• 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.

• Journal of Life Science
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• v.23 no.11
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• pp.1342-1350
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• 2013

We examined the effect of hydrogen sulfide ($H_2S$) in chemical hypoxia-induced injury in mouse hepatocytes. Cell viability was significantly decreased by cobalt chloride ($CoCl_2$), a well-known hypoxia mimetic agent in a time- and dose- dependent manner. Sodium hydrosulfide (NaHS, a donor of $H_2S$) pretreatment before exposure to $CoCl_2$ significantly attenuated the $CoCl_2$-induced decrease of cell viability. $CoCl_2$ treatment resulted in an increase of intracellular ROS generation, which is inhibited by NaHS or N-acetyl-cysteine (NAC, a ROS scavenger), and p38 MAPK phosphorylation, which is also blocked by NaHS or NAC. The $CoCl_2$-induced increase of the Bax/Bcl-2 ratio was attenuated by NaHS, NAC, and SB 203580 (p38 MAPK inhibitor). The $CoCl_2$-induced decrease of cell viability was also attenuated by NaHS, NAC, and SB 203580 pretreatment. Additionally, NaHS inhibited the $CoCl_2$-induced COX-2. Similar to the effect of NaHS, NAC blocked $CoCl_2$-induced COX-2 expression. Furthermore, NS-398 (a selective COX-2 inhibitor) attenuated not only the $CoCl_2$-induced increase of the Bax/Bcl-2 ratio, it also decreased cell viability. Taken together, $H_2S$ protects primary cultured mouse hepatocytes against $CoCl_2$-induced cell injury through inhibition of the ROS-activated p38 MAPK cascade and the COX-2 pathway.

• Journal of Nutrition and Health
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• v.35 no.3
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• pp.296-302
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• 2002

This study was designed to investigate the effects of a butanol extract of pine needles (Pinus densiflora Sieb et Zucc) on lipid metabolism and oxidative stress in rats. Twenty-eight male Sprague-Dawley (SD) rats were divided into four groups over a 45 days study period: the control group on a basic diet, and three experimental groups on three different dietary levels of the butanol fraction, specifically 25 mg (BuOH-25), 50 mg (BuOH-50), and 100 mg (BuOH-100) butanol fraction/kg body weight/day, thereby 0.025%, 0.05%, 0.1% of butanol extract of pine needles was added to basic diet respectively. At the end of the experimental period, body weights and food intakes were food intakes were not different among the four groups. Total and LDL-cholesterol levels were markedly decreased in the BuOH-25, BuOH-50, and BuOH-100 groups, respectively, as follows: 12.8%, 19.1% and 21.6% reductions in total cholesterol; and 10.2%, 15.6% and 23.7% reductions in LDL-cholesterol. However, HDL-cholesterol levels were significantly increased (by approximately 20%) in the serum of the BuOH-100 group only, compared with the control and other experimental groups. Atherogenic indices were also markedly decreased in the three experimental groups, by 24.8%, 30.4% and 36.2%, for each of the BuOH-25, BuOH-50, and BuOH-100 groups, respectively, compared with the control group. The levels of the hydroxyl radical (·OH) and of lipid peroxide (LPO) in the serum of the three experimental groups were significantly reduced, by 9.8%, 19.7% and 21.2%; and by 13.3%, 13.3% and 16.7%, for the BuOH-25, BuOH-50, and BuOH-100 groups, respectively Significant increases in serum superoxide dismutase (SOD) were observed in the BuOH-50 and BuOH-100 groups; specifically, 12.1% in the BuOH-50 group and 23.3% in the BuOH-100 group, compared with the control group. Significant increases in catalase (CAT) avtivities, of 24.7% in the BuOH-50 group and 29.2% in the BuOH-100 group, were also observed, compared to the control group. These results suggest that a butanol extract of pine needles could inhibit chronic degenerative disease through improving lipid metabolism, and could also effectively modulate the aging process attenuating oxidative stress.

• The Korean Journal of Pharmacology
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• v.21 no.1
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• pp.62-77
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• 1985

In tile Iron-catalyzed Haber-Weiss reaction to produce OH., the requirement for $O^{-}_{2}{\cdot}$ is only to reduce $Fe^{+++}$. Possibly, the role of $O^{-}_{2}{\cdot}$ can be replaced by other reducing agents. Ascorbate is one of them in biological system. In the present study, the ability of ascorbate to produce $OH{\cdot}$ in the presence of $Fe^{++}$ and $H_2O_2$ was investigated by observing the degradation of hyaluronic acid and ethylene production from methional. Ascorbate stimulated the degradation of hyaluronic by $Fe^{++}$ and $H_2O_2$. That was confirmed by both viscosity change and gel-permeation chromatographic analysis. The observed degradation was almost completely prevented by catalase and $OH{\cdot}$ scavengers. In support of the above results, ascorbate enhanced the prouction of ethylene from methional in the presence of $Fe^{++}$ and $H_2O_2$. Other reducing agents (cysteine, glutathione, NADH and NADPH) showed similar activities to ascorbate in the degradation of hyaluronic acid and ethylene production. But no stimulatory effects were observed with their oxidized forms such as NAD and NADP. Thus, it appears that reduction of the metal ion was needed for $OH{\cdot}$ production. Among the metal ions tested, $Fe^{++}$ showed most potent catalytic action in the production of $OH{\cdot}$ The results obtained support that ascorbate can substitute $O^{-}_{2}{\cdot}$ in the metal-catalyzed reactions, particularly with $Fe^{++}$ by which $OH{\cdot}$ is produced with $H_2O_2$. The significance of the ascorbate-dependent production of $OH{\cdot}$ was considered with respect to possible role of ascorbate in the damage of inflamed joints.

• Journal of the Korean Applied Science and Technology
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• v.32 no.4
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• pp.702-711
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• 2015

This study was conducted to determine the feasibility of using Gastrodia elata Blume as a cosmetic raw material by investigating the physiological activities of its extracts, varying the concentration, solvent, and fermentation method (non-fermentation and fermentation using lactic acid bacteria and effective microorganisms). Of the extracts in three different solvents-water, EtOH, and 70% EtOH-at four different concentrations (0.725, 1.25, 2.5, and 5 mg/mL), the EtOH extracts demonstrated the highest contents of antioxidants (flavonoids, polyphenols, and DPPH free radical scavengers). The DPPH free radical scavenging activity in the EtOH extracts of EM-fermented Gastrodia elata Blume increased from $27.08{\pm}0.5%$ at 1.25 mg/mL to $35.89{\pm}0.8%$ at 2.5 mg/mL. The tyrosinase inhibitory activity test was performed to measure skin-whitening capacity and revealed the LB-fermented EtOH extracts to be the most efficacious ($39.1{\pm}0.4%$ at 0.725 mg/mL, $62.8{\pm}1.5%$ at 2.5 mg/mL). Viability was found to exceed 85% in RAW 264.7 cells treated with all extracts (water, EtOH, 70% EtOH at 10, 25, $50{\mu}L$, fermented and non-fermented), thus proving that Gastrodia elata Blume extracts do not cause inflammation. When RAW 264.7 cells were stimulated with lipopolysaccharide as positive controls under the same conditions to determine the antioxidant activity in the presence of reactive oxygen species (ROS), EM-fermentation was found to impart excellent antioxidant capacity. This study verified the physiological activities of fermented Gastrodia elata Blume extracts that are best suited for cosmetic ingredients, such as antioxidants, tyrosinase inhibitors and anti-inflammatory agents.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.10
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• pp.1458-1469
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• 2015

This study was carried out to investigate the nitrite scavenging activities (NSA) of nine kinds of wild vegetables in a $NaNO_2$ model system and nitrite of Chinese cabbage as well as the inhibitory effect of kimchi containing a mixture of wild vegetables (MWV) with nitrite scavenging activity on brain neuronal cell death. NSA was higher at pH 1.2 than pH 4.2 in all samples. NSA of extracts from sprouts of Oenothera laciniata and Aster scaber (AS) was above 90% at pH 1.2. AS, Codonopsis lanceolate (CL), Adenophora triphylla (AT), Platycodon grandiflorum (PG), and Taraxacum officinale (TO) extracts showed significantly higher levels of NSA than those from other extracts at pH 4.2. CL, AT, PG, and TO extracts showed high NSA on nitrite of Chinese cabbage. In addition, the effects of MWV on antioxidant and brain neuronal cell death induced by oxidative stress were investigated in human brain neuroblastoma SK-N-SH cells. MWV extract attenuated $H_2O_2$-induced cell death and reactive oxygen species (ROS) generation in SK-N-SH cells. MWV extract showed significantly higher DPPH radical scavenger activity when compared to normal kimchi extract. MWV extract showed an inhibitory effect on brain neuronal cell death against oxidative stress by antioxidant activities.

• Korean Journal of Environmental Biology
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• v.18 no.3
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• pp.331-336
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• 2000

In order to examine the effect of SO$_2$, which is the major component of acid rain, on the peroxidase activity, rice (Oryza sativa) seedlings were grown on the media containing various concentrations of Na$_2$SO$_3$. Na$_2$SO$_3$ concentrations needed for the 50% inhibition of rice seed germination were determined to be 300$\mu\textrm{g}$/ml at pH 7, 8$\mu\textrm{g}$/ml at pH 5 and 2$\mu\textrm{g}$/ml at pH 3. Notably, about 8 fold and 4 fold increase of the specific activity of the enzyme were observed with the seedlings treated with 8$\mu\textrm{g}$/ml Na$_2$SO$_3$ at pH 5 and 2$\mu\textrm{g}$/ml Na$_2$SO$_3$ at pH 3, respectively. The effects of Cd and Pb on the peroxidase activities and chlorophyll contents were also examined. About 3.9 fold higher peroxidase activities were found at 0.03mM Cd, and the chlorophyll contents were reduced to 63% of the control seedlings. At 0.04mM Pb, 2.5 fold higher enzyme activities were found and the chlorophyll contents were reduced to 72%. Therefore, the increases of rice peroxidase activities might be involved in the defense mechanism of the cell against various environmental stresses such as Na$_2$SO$_3$, Cd and Pb. The effects of Cu and Fe, which are the inducers of oxidative stresses by the generations of reactive oxygen species, on the peroxidase activities were also investigated. About 57% and 65% activity losses were found at 0.5mM CuSO$_4$ and 0.5mM FeSO$_4$, respectively, and radical scavenger ethanol almost completely protected both inactivations. However, dimethyl sulfoxide, mannitol, thiourea and histidine showed different radical scavenging effects one another against Cu and Fe inactivation.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.1
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• pp.13-24
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• 2006

Neuronal apoptotic events, consequently resulting in neuronal cell death, are occurred in hypoxic/ischemic condition. This cell death has been shown to be accompanied with the production of reactive oxygen species (ROS), which can attack cellular components such as nucleic acids, proteins and phospholipid. However, the underlying mechanisms of apoptosis induced in hypoxic/ischemic condition and its treatment methods are unsettled. Cobalt chloride $(CoCl_2)$ has been known to mimic hypoxic condition including the production of ROS. Epigallocatechin gallate (EGCG), a green tea polyphenol, has diverse pharmacologial activities in cell growth and death. This study was aimed to investigate the apoptotic mechanism by $CoCL_2$ and effects of EGCG on $CoCl_2-induced$ apoptosis in PC12 cells. Administration of $CoCl_2$ decreased cell survival in dose- and time-dependent manners and induced genomic DNA fragmentation. Treatment with $100{\mu}M$ EGCG for 30 min before PC12 cells were exposed to $150{\mu}M$ $CoCl_2$, being resulted in the cell viability and DNA fragmentation being rescued. $CoCl_2$ caused morphologic changes such as cell swelling and condensed nuclei whereas EGCG attenuated morphologic changes by $CoCl_2$. EGCG suppressed the apoptotic peak and a loss of ${\Delta}{\psi}_m$ induced by $CoCl_2$. $CoCl_2$ decreased Bcl-2 expression but Bax expression was not changed in $CoCl_2$- treated cells. EGCG attenuated the Bcl-2 underexpression by $CoCl_2$. $CoCl_2$ augumented the cytochrome c release from mitochondria into cytoplasm and increased caspase-8, -9 and caspase-3 activity a marker of the apoptotic executing stage. EGCG ameliorated the incruement in caspase-8, -9 and -3 activity, and cytochrome c release by $CoCl_2$ NAC (N-acetyl-cysteine), a scavenger of ROS, attenuated $CoCl_2-induced$ apoptosis in consistent with those of EGCG. These results suggest that $CoCl_2$ induces apoptotic cell death through both mitochondria- and death receptor-dependent pathway and EGCG has neuroprotective effects against $CoCl_2-induced$ apoptosis in PC12 cells.

• Korean Journal of Environmental Biology
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• v.39 no.3
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• pp.354-361
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• 2021

Understanding the phytotoxic mechanism of methyl bromide (MB), an essential fumigant during the quarantine and pre-shipment process, is urgently needed to ensure its proper use and reduce international economic losses. In a previous study, two main MB-induced toxic mechanisms such as reactive oxygen species (ROS) and auxin distribution were selected by analyzing transcriptomic analysis. In the study, a 3-week-old A. thaliana was supplied with 1 mM ROS scavengers [N-acetyl-L-cysteine (NAC) or L-glutathione (GSH)] and 1µM indole-3-acetic acid(IAA) three times every 12 h, and visual and gene expression assessments were performed to evaluate the reduction in phytotoxicity by supplements. Phytotoxic effects on the MB-4h exposed group were decreased with GSH application compared to the other single supplements and a combination of supplements at 7 days post fumigation. Among these supplements, GSH at a concentration of 1, 2, and 5mM was suppled to A. thaliana with MB-fumigation. During a long-term observation of 2 weeks after the fumigation, 5 mM GSH application was the most effective in minimizing MB-induced phytotoxic effects with up-regulation of HSP70 expression and increase in main stem length. These results indicated that ROS was a main key factor of MB-induced phytotoxicity and that GSH can be used as a supplement to reduce the phytotoxicity of MB.