anticancer activity than that of the positive control cisplatin. DRG inhibited the proliferation of human cancer cells, A431, A2780, A549, K562, and HCT-15, with IC50 (micromol L(-1)) values of 9.33 +/- 0.22, 18.7 +/- 0.16, 9.98 +/- 0.38, 6.44 +/- 0.10, and 5.86 +/- 0.14 respectively. It was then found, by morphological observation, "DNA ladder" detection and flow cytometric analysis, that DRG exerts its anticancer effect through inducing apoptosis on HCT-15 cells. Furthermore, it has been demonstrated that DRG triggers a mitochondria-controlled apoptotic pathway to induce apoptosis on HCT-15 cells, which involves the reduction of the mitochondrial potential (deltapsim), the release of cytochrome c from mitochondria into the cytosol, and the down-regulation of the ratio of Bcl-2/Bax expression level. The present results reasonably suggest that regulating the balance of Bcl-2/Bax expression level plays a key role in the DRG-induced apoptosis. Such findings provide novel knowledge to elucidate the biological properties of DRG, even though DRG was discovered early in the late 1960s. These results suggest that DRG may be a good candidate as a chemotherapeutic agent to treat human colon carcinoma.

Antineoplastic Agents, Phytogenic↗

PubMed2004

Effects of oolong tea on plasma antioxidative capacity in mice loaded with restraint stress assessed using the oxygen radical absorbance capacity (ORAC) assay.

In the present study, we investigated the antioxidative effect of oolong tea in vitro and in vivo using the oxygen radical absorbance capacity (ORAC) assay. An oolong tea extract, catechin and related compounds suppressed the oxidation of fluorescence induced by AAPH in a dose-dependent manner, that is, they prolonged the antioxidant time in vitro. Oral administration of the oolong tea extract to mice treated with restraint stress increased ORAC activity in plasma as compared with a stress control group. The extract also increased plasma vitamin C levels, and there was a good relationship between ORAC activity and the vitamin C level in plasma. The elevation of plasma ORAC and vitamin C level may have been related to the stress-relieving effect of oolong tea. These effects are probably due to the antioxidative properties of the tea. Thus, these findings suggested that oolong tea has beneficial effects on health related to its antioxidative action.

Animals↗

PubMed2003

Euphane and tirucallane triterpenes from the roots of Euphorbia kansui and their in vitro effects on the cell division of Xenopus.

Four new euphane-type triterpenes, kansenone (1), kansenonol (3), 11-oxo-kansenonol (4), kansenol (5), and a new tirucallane-type triterpene, epi-kansenone (2), were isolated from a 60% EtOH extract of Euphorbia kansui, together with alpha-euphol. Their structures were elucidated on the basis of extensive analysis of their 1D and 2D NMR spectral data. This appears to be the first report of the natural occurrence of euphane/tirucallane-type triterpenes with a ketone at C-7. In vitro treatment of cultured individual Xenopus laevis cells at the blastular stage with 1-4 significantly arrested cleavage of the cells (10 microg/mL of each compound resulted in >50% cleavage arrest).

Animals↗

PubMed2003

New furostanol glycosides from the rhizomes of Dioscorea futschauensis R. Kunth.

Two new furostanol glycosides, 26-O-beta-D-glucopyranosyl-3beta,26-dihydroxy-23(S)-methoxyl-25(R)-furosta-5,20(22)-dien-3-O-alpha-L-rhamnopyranosyl(1 --> 2)-[beta-D-glucopyranosyl(1 --> 3)]-beta-D-glucopyranoside (dioscoreside E, 1) and 26-O-beta-D-glucopyranosyl-3beta,26-dihydroxy-25(R)-furosta-5,20(22)-dien-3-O-alpha-Lrhamnopyranosyl(1 --> 2)-[beta-D-glucopyranosyl (1 --> 3)]-beta-D-glucopyranoside (prtotogracillin, 2), together with 11 known furostanol glycosides were isolated from the rhizomes of Dioscorea futshauensis R. Kunth. Their structures were elucidated on the basis of spectroscopic analysis (NMR and FABMS). Their anti-fungal activity against the plant pathogenic fungus Pyricularia oryzae and cytotoxic activity on K562 cancer cell line were evaluated in vitro.

Antifungal Agents↗

PubMed2003

Influence of histamine in a liver injury model induced by Propionibacterium acnes and lipopolysaccharide.

In normal mice, plasma histamine levels were 29.4+/-10.1 pmol/ml. When 0.1 microg of lipopolysaccharide (LPS) was intravenously injected into Propionibacterium acnes (P. acnes)-primed ICR mice, histamine levels increased remarkably to 61.2+/-15.9 pmol/ml (p<0.001). An increase was also observed in liver tissues. Oral administration of histidine at 200 mg/kg once daily for 5 d before intravenous LPS injection increased the plasma alanine aminotransferase (ALT) activity to 2936.5+/-356.3 IU/l, a significant change compared with the controls (2244.8+/-425.5 IU/l, p<0.05). The 24 h survival rate after LPS injection was 72.7% in the mice treated with 50 mg/kg of ranitidine, in contrast with 50% in the control group although the treatment did not significantly decrease the plasma ALT activity. On the other hand, 50 mg/kg of pyrilamine significantly reduced plasma ALT activity (p<0.001). The results suggested that histamine levels are related to hepatic damage in the P. acnes plus LPS induction of liver injury.

Alanine Transaminase↗

PubMed2003

Steroidal saponins from rhizomes of Tupistra wattii Hook. f.

Chemical examination of the fresh rhizomes of Tupistra wattii HOOK. f. led to the isolation of three new steroidal saponins, wattoside G (1), H (2), and I (3), together with one known steroidal saponin, (25S)-1beta,3beta,4beta-trihydroxyspirotan-5beta-yl-O-beta-D-glucopyranoside (4). The structures of 1-3 were established to be (25R)-1beta,2beta,3beta,5beta-tetrahydroxyspirostan-4beta-yl-O-beta-D-xylopyranoside (1), (24S,25S)-24-[(beta-D-glucopyranosyl)oxy]-1beta,2beta,3beta,4beta,5beta,7beta-hexahydroxyspirostan-6-one (2), and (24S,25S)-1beta,3beta-dihydroxy-5beta-spirostan-24-yl-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside (3) on the basis of detailed analyses of physical, chemical, and spectral data. The isolated compounds were evaluated for cytotoxic activity against the cancer cell line K562 in vitro.

Humans↗

PubMed2003

Diterpenes from the roots of Euphorbia kansui and their in vitro effects on the cell division of Xenopus (part 2).

Four new ingenane-type diterpenes, 3-O-(2,3-dimethylbutanoyl)-13-O-dodecanoyl-20-O-acetylingenol (1), 3-O-(2,3-dimethylbutanoyl)-13-O-dodecanoyl-20-deoxyingenol (2), 3-O-(2E,4Z-decadienoyl)-20-deoxyingenol (3), and 3-O-(2E,4E-decadienoyl)-20-deoxyingenol (4), two new jatrophane-type diterpenes, kansuinins D (9) and E (10), and four known ingenane-type diterpenes were isolated from the root of Euphorbia kansui. Their structures were elucidated by spectroscopic and chemical analysis, and individual Xenopus cells at the blastular stage were cultured with the diterpenes to test for biological activity. 20-Deoxyingenol diterpenes 3 and 4 induced the greatest cell cleavage arrest (0.5 micro g/ml of each compound resulted in >75% cleavage arrest), but cell cleavage inhibitory activity became weak when C-16 had an acyl residue. In contrast, the jatrophane diterpene kansuinin D (9) showed no activity.

Animals↗

PubMed2003

[Apoptosis of human chronic myeloid leukemia k562 cell induced by prosapogenin B of dioscin (P.B) in vitro].

BACKGROUND & OBJECTIVE: The authors have isolated prosapogenin B of dioscin (P.B) newly from Dioscorea futschauensis R. Kunth (Dioscoreaceae) and found that P.B could significantly inhibit the cell proliferation of several human cancer cell lines for the first time. The objective of this paper was designed to investigate whether P.B could inhibit cancer cell proliferation by inducing apoptosis. METHODS: Morphological changes of cell nuclei were observed under invert fluorescence microscope and transmission electron microscope. The changes in the cell size distribution were analyzed by Coulter Multisizer II particle analyzer. DNA ladder and apoptotic cells were analyzed respectively by DNA agarose gel electrophoresis and flow cytometry. RESULTS: The K562 cells treated with 10 micromol/L P.B for 24 hours showed morphological characteristics of apoptotic cells, such as decrease in cellular volume, nuclear chromatin condensation, nuclear fragmentation, and plasma membrane bleb formation. The treatment of K562 cells with 10 micromol/L P.B for 6, 12,and 24 hours caused the increase of the detected DNA ladder and the decrease of normal size cells both in a time-dependent manner. The percentage of apoptotic bodies detected in the sub-G(0)/G(1) peak region by flow cytometry was also increased time-dependently as analyzed as 6.12% for 6 hours, 35.6% for 12 hours and 45.7% for 24 hours treatments, respectively. CONCLUSION: These results suggested that P.B exerts its anti-proliferative effect on K562 cells through inducing apoptosis of the cells.

Antineoplastic Agents, Phytogenic↗

PubMed2002

Diterpenes from the roots of Euphorbia kansui and their in vitro effects on the cell division of Xenopus.

Twelve polycyclic diterpenes have been isolated from the roots of Euphorbia kansui. Nine were assigned with an ingenol skeleton, 20-O-(2'E,4'E-decadienoyl)ingenol (1), 20-O-(2'E,4'Z-decadienoyl)ingenol (2), 3-O-(2'E,4'Z-decadienoyl)ingenol (3), 3-O-(2'E,4'E-decadienoyl)ingenol (4), 3-O-(2'E,4'Z-decadienoyl)-5-O-acetylingenol (5), 3-O-(2'E,4'Z-decadienoyl)-20-O-acetylingenol (6), 3-O-(2'E,4'E-decadienoyl)-20-O-acetylingenol (7), 20-O-(decanoyl)ingenol (8), and 5-O-(2'E,4'E-decadienoyl)ingenol (9), and three with a jatrophane skeleton, kansuinins A (12), B (11), and C (10). Compounds 1, 2, 5, 9, and 12 are new compounds, while 4 and 7 were assigned with new geometric configurations. Their structures were elucidated by spectroscopic and chemical analysis. In vitro treatment of cultured individual Xenopus cells at the blastular stage with 1-9 arrested cleavage significantly (0.5 microg/mL of each compound resulted in >75% cleavage arrest). Of the three jatrophane diterpenes (10-12), only kansuinin B (11) showed any activity, resulting in 87% cleavage arrest at 50 microg/mL.

Animals↗

PubMed2002

Carbazole alkaloids as new cell cycle inhibitor and apoptosis inducers from Clausena dunniana Levl.

Carbazole alkaloids, 3-methylcarbazole (1), murrayafoline A (2), girinimbine (3), mahanimbine (4) and bicyclomahanimbine (5), were isolated for the first time from Clausena dunniana Levl. by bioassay-guided separation procedure and were identified by spectroscopic methods. Compounds 1-5 showed growth inhibitory activity (1, IC50 25 microg/ml) on human fibrosarcoma HT-1080 cells and cell cycle M-phase inhibitory (2, MIC 0.78 microg/ml) and apoptosis inducing (2, MIC 1.56 microg/ml; 3, MIC 25 microg/ml; 4, MIC 20 microg/ml; 5, MIC 30 microg/ml) activities on mouse tsFT210 cells, respectively, and 2-5 provided the first examples of carbazole alkaloids as new cell cycle inhibitors and apoptosis inducers.

Alkaloids↗

PubMed2002

Two new and four known polyphenolics obtained as new cell-cycle inhibitors from Rubus aleaefolius Poir.

Two new polyphenolics, rubuphenol (1) and sanguiin H-2 ethyl ester (2), were isolated together with ellagic acid (3), ethyl gallate (4), 1,2,3,4,6-penta-O-galloyl-beta-D-glucopyranose (5) and 1,2,3,6-tetra-O-galloyl-beta-D-glucopyranose (6) as new cell-cycle inhibitors from Rubus aleaefolius by bioassay-guided separation procedure and the structures of 1 and 2 were elucidated by spectroscopic method. Compounds 1-6 inhibited the cell cycle progression of tsFT210 cells at the G0/G1 phase with the MIC values of 14.6 microM (1), 22.1 microM (2), 10.3 microM (3), 7.8 microM (4), 7.9 microM (5) and 6.6 microM (6).

Animals↗

PubMed2002

A new ergostanol saponin from Dioscorea deltoidea Wall var. orbiculata.

From the fresh rhizomes of Dioscorea deltoidea Wall var. orbiculata, a novel ergostanol saponin, orbiculatoside A (1), was isolated and identified as 3-O-beta-D-glucopyranosyl-ergost-5-ene-3beta, 26-diol-26-O-beta-D-glucopyranosyl(1-->3)-[beta-D-glucopyranosyl(1-->2)-beta-D-glucupyranosyl(1-->6)]-beta-D-glucopyranoside by various NMR techniques in combination with chemical methods. The new saponin showed strong activity against Pyricularia oryzae, with a MMDC (minimum morphological deformation concentration) value of 28.04 micromol/l and was cytotoxic to cancer cell line K562, HCT-15, A549, HT1080, and A2780a in vitro.

Antineoplastic Agents↗

PubMed2002

Bioactive steroids from the brown alga Sargassum carpophyllum.

By activity-guided fractionation, two new sterols, 3beta,28xi-dihydroxy-24-ethylcholesta-5,23Z-dien (1) and 2a-oxa-2-oxo-5alpha-hydroxy-3,4-dinor-24-ethylcholesta-24(28)-ene (2), together with five known steroids, fucosterol (3), 24-ethylcholesta-4,24(28)-dien-3,6-dione (4), 24xi-hydroperoxy-24-vinylcholesterol (5), 24-ketocholesterol (6), 24R,28R- and 24S, 28S-epoxy-24-ethylcholesterol (7), were isolated from the brown alga Sargassum carpophyllum as active compounds causing morphological abnormality of Pyricularia oryzae mycelia. Compounds 1, 3, 4, 5 and 7 also exhibited cytotoxic activity against various cancer cell lines. The IC50 values for 1 and 5 against HL-60 were 7.8 and 8.5 microg/ml, 3 and 4 against P-388 were 0.7 and 0.8 microg/ml, whereas 7 against MCF-7, HCT-8, 1A9, HOS and PC-3 were 4.0, 8.8, 10.0, 10.0 and 7.2 microg/ml, respectively.

Biological Assay↗

PubMed2002

A method for constructing reshaping single-domain antibody.

The aim of this research was to demonstrate a novel and practical method for constructing reshaping Single-domain antibodies. Different from other methods, our method does not need to model the configuration of antibodies with specific sequences to determine the sequences of human acceptor FRs and then determine which amino acid residues in human acceptor FRs should be substituted. Most importantly, reshaping and enhancing the antigen binding affinity shared one procedure at the same time. Using this method, the reshaping anti-CD28 single-domain antibodies were constructed. According to the amino acid sequence of a mouse anti-human CD28 monoclonal antibody VH, two most homologous sequences of human antibodies were selected from GenBank and one of them was used as a main framework region for constructing the reshaping antibody. Before the original mouse antibody CDRs were inserted into the human acceptor FRs, some amino acid residues which were different from those of the original mouse antibody in the corresponding positions of the human acceptor FRs were determined or alternatively mutated by their conservative properties in Kabat classification. When the synthesized nucleotide fragments in different length were spliced by overlap PCR into the entire reshaping genes, Taq DNA polymerase and high Mg2+ concentration were used to introduce more mutation in FRs and CDRs randomly. A phage library was constructed using these PCR products and several reshaping Single-domain antibodies with high antigen binding affinity were selected after three rounds of panning. Two of them were expressed in E. coli BL21 (DE3). The antigen-binding affinity of refolded proteins was still in a high level measured by ELISA. These results suggested that this method was feasible and efficient for constructing reshaping Single-domain antibodies.

Amino Acid Sequence↗

PubMed2000

Inhibitory Effects of Antioxidants on NF-KappaB Activation in Bovine Carotid Artery Endothelial Cells.

NF-Kappa B is one of important transcription factor, which plays an important role in many immune and inflammatory responses. A large variety of stimulus can induce the degradation of IKappa B-alpha, an inhibitor of NF-KappaB, leading to the activation and translocation of NF-KappaB into nuclei. In the present study, the effects of antioxidants on TNF-alpha-induced NF-KappaB activation were tested by using cultured bovine carotid artery endothelial cells. The degradation of IKappaB-alpha were checked by Western blot, and the nuclear translocation of NF-KappaB were tested by immunofluorescence. Our results showed that pyrrolidine dithio-carbamate (PDTC) completely inhibited IKappaB-alpha degradation and nuclear translocation of NF-KappaB induced by TNF-alpha, and other antioxidants also exhibited inhibitory activities on TNF-alpha-induced I B-alpha degradation.

Journal Article↗