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Proposed cytotoxic mechanisms of the saffron carotenoids crocin and crocetin on cancer cell lines
Kim, Se Hyeuk,Lee, Jung Min,Kim, Sun Chang,Park, Chan Bae,Lee, Pyung Cheon Canadian Science Publishing 2014 Biochemistry and cell biology Vol.92 No.2
<P> We investigated the cytotoxic activities of crocin and crocetin, 2 major carotenoids isolated from the stigma of Crocus sativus (saffron), on 5 human cancer cell lines and proposed their possible anticancer mechanisms. Crocetin, a glycosylated carotenoid, showed approximately 5- to 18-fold higher cytotoxicity than crocin, a carboxylic carotenoid (IC50 of 0.16-0.61 mmol/L for crocetin vs. 2.0-5.5 mmol/L for crocin). This suggests that structural differences account for the different efficacies between them. Fluorescence-activated cell sorting (FACS) analysis showed that crocetin induced a significant level of cellular reactive oxygen species (ROS) in HeLa cells, whereas crocin did not. This ROS induction supported the cytotoxicity of crocetin, but not of crocin. A significant activation of nuclear factor erythroid 2-related factor 2 (Nrf2) was observed in both HeLa cells treated with crocin and crocetin: a 3.0-fold increase by 1 mmol/L crocetin and a 1.6-fold increase by 0.8 mmol/L crocin compared to the control. Furthermore, both crocetin and crocin reduced the protein expression of lactate dehydrogenase A (LDHA), one of the targets for chemoprevention in cancer cells, by 34.2% and 10.5%, respectively, compared to the control in HeLa cells. These findings suggest that crocetin and crocin have different mechanisms for their observed cytotoxicity in cancer cell lines. </P>
Kim, Se Hyeuk,Park, Yun Hee,Schmidt-Dannert, Claudia,Lee, Pyung Cheon American Society for Microbiology 2010 Applied and environmental microbiology Vol.76 No.15
<B>ABSTRACT</B><P>In this study, the carotenoid biosynthetic pathways of <I>Brevibacterium linens</I> DSMZ 20426 were reconstructed, redesigned, and extended with additional carotenoid-modifying enzymes of other sources in a heterologous host <I>Escherichia coli</I>. The modular lycopene pathway synthesized an unexpected carotenoid structure, 3,4-didehydrolycopene, as well as lycopene. Extension of the novel 3,4-didehydrolycopene pathway with the mutant <I>Pantoea</I> lycopene cyclase CrtY2 and the <I>Rhodobacter</I> spheroidene monooxygenase CrtA generated monocyclic torulene and acyclic oxocarotenoids, respectively. The reconstructed β-carotene pathway synthesized an unexpected 7,8-dihydro-β-carotene in addition to β-carotene. Extension of the β-carotene pathway with the <I>B. linens</I> β-ring desaturase CrtU and <I>Pantoea</I> β-carotene hydroxylase CrtZ generated asymmetric carotenoid agelaxanthin A, which had one aromatic ring at the one end of carotene backbone and one hydroxyl group at the other end, as well as aromatic carotenoid isorenieratene and dihydroxy carotenoid zeaxanthin. These results demonstrate that reconstruction of the biosynthetic pathways and extension with promiscuous enzymes in a heterologous host holds promise as a rational strategy for generating structurally diverse compounds that are hardly accessible in nature.</P>
Han, Hyeuk Jin,Jeong, Jae Won,Yang, Se Ryeun,Kim, Cheolgyu,Yoo, Hyeon Gyun,Yoon, Jun-Bo,Park, Jae Hong,Lee, Keon Jae,Kim, Taek-Soo,Kim, Seong-Woong,Jung, Yeon Sik American Chemical Society 2017 ACS NANO Vol.11 No.11
<P>The fabrication of a highly ordered array of single-crystalline nanostructures prepared from solution-phase or vapor-phase synthesis methods is extremely challenging due to multiple difficulties of spatial arrangement and control of crystallographic orientation. Herein, we introduce a nanotransplantation printing (NTPP) technique for the reliable fabrication, transfer, and arrangement of single-crystalline Si nanowires (NWs) on diverse substrates. NTPP entails (1) formation of nanoscale etch mask patterns on conventional low-cost Si <I>via</I> nanotransfer printing, (2) two-step combinatorial plasma etching for defining Si NWs, and (3) detachment and transfer of the NWs onto various receiver substrates using an infiltration-type polymeric transfer medium and a solvent-assisted adhesion switching mechanism. Using this approach, high-quality, highly ordered Si NWs can be formed on almost any type of surface including flexible plastic substrates, biological surfaces, and deep-trench structures. Moreover, NTPP provides controllability of the crystallographic orientation of NWs, which is confirmed by the successful generation of (100)- and (110)-oriented Si NWs with different properties. The outstanding electrical properties of the NWs were confirmed by fabricating and characterizing Schottky junction field-effect transistors. Furthermore, exploiting the highly flexible nature of the NWs, a high-performance piezoresistive strain sensor, with a high gauge factor over 200 was realized.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2017/ancac3.2017.11.issue-11/acsnano.7b06696/production/images/medium/nn-2017-06696r_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn7b06696'>ACS Electronic Supporting Info</A></P>