• Food Science of Animal Resources
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• v.44 no.3
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• pp.699-709
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• 2024

Oxya chinensis sinuosa (OC) is a well-known edible insect. Several researches on the health benefits of OC consumption have been performed to date; however, their effect on eye health remains largely unknown. This study aimed to assess the protective effects of OC extracts on the oxidative stress on the retinal pigment epithelium (RPE) cells. Oxidative damage has been identified as one of the key regulatory factors in agerelated macular degeneration. H₂O₂-induced reactive oxygen species (ROS) production, a well-known oxidative stress factor, can cause cell death in retinal pigment epithelia cells. In this study, we found that three OC extracts effectively prevented H₂O₂-induced ROS production and subsequent death of ARPE-19 cells in a dose-dependent manner. In addition, the OC extracts inhibited the phosphorylation of mitogen-activated protein kinases including p38, JNK, and ERK. The OC extracts restored IκBα degradation induced by H₂O₂, indicating that OC extracts suppressed the activation of nuclear factorκB. Furthermore, the three OC extracts were shown to have antioxidant effects by upregulating the intracellular expression of key antioxidant proteins such as SOD, NQO, and HO-1. Here we demonstrated the antioxidant and anti-apoptotic effects of the OC extracts on ARPE-19, indicating their potential role in improving eye health. These results suggest that three OC extracts plays a critical role in oxidative stress-induced cell death protects in ARPE-19 cells.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.103-103
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• 2018

Oenothera biennis, commonly known as evening primrose, a potential source of natural bioactive substances: flavonoids, steroids, tannins, fatty acids and terpenoids responsible for a diverse range of pharmacological functions. However, whether extract prepared from aerial part of O. biennis (APOB) protects skin against oxidative stress remains unknown. To investigate the protective effects of APOB against oxidative stress-induced cellular damage and elucidated the underlying mechanisms in the HaCaT human skin keratinocytes. Our results revealed that treatment with APOB prior to hydrogen peroxide ($H_2O_2$) exposure significantly increased viability, and the highest DPPH radical-scavenging activities and reducing power of HaCaT cells. APOB also effectively attenuated H2O2-induced comet tail formation and inhibited the $H_2O_2$-induced phosphorylation levels of the histone ${\gamma}H2AX$, as well as the number of apoptotic bodies and Annexin V-positive cells. In addition, APOB exhibited scavenging activity against intracellular reactive oxygen species (ROS) accumulation and restored the mitochondrial membrane potential loss by $H_2O_2$. Moreover, $H_2O_2$ enhanced the cleavage of caspase-3 and degradation of poly (ADP-ribose)-polymerase (PARP), a typical substrate protein of activated caspase-3, as well as DNA fragmentation; however, these events were almost totally reversed by pretreatment with APOB. Furthermore, APOB increased the levels of heme oxygenase-1 (HO-1), which is a potent antioxidant enzyme, associated with the induction of nuclear factor-erythroid 2-related factor 2 (Nrf2). According to our data, APOB is able to protect HaCaT cells from $H_2O_2$-induced DNA damage and cell death through blocking cellular damage related to oxidative stress through a mechanism that would affect ROS elimination and activating the Nri2/HO-1 signaling pathway.

• Biomolecules & Therapeutics
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• v.28 no.5
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• pp.443-455
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• 2020

The thioredoxin (Trx) system plays critical roles in regulating intracellular redox levels and defending organisms against oxidative stress. Recent studies indicated that Trx reductase (TrxR) was overexpressed in various types of human cancer cells indicating that the Trx-TrxR system may be a potential target for anti-cancer drug development. This study investigated the synergistic effect of auranofin, a TrxR-specific inhibitor, on sulforaphane-mediated apoptotic cell death using Hep3B cells. The results showed that sulforaphane significantly enhanced auranofin-induced apoptosis by inhibiting TrxR activity and cell proliferation compared to either single treatment. The synergistic effect of sulforaphane and auranofin on apoptosis was evidenced by an increased annexin-V-positive cells and Sub-G1 cells. The induction of apoptosis by the combined treatment caused the loss of mitochondrial membrane potential (ΔΨm) and upregulation of Bax. In addition, the proteolytic activities of caspases (-3, -8, and -9) and the degradation of poly (ADP-ribose) polymerase, a substrate protein of activated caspase-3, were also higher in the combined treatment. Moreover, combined treatment induced excessive generation of reactive oxygen species (ROS). However, treatment with N-acetyl-L-cysteine, a ROS scavenger, reduced combined treatment-induced ROS production and apoptosis. Thereby, these results deduce that ROS played a pivotal role in apoptosis induced by auranofin and sulforaphane. Furthermore, apoptosis induced by auranofin and sulforaphane was significantly increased through inhibition of the phosphoinositide 3-kinase (PI3K)/Akt pathway. Taken together, the present study demonstrated that down-regulation of TrxR activity contributed to the synergistic effect of auranofin and sulforaphane on apoptosis through ROS production and inhibition of PI3K/Akt signaling pathway.

• Tuberculosis and Respiratory Diseases
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• v.65 no.6
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• pp.476-486
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• 2008

Background: TRAIL (TNF-related apoptosis inducing ligand) is a newly identified member of the TNF gene family which appears to have tumor-selective cytotoxicity due to the distinct decoy receptor system. TRAIL has direct access to caspase machinery and induces apoptosis regardless of p53 phenotype. Therefore, TRAIL has a therapeutic potential in lung cancer which frequently harbors p53 mutation in more than 50% of cases. However, it was shown that TRAIL also could activates $NF-{\kappa}B$ in some cell lines which might inhibit TRAIL-induced apoptosis. This study was designed to investigate whether TRAIL can activate $NF-{\kappa}B$ in lung cancer cell lines relatively resistant to TRAIL-induced apoptosis and inhibition of $NF-{\kappa}B$ activation using proteasome inhibitor MG132 which blocks $I{\kappa}B{\alpha}$ degradation can sensitize lung cancer cells to TRAIL-induced apoptosis. Methods: A549 (wt p53) and NCI-H1299 (null p53) lung cancer cells were used and cell viability test was done by MTT assay. Apoptosis was confirmed with Annexin V assay followed by FACS analysis. To study $NF-{\kappa}B$-dependent transcriptional activation, a luciferase reporter gene assay was used after making A549 and NCI-H1299 cells stably transfected with IgG ${\kappa}-NF-{\kappa}B$ luciferase construct. To investigate DNA binding of $NF-{\kappa}B$ activated by TRAIL, electromobility shift assay was used and supershift assay was done using anti-p65 antibody. Western blot was done for the study of $I{\kappa}B{\alpha}$ degradation. Results: A549 and NCI-H1299 cells were relatively resistant to TRAIL-induced apoptosis showing only 20~30% cell death even at the concentration 100 ng/ml, but MG132 ($3{\mu}M$) pre-treatment 1 hour prior to TRAIL addition greatly increased cell death more than 80%. Luciferase assay showed TRAIL-induced $NF-{\kappa}B$ transcriptional activity in both cell lines. Electromobility shift assay demonstrated DNA binding complex of $NF-{\kappa}B$ activated by TRAIL and supershift with p65 antibody. $I{\kappa}B{\alpha}$ degradation was proven by western blot. MG132 completely blocked both TRAIL-induced $NF-{\kappa}B$ dependent luciferase activity and DNA binding of $NF-{\kappa}B$. Conclusion: This results suggest that inhibition of $NF-{\kappa}B$ can be a potentially useful strategy to enhance TRAIL-induced tumor cell killing in lung cancer.

• Journal of Life Science
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• v.25 no.9
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• pp.984-992
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• 2015

Sanguinarine is a benzophenanthridine alkaloid originally isolated from the roots of Sanguinaria canadensis. It has multiple biological activities (e.g., antioxidant and antiproliferative) and immune-enhancing potential. In this study, we explored the proapoptotic properties and modes of action of sanguinarine in human hepatocellular carcinoma HepG2 cells. Our results revealed that sanguinarine inhibited HepG2 cell growth and induced apoptosis in a dose-dependent manner. The induction of apoptosis by sanguinarine was associated with the up-regulation of Fas and Bax, the release of cytochrome c from the mitochondria to the cytosol, and the loss of the mitochondrial membrane potential. In addition, sanguinarine activated caspase-9 and -8, initiator caspases of the intrinsic and death extrinsic pathways, respectively, and caspase-3, accompanied by proteolytic degradation of poly (ADP-ribose) polymerase. Sanguinarine also triggered the generation of reactive oxygen species (ROS). The elimination of ROS by N-acetylcysteine reversed sanguinarine-induced apoptosis. Furthermore, sanguinarine induced the dephosphorylation of Akt and the phosphorylation of mitogen-activated protein kinases, including extracellular signal-regulated kinase (ERK), c-jun N-terminal kinase (JNK), and p38. The growth inhibition was enhanced by the combined treatment of sanguinarine with a phosphatidylinositol 3'-kinase (PI3K) inhibitor and an ERK inhibitor but not JNK and p38 inhibitors. Overall, our data indicate that the proapoptotic effects of sanguinarine in HepG2 cells depend on ROS production and the activation of both intrinsic and extrinsic signaling pathways, which is mediated by blocking PI3K/Akt and activating the ERK pathway. Thus, our data suggest that sanguinarine may be a natural compound with potential for use as an antitumor agent in liver cancer.

• Korean Journal of Acupuncture
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• v.29 no.2
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• pp.271-289
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• 2012

Objectives : Ganoderma lucidum(Ganoderma or lingzhi, 靈芝) is a well-known oriental medical mushroom containing many bioactive compounds. The possible mechanisms involved in its effects on cancer cells remain to be elucidated. In the present study, the anti-proliferative and apoptotic activities of the G. lucidum ethanol extract(GEE), in AGS human gastric cancer cells were investigated. Methods : It was found that exposure of AGS cells to GEE resulted in the growth inhibition in a dose and time dependent manner as measured by trypan blue count and MTT assay. The anti-proliferative effect of GEE treatment in AGS cells was associated with morphological changes and formation of apoptotic bodies, and the flow cytometry analysis confirmed that GEE treatment increased the populations of apoptotic-sub G1 phase. Growth inhibition and apoptosis of AGS cells by GEE were connected with a concentration and time-dependent up-regulation of tumour necrosis factor-related apoptosis-inducing ligand(TRAIL) expression. Results : The levels of XIAP and survivin expression, members of IAP family proteins, were gradually down-regulated by GEE treatment. However other members of IAP family proteins such as cIAP-1 and cIAP-2 remained unchanged in GEE-treated AGS cells. GEE treatment also induced the proteolytic activation of caspase-3, caspase-8 and caspase-9 and a concomitant degradation of poly(ADP-ribose) polymerase(PARP) protein, a caspase-3 substrate protein. Additionally, GEE-induced apoptosis was associated with the inhibition of Akt activation in a concentration and time-dependent manner, and pre-treatment with LY294002, a phosphoinositide 3-kinase(PI3K)/Akt inhibitor, significantly increased GEE-induced growth inhibition and apoptosis. Conclusions : Therefore, G. lucidum has a strong potential as a therapeutic agent for preventing cancers such as gastric cancer cells.

• 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.

• ALGAE
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• v.30 no.4
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• pp.313-323
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• 2015

Lipid peroxidation means the oxidative degradation of lipids. The process from the cell membrane lipids in an organism is generated by free radicals, and result in cell damage. Phlorotannins, well-known marine brown algal polyphenols, have been utilized in functional food supplements as well as in medicine supplements to serve a variety of purposes. In this study, we assessed the potential anti-lipid peroxidation activity of phlorofucofuroeckol-A (PFF-A), one of the phlorotannins, isolated from Ecklonia cava by centrifugal partition chromatography in 2,2-azobis (2-amidinopropane) dihydrochloride (AAPH)-stimulated Vero cells and zebrafish system. PFF-A showed the strongest scavenging activity against alkyl radicals of all other reactive oxygen species (ROS) and exhibited a strong protective effect against ROS and a significantly strong inhibited of malondialdehyde in AAPH-stimulated Vero cells. The apoptotic bodies and pro-apoptotic proteins Bax and caspase-3, which were induced by AAPH, were strongly inhibited by PFF-A in a dose-dependent manner and expression of Bcl-xL, an anti-apoptotic protein, was induced. In the AAPH-stimulated zebrafish model, additionally PFF-A significantly inhibited ROS and cell death, as well as exhibited a strong protective effect against lipid peroxidation. Therefore, these results suggest that PFF-A has excellent protective effects against ROS and lipid peroxidation induced by AAPH in both an in vitro Vero cell model and an in vivo zebrafish model.

• International Journal of Oral Biology
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• v.39 no.2
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• pp.65-73
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• 2014

Chios Gum Mastic (CGM) is a natural resin extracted from the leaves of Pistacia lentiscus, a plant endemic to the Greek island of Chios. It has been used by traditional healers, and it has antibacterial, antifungal properties, and therapeutic benefits for the skin. The CGM reduces the formation of dental plaque and bacterial growth in oral saliva, and recent studies have demonstrated the role of antioxidant activity of CGM. Although CGM has been widely investigated, its protective effect against oxidative-damage to keratinocytes, as well as the relationship between CGM and autophagy, has not been investigated. The aim of this study was to assess the protective effect of CGM against $H_2O_2$-induced oxidative stress and to evaluate the autophagic features induced by CGM in human keratinocytes. The pretreatment with CGM significantly reduced apoptosis in $H_2O_2$-exposed HaCaT cells. It promoted the degradation of caspase-3, caspase-8, and caspase-9; and it induced the formation of the processed PARP. The treatment with CGM caused an increase in vesicle formation compared to control group. The level of p62 was reduced and the conversion of LC3-I to LC3-II was increased in CGM treated HaCaT cells. Also, the treatment with CGM increased cleavage of ATG5-ATG12 complex. In summary, CGM helps the cells to survive under stressful conditions by preventing apoptosis and enhancing autophagy. Besides, the present investigation provides evidence to support the antioxidant potential of CGM in vitro and opens up a new horizon for future experiments.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.66-66
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• 2019

Heracleum moellendorffii roots (HM-R) have been long treated for inflammatory diseases such as arthritis, backache and fever. However, an anti-inflammatory effect and the specific mechanism of HM-R were not yet clear. In this study, we for the first time explored the anti-inflammatory of HM-R. Results: HM-R dose-dependently blocked LPS-induced NO and PGE2 production. In addition, 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. Furthermore, HM-R inhibited MAPK signaling activation by attenuating the phosphorylation of ERK1/2, p38 and JNK. HM-R increased nuclear accumulation of Nrf2 and HO-1 expression. However, NAC reduced the increased nuclear accumulation of Nrf2 and HO-1 expression by HM-R. In HPLC analysis, falcarinol was detected from HM-R as an anti-inflammatory compound. These results indicate that HM-R may exert anti-inflammatory activity by inhibiting $NF-{\kappa}B$ and MAPK signaling, and activating ROS/Nrf2/HO-1 signaling. From these findings, HM-R may have potential to be a candidate for the development of anti-inflammatory drugs.