• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.89-89
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• 2020

In this study, we evaluated the effect of the extracts from Lonicera caerulea leaves (LCLE), branches (LCBE) and fruits (LCFE) on the cell growth and migration in human colorectal cancer cells, HCT116 and SW480 cells. LCLE and LCBE dose- and time-dependently inhibited the proliferation of HCT116 and SW480 cells. However, LCFE did not affect the proliferation of HCT116 and SW480 cells. In addition, LCLE and LCBE dramatically cell migration and wound healing in HCT116 cells. LCLE and LCBE decreased β-catenin protein level but not mRNA level in HCT116 and SW480 cells. Furthermore, LCLE decreased TCF4 level in both protein and mRNA level in HCT116 and SW480 cells. However, LCBE decreased TCF4 protein level but not mRNA level in HCT116 and SW480 cells. Based on these findings, LCLE and LCBE may inhibit the cell proliferation and migration through blocking Wnt signaling activation in human colorectal cancer cells. Therefore, LCLE and LCBE may be a potential candidate for the development of chemopreventive or therapeutic agents for human colorectal cancer.

• Archives of Pharmacal Research
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• v.23 no.6
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• pp.605-612
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• 2000

Green tea polyphenols (GTP) have been demonstrated to suppress tumorigenesis in several chemical-induced animal carcinogenesis models, and predicted as promising chemopreventive agents in human. Recent studies of GTP extracts showed the involvement of mitogen-activated protein kinases (MAPKs) in the regulation of Phase II enzymes gene expression and induction of apoptosis. In the current work we compared the biological actions of five green tea catechins: (1) induction of ARE reporter gene, (2) activation of MAP kinases, (3) cytotoxicity in human hepatoma HepG2-C8 cells, and (4) caspase activation in human cervical squamous carcinoma HeLa cells. For the induction of phase IIgene assay, (-)-epigallocatechin-3-gallate (EGCG) and (-)-epicatechin-3-gallate (ECG) potently induced antioxidant response element (ARE)-mediated luciferase activity, with induction observed at 25 $\mu\textrm{m}$with EGCG. The induction of ARE reporter gene appears to be structurally related to the 3-gallate group. Comparing the activation of MAPK by the five polyphenols, only EGCG showed potent activation of all three MAPKs (ERK, JNK and p38) in a dose- and time-dependent manner, whereas EGC activated ERK and p38. In the concentration range of 25 $\mu\textrm{m}$ to 1 mM, EGCG and ECG strongly suppressed HepG2-ARE-C8 cell-growth. To elucidate the mechanisms of green tea polyphenol-induced apoptosis, we measured the activation of an important cell death protein, caspase-3 induced by EGCG, and found that caspase-3 was activated in a dose- and time-dependent manner. Interestingly, the activation of caspase-3 was a relatively late event (peaked at 16 h), whereas activation of MAPKs was much earlier (peaked at 2 h). It is possible, that at low concentrations of EGCG, activation of MAPK leads to ARE-mediated gene expression including phase II detoxifying enzymes. Whereas at higher concentrations of EGCG, sustained activation of MAPKs such as JNK leads to apoptosis. These mechanisms are currently under investigation in our laboratory. As the most abundant catechin in GTP extract, we found that EGCG potently induced ARE-mediated gene expression, activated MAP kinase pathway, stimulated caspase-3 activity, and induced apoptosis. These mechanisms together with others, may contribute to the overall chemopreventive function of EGCG itself as well as the GTP.

• Journal of Food Hygiene and Safety
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• v.13 no.3
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• pp.243-251
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• 1998

Panax ginseng C.A. Meyer has been extensively used in the traditional oriental medicine as a restorative, tonic and prophylatic agent. Petroleum ether extract of panax ginseng C.A. Meyer (GPE) and its several fractions (PI-P5) were tested for the evaluation of antigenotoxicity against N-methyl-N-nitrosourea (MNU) and benzo(a)pyrene [B(a)P]-induced micronucleated reticulocytes in mouse peripheral blood. GPE and P2 showed more significant anticlastogenicity than other fractions did. To elucidate the anticlastogenic action mechanism of GPE and P2 against B(a)P, the alteration of B(a)P metabolism was studied. GPE and P2 inhibited B(a)P metabolism in the presence of 8-9 mix and decreased B(a)P-DNA binding in calf thymus DNA with 8-9 mix. They also decreased [$^3H$] MNU induced DNA binding and methylation to 7-methyl guanine and $O^{6}-methyl$ guanine adducts in calf thymus DNA by RPLC analysis. These results suggest that the anticlastogenicity of GPE and P2 on the B(a)P or MNU-induced clastogenicity is due to decrease of DNA binding with B(a)P or MNU, the inhibition of metabolism with B(a)P and the inhibition of methylation in DNA. Therefore, GPE and P2 may be useful chemopreventive agents of alkylating agent like MNU and secondary carcinogen like B(a)P.

• Archives of Pharmacal Research
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• v.29 no.8
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• pp.633-644
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• 2006

In last couple of decades the use of natural compounds like flavonoids as chemopreventive agents has gained much attention. Our current study focuses on identifying chemopreventive flavonoids and their mechanism of action on human prostate cancer cells. Human prostate cancer cells (PC3), stably transfected with activator protein 1 (AP-1) luciferase reporter gene were treated with four main classes of flavonoids namely flavonols, flavones, flavonones, and isoflavones. The maximum AP-1 luciferase induction of about 3 fold over control was observed with $20\;{\mu}M$ concentrations of quercetin, chrysin and genistein and $50\;{\mu}M$ concentration of kaempferol. At higher concentrations, most of the flavonoids demonstrated inhibition of AP-1 activity. The MTS assay for cell viability at 24 h showed that even at a very high concentration $(500\;{\mu}M)$, cell death was minimal for most of the flavonoids. To determine the role of MAPK pathway in the induction of AP-1 by flavonoids, Western blot of phospho MAPK proteins was performed. Four out of the eight flavonoids namely kaempferol, apigenin, genistein and naringenin were used for the Western Blot analysis. Induction of phospho-JNK and phospho-ERK activity was observed after two hour incubation of PC3-AP1 cells with flavonoids. However no induction of phospho-p38 activity was observed. Furthermore, pretreating the cells with specific inhibitors of JNK reduced the AP-1 luciferase activity that was induced by genistein while pretreatment with MEK inhibitor reduced the AP-1 luciferase activity induced by kaempferol. The pharmacological inhibitors did not affect the AP-1 luciferase activity induced by apigenin and naringenin. These results suggest the possible involvement of JNK pathway in genistein induced AP-1 activity while the ERK pathway seems to play an important role in kaempferol induced AP-1 activity.

• Korean Journal of Plant Resources
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• v.31 no.3
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• pp.211-217
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• 2018

Hibiscus syriacus (H. syriacus) as the national flower of Korea has been used as the herbal medicine in Asia. In this study, we evaluated the anti-inflammatory effect of 70% ethanol extracts from the root of Hibiscus syriacus (RHS-E70) and elucidated the potential signaling pathway in LPS-stimulated RAW264.7 cells. RHS-E70 dose-dependently suppressed NO production by inhibiting iNOS and IL-${\beta}$ expression in LPS-stimulated RAW264.7 cells. RHS-E70 inhibited the phosphorylation and degradation of $I{\kappa}B-{\alpha}$, which contributed to the inhibition of p65 nuclear accumulation and NF-${\kappa}B$ activation. Furthermore, RHS-E70 suppressed the phosphorylation of ERK1/2 and p38, which results in the inhibition of ATF2 phosphorylation and subsequent nuclear accumulation. These results indicate that RHS-E70 may exert anti-inflammatory activity by inhibiting NF-${\kappa}B$ and MAPK/ATF2 signaling. From these findings, RHS-E70 has potential to be a candidate for the development of chemopreventive or therapeutic agents for the inflammatory diseases.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.96-96
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• 2018

Although the roots of Heracleum moellendorffii (HM-R) have been long treated for inflammatory human diseases, scientific evidence for the anti-inflammatory activity of HM-R is not sufficient. In this study, we investigated anti-inflammatory activity and mechanism of action of HM-R in LPS-stimulated RAW264.7 cells. HM-R blocked LPS-induced NO and PGE2 production, but not HM-L. HM-R inhibited LPS-induced overexpression of iNOS, COX-2, $IL-1{\beta}$ and IL-6 in RAW264.7 cells. HM-R inhibited LPS-induced $NF-{\kappa}B$ signaling activation through blocking $I{\kappa}B-{\alpha}$ degradation and p65 nuclear accumulation. In addition, HM-R inhibited MAPK signaling activation by attenuating the phosphorylation of ERK1/2, p38 and JNK. Furthermore, HM-R inhibited attenuated LPS-mediated overexpression of the osteoclast-specific factors such as NFATc1, cathepsin K, MCP-1 and TRAP. These results indicate that HM-R may exert anti-inflammatory activity by inhibiting $NF-{\kappa}B$ and MAPK signaling activation. From these findings, HM-R has potential to be a candidate for the development of chemopreventive or therapeutic agents for the inflammation and inflammatory diseases.

• Korean Journal of Plant Resources
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• v.33 no.5
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• pp.460-466
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• 2020

In this study, we evaluated the anti-cancer activity and potential molecular mechanism of 70% ethanol extracts of leaves from Rodgersia podophylla against human colorectal cancer cells, HCT116. RPL dose-dependently decreased the cell viability through RPL-induced apoptosis in HCT116 cells. RPL induced inactivation the nuclear factor κB(NF-κB) through blocking IκB-α degradtion and P65 nuclear accumulation. The inhibition of GSK3β by LiCl attenuated RP-L-mediated NF-κB signaling inactivation. In addition, RP-L induced GSK3β activation. Based on these findings, RPL may be a potential candidate for the development of chemopreventive or therapeutic agents for human colorectal cancer.

• BMB Reports
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• v.41 no.4
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• pp.328-333
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• 2008

A variety of anti-inflammatory agents have been shown to exert chemopreventive activity via targeting of transcription factors such as NF-${\kappa}B$ and AP-1. Lithospermum erythrorhizon (LE) has long been used in traditional oriental medicine. In this study, we demonstrated the inhibitory effects of LE extracts on lipopolysaccharide (LPS)-stimulated production of inflammatory cytokines. As an underlying mechanism of inhibition, LE extracts reduced LPS-induced transactivation of AP-1 as well as NF-${\kappa}B$ in mouse macrophage cells. Electrophoretic mobility shift assays indicated that LE extracts inhibited the DNA binding activities of AP-1 and NF-${\kappa}B$. In addition, phosphorylation of $I{\kappa}B-{\alpha}$ protein was suppressed by LE extracts. Moreover, LE extracts inhibited c-Jun N-terminal kinase and extracellular signal-regulated signaling pathways. Our results suggest that the anti-inflammatory activity of LE extracts may be mediated by the inhibition of signal transduction pathways that normally lead to the activation of AP-1and NF-${\kappa}B$. These inhibitory effects may be useful for chemoprevention of cancer or other chronic inflammatory diseases.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1177-1182
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• 2012

Protein kinase C (PKC) has been implicated in carcinogenesis and displays variable expression profiles during cancer progression. Studies of dietary phytochemicals on cancer signalling pathway regulation have been conducted to search for potent signalling regulatory agents. The present study was designed to evaluate any suppressive effect of maslinic acid on PKC expression in human B-lymphoblastoid cells (Raji cells), and to identify the PKC isoforms expressed. Effects of maslinic acid on PKC activity were determined using a PepTag$^{(R)}$ assay for non-radioactive detection of PKC. The highest expression in Raji cells was obtained at 20 nM PMA induced for 6 hours. Suppressive effects of maslinic acid were compared with those of four PKC inhibitors (H-7, rottlerin, sphingosine, staurosporine) and two triterpenes (oleanolic acid and ursolic acid). The $IC_{50}$ values achieved for maslinic acid, staurosporine, H-7, sphingosine, rottlerin, ursolic acid and oleanolic acid were 11.52, 0.011, 0.767, 2.45, 5.46, 27.93 and $39.29\;{\mu}M$, respectively. Four PKC isoforms, PKC ${\beta}I$, ${\beta}II$, ${\delta}$, and ${\zeta}$, were identified in Raji cells via western blotting. Maslinic acid suppressed the expression of PKC ${\beta}I$, ${\delta}$, and ${\zeta}$ in a concentration-dependent manner. These preliminary results suggest promising suppressive effects of maslinic acid on PKC activity in Raji cells. Maslinic acid could be a potent cancer chemopreventive agent that may be involved in regulating many downstream signalling pathways that are activated through PKC receptors.

• Korean Journal of Plant Resources
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• v.33 no.4
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• pp.263-270
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• 2020

In this study, we evaluated the effect of the extracts from Lonicera caerulea leaves (LCLE), branches (LCBE) and fruits (LCFE) on the cell growth and migration in human colorectal cancer cells, HCT116 and SW480 cells. LCLE and LCBE dose- and time-dependently inhibited the proliferation of HCT116 and SW480 cells. However, LCFE did not affect the proliferation of HCT116 and SW480 cells. In addition, LCLE and LCBE dramatically cell migration and wound healing in HCT116 cells. LCLE and LCBE decreased β-catenin protein level but not mRNA level in HCT116 and SW480 cells. Furthermore, LCLE decreased TCF4 level in both protein and mRNA level in HCT116 and SW480 cells. However, LCBE decreased TCF4 protein level but not mRNA level in HCT116 and SW480 cells. Based on these findings, LCLE and LCBE may inhibit the cell proliferation and migration through blocking Wnt signaling activation in human colorectal cancer cells. Therefore, LCLE and LCBE may be a potential candidate for the development of chemopreventive or therapeutic agents for human colorectal cancer.