• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.88-88
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• 2022

In this study, we investigated the effect of Solanum nigrum aerial parts (SNAP) on macrophage activation and macrophage autophagy in RAW264.7 cells. SNAP increased the production of immunostimulatory factors and phagocytosis in RAW264.7 cells. TLR4 inhibition blocked SNAP-mediated production of immunostimulatory factors. In addition, the JNK inhibition reduced the SNAP-mediated production of immunostimulatory factors, and the SNAP-mediated JNK activation was blocked by the TLR4 inhibition. SNAP activated macrophage autophagy. TLR4 inhibition blocked SNAP-mediated macrophage autophagy and inhibition of p38 and JNK attenuated SNAP-mediated macrophage autophagy. These findings indicate that SNAP may induce TLR4/JNK-mediated macrophage activation and TLR4/p38 and JNK-mediated macrophage autophagy.

• Korean Journal of Child Studies
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• v.28 no.4
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• pp.113-126
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• 2007

This study explored mediating effects of the maternal emotional expressiveness between maternal behavioral inhibition/behavioral activation system and children's emotional intelligence. subjects were 138 4- to 5-year-old preschoolers (92 boys, 46 girls) and their mothers. The maternal behavioral inhibition/behavioral activation system was measured by BIS/BAS(Behavioral Inhibition System/Behavioral Activation System, Carver & White, 1994), maternal emotional expressiveness was measured by the Self-Expressiveness in the Family Questionnaire (Halberstadt, 1995), and children's emotional intelligence was measured by the Emotional Intelligence Questionnaire (Lee, 1998). Data were analyzed by descriptive statistics and multiple regression analysis. Results were that maternal positive expressiveness mediated the effects of maternal BIS on children's self-understanding and maternal negative expressiveness mediated the effects of maternal BAS on children's self-regulation.

• Biomolecules & Therapeutics
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• v.24 no.4
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• pp.380-386
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• 2016

Silymarin from milk thistle (Silybum marianum) has been reported to show an anti-cancer activity. In previous study, we reported that silymarin induces cyclin D1 proteasomal degradation through NF-${\kappa}B$-mediated threonine-286 phosphorylation. However, mechanism for the inhibition of Wnt signaling by silymarin still remains unanswered. Thus, we investigated whether silymarin affects Wnt signaling in human colorectal cancer cells to elucidate the additional anti-cancer mechanism of silymarin. Transient transfection with a TOP and FOP FLASH luciferase construct indicated that silymarin suppressed the transcriptional activity of ${\beta}$-catenin/TCF. Silymarin treatment resulted in a decrease of intracellular ${\beta}$-catenin protein but not mRNA. The inhibition of proteasome by MG132 and $GSK3{\beta}$ inhibition by SB216763 blocked silymarin-mediated downregulation of ${\beta}$-catenin. In addition, silymarin increased phosphorylation of ${\beta}$-catenin and a point mutation of S33Y attenuated silymarin-mediated ${\beta}$-catenin downregulation. In addition, silymarin decreased TCF4 and increased Axin expression in both protein and mRNA level. From these results, we suggest that silymarin-mediated downregulation of ${\beta}$-catenin and TCF4 may result in the inhibition of Wnt signaling in human colorectal cancer cells.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.12
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• pp.5975-5979
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• 2012

Background: To investigate the influence of telomerase activity, apoptosis, radiosensitivity of cervical cancer after siRNA-mediated knockdown of telomerase RNA and evaluate in vivo growth with gene interference. Methods: We studied siRNA-targeting-telomerase RNA transfection into the Hela cell line. Expression of hTERC mRNA was detected by RT-PCR and telomerase activity was measured by the TRAP assay. Growth inhibition was determined by MTT assay and radiosensitivity of the cervical cancer cells was examined by colony formation assay. In addtion, effects of hTERC inhibition in vivo were studied by injection of siRNA-transfected Hela cells into nude mice. Results: The hTERC siRNA effectively downregulated the expression of hTERC mRNA and also reduced the telomerase activity to 30% of the untreated control vlaue. The viability of hTERC siRNA transfected Hela cells was reduced by 44.7% after transfection. After radiation treatment, the radiosensitivity of Hela cells with hTERC knockdown was increased. In vivo, the tumors developing from the hTERC siRNA-transfected cells were of reduced size, indicating that the hTERT siRNA also depressed the tumorigenic potential of the Hela cells. Conclusions: Our results supported the concept of siRNA-mediated inhibition of telomerase mRNA which could inhibit the expression of hTERC and telomerase activity. Furthermore, radiosensitivity was upregulated after knockdown the hTERC in vivo and in vitro.

• Korean Journal of Childcare and Education
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• v.16 no.6
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• pp.71-88
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• 2020

Objective: The main purpose of this study was to investigate the direct effect of preschoolers' behavioral inhibition and indirect effects through maternal overprotective parenting and autonomy support on preschoolers' anxiety. Methods: A total of 295 preschoolers and their mothers were the subjects of this study. Mothers completed a questionnaire that included measures of their parenting behavior, preschoolers' behavioral inhibition and anxiety. Data were analyzed using structural equation modeling. Results: First, preschoolers' behavioral inhibition had a direct effect on their anxiety. Preschoolers with higher behavioral inhibition displayed higher levels of anxiety. Second, maternal overprotective parenting mediated the relationship between preschoolers' behavioral inhibition and anxiety. Third, maternal autonomy support mediated the relationship between preschoolers' behavioral inhibition and anxiety. Conclusion/Implications: The findings of this study emphasize the importance of reducing maternal overprotective parenting and promoting autonomy support to prevent preschoolers' anxiety. These findings could be used as a foundation for developing parent education programs for mothers with behaviorally inhibited preschoolers.

• Journal of Microbiology and Biotechnology
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• v.8 no.1
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• pp.89-91
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• 1998

Cryptotanshinone induced topoisomerase I-mediated DNA cleavage in vitro as strongly as camptothecin, whereas topoisomerase II-mediated DNA cleavage was not induced by this agent. In DNA relaxation assay using calf thymus DNA topoisomerase I and supercoiled pBR322 DNA, cryptotanshinone inhibited topoisomerase I-mediated DNA relaxation in a dose-dependent manner. In unwinding assay, cryptotanshinone ($50{\mu}M$) did not shift the topoisomers of DNA. These results suggest that cryptotanshinone exerted a preferential inhibition of topoisomerase I without intercalating into DNA.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.93-93
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• 2022

Hovenia dulcis, one of the traditional medicinal plants, is currently being used as a functional ingredient for the development of health functional foods that protects the liver from alcohol damage in Korea. A variety of pharmacological effects of Hovenia dulcis have been reported so far, but studies on immune-enhancing activity are insufficient. Thus, in this study, we report that Hovenia dulcis branches (HDB) induce the activation of macrophages. HDB increased the production of immunostimulatory factors and phagocytosis in RAW264.7 cells. TLR4 inhibition blocked HDB-mediated production of immunostimulatory factors. In addition, the JNK inhibition reduced the HDB-mediated production of immunostimulatory factors, and the HDB-mediated JNK activation was blocked by the TLR4 inhibition. HDB increased the level of LC3-II and p62/SQSTM1. TLR4 inhibition blocked HDB-mediated increase in the level of LC3-II and p62/SQSTM1. These findings indicate that HDB may induce TLR4/JNK-dependent macrophage activation and TLR4-dependent macrophage autophagy.

• Korean Journal of Plant Resources
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• v.30 no.3
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• pp.265-271
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• 2017

In this study, we elucidated the molecular mechanism of silymarin by which silymarin may inhibits cell proliferation in human colorectal cancer cells in order to search the new potential anti-cancer target associated with the cell growth arrest. Silymarin reduced the level of c-Myc protein but not mRNA level indicating that silymarin-mediated downregulation of c-Myc may result from the proteasomal degradation. In the confirmation of silymarin-mediated c-Myc degradation, MG132 as a proteasome inhibitor attenuated c-Myc degradation by silymarin. In addition, silymarin phosphorylated the threonine-58 (Thr58) of c-Myc and the point mutation of Thr58 to alanine blocked its degradation by silymarin, which indicates that Thr58 phosphorylation may be an important modification for silymarin-mediated c-Myc degradation. We observed that the inhibition of ERK1/2, p38 and $GSK3{\beta}$ blocked the Thr58 phosphorylation and subsequent c-Myc degradation by silymarin. Finally, the point mutation of Thr58 to alanine attenuated silymarin-mediated inhibition of the cell growth. The results suggest that silymarin induces the cell growth arrest through c-Myc proteasomal degradation via ERK1/2, p38 and $GSK3{\beta}-dependent$ Thr58 phosphorylation.

• Journal of Microbiology and Biotechnology
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• v.25 no.11
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• pp.1908-1919
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• 2015

This work investigated the potential of curcumin (CCM) and (-)-epigallocatechin gallate (EGCG) to inhibit N-acyl homoserine lactone (AHL)-mediated biofilm formation in gram-negative bacteria from membrane bioreactor (MBR) activated sludge. The minimum inhibitory concentrations (MICs) of CCM alone against all the tested bacteria were 200-350 μg/ml, whereas those for EGCG were 300-600 μg/ml. Biofilm formation at one-half MICs indicated that CCM and EGCG alone respectively inhibited 52-68% and 59-78% of biofilm formation among all the tested bacteria. However, their combination resulted in 95-99% of biofilm reduction. Quorum sensing inhibition (QSI) assay with known biosensor strains demonstrated that CCM inhibited the expression of C4 and C6 homoserine lactones (HSLs)-mediated phenotypes, whereas EGCG inhibited C4, C6, and C10 HSLs-based phenotypes. The Center for Disease Control biofilm reactor containing a multispecies culture of nine bacteria with one-half MIC of CCM (150 μg/ml) and EGCG (275 μg/ml) showed 17 and 14 μg/cm² of extracellular polymeric substances (EPS) on polyvinylidene fluoride membrane surface, whereas their combination (100 μg/ml of each) exhibited much lower EPS content (3 μg/cm²). Confocal laser scanning microscopy observations also illustrated that the combination of compounds tremendously reduced the biofilm thickness. The combined effect of CCM with EGCG clearly reveals for the first time the enhanced inhibition of AHL-mediated biofilm formation in bacteria from activated sludge. Thus, such combined natural QSI approach could be used for the inhibition of membrane biofouling in MBRs treating wastewaters.

• Korean Journal of Plant Resources
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• v.36 no.3
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• pp.191-197
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• 2023

Autophagy contributes to enhancing the immune system (innate and adaptive immune system) against foreign pathogens. Autophagy of macrophages is used as a major indicator for developing vaccine adjuvants to increase the adaptive immune response. In this study, HSL increased p62/SQSTM1 expression. Inhibition of TLR4, p38, JNK, and NF-κB blocked HSL-mediated increase of p62/SQSTM1. HSL activated p38, JNK, and NF-κB signaling, but HSL-mediated activation of p38, JNK, and NF-κB signaling was reversed by TLR4 inhibition. In addition, HSL increased Nrf2 expression, but HSL-mediated Nrf2 expression did not occur in the inhibition of TLR4, p38, JNK, and NF-κB. Taken together, it is believed that HSL-mediated autophagy may be dependent on activating Nrf2 expression via TLR4-dependent activation of p38, JNK, and NF-κB in macrophages.