Pharmacogenetics of azathioprine in inflammatory bowel disease: A role for glutathione-S-transferase?

Azathioprine is a purine antimetabolite drug commonly used to treat inflammatory bowel disease (IBD). In vivo it is active after reaction with reduced glutathione (GSH) and conversion to mercaptopurine. Although this reaction may occur spontaneously, the presence of isoforms M and A of the enzyme glutathione-S-transferase (GST) may increase its speed. Indeed, in pediatric patients with IBD, deletion of GST-M1, which determines reduced enzymatic activity, was recently associated with reduced sensitivity to azathioprine and reduced production of azathioprine active metabolites. In addition to increase the activation of azathioprine to mercaptopurine, GSTs may contribute to azathioprine effects even by modulating GSH consumption, oxidative stress and apoptosis. Therefore, genetic polymorphisms in genes for GSTs may be useful to predict response to azathioprine even if more in vitro and clinical validation studies are needed.

Glutathione-S-transferases genes-promising predictors of hepatic dysfunction

diseases pathogenesis are genes that encodes the synthesis of glutathione-Stransferase(GST),known as the second phase enzyme detoxification system that protects against endogenous oxidative stress and exogenous toxins,through catalisation of glutathione sulfuric groups conjugation and decontamination of lipid and deoxyribonucleic acid oxidation products.The group of GST enzymes consists of cytosolic,mitochondrial and microsomal fractions.Recently,eight classes of soluble cytoplasmic isoforms of GST enzymes are widely known:α-,ζ-,θ-,κ-,μ-,π-,σ-,andω-.The GSTs gene family in the Human Gene Nomenclature Committee,online database recorded over 20 functional genes.The level of GSTs expression is considered to be a crucial factor in determining the sensitivity of cells to a broad spectrum of toxins.Nevertheless,human GSTs genes have multiple and frequent polymorphisms that include the complete absence of the GSTM1 or the GSTT1 gene.Current review supports the position that genetic polymorphism of GST genes is involved in the pathogenesis of various liver diseases,particularly non-alcoholic fatty liver disease,hepatitis and liver cirrhosis of different etiology and hepatocellular carcinoma.Certain GST allelic variants were proven to be associated with susceptibility to hepatological pathology,and correlations with the natural course of the diseases were subsequently postulated.

Glutathione-S-transferase M1 polymorphisms on the susceptibility to esophageal cancer among three Chinese minorities:Kazakh,Tajik and Uygur

AIM： To investigate the glutathione-S-transferase M1 （GSTM1） polymorphisms in three Chinese minorities, Kazakh, Uygur, and Tajik; and the pathological significance of GSTM1 polymorphisms in esophageal carcinogenesis in Kazakh.METHODS： A total of 1121 blood samples （442 males and 679 females） were obtained from healthy Kazakh （654）, Uygur （412） and Tajik （55）. Primary esophageal squamous cell cancer （ESCC） tissues from Kazakh were obtained from 116 patients who underwent surgery. GSTM1 polymorphisms were analyzed by a combined approach of PCR and electrophoresis techniques.RESULTS： GSTM1 null genotype was found in 62.63% Uygur, 50.91% Tajik and 47.40% Kazakh. A significantly higher frequency of GSTM1 null genotype in Uygur was observed compared with Kazakh （OR： 1.859, 95% CI： 1.445 -2.391, χ^2 = 23.71, P = 0.000）. In addition, GSTM1 null genotype was found in 23.53% of welldifferentiated ESCC in Kazakh, in 49.23% of poorly differentiated ESCC, with a significant difference （OR： 3.152, 95% CI： 1.403-7.080, χ^2 = 8.018, P = 0.007）.CONCLUSION： There is a marked difference in the frequency of common GSTM1 null genotype between Uygur and Kazakh. GSTM1 null genotype is associated with differentiation of ESCC in Kazakh.

β-catenin accumulation in nuclei of hepatocellular carcinoma cells up-regulates glutathione-s-transferase M3 mRNA

AIM: To identify the differentially over-expressed genes associated with β-catenin accumulation in nuclei of hepatocellular carcinoma (HCC) cells. METHODS: Differentially expressed genes were identified in radiation-induced B6C3 F1 mouse HCC cells by mRNA differential display, Northern blot and RT-PCR, respectively. Total glutathione-s-transferase (GST) activity was measured by GST activity assay and β-catenin localization was detected with immunostaining in radiation-induced mouse HCC cells and in HepG2 cell lines.RESULTS: Two up-regulated genes, glutamine synthetase and glutathione-s-transferase M3 (GSTM3), were identified in radiation-induced mouse HCC cells. Influence of β-catenin accumulation in nuclei of HCC cells on upregulation of GSTM3 mRNA was investigated. The nearby upstream domain of GSTM3 contained the β-catenin/TcfLef consensus binding site sequences [5'-(A/T)(A/T) CAAAG-3'], and the total GST activity ratio was considerably higher in B6C3F1 mouse HCC cells with β-catenin accumulation in nuclei of HCC cells than in those without β-catenin accumulation (0.353 ± 0.117vs 0.071 ± 0.064, P < 0.001). The TWS119 (a distinct GSK-3β inhibitor)-induced total GST activity was significantly higher in HepG2 cells with β-catenin accumulation than in those without β-catenin accumulation in nuclei of HCC cells. Additionally, the GSTM3 mRNA level was significantly higher at 24 h than at 12 h in TWS119-treated HepG2 cells. CONCLUSION: β-catenin accumulation increases GST activity in nuclei of HCC cells, and GSTM3 may be a novel target gene of the β-catenin/Tcf-Lef complex.

Prognostic Significance of Comparison of Clinical Indicators with Manifestations of Genetic Polymorphism of Glutathione-S-Transferases in Non-Small Cell Lung Cancer

The article presented the results of comparison of polymorphic variants of the genes GSTM1, GSTT1, GSTP1 and clinical manifestations of non-small cell lung carcinoma. The association of the genotype GSTT1 (del) with the risk of developing squamous cell lung cancer has been revealed (OR = 2.54 CI: 1.13 - 5.72, p = 0.035). Analysis of patient survival rate (n = 173) in groups of various histological types of lung cancer showed that in the group of squamous cell lung cancer (n = 91) in patients with genotype GSTT1 (del), the survival rate median was significantly higher—84 months (95% CI 12.4 - 155.7) than in patients with the genotype GSTT1 (+)—36 months (95% CI 25.2 - 46.8, p = 0.045). In contrast, in the adenocarcinoma group (n = 82), the survival rate median in patients with the genotype GSTT1 (del) was 19 months. (95% CI 6.2 - 33.5), and in patients with genotype GSTT1 (+)—67 months (95% CI 50.1 - 84.0), which is the basis for continuing this comparison in an additional group of testees, as the sampling did not achieve the reliability of p = 0.12. Hypothetically, these differences may be due to differences in the gender composition of squamous cell lung cancer and adenocarcinoma and the involvement of GST enzymes in the metabolism of estrogens in adenocarcinoma in women and other hormonal background and reactivity of the male body with squamous cell carcinoma. Further research and subsequent analysis of the results will be aimed at confirming this hypothesis.

Evaluation of Glutathione-S-transferase and ceruloplasmin levels in gingival crevicular fluid and gingival tissue as diagnostic markers for chronic periodontitis

Periodontitis, is an infectious ailment of multifactorial origin, that brings about destruction of bone and surrounding tissues. There are various oral pathogens that may be responsible for the destruction. The host encounters these microbial invasions and their products by the production and release of inflammatory mediators from the cells within the body. Glutathione-S-transferase (GST) are a group of enzymes that utilize glutathione in conditions resulting in oxidative stress. These enzymes play a key role in the detoxifycation of such substance. It aids in preventing damage to important cellular components caused by release of free reactive oxygen species. Ceruloplasmin is a ferroxidase enzyme. It plays a role as an anti-inflammatory agent, by its ability to scavenge free radicals within the body. The present study was targeted at evaluating the levels of Glutathione-S-Transferase (GST) and Ceruloplasmin as diagnostic markers for patients with chronic periodontitis in gingival crevicular fluid (GCF) and the gingival tissues. Thirty patients were divided into two groups. Experimental group comprising of 15 subjects with chronic perio- dontitis and the control group was composed of 15 healthy individuals. Highly significant changes in GST between the diseased and normal patients (P = 0.001) were detected. There was a decrease in GST level in both gingival tissue & GCF in diseased patients when compared to the control patients. The ceruloplasmin levels in GCF and gingival tissues showed no difference between the control and diseased group. Hence,these results indicate a relationship suggesting that GST produced during chronic inflammation could be used as biomarker that indicate periodontal disease .

Immunoprophylactic potential of filarial glutathione-s-transferase in lymphatic filariaisis

Objective:To elucidates the immunoprophylactic potential of glutathion-s-transferase(GST) from cattle filarial parasite Setaria digitata(S.digitata) against lymphatic filariasis.Methods: GST was purified through affinity chromatography(SdGST) and chacterized by SDS-PAGE and Nano-LC MS/MS analysis.Antibody isotypes to SdGST were measured by ELISA.Antibody dependant cellular cytotoxicity(ADCC) was performed in vitro using sera from immunized animals and immune individuals.T-cell proliferation and cytokine response to SdGST in different groups of filariasis were measured.Immunoprophylactic potential of SdGST was evaluate in animal model.Results:SdGST exhibited 30-fold enhancement of enzyme activity over crude parasitic extract.It was found to be 26 kDa by SDS-PAGE.Nano LC-MS/MS analysis followed by blast search showed 100%homology with Dirqfilaria immitis(D.immitis) and only 43%with Homo sapiens(H.sapiens).Immunoblotting analysis showed putatively immune individuals carry significant level of antibodies to SdGST as compared with microfilaraemics.Immunized sera and sera endemic normal could neutralize the enzymatic activity of SdGST and inducing in vitro cytotoxicity of microfilariae.Peripheral blood mononuclear cells(PBMC) from endemic normals upon stimulation with SdGST showed a mixed type of Th1/Th2 response.SdGST immunization clear microfilariae from circulation in S.digitata implanted mastomys.Conclusions:The heterologous GST could be potentially developed as a vaccine candidate against lymphatic filarial parasite.

Modification of the Genetic Polymorphism of Glutathione-S-Transferase (GSTM1 and GSTT1) in Motorcycle Drivers Exposed to BTEX in Cotonou

The glutathione-S-transferase genes mainly the GSTM1 and GSTT1 alleles are responsible for the synthesis of detoxication enzymes that can remove toxic substances. The objective of this study is to seek changes in the genetic polymorphism of glutathione-S-transferase GSTM1 and GSTT1 in motorcycle drivers exposed to BTEX. Our study group consists of 60 motorcycle drivers including 30 professional and 30 non-professional. Blood samples were preleveled from the study population in the EDTA tubes and DNA was extracted by the phenol/chloroform method. The PCR technique was used to determine the presence or absence of genes. Our results showed that the percentage of GSTM1 null genotype has a statistically significant difference (P = 0.02), while the percentage of GSTT1 null genotype was non-significant (P = 0.76) between the two groups. The percentage of deletion of both genes is higher in professional than non-professional motorcycle drivers. Air pollution in Cotonou by BTEX seems to influence the deletion of the GSTM1 and GSTT1 genes at a higher percentage among professional than non-professional motorcycle drivers.

Carboxylesterase and Glutathione-S-Transferase （GST＇s） Induced Resistance to Bacillus thuringiensis Toxin CrylAb in Rice Leaf Folder, Cnaphalocrocis medinalis （Guenee） Populations

The rice leaf folder （RLF）, Cnaphalocrocis medinalis （Guenee） （lnsecta： Lepidoptera： Pyralidae）, is an important pest, widely distributed in many rice growing areas of Asia. The over-use of broad-spectrum chemical insecticides has been cited as a major cause of outbreaks of C. medinalis as excessive spraying of insecticide disrupts natural biological control insecticides still remain the major control tactics against leaf folder. Carbofuran and fenthion, bendiocarb, acephate, carbosulfan, quinolphos, monocrotophos, phosphamidon and fenvalerate are the common ones used against rice leaf folder. Genetically, modified rice lines expressing B. thuringiensis insecticidal crystal proteins produced are highly tolerant to leidopteran pests. Though economic and environmental benefits of GM crops is well established, the matter of concern is the possibility of target insect pest developing resistance to this B. thuringiensis insecticidal toxins, evident from many laboratory and field experiments against many insect pests. The involvement of GSH S-transferase, carboxylesterase, and microsomal monooxygenase in insecticide resistance has been reported in insecticide-resistant strains of many insect species. Hence, the present study was taken up to monitor for cross resistance between B. thuringiensis cry toxins and synthetic insecticides in larvae of leaf folder as it is mediated by carboxylesterase titre and other enzymes by bioassay for two selected rice leaf folder field populations at the Entomology division of Directorate of Rice Research which showed 2-fold resistance ratio. Qualitative and quantitative changes of carboxylesterase （CarE） and glutathione-s-transferase （GST＇s） were worked out with midguts extracts of the two C. medinalis populations in the presence of a-napthyl acetate and chlorodi-nitro benzene substrates.

Genetic polymorphism of glutathione-S-transferase M1 and T1 in associated with carcinogenesis of hepatocellular carcinoma and nasopharyngeal carcinoma

Objective:The aim of our study was to investigate the distribution of glutathione-S-transferase M1 (GSTM1) and T1 (GSTT1) gene polymorphism in hepatocellular carcinoma (HCC) and nasopharyngeal carcinoma (NPC) patients in a high risk area in Guangxi Zhuang Autonomous Region,China.Methods:It was a case-control study.The genotypes of GSTM1 and GSTT1 in 181 HCC and 126 NPC patients were compared with 641 matched control.The GSTM1 and GSTT1 genotypes were detected using conventional multiplex PCR method.Results:The frequency of GSTM1 null genotype in HCC,NPC and control groups were 65.2%,61.9% and 47.6% respectively,significant difference between these two cancer groups and control was observed (P < 0.01).The frequency of GSTT1 null genotype in HCC,NPC and control groups were 57.5%,62.7% and 43.1% respectively,significant difference between these two cancer groups and control was observed (P < 0.01).Conclusion:The distributions of GSTM1 and T1 genes are polymorphic in HCC and NPC patients in a high risk area in Guangxi,individuals with GSTM1-null or GSTT1-null would have an increasing risk of developing HCC and NPC,especially when combination with virus infection (HBV or EBV) and absorbed chemical toxin (AFB1 or cigarette).

Plasma catalase,glutathione-s-transferase and total antioxidant activity levels of children with attention deficit and hyperactivity disorder

Objective: In this study, we plan to measure plasma Catalase (CAT), Antioxidant Activity (AOA) and Glu- tathione-S-Transferase (GST) levels to understand whether oxidative stress develops or not and whether or not the detoxification mechanism properly functions in children with Attention Deficit and Hyperactivity Disorder (ADHD) with unknown etiology and pathogenesis. Method and Results: Plasma CAT, AOA, and GST activities were spectrophotometrically measured in forty patients (average age 10.27 ± 2.54) and thirty-five (average age, 9.97 ± 2.59) healthy individuals as the control group. While the CAT activity showed no difference in the patient group (P > 0.05) compared to the control group, AOA and GST levels were found significantly meaningful (P = 0.001). Conclusion: In this pilot study ,the study shows that no oxidative stress develops in individuals with ADHD in high AOA and stable CAT activity, and that the de- toxification mechanism functions extremely in high GST activity. These findings need to be supported by other studies.

Expression of thymidylate synthase and glutathione-stransferase π in patients with esophageal squamous cell carcinoma

AIM： To investigate the expression of thymidylate synthase （TS） and glutathione-s-transferase π （GST-π） in esophageal squamous cell carcinoma and their association with the clinicopathologic characteristics. METHODS： Immunohistochemical methods were used to detect the expression of TS and GST-π in surgically resected formalin-fixed, paraffin-embedded esophageal squamous cell carcinoma （ESCC） tissue sections from 102 patients （median age, 58 years） and in 28 normal esophageal mucosa （NEM） samples. The relationship between TS and GST-π expression and clinicopathologic factors was examined. RESULTS： The expression of TS and GST-π was not statistically significantly associated with age of the patients, tumor size, lymph node metastasis, depth of invasion or tumor stage. TS staining was positive in 17.86% of normal esophageal mucosa and in 42.16% of ESCC samples （P 〈 0.05）. The expression level of TS was not only significantly lower in well-differentiated （21.88%） than in poorly-differentiated carcinomas （51.43%, P 〈 0.05）, but was also significantly higher in samples from male patients （46.51%） than from female patients （18.75%, P 〈 0.05）. GST-π was positively stained in 78.57% of normal esophageal mucosa and in 53.92% of ESCC samples （P 〈 0.05）. The expression level of GST-π was also significantly higher in welldifferentiated carcinomas （65.63%） than in poorly- differentiated carcinomas （35.00%, P 〈 0.05）. CONCLUSION： The expression of TS and of GST-π may be used as molecular markers for the characterization of ESCC. Poorly-differentiated cells showed increased expression of T5 and reduced expression of GST-π.

Expression of multidrug-resistance associated proteins in human retinoblastoma treated by primary enucleation

AIM： To reveal the expression of multidrug-resistance associated proteins： glutathione-S-transferase π（GSTπ）, P-glycoprotein（P-gp） and vault protein lung resistance protein（LRP） in retinoblastoma（RB） without any conservative treatment before primary enucleation and to correlate this expression with histopathological tumor features. METHODS： A total of 42 specimens of RB undergone primary enucleation were selected for the research. Sections from the formalin-fixed, paraffin-embedded specimens were stained with HE and immunohistochemistry to detect the expression of GSTπ, P-gp and LRP.RESULTS： GSTπ was expressed in 39/42（92.86%） RBs and in 9/9（100%） well-differentiated RBs. P-gp/GSTπ was found in 30（71.42%） of 42 RBs. Totally 9（21.43%） tumors were well differentiated and 33（78.57%） were poorly differentiated. Totally 15（35.71%） eyes had optic nerve（ON） tumor invasion, 36（85.71%） had choroidal tumor invasion, and 14（33.33%） had simultaneous choroidal and ON invasion. There was no statistically significant relationship between P-gp, GSTπ, LRP positivity and the degree of ocular layer tumor invasion and ON tumor invasion（P〉0.05）. CONCLUSION： RB intrinsically expresses GSTπ, P-gp and LRP. GSTπ expression is positive in 100% welldifferentiation ones, so in which way it is correlated with differentiation. But the other two proteins expressions are not related to tumor differentiation and to the degree of tumor invasion. GSTπ may be a new target of chemotherapy in RB.

Control of Tetranychus urticae Koch by extracts of three essential oils of chamomile,marjoram and Eucalyptus

Objective:To evaluate the acaricidal activity of extracts of three essential oils of chamomile,marjoram and Eucalyptwi against Tetranychus urtiaie(T.urticae.)Koch.Methods:Extracts of three essential oils of chamomile,marjoram and Eucalyptus with different concentrations(0.5%,1.0%,2.0%,3.0%and 4.0%)were used to control T.urticae Koch.Results:The results showed that chamomile(Chamomilla recutita)represented the most potent efficient acaricidal agent against Tetranychus followed by marjoram(Marjorana hortensis)and Eucalyptus.The LC_(50)values of chamomile,marjoram and Eucalyptus for adults were 0.65,1.84 and 2.18,respectively and for eggs 1.17,6.26 and 7.33,respectively.Activities of enzymes including glutathione-Stxansferase,esterase(α-esterase andβ-esterase)and alkaline phosphatase in susceptible mites were determined and activities of enzymes involved in the resistance of acaricides were proved.Protease enzyme was significantly decreased at LC_(50)of both chamomile and marjoram compared with positive control.Gas chromatography-mass spectrometer(CC-MS)proved that the major compositions of Chamomilla recutita areα-bisabolol oxide A(35.251%),and trans-3-farersene(7.758%),while the main components of Marjorana hortensis are terpincne-4-ol(23.860%),p-cymene(23.404%)and sabinene(10.904%).Conclusions:It can be concluded that extracts of three essential oils of chamomile,marjoram and Eucalyptus possess acaricidal activity against T.urticae.

Construction of Prokaryotic Expression Vector of Mouse Nanog Gene and Its Expression

The aim of this study is to construct a prokaryotic expression vector of mouse Nanog gene and to express it in E. coli. A pair of primers was designed according to digestion sites in plasmid pGEX-KG and the Nanog gene sequence published by GenBank. The DNA fragment of 918 bp was amplified by polymerase chain reaction （PCR） from the pNA992 recombinant plasmid with Nanog gene, then cloned into pGEX-KG and transformed into the host E. coli strain TG Ⅰ. The sequence of the fragment was matched with the original sequence of pNA992. It indicated that fusion expression vector, pGEX-KG- Nanog, was constructed successfully. The pGEX-KG-Nanog plasmid was extracted from E. coli strain TG Ⅰ and was transformed into BL21（DE3） for expression. After induction by isopropyl-β-D-thiogalactoside （IPTG） at 37℃, the expression product of Nanog gene was identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis （SDS-PAGE）, and the expression condition was optimized. Nanog fusion protein was successfully expressed in the form of inclusion bodies. The molecular weight of the inclusion body was 63 kDa. Meanwhile, the optimum condition for the expression of Nanog fusion protein was induced with 0.8 mmol L^-1 IPTG for 5 h. The mouse Nanog gene was successfully expressed in E. coli, which laid a foundation for the purification of Nanog protein and for the preparation of polyclonal antibody.

Antioxidant Enzymes and Cancer

Although oxidation is the most common biological and energy producing reaction, oxidative stress is harmful to cell, because the products of oxidation such as free radicals and peroxides damage the cellular components, causing several diseases. Damage in DNA is responsible for cancer formation and progression. However, several enzymes such as superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione S-transferase etc. act as antioxidants to influence oxidative stress. Polymorphisms in these enzymes are supposed to be associated with DNA damage and subsequently the individual＇s risk of cancer susceptibility. This review article aims to further elucidate the relationship between antioxidant enzymes and cancers by summarizing the findings of some of the important study concerning expression levels and genetic polymorphisms of antioxidant enzymes in cancer patients.

Pistacia chinensis:Strong antioxidant and potent testicular toxicity amelioration agent

Objective:To evaluate in ritro and in riro antioxidant potency of Pistacia chinensis(P.chinensis) bark and leaves extracts along with its protective role against CCl_4 induced toxicity in testis of the rat.Methods Various in vitro models such as DPPH,ABTS,hydrogen peroxide,superoxide,hydroxyl and nitric oxide scavenging activities,anti-lipid peroxidation activity,phospho-molybdenum activity.β carotene bleaching assay was used for analysis of antioxidant potential.Experimental groups for in riro study were:Group Ⅰ(control)untreated.Group Ⅱ(Vehicle control).Group Ⅲ(1 mL/kg b.w 30%CCl_4).Group Ⅳ(1 mL/kg b.w CCk_4+Silymarin).Group Ⅴ(200 mg/kg b.w PCBE+CCl_4),Group Ⅵ(400 mg/kg b.w PCBE+CCl_4) and Group Ⅶ(400 mg/kg b.w PCBE alone).Results:In ritro antioxidant assays displayed significant results and the highest activity was not specified to a specific extract.However,ethyl acetate extract of bark(PCBF) showed highest results in most of the antioxidant assays i.e.beta-carotene bleaching,hydroxyl radical scavenging.ABTS.lipid peroxidation and superoxide radical scavenging activity.On this base,this fraction was selected for in riro antioxidant experiment.Testis tissues were analyzed to observe the protective effects of PCBE on antioxidant enzymes:cataluse,superoxide dismutase.peroxidase.glutathione-Stransferase.glutathione reductase,glutathione peroxidase and quinone reductase activities and glutathione(GSH) as well as nitrite content.Profile of plasma testosterone was also compared to various treatments.Observation suggests a protective role of P.chinensis against CCl_4induced toxicity.Conclusions:It is concluded that some bioactive antioxidants of P.chinensis bark might be a good source to isolate the potent antioxidant components.

Natural Products Modulate the Multifactorial Multidrug Resistance of Cancer

Multidrug resistance (MDR) is a critical problem in cancer chemotherapy. Cancer cells can develop resistance not only to a single cytotoxic drug, but also to entire classes of structurally and functionally unrelated compounds. Several mechanisms can mediate the development of MDR, including increased drug efflux from the cells by ABC-transporters (ABCT), activation of metabolic enzymes, and defective pathways towards apoptosis. Many plant secondary metabolites (SMs) can potentially increase sensitivity of drug-resistant cancer cells to chemotherapeutical agents. The present thesis investigates the modulation of MDR by certain medicinal plants and their active compounds. The inhibition of ABCTs (P-gp/MDR1, MRP1, BCRP) and metabolic enzymes (GST and CYP3A4), and the induction of apoptosis are useful indicators of the efficacy of a potential medicinal drug. The focus of this study was the possible mechanisms of drug resistance including: expression of resistance proteins, activation of metabolic enzymes, and alteration of the apoptosis and how to overcome their resistance effect on cancer cells. The overall goal of this review was to evaluate how commonly used medicinal plants and their main active secondary metabolites modulate multidrug resistance in cancer cells in order to validate their uses as anticancer drugs, introduce new therapeutic options for resistant cancer, and facilitate the development of their anticancer strategies and/or combination therapies. In conclusion, SMs from medicinal plants exhibit multitarget activity against MDR-related proteins, metabolic enzymes, and apoptotic signaling, this may help to overcome resistance towards chemotherapeutic drugs.

Expression of GST-IL-1 fusion gene

Two GST-IL-1 fusion genes were constructed by inserting different cDNA fragments of human interleukin1 (IL-1) into the 3'-terminus of GST gene in the fusion protein expression vector pGEX-4T. After IPTG induction ,SDS-PAGE was employed to detect the gene expression. No corresponding protein encoded by GST gene fused with the whole-length 816 bp IL-1 cDNA was observed, nor was free GST protein. However, the fusion protein of GST and IL-1 cDNA without the 189 bp at the 5'- terminus was detected, amounting to 30% of the total bacterial protein expressed. This might suggest that the sequence of 1-189 bp of IL-1 cDNA affected the expression of the fusion gene. That is to say, the downstream sequence distant from the translation start codon AUG in the target gene could significantly affect the expression of the fusion gene.

人类常用止痛剂布洛芬(Ibuprofen)及乙酰胺酚(Acetaminophen)对多齿新米虾(Neocaridina denticulate)的影响

近年来许多研究指出,人类长期使用的药物如抗生素或止痛剂等医疗药品,无法经由污水处理厂而完全分解消失,当这些药物进入环境中时将可能具有生物毒性,并对生态环境系统造成冲击。为了解人类常用止痛剂—布洛芬(ibuprofen, IBU)及乙酰胺酚(acetaminophen, ACE)残留于水体后对水生生物可能的影响。本研究应用多齿新米虾(Neocaridina denticulate,后简称米虾)进行0.1、1和5 mg/L的IBU及ACE不同浓度的曝露。并于曝露后1、4及7天,并测定米虾体内解毒酵素的活性(monooxygenase, Mon)及glutathione-S-transferase, GST)与肝胰脏受损指标(glutamic oxaloacetic transaminase, GOT)及(glutamic pyruvic transaminase, GPT)。试验结果显示,米虾曝露IBU及ACE后1,4及7天,各处理组间Mon活性并无明显高于对照组(37.8 ± 9.1 ΔA650mm/30 min/mg),GST活性在曝露5 mg/L的IBU及ACE处理组中有明显上升的趋势;5 mg/L IBU处理组在7天时GOT及GPT有上升的情况,代表IBU可能米虾的肝胰脏造成影响。综合实验结果,止痛剂IBU及ACE等药物于水体中残留时,不但会诱发米虾的解毒机制,甚至可能造成肝胰脏的发炎的现象。初步结果显示,止痛剂IBU及ACE等药物残留于水体中确实会对水生生物生理上的影响,此等问题势必会成为环境生态重要议题之一。