• Journal of Life Science
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• v.25 no.11
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• pp.1331-1337
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• 2015

S-allylcysteine (SAC) is an aged garlic derived water soluble organosulfur compound and has been suggested to have anticarcinogenic activity against diverse types of cancer cells. This review summarizes the cellular signaling pathways and molecular mechanisms whereby SAC exerts its effects on cellular proliferation, apoptosis, cell cycle progression and metastasis based on the results from both in vitro and in vivo studies. SAC activates proapoptotic proteins including Bax and caspase-3, but suppresses antiapoptotic Bcl-2 family proteins to bring about cancer cell death through mitochondria-mediated intrinsic pathway. SAC also inhibits cellular proliferation by inducing cell cycle arrest in which SAC reduces expression and activation of NF-κB, cyclins, Cdks, PCNA and c-Jun, but elevates expression of cell cycle inhibitor proteins p16 and p21 through suppression of both PI3K/Akt/mTOR and MAPK/ERK signaling pathways. And, SAC inhibits invasion and metastasis of cancer cells by inducing suppression of both angiogenesis and epithelial-mesenchymal transition (EMT) through decreased cyclooxygenase (COX)-2 expression and increased E-cadherin expression which were then caused by suppression of inhibitory transcription factors Id-1 and SLUG from SAC-mediated inactivation of both MAPK/ERK and PI3K/Akt/mTOR/NF-κB signaling pathways. Furthermore, SAC prevents toxic compound-induced carcinogenesis by inducing antioxidant enzymes such as glutathione-s-transferase (GST). Thus, SAC can be considered as a potential chemotherapeutic agent for the prevention and treatment of cancer.

• BMB Reports
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• v.53 no.10
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• pp.527-532
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• 2020

We recently reported that N-adamantyl-4-methylthiazol-2-amine (KHG26693) attenuates glutamate-induced oxidative stress and inflammation in the brain. In this study, we investigated KHG 26693 as a therapeutic agent against glutamate-induced autophagic death of cortical neurons. Treatment with KHG26693 alone did not affect the viability of cultured cortical neurons but was protective against glutamate-induced cytotoxicity in a concentration-dependent manner. KHG26693 attenuated the glutamate-induced increase in protein levels of LC3, beclin-1, and p62. Whereas glutamate decreased the phosphorylation of PI3K, Akt, and mTOR, these levels were restored by treatment with KHG26693. These results suggest that KHG26693 inhibits glutamate-induced autophagy by regulating PI3K/Akt/mTOR signaling. Finally, KHG26693 treatment also attenuated glutamate-induced increases in reactive oxygen species, glutathione, glutathione peroxidase, and superoxide dismutase levels in cortical neurons, indicating that KHG26693 also protects cortical neurons against glutamate-induced autophagy by regulating the reactive oxygen species scavenging system.

• The Journal of Internal Korean Medicine
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• v.38 no.4
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• pp.409-418
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• 2017

In Korea, Rhus verniciflua Stokes is used to purge hardness, alleviate blood stasis, and treat cancer. However, the mechanisms of related anti-cancer activity are not fully understood in human cancer cells. This study investigated the anti-cancer effects and mechanisms of Rhus verniciflua Stokes on MDA-MB-231 human breast cancer cells and found that treatment with a Rhus verniciflua Stokes extract resulted in time- and concentration-responses that indicated growth inhibition of breast cancer cells by induced apoptosis. This was followed by a decrease in mitochondrial membrane potential; the activation of caspase-3, -8, and -9; and the up-regulation of tBid. Caspase-dependent apoptosis was induced through the inhibition of phosphatidylinositol 3-kinase (PI3K) and the Akt signaling pathway. This study provides evidence that Rhus verniciflua Stokes might be useful for the treatment of breast cancer.

• IMMUNE NETWORK
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• v.11 no.2
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• pp.123-133
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• 2011

Background: Mycobacterium tuberculosis (Mtb) heparin binding hemagglutinin (HBHA) is an Ag known to evoke effective host immune responses during tuberculosis infection. However, the molecular basis of the host immune response to HBHA has not been fully characterized. In this study, we examined the molecular mechanisms by which HBHA can induce the expression of proinflammatory cytokines in macrophages. Methods: HBHA-induced mRNA and protein levels of proinflammatory cytokines were determined in bone marrow-derived macrophages (BMDMs) using RT-PCR and ELISA analysis. The roles of intracellular signaling pathways for NF-${\kappa}B$, PI3-K/Akt, and MAPKs were investigated in macrophage proinflammatory responses after stimulation with HBHA. Results: HBHA robustly activated the expression of mRNA and protein of both TNF-${\alpha}$ and IL-6, and induced phosphorylation of NF-${\kappa}B$, Akt, and MAPKs in BMDMs. Both TNF-${\alpha}$ and IL-6 production by HBHA was regulated by the NF-${\kappa}B$, PI3-K, and MAPK pathways. Furthermore, PI3-K activity was required for the HBHA-induced activation of ERK1/2 and p38 MAPK, but not JNK, pathways. Conclusion: These data suggest that mycobacterial HBHA significantly induces proinflammatory responses through crosstalk between the PI3-K and MAPK pathways in macrophages.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.3
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• pp.437-443
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• 2003

Epidemiological data suggest that lycopene has anticancer activities in humans. Insulin-like growth factor-I receptor (IGF-IR) is a transmembrane tyrosine kinase that mediates the biological actions of IGFs and may play an active role in cancer progression. Because our previous in vitro studies have indicated lycopene inhibits HT-29 cell growth, the aim of this study was to determine whether lycopene induces apoptotic cell death and the inhibitory effect of lycopene on HT-29 cell growth is related to changes in IGF-IR levels and the receptor's intracellular signalling pathways. HT-29 cells were incubated for 4 days in serum-free medium in the presence of 0, 25, 50, or 100 $\mu$M lycopene, and the DNA fragmentation assay was performed. Cells treated with lycopene produced a distinct oligonucleosomal ladder with different sizes of DNA fragments, a typical characteristic of cells undergoing apoptosis. HT-29 cells were cultured for 4 days in serum-free medium in the presence of 0~100 $\mu$M lycopene and IGF-I (10nM) was added for 0~60 minutes immediately prior to lysate preparations. Western blot analysis of total lysates revealed that lycopene decreased the levels of IRS-1, Akt, phosphatidylinositol 3-kinase (PI3K), and IGF-IR $\beta$-subunit, and increased the levels of the IGF-IR precursor dose dependently. Lycopene also decreased IGF-I-induced phosphorylation of IGF-IR$\beta$, IRS-1 and Akt, which were, at least in part, due to decreased expression of these proteins. These results suggest that lycopene induces apoptosis of HT-29 cells by inhibiting IGF-IR signaling thereby interfering with an IGF-II-driven autocrine growth loop, which is known to exist in this cell line.

• Journal of The Korean Society of Integrative Medicine
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• v.11 no.3
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• pp.159-169
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• 2023

Purpose : Though other Citrus spp. have reported their anti-inflammatory and antioxidative activities in previous studies, the biological activity of Kiyomi (Citrus unshiu × C. sinensis) has not been reported yet. Therefore, this study attempted to analyze the anti-inflammatory mechanisms of Kiyomi leaf ethanol extract (KLEE) in lipopolysaccharide (LPS) stimulated RAW 264.7 cells. Methods : The cytotoxic effect of KLEE in RAW 264.7 cells was determined by WST-1 assay. Bacterial endotoxin, the concentration of nitric oxide (NO) was analyzed by the Griess reaction. In addition, Western blot analysis was applied to measure the protein expression level of inducible NO synthase (iNOS). The phosphorylated status of the critical inflammatory transcription factor, nuclear factor (NF)-𝜅B, and its upstream signaling molecules, phosphoinositide 3-kinase (PI3K)/Akt as well as mitogen-activated protein kinases (MAPKs), were also measured by Western blot analysis. Results : KLEE was not cytotoxic up to a concentration of 200 ㎍/㎖, and protein expression levels of iNOS and cyclooxygenase (COX)-2, enzymes that counteract NO and prostaglandin (PG) E2 production, were inhibited by KLEE treatment. The phosphorylated status of PI3K/Akt as well as MAPKs including extracellular regulated kinase (ERK), c-jun NH2kinase (JNK), and p38, were significantly attenuated by KLEE treatment in LPS stimulated RAW 264.7 cells. Moreover, one of phase II enzymes, heme oxygenase (HO)-1 which has known for its anti-inflammatory capacity, was strongly induced by KLEE treatment. Conclusion : Consequently, KLEE treatment significantly attenuated the production of NO as well as the expression levels of iNOS and COX-2 in LPS-stimulated RAW 264.7 cells. The inflammatory transcription factor, NF-𝜅B, as well as its upstream signaling molecules, PI3K/Akt and MAPKs, were also diminished by KLEE treatment with statistical significance in LPS-stimulated RAW 264.7 cells. These results suggest that KLEE might be a promising candidate for the attenuation of inflammatory disorders.

• Journal of Life Science
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• v.22 no.12
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• pp.1621-1627
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• 2012

Cell motility plays an essential role in many physiological responses, such as development, immune reaction, and angiogenesis. In the present study, we showed that lysophosphatidic acid (LPA) modulates cancer cell migration by regulation of generation of reactive oxygen species (ROS). Stimulation of SKOV-3 ovarian cancer cells with LPA strongly promoted migration. but this migration was completely blocked by pharmacological inhibition of phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. Inhibition of the ERK pathway had no effect on migration. Stimulation of SKOV-3 ovarian cancer cells with LPA significantly induced the generation of ROS in a time-dependent manner. LPA-induced generation of ROS was significantly blocked by pharmacological inhibition of PI3K or Akt, but inhibition of the ERK signaling pathway had little effect. LPA-induced generation of ROS was blocked by pretreatment of SKOV-3 ovarian cancer cells with an NADPH oxidase inhibitor, whereas inhibition of xanthine oxidase, cyclooxygenase, or mitochondrial respiratory chain complex I had no effect. Scavenging of ROS by N-acetylcysteine completely blocked LPA-induced migration of SKOV-3 ovarian cancer cells. Inhibition of NADPH oxidase blocked LPA-induced migration whereas inhibition of xanthine oxidase, cyclooxygenase, or mitochondrial respiratory chain complex I did not affect LPA-induced migration of SKOV-3 ovarian cancer cells. Given these results, we suggest that LPA induces ROS generation through the PI3K/Akt/NADPH oxidase signaling axis, thereby regulating cancer cell migration.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.87-87
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• 2022

Under the COVID-19 pandemic, interest in immune enhancement and anti-obesity is increasing. Thus, in this study, we investigated whether Kadsura japonica fruits (KJF) exhibits immunostimulatory activity and anti-obesity activity. KJF increased the production of immunostimulatory factors and phagocytosis in RAW264.7 cells. Inhibition of TLR2 and TLR4 blocked KJF-mediated production of immunostimulatory factors in RAW264.7 cells. In addition, the inhibition of MAPK and PI3K/AKT signaling pathway reduced KJF-mediated production of immunostimulatory factors, and the activation of MAPK and PI3K/AKT signaling pathway by KJF suppressed the inhibition of TLR2/4. KJF attenuated the lipid accumulation and the protein expression such as CEBPα, PPARγ, perilipin-1, adiponectin, and FABP4 related to the lipid accumulation in 3T3-L1 cells. In addition, KJF inhibited excessive proliferation of 3T3-L1 cells and protein expressions such as β-catenin and cyclin D1 related to cell growth. These findings indicate that KJF may have immunostimulatory activity and anti-obesity activity.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.1
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• pp.79-86
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• 2014

Hydroxycinnamic acids have been reported to possess numerous pharmacological activities such as antioxidant, anti-inflammatory, and anti-tumor properties. However, the biological activity of 1-p-coumaroyl ${\beta}$-D-glucoside (CG), a glucose ester derivative of p-coumaric acid, has not been clearly examined. The objective of this study is to elucidate the anti-inflammatory action of CG in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells. In the present study, CG significantly suppressed LPS-induced excessive production of pro-inflammatory mediators such as nitric oxide (NO) and $PGE_2$ and the protein expression of iNOS and COX-2. CG also inhibited LPS-induced secretion of pro-inflammatory cytokines, IL-$1{\beta}$ and TNF-${\alpha}$. In addition, CG significantly suppressed LPS-induced degradation of $I{\kappa}B$. To elucidate the underlying mechanism by which CG exerts its anti-inflammatory action, involvement of various signaling pathways were examined. CG exhibited significantly increased Akt phosphorylation in a concentration-dependent manner, although MAPKs such as Erk, JNK, and p38 appeared not to be involved. Furthermore, inhibition of Akt/PI3K signaling pathway with wortmannin significantly, albeit not completely, abolished CG-induced Akt phosphorylation and anti-inflammatory actions. Taken together, the present study demonstrates that Akt signaling pathway might play a major role in CG-mediated anti-inflammatory activity in LPS-stimulated RAW264.7 macrophage cells.

• Journal of Applied Biological Chemistry
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• v.64 no.4
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• pp.447-451
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• 2021

In this study, we discovered for the first time that linarin, a flavonoid compound, enhances melanin biosynthesis in B16F10 cells, and subsequently elucidated the underlying mechanism of linarin-induced melanogenesis. Linarin showed no cytotoxicity at a concentration of 42 μM and significantly increased intracellular tyrosinase activity and melanin content in B16F10 cells. Mechanistic analysis showed that linarin increased the expression of tyrosinase, tyrosinase-related protein 1 (TRP-1), and microphthalmia-associated transcription factor (MITF) that are related to melanogenesis. Moreover, linarin decreased the phosphorylation of extracellular signal-regulated kinase (ERK) and protein kinase B (AKT). Finally, we evaluated the effect of the structure-activity relationship of linarin and its aglycone on melanogenesis. The results indicated that linarin enhances the expression of melanogenic proteins by activating MITF expression via the modulation of mitogen-activated protein kinase (MAPK), phosphatidylinositol 3-kinase (PI3K), and protein kinase B signaling pathways in B16F10 cells, thereby enhancing melanogenesis.