• Biomolecules & Therapeutics
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• v.30 no.6
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• pp.501-509
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• 2022

Atopic dermatitis (AD) is a chronic inflammatory skin disorder. Suppression of MAPKs and NF-κB is implicated as a vital mechanism of action of several traditional Chinese medicines for AD therapy. Although overexpression of MAPK mRNA in the skin tissue has been shown in the AD model, the roles of each MAPK in AD pathogenesis have rarely been studied. This study examined the effect of NJK14047, an inhibitor of p38 MAPKs, on AD-like skin lesions induced in BALB/c mice by sensitization and challenges with 1-chloro-2,4-dinitrobenzene (CDNB) on dorsal skin and ears, respectively. After induction of AD, NJK14047 (2.5 mg/kg) or dexamethasone (10 mg/kg) was administrated for 3 weeks via intraperitoneal injection. Following its administration, NJK14047 suppressed CDNB-induced AD-like symptoms such as skin hypertrophy and suppressed mast cell infiltration into the skin lesions. It also reduced CDNB-induced increase in T_H2 cytokine (IL-13) and T_H1 cytokines (interferon-γ and IL-12A) levels but did not decrease serum IgE level. Furthermore, NJK14047 blocked CDNB-induced lymph node enlargement. These results suggest that NJK14047, a p38 MAPK inhibitor, might be an optimal therapeutic option with unique modes of action for AD treatment.

• Microbiology and Biotechnology Letters
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• v.25 no.4
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• pp.374-378
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• 1997

Glutathione S-transferase (GST) was purified from Pseudomonas sp. DJ77, and its N-terminal sequence was determined to be MKLFISPGACSL. A specific tyrosyl residue in the vicinity of the N terminus is conserved in all the known cytosolic GSTs and has been shown to function as a catalytic residue in $\alpha$, $\mu$, $\pi$ class GSTs from mammals. However, Pseudomonas sp. DJ77 GST has the Phe-4 and Ile-5 instead of Tyr in N-terminus. Its replacement with tyrosine did not significantly affect the enzyme activity. Results from in vitro biochemical analyses were confirmed by the in vivo activity-based CDNB growth inhibition analyses. Our results clearly indicate that GST of Pseudomonas sp. DJ77 has a novel reaction mechanism different from that of mammalian GSTs.

• Korean Journal of Medicinal Crop Science
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• v.10 no.4
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• pp.294-297
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• 2002

A gene coding for the GST of cotton (Gh-5) was cloned into Escherichia coli and experssed. The enzyme remained within the cytoplasm of E. coli. An 696 bp open reading frame was in the 988 base pair fragment of the recombinant plasmid pET-30b(+). The deduced protein sequence consists of 232 amino acids and has a molecular mass of 30235.58 Da. The cloned enzyme conjugated reduced glutathione and 1-chloro-2,4-dinitrobenzene (CDNB). Plant GST cDNA was expressed in microbe and produced polypeptide had function as an enzyme.

• Archives of Pharmacal Research
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• v.19 no.1
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• pp.12-17
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• 1996

Our previous studies demonstrate that menadione (MEN) is cytotoxic to platelets of rats by depleting glutathione (GSH). In order to clarify whether GSH has a role in protecting against menadione-induced cytotoxicity, the effect of GSH depletors as well as GSH precusors on menadione-induced cytotoxicity was investigated. Cysteine and dithiothreitol (DTT) prevent MEN-induced cytotoxicity in a dose-dependent manner, as determined by LDH leakage and change in turbidity. When platelets were treated with 1-chloro-2,4-dinitrobenzene (CDNB) and diethylmaleate (DEM), both of which deplete intracellular GSH, MEN-induced cytotoxicity was potentiated in the CDNB-treated paltelets, but not in the DEM-treated platelets. These data suggest that the GSH in platelets plays an important role in protecting against cytotoxicity induced by menadione.

• BMB Reports
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• v.33 no.2
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• pp.179-183
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• 2000

The glutathione S-transferase (GST) activities of S-type and L-type thioltransferases (TTases), which are purified from the seeds and leaves of Arabidopsis thaliana, respectively, were identified and compared. The S-type and L-type TTases showed $K_m$ values of 9.72 mM and 3.18mM on 1-chloro-2,4-dinitrobenzene (CDNB), respectively, indicating the L-type TTase has higher affinity for CDNB. The GST activity of the L-type TTase was rapidly inactivated after being heated at $70^{\circ}C$ or higher. The GST activity of the S-type TTase remains active in a range of $30-90^{\circ}C$. $Hg^{2+}$ inhibited the GST activity of the S-type TTase, whereas $Ca^{2+}$ and $Cd^{2+}$ inhibited the GST activity of the L-type TTase. Our results suggest that the GST activities of two TTases of Arabidopsis thaliana may have different catalytic mechanisms. The importance of the co-existence of TTAse and GST activities in one protein remains to be elucidated.

• Journal of Crop Science and Biotechnology
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• v.11 no.3
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• pp.187-192
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• 2008

The effects of some coumarins(coumarin, 7-hydroxycoumarin, scopoletin and esculetin) were investigated on pumpkin(Cucurbita maxima Duch.) seedlings and on pumpkin glutathione S-transferases(GSTs). Coumarin and esculetin suppressed the growth of seedlings, especially the elongation of roots as well as hypocotyls. Among the compounds tested, only esculetin inhibited the activity of a particular pumpkin GST by 50%, CmGSTU3 toward 1-chloro-2, 4- dinitrobenzene(CDNB) and at a concentration of 22 ${\mu}M$. Both ethylacetae(EtOAc) and water fractions in pumpkin seedlings and different organs of one-month-old pumpkin plants contained esculetin or similar hydrophobic fluorescent substances as well as hydrophilic substances, which showed different degrees of inhibitory effects on CmGSTU3 activity.

• Journal of Crop Science and Biotechnology
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• v.10 no.2
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• pp.117-122
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• 2007

Distributions of physiological inhibitors of a tau-type pumpkin glutathione S-transferase(CmGSTU3) have been investigated in different organs of pumpkin plants, including the onion bulb and water hyacinth root. Inhibitory effects were observed in alcoholic extracts of all plant parts, but the extracts prepared from the roots of either water hyacinth or pumpkin plant showed the highest effect on CmGSTU3 toward 1-chloro-2,4- dinitrobenzene(CDNB). Results of various chromatographies indicated that a number of inhibitory substances were present in the alcoholic extract of each plant organ. Some macromolecules in the plant extracts exhibited inhibitory effects; however, the extracts might contain a large number of unknown low-molecular-weight inhibitory substances. Some of the low-molecular-weight inhibitors in water hyacinth root extract showed characteristics fluoresce under UV light.

• Toxicological Research
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• v.7 no.2
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• pp.191-208
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• 1991

Pulmonary conjugation pathways may be important for the metabolism of xenobiotics introduced via airways of systemically. The objective of this study was to determine the pulmonary conjugating capacity in both the isolated perfused rabbit lung (IPRL) and in vitro, and the ability of ethanol to alter the above. The IPRL was capable of conjugating glutathione (GSH) with either 1-chloro-2,4-dinitrobenzene (CDNB) of 1,2-epoxy-(p-nitrophenoxy) propane(ENP). The pulmonary GSH conjugation with ENP was inhibited by cibacron blue, indicating the presence of glutathione-S-transferase (GST) u and/or classes, but it was not altered by buthionine sulfoximine, a selective inhibitor of Gamma-glutamylcysteine synthetase.

• Biomolecules & Therapeutics
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• v.8 no.4
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• pp.299-304
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• 2000

The modulation of cytochrome P450(P450) activities and glutathione S-transferase (GST) was investigated after i.p. administration of glucose-diethyldithiocarbamate (Glu-DDTC) to rats. P450 1 A2 and 2El activities were inhibited by 60% 4 hr after the administration of 200 mg Glu-DDTC/kg and those activities were recovered to original levels 24 hr after dosing. In contrast, GST activities were enhanced up to 24 hr after dosing. These results seem to be due to the bifunctional activity of Glu-DDTC. Glu-DDTC acts as an inhibitor of P450 enzymes as well as inducer of GST enzyme. Glu-DDTC inhibited PNP hydroxylation (P450 2El) and ethoxycoumarin O-deethylation (P450 1A2) in a dose-dependent manner up to 200 mg/kg wherease it did not affect testosterone 6$\beta$-hydroxylation (P450 3A) and pentoxyresorufin O-dealkylation (P450 2B) activities. Induction of GST activity toward 1-chloro-2,4-dinitrobenzene (CDNB) and 1,2-dichloro-4-nitrobenzenen (DCNB) was dependent on the dose of Glu-DDTC and no species difference in the GST induction was seen between rat and mouse. Amoung GST subunits, Ya, Yb1 and partially Yb2 were induced by Glu-DDTC as conjugated by western blotting. The levels Yp, Yk and Yc subunits were not affected by Glu-DDTC treatment. Therefore the enhanced activity of GST toward CDNB and DCNB might be due to the induction of Ya, Ybl and partially Yb2 subunits. In conclusion, Glu-DDTC selectively inhibited P45O 1A2 and P450 2El activities whereas it enhanced Ya, Ybl subunits and partially Yb2 subunits of GST and the antimutagenic activity of this compound might be attributed from the modulation of these enzyme activities in animals.

• Journal of Bio-Environment Control
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• v.11 no.3
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• pp.139-143
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• 2002

Cotton Glutathione S-Transferase (GST: EC 2.5.1.18) was cloned and overexpressed in tobacco (Nicotiana tabacum) plants. Northern blot analysis confirmed the successful transformation of cotton gst gene in tobacco plant. Type I and Type ll transcript patterns were identified in transgenic tobacco plants and only Type I transcripts were discussed in this paper, The activity of GST in the type II transgenic plants was about 1.5-fold higher than those of the wild type and non-expresser by using 1-chloro-2,4-dinitrobenzene (CDNB) and reduced glutathione as the substrate. The expression of cotton GST in tobacco plants proved that Gh-5 could be translated into functional protein. Type II transgenic plants produced functional GST in the cells. The effects of cotton GST in the seedlings was evaluated by growing the control and transgenic seedlings at $15^{\circ}C$ in the growth chamber in the light. Overexpressors were grown well compared to the control plants (non-expressors). lo test far tolerance to salinity, seeds of Gh-5 overexpressors and the wild type Xanthi seedlings were grown at 0, 50, 100, 150, and 200 mM NaCl solution. Gh-5 transgenic seedlings showed higher growth rate over control seedlings on 50 and 100 mM NaCl solution. There was no difference in growth rate at 150 and 200mM NaCl concentration.