Advanced Materials Research Vols. 781-784

Abstract: The trametenolic acid B was a bioactive lanostane-type triterpenoid in Trametes lactinea (Berk.) Pat with. Five novel trametenolic acid B derivatives were synthesized, characterized and evaluated the cytotoxicity against MDA-MB-231 cells with the aim of obtaining better anti-tumtor agents. The compound IV exhibited significantly cytotoxicity activities with IC₅₀ value of 22.39 μM.

Abstract: A platinum (II) complex has been synthesized and characterized. The complex binding properties with G-quadruplex DNA and ds26 were examined by FID and CD spectroscopic methods. The results revealed that the platinum (II) complex can induce the antiparallel G-quadruplex structure of HTG21 conformation in the absence of added K⁺ with selectivity over other G-quadruplex DNA and duplex DNA. The cytotoxicity of the platinum (II) was screened against four cancer cell lines and normal cells of HL-7702 in comparison to cisplatin and it showed a higher activity than cisplatin, with inhibition rates ranging from (40.06±1.65)% to (89.47±1.14)%. Furthermore, the platinum (II) complex displayed lower cytotoxic activities to HL-7702 (normal cell) compared with the cancer cell lines.

Abstract: From the fresh bulbs of Fritillaria monatha Migo., ten compounds were isolated and identified as peimine (1), peiminine (2), isovertifine (3), pengbeimine A(4), pengbeimine B(5), pengbeimine C(6), pengbeimine D(7),stearic acid (8), daucosterol (9) and campesterol (10). Their structures were determined by NMR, MS spectral data.

Abstract: La (III) complex with apigenin was synthesized and characterized by UV, IR, ¹HNMR and thermal analysis. The scavenging activity of the complex on superoxide anion radical (O₂^-·) and hdroxyl radical (·OH) was also investigated by improved pyrogallic acid way and ortho-oxybenzoic acid way. The results show that the complex had remarkable scavenging effects on O₂^-· and ·OH, and its scavenging effect on free radicals was better than apigenin.

Abstract: Disorder of cholesterol metabolism plays important roles in pathogenesis of Alzheimer’s disease (AD). Plant compound curcumin has been reported to decrease Aβ deposition and cholesterol in serum, while the detailed mechanism is still unknown. To investigate the effect of curcumin on the cholesterol metabolism in Alzheimer’s disease, APPswe/PS1dE9 double transgenic mice were fed with 500ppm of curcumin every day for six months. Immunohistochemistry results showed that the expression of ATP-binding cassette transporter A1 (ABCA1) in hippocampal neurons was increased significantly, whereas the expression of scavenger receptor class B type I (SR-BI) was not detected. These findings suggest that curcumin may promote cholesterol efflux via ABCA1 transmembrane-transport system rather than SR-BI in neurons of AD.

Abstract: More and more studies have reported that β-amyloid (Aβ)-induced oxidative stress and protein metabolism disorders along with their interactions are likely to be the key factors to the pathogenesis of Alzheimers disease (AD). Heme oxygenase (HO) is one member of stress responsive enzyme super family and is a joint of many hypothesis for AD, while oxidative stress, iron metabolism disorders and Aβ deposition are closely related with HO. Therefore, HO is expected to become a therapeutic target for AD. HO-1 and HO-2 are the main members of HO family, and keep dynamic balance. In normal aging brain tissues, the expression of HO-2 is high, and that of HO-1 is low; while in the cerebral cortex and hippocampus of AD patients, the expression of HO-1 is significantly increased. This phenomenon indicates that HO-1 has a protective effect to the neurons from the oxidative stress. Furthermore, heme and Aβ could form Aβ-heme compound, which is a peroxidase complex, which increase the oxidative damage to neurons. Recently, Curcumin has been shown cytoprotective properties by inducing HO-1 and by preventing the formation of Aβ-heme in neurons; however, the underlying mechanisms are still unclear to date. Therefore, there has been great interest in understanding the molecular mechanisms based on curcumin acts on.

Abstract: The invasion behavior of tumor cells is important in the metastasis process of ovarian cancer cells. In this study we investigated the effects of Genistein on invasion inhibition in ovarian carcinoma cell line SKOV3 in vivo and in vitro. The abilities of the Genistein-treated SKOV3 cells to invade through reconstitute matrigel in transwell chambers were investigated in vitro and the invasion effect in vivo was determined by using the xenograft models of SKOV3 in nude mice. The ability of the 20μmol/L Genistein-treated cells to invade the reconstitute basement membrane was decreased significantly at 72h. This inhibition was dose-dependent. 40μmol/L Genistein had the strongest effect. The in vivo result suggested that the grade of invasion in control SKOV3 cells was time-dependent and Genistein-treated group could apparently inhibit the progress of invasion, localizing the tumor in invasion Grade 0 or Grade I and decreasing the proportion of Grade II, III and IV. The results suggested that Genistein possessed inhibitory effect on invasion in human ovarian carcinoma cell lines SKOV3 in vivo and in vitro.

Abstract: Angiogenesis is crucial for tumor progression and and migration of endothelial cells into tumor is important in the formation of new blood vessels in tumors. In this study we investigated the effect of Genistein on migration of human endothelial cells ECV-304 induced by human ovarian serous cystadenocarcinoma cell line SKOV3, and explored the mechanism of anti-angiogenesis of Genistein. Millicell chamber and coculture method were used to observe the influence on migration of ECV-304 induced by SKOV3 cells or its conditioned medium. The expression of angiogenesis associated protein VEGFbFGF and TGFβ-1 were determined using immunocytochemical assay. The results showed that either SKOV3 cells or its conditioned medium could induce the committed chemotactic migration of ECV-304. The chemotactic migrations of ECV-304 induced by SKOV3 or its conditioned medium were significantly inhibited by Genistein in a dose-dependent manner. 20μmol/L Genistein could down-regulate the expression of bFGF, and up-regulate the expression of TGFβ-1. Migrations of ECV-304 induced by SKOV3 or its conditioned medium are apparently inhibited by Genistein. It suggests that this inhibitory effect of Genistein is completed by down-regulating the expression of vessel growth-promoting factor bFGF, and up-regulating the expression of negative regulator TGFβ-1. This may be one of the mechanisms of anti-angiogenesis of Genistein.

Abstract: As a promising prevention and therapeutic intervention in Alzheimer’s disease, natural food dyes curcumin could obviously inhibit the generation of Aβ, but the mechanism is not fully defined. This study aims to investigate the effects of curcumin on the amyloidogenic pathway of APP in vitro. Plasmids APPswe and BACE1-mychis were transiently co-transfected into SH-SY5Y and HEK293 cells. Then, they were treated with curcumin at 0, 1.25, 5, 20 μmol/L for 24 h, or with curcumin at 5μmol/L for 0, 12, 24 and 48 h for the time course assay. Our findings showed that curcumin could inhibit the expression of the APP at mRNA level; the expression of the BACE1 and C99 at mRNA and protein levels, furthermore it could inhibit the generation of Aβ40/42, and those changes were dose-time dependent (p<0.05). Our study indicates that Aβ40/42 generation inhibition effect of curcumin might due to its influence on amyloidogenic pathway. This may provide important experimental basis for AD treatment with curcumin.

Abstract: Side chain cleavage of progesterone occurred in the biotransformation by Aspergillus versicolor. The conversion products were purified by column chromatography with ether/EtOAc and characterized by spectroscopic methods including ¹H NMR, ¹³C NMR, IR, UV, MS and physical constants such as melting point and optical rotation. Those conversion products were identified as testosterone, androstenedione and androstenediendione.