• Toxicological Research
• /
• 제31권1호
• /
• pp.25-32
• /
• 2015

The objectives of this study were to investigate the individual characteristics, lifestyle habits, exposure levels, and genetic diversity of xenobiotic-metabolizing enzymes involved in toluene metabolism in Korean and foreign workers exposed to toluene at a manufacturing plant. This study was conducted to determine the effects of culture or ethnicity on toluene metabolism. The results showed that blood and urinary toluene concentrations were dependent on the level of exposure to toluene. We analyzed the correlation between toluene metabolism and genetic diversity in glutathione S-transferase (GST) (M1), GSTT1, and cytochrome p-450 (CYP) $2E1^*5$ as well as lifestyle habits (smoking, drinking, and exercise habits). The results revealed significant correlations between toluene metabolism and GSTM1 and GSTT1 genetic diversity, as well as smoking and exercise.

• Biomolecules & Therapeutics
• /
• 제24권5호
• /
• pp.510-516
• /
• 2016

Isoegomaketone (IK) was isolated from Perilla frutescens, which has been widely used as a food in Asian cuisine, and evaluated for its biological activity. We have already confirmed that IK induced the HO-1 expression via Nrf2 activation in RAW264.7 cells. In this study, we investigated the effect of IK on the mechanism of HO-1 expression. IK upregulated HO-1 mRNA and protein expression in a dose dependent manner. The level of HO-1 mRNA peaked at 4 h after $15{\mu}M$ IK treatment. To investigate the mechanisms of HO-1 expression modulation by IK, we used pharmacological inhibitors for the protein kinase C (PKC) family, PI3K, and p38 MAPK. IK-induced HO-1 mRNA expression was only suppressed by SB203580, a specific inhibitor of p38 MAPK. ROS scavengers (N-acetyl-L-cysteine, NAC, and glutathione, GSH) also blocked the IK-induced ROS production and HO-1 expression. Furthermore, both NAC and SB203580 suppressed the IK-induced Nrf2 activation. In addition, ROS scavengers suppressed other oxidative enzymes such as catalase (CAT), glutathione S-transferase (GST), and NADH quinone oxidoreductase (NQO-1) in IK-treated RAW264.7 cells. Taken together, it can be concluded that IK induced the HO-1 expression through the ROS/p38 MAPK/Nrf2 pathway in RAW264.7 cells.

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제6권2호
• /
• pp.144-149
• /
• 2001

For the production and purification of a single chain human insulin precursor, four types of fusion peptides $\beta$-galactosidase (LacZ), maltose binding protein (MBP), glutathione-S-transferase (GST), and (His)(sub)6-tagged sequence (HTS) were investigated. Recombinant E. coli harboring hybrid genes was cultivated at 37$\^{C}$ for 1h, and gene induction occurred when 0.2mM of isopropyl-D-thiogalactoside (IPTG) was added to the culture broth, except for E. coli BL21 (DE3) pLysS harboring a pET-BA cultivation with 1.0mM IPTG, followed by a longer than 4h batch fermentation respectively. DEAE-Sphacel and Sephadex G-200 gel filtration chromatography, amylose affinity chromatography, glutathione-sepharose 4B affinity chromatography, and a nickel chelating affinity chromatography system as a kind of immobilized metal ion affinity chromatography (IMAC) were all employed for the purification of a single chain human insulin precursor. The recovery yields of the HTS-fused, GST-fused, MBP-fused, and LacZ-fused single chain human insulin precursors resulted in 47%, 20%, 20%, and 18% as the total protein amounts respectively. These results show that a higher recovery yield of the finally purified recombinant peptides was achieved when affinity column chromatography was employed and when the fused peptide had a smaller molecular weight. In addition the pET expression system gave the highest productivity of a fused insulin precursor due to a two-step regulation of the gene expression, and the HTS-fused system provided the highest recovery of a fused insulin precursor based on a simple and specific separation using the IMAC technique.

• Asian Pacific Journal of Cancer Prevention
• /
• 제17권4호
• /
• pp.2145-2150
• /
• 2016

Background: Infection with hepatitis B virus (HBV) is a major global public health problem, with a wide spectrum of clinical manifestations. Human cytosolic glutathione-S-transferases (GSTs) include several classes such as alpha (A), mu (M), pi (P), sigma (S), zeta (Z), omega (O) and theta (T). The present study aimed to investigate the role of GST omega genes (GSTO1 and GSTO2) in different groups of patients infected with HBV. Materials and Methods: HBV groups were classified according to clinical history, serological tests and histological analysis into normal carriers (N), acute (A), chronic (CH), cirrhosis (CI) and hepatocellular carcinoma (HCC) cases. The study focused on determination of the genotypes of GST omega genes (GSTO1 and GSTO2) and GST activity and liver function tests. Results: The results showed that GSTO1 (A/A) was decreased in N, A, CH, CI and HCC groups compared to the C-group, while, GSTO1 (C/A) and GSTO1(C/C) genotypes were increased significantly in N, A, CH, CI and HCC groups. GSTO2 (A/A) was decreased in all studied groups as compared to the C-group but GSTO2(A/G) and GSTO2(G/G) genotypes were increased significantly. In addition, GST activities, albumin and TP levels were decreased in all studied groups compared to the C-group, while the activities of transaminases were increased to differing degrees. Conclusions: The results indicate that GSTO genetic polymorphisms may be considered as biomarkers for determining and predicting the progression of HBV infection.

• Archives of Pharmacal Research
• /
• 제24권2호
• /
• pp.114-118
• /
• 2001

The present study was undertaken to investigate whether or not the hepatoprotective activity of acetylbergenin was superior to bergenin in carbon tetrachloride ($CCl_4$)-intoxicated rat. Acetylbergenin was synthesized by acetylating bergenin, which was isolated from Mallotus japonicus. The hepatoprotective effects of acetylbergenin were examined against $CCl_4$-induced liver damage in rats by means of serum and liver biochemical Indices. Acetylbergenin was administered orally once daily for 7 successive days, then a 0.5 ${m/kg}$ mixture of $CCl_4$in olive oil (1:1) was intraperitoneally injected at 12 h and 36 h after the final administration of acetylbergenin. Pretreatment with acetylbergenin reduced the elevated serum enzymatic activities of alanine/aspartate aminotransferase, sorbitol dehydrogenase and $\gamma$-glutamyltransferase in a dose dependent fashion. Acetylbergenin also prevented the elevation of hepatic malondialdehyde formation and depletion of glutathione content dose dependently in $CCl_4$-intoxicates rats. In addition, the decreased activities of glutathione S-transferase and glutathione reductase were restored to almost normal levels. The results of this study strongly suggest that acetylbergenin n has potent hepatoprotective activity against $CCl_4$-induced hepatic damage in rats by glutathione-mediated detoxification as well as having free radical scavenging activity. In addition, acetylbergenin doses of 50 ${mg/kg}$showed almost the same levels of hepatoprotection activity as 100 ${mg/kg}$ of bergenin, indicating that lipophilic acetylbergenin is more active against the antihepatotoxic effects of $CCl_4$ than those of the much less lipophilic bergenin.

• Asian Pacific Journal of Cancer Prevention
• /
• 제16권2호
• /
• pp.541-549
• /
• 2015

Triple negative breast cancer (TNBC) is an aggressive subtype of breast cancer (BC) with higher metastatic rate and both local and systemic recurrence compared to non-TNBC. The generation of reactive oxygen species (ROS) secondary to oxidative stress is associated with DNA damage, chromosomal degradation and alterations of both hypermethylation and hypomethylation of DNA. This study concerns differential methylation of promoter regions in specific groups of genes in TNBC and non-TNBC Saudi females in an effort to understand whether epigenetic events might be involved in breast carcinogenesis, and whether they might be used as markers for Saudi BCs. Methylation of glutathione S-transferase P1 (GSTP1), T-cadherin (CDH13), Paired box protein 5 (PAX5), death associated protein kinase (DAPK), twist-related protein (TWIST), DNA-binding protein inhibitor (ID4), High In Normal-1 (HIN-1), cyclin-dependent kinase inhibitor 2A (p16), cyclin D2 and retinoic acid receptor-${\beta}$ ($RAR{\beta}1$) genes was analyzed by methylation specific polymerase chain reaction (MSP) in 200 archival formalin-fixed paraffin embedded BC tissues divided into 3 groups; benign breast tissues (20), TNBC (80) and non-TNBC (100). The relationships between methylation status, and clinical and pathological characteristics of patients and tumors were assessed. Higher frequencies of GSTP1, ID4, TWIST, DAPK, PAX5 and HIN-1 hypermethylation were found in TNBC than in non-TNBC. Hypermethylation of GSTP1, CDH13, ID4, DAPK, HIN-1 and PAX5 increased with tumor grade increasing. Other statistically significant correlations were identified with studied genes. Data from this study suggest that increased hypermethylation of GSTP1, ID4, TWIST, DAPK, PAX5 and HIN-1 genes in TNBC than in non-TNBC can act as useful biomarker for BCs in the Saudi population. The higher frequency of specific hypermethylated genes paralleling tumor grade, size and lymph node involvement suggests contributions to breast cancer initiation and progression.

• 식품기술
• /
• 제12권2호
• /
• pp.26-38
• /
• 1999

조리가공 중 생성되는 주요 발암성 이환방향족아민(heterocyclic aromatic amine)인 Trp-P-1 및 Trp-P-2가 human 및 rat keratinocytes에 대해 나타내는 세포 독성을 colony expansion법의 의해 조사, 비교하였다. 특히 Trp-P-2는 human keratinocytes에 대해서는 독성을 나타내지 않은데 반해 rat keratinocytes(계대수 2-5)에 대해서는 독성을 나타내는 선택성을 나타내었다. 이러한 Trp-P-2의 종(species)간 독성감수성 차이가 대사 효소계 활성이나 mutagenic activation상의 차이에 기인되는지를 살펴본 결과, CYP4501As 및 독성감수성 차이가 크게 나타났던 human 및 rat keratinocytes의 microsome에서 거의 같았다. 이와 같은 결과는 CYP4501A1 및 CYP1B1의 mRNA의 발현정도를 northernblot에 의해 살펴보았던 결과에서도 일치하였다. 반면 Trp-P-2의 대사활성화 및 해독화에 관여하는 효소인 N.O-acetyltransferase(NAT)활성은 rat keratinocytes보다 human keratinocytes에서 높았다. 일반적으로 독성물질의 해독화에 관여하는 glutathione S-transferase(GST) 또한 rat keratinocytes보다 human keratinocytes에서 높게 나타났다. Trp-P-2가 mutagenic metabolite로 활성화되는 정도를 salmonella microsome microsuspension assay로 살펴본 결과, 독성 감수성 차이가 크게 나타났던 human 및 rat keratinocytes간의 활성은 비슷한 것으로 나타났다. DNA 및 단백질 adduct형성능의 경우, human 및 rat keratinocytes간 DNA adduct형성능에는 차이가 없었고, 단백질 adduct형성능의 경우만 Trp-P-2에 대한 독성감수성 정도가 컸던 rat keratinocytes가 다른 세포들에 비해 크게 나타났다. 이상의 결과를 종합해 볼 때, CYP1A- 또는 CYP1B1-관련 마이크로솜 효소활성이나 mutagenic activation은 human 및 rat keratinocytes간에 나타났던 독성 감수성의 차이를 설명할 수 없으며, 해독화에 관여하는 효소활성이 종간 관찰되었던 독성 감수성의 차이에 더 중요한 역할을 하는 것으로 보인다.

• 한국환경보건학회지
• /
• 제27권2호
• /
• pp.22-29
• /
• 2001

To evaluate the cutaneous injury in liver damaged rats by toluene application to the skin, toluene(35mg/㎤) was sequentially applied for 5 days to the dorsal skin of liver damaged rats with $CCl_4$ (6 times ever other day:0.1$m\ell$/100 g body weight-50% $CCl_4$in olive oil). The cutaneous ultrastructural changes were unexoectably not observed in liver from $CCl_4$-treated rats although necrotic liver damage appeared under light microscope. In these animals by the application of toluene to rat skin the cutaneous xanthine oxidase activity was significantly increased(p<0.05), but cytochrome P450 content was not different from that of the control or only $CCl_4$-treated rats. On the other hand, the cutaneous superoxide dismutase and catalase activities in liver damaged animals were significantly respectively(p<0.05, p<0.001), decreased by toluene application to the skin compared with control and especially the former enzyme activity was significantty decreased(p<0.01), compared with that of liver damaged rate rat but glutathione peroxidase, glutathione-S-transferase activities were not significantly different from those of the control or liver damaged rats. Futhermore, the reduced gluathione content of skin was also significantly decreased by toluene application to the liver damaged animals. In conclusion, the great deposits of cerrous peroxide and ultramorphological changes in skin tissue of liver damaged animals by toluene application may be responsible for the oxygen free radical.

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권10호
• /
• pp.4281-4287
• /
• 2014

Background: Methylation of tumor suppressor genes has been investigated in all kinds of cancer. Tumor specific epigenetic alterations can be used as a molecular markers of malignancy, which can lead to better diagnosis, prognosis and therapy. Therefore, the aim of this study was to evaluate the association between gene hypermethylation and expression of fragile histidine triad (FHIT), glutathione S-transferase P1 (GSTP1) and p16 genes and various clinicopathologic characteristics in primary non-small cell lung carcinomas (NSCLC). Materials and Methods: The study included 28 primary non-small cell lung carcinomas, where an additional 28 tissue samples taken from apparently normal safety margin surrounding the tumors served as controls. Methylation-specific polymerase chain reaction (MSP) was performed to analyze the methylation status of FHIT, GSTP1 and p16 while their mRNA expression levels were measured using a real-time PCR assay with SYBR Green I. Results: The methylation frequencies of the genes tested in NSCLC specimens were 53.6% for FHIT, 25% for GSTP1, and 0% for p16, and the risk of FHIT hypermethylation increased among patients with NSCLC by 2.88, while the risk of GSTP1 hypermethylation increased by 2.33. Hypermethylation of FHIT gene showed a highly significant correlation with pathologic stage (p<0.01) and a significant correlation with smoking habit and FHIT mRNA expression level (p<0.05). In contrast, no correlation was observed between the methylation of GSTP1 or p16 and smoking habit or any other parameter investigated (p>0.05). Conclusions: Results of the present study suggest that methylation of FHIT is a useful biomarker of biologically aggressive disease in patients with NSCLC. FHIT methylation may play a role in lung cancer later metastatic stages while GSTP1 methylation may rather play a role in the early pathogenesis.

• Parasites, Hosts and Diseases
• /
• 제54권3호
• /
• pp.247-252
• /
• 2016

This study was conducted to investigate the occurrence of oxidative stress in the heart tissue of rats infected with Trypanosoma evansi. Rats were divided into 2 groups (A and B) with 12 animals each, and further subdivided into 4 subgroups (A1 and A2, 6 animals/each; and B1 and B2, 6 animals/each). Animals in the groups B1 and B2 were subcutaneously inoculated with T. evansi. Thiobarbituric acid reactive substances (TBARS), superoxide dismutase activity (SOD), glutathione S-transferase activity (GST), reduced glutathione activity (GSH), and non-protein thiols (NPSH) in the heart tissue were evaluated. At day 5 and 15 post-infection (PI), an increase in the TBARS levels and a decrease in the SOD activity (P<0.05) were observed. GSH and GST activities were decreased in infected animals at day 15 PI (P<0.05). Considering the proper functioning of the heart, it is possible that the changes in the activity of these enzymes involved in the oxidative stress may be related, at least in part, in the pathophysiology of rats infected with T. evansi.