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1.
M A Benhura 《Comparative biochemistry and physiology. B, Comparative biochemistry》1985,80(4):821-825
The metabolism of cytosine arabinoside (araC) in Tetrahymena pyriformis amicronucleate strain W was studied. araC inhibited cell multiplication and protein synthesis at concentrations higher than 0.1 and 0.25 M respectively. araC had no effect on protein synthesis. araC was converted to araCMP, araCDP and araCTP by homogenized cell preparations. A deaminase activity converted araC to uracil arabinoside. The deaminase activity totally inhibited by tetrahydrouridine (THU) at a concn of 4 X 10(-6) M. The Ki for THU was 8 X 10(-8) M. 相似文献
2.
Induction of a novel class of diacylglycerol acyltransferases and triacylglycerol accumulation in Mycobacterium tuberculosis as it goes into a dormancy-like state in culture
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Daniel J Deb C Dubey VS Sirakova TD Abomoelak B Morbidoni HR Kolattukudy PE 《Journal of bacteriology》2004,186(15):5017-5030
Mycobacterium tuberculosis enters the host by inhalation of an infectious aerosol and replicates in the alveolar macrophages until the host's immune defense causes bacteriostasis, which leads the pathogen to go into nonreplicative drug-resistant dormancy. The dormant pathogen can survive for decades till the host's immune system is weakened and active tuberculosis develops. Even though fatty acids are thought to be the major energy source required for the persistence phase, the source of fatty acids used is not known. We postulate that the pathogen uses triacylglycerol (TG) as a storage form of fatty acids. Little is known about the biosynthesis of TG in M. tuberculosis. We show that 15 mycobacterial genes that we identified as putative triacylglycerol synthase (tgs) when expressed in Escherichia coli showed TGS activity, and we report some basic catalytic characteristics of the most active enzymes. We show that several tgs genes are induced when the pathogen goes into the nonreplicative drug-resistant state caused by slow withdrawal of O(2) and also by NO treatment, which is known to induce dormancy-associated genes. The gene (Rv3130c) that shows the highest TGS activity when expressed in E. coli shows the highest induction by hypoxia and NO treatment. Biochemical evidence shows that TG synthesis and accumulation occur under both conditions. We conclude that TG may be a form of energy storage for use during long-term dormancy. Therefore, TG synthesis may be an appropriate target for novel antilatency drugs that can prevent the organism from surviving dormancy and thus assist in the control of tuberculosis. 相似文献
3.
G Kocsy P von Ballmoos A Rüegsegger G Szalai G Galiba C Brunold 《Plant physiology》2001,127(3):1147-1156
With the aim of analyzing their protective function against chilling-induced injury, the pools of glutathione and its precursors, cysteine (Cys) and gamma-glutamyl-Cys, were increased in the chilling-sensitive maize (Zea mays) inbred line Penjalinan using a combination of two herbicide safeners. Compared with the controls, the greatest increase in the pool size of the three thiols was detected in the shoots and roots when both safeners were applied at a concentration of 5 microM. This combination increased the relative protection from chilling from 50% to 75%. It is interesting that this increase in the total glutathione (TG) level was accompanied by a rise in glutathione reductase (GR; EC 1.6.4.2) activity. When the most effective safener combination was applied simultaneously with increasing concentrations of buthionine sulfoximine, a specific inhibitor of glutathione synthesis, the total gamma-glutamyl-Cys and TG contents and GR activity were decreased to very low levels and relative protection was lowered from 75% to 44%. During chilling, the ratio of reduced to oxidized thiols first decreased independently of the treatments, but increased again to the initial value in safener-treated seedlings after 7 d at 5 degrees C. Taking all results together resulted in a linear relationship between TG and GR and a biphasic relationship between relative protection and GR or TG, thus demonstrating the relevance of the glutathione levels in protecting maize against chilling-induced injury. 相似文献
4.
Freda, Celia E. (University of Pennsylvania School of Medicine, Philadelphia), and Seymour S. Cohen. Streptomycin and infection of Escherichia coli by T6r(+) bacteriophage. J. Bacteriol. 92:1670-1679. 1966.-The thymineless, histidineless, uracil-less Escherichia coli 15 THU was shown to be sensitive to streptomycin, dying in patterns comparable to that of strain 15 TAU in the presence or absence of the required amino acid histidine. In the absence of histidine, the antibiotic stimulated ribonucleic acid (RNA) synthesis without a detectable inhibition or stimulation of deoxyribonucleic acid (DNA) synthesis. In the presence of streptomycin (40mug/ml) under conditions of multiple infection with T6r(+), lysis of THU occurred 1 hr earlier than did the control, having produced about one-third as much DNA and phage as did the control. In the absence of histidine, thereby preventing synthesis of phage DNA, accumulation of virus-induced RNA was similar for about 30 min in control and streptomycin-treated systems. In the presence of the antibiotic, however, the infected cells accumulated about 50 to 70% more RNA than did the control after 90 min. Nevertheless, the turnover of RNA was not detectably affected by streptomycin. The rate of production and final amount of deoxycytidylate hydroxymethylase, as well as the cut off time of synthesis of this enzyme, were scarcely affected by streptomycin. The beginning of DNA synthesis was delayed about 3 to 4 min by the antibiotic. The incorporation of histidine in infected cells was unaffected for 10 min and was only about 10% less than the control at 70 min. Lysozyme production began at about 10 min in control and antibiotic-treated systems, continued at essentially similarly increasing rates for 20 min, but stopped abruptly in the streptomycin-treated cells despite continuing protein synthesis. With the exception of lysozyme, the production of phage-specific polymers in a streptomycin-sensitive bacterium was only slightly affected by the antibiotic. 相似文献
5.
Physiological and genetic regulation of the aldohexuronate transport system in Escherichia coli. 总被引:12,自引:9,他引:3
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In Escherichia coli K-12, the specificity of the aldohexuronate transport system (THU) is restricted to glucuronate and galacturonate. There is a relatively high basal-level activity in uninduced wild-type or isomeraseless strains. Supplementary activity is obtained with the inducers mannonic amide (five-fold), galacturonate (fourfold), fructuronate (fivefold), and tagaturonate (sevenfold). Specific THU- mutants were selected as strains unable to grow on either aldohexuronate but able to grow on fructuronate or tagaturonate. The remaining transport activity in uninduced and induced THU- starins represents less than 20% of that found in the wild type. Conjugation and transduction experiments indicate that all of the THU- mutations are located in a unique locus, exuT, half-way between the tolC (59 min) and argG (61 min) markers. exuT is closely linked to the uxaC-uxaA operon (60 min) and to the regulatory gene exuR (60 min), which controls the above-mentioned operon and the uxaB operon (45 min). Growth on either aldohexuronate and transport activity are fully recovered when exuT mutants are allowed to revert to exuT+ on galacturonate or glucuronate. Reversion on glucuronate alone may lead to the mutational derepression of the 2-keto-3-deoxygluconate transport system, which is uninducible in the wild type, which also takes up glucuronate, and whose structural gene belongs to the kdg regulon. Such strains, which remain unable to grow on galacturonate, are exuT and kdgR (constitutive allele of the regulatory gene kdgR of the kdg regulon). THU activity is superrepressed in an exuR mutant in which the uxaC-uxaA operon and the uxaB operon are superrepressed; exuR+/exuR merodiploids are also superrepressed. In a thermosensitive exuR mutant in which the above-mentioned operons are constitutive at 42 degrees C, the THU activity is fully derepressed at this temperature. On the basis of these and other results, it is concluded that THU is coded for by the structural gene exuT, which is negatively controlled by the exuR gene product and which probably belongs to an operon distinct from the uxaA-uxaC operon. 相似文献
6.
Vlamis-Gardikas A 《Biochimica et biophysica acta》2008,1780(11):1170-1200
Electron flow via thiols is a theme with many variations in all kingdoms of life. The favourable physichochemical properties of the redox active couple of two cysteines placed in the optimised environment of the thioredoxin fold allow for two electron transfers in between top biological reductants and ultimate oxidants. The reduction of ribonucleotide reductases by thioredoxin and thioredoxin reductase of Escherichia coli (E. coli) was one of the first pathways to be elucidated. Diverse functions such as protein folding in the periplasm, maturation of respiratory enzymes, detoxification of hydrogen peroxide and prevention of oxidative damage may be based on two electron transfers via thiols. A growing field is the relation of thiol reducing pathways and the interaction of E. coli with different organisms. This concept combined with the sequencing of the genomes of different bacteria may allow for the identification of fine differences in the systems employing thiols for electron flow between pathogens and their corresponding mammalian hosts. The emerging possibility is the development of novel antibiotics. 相似文献
7.
Tadashi Sudo Hideo Nagayama Kinjiro Tamari 《Bioscience, biotechnology, and biochemistry》2013,77(7):1651-1659
Occurrence of cellulase activity was demonstrated in the filtrates of germinating conidiospores and growing mycelia of P. oryzae. Activity and some properties of cellulase in the filtrate of mycelia grown on rice plant powder as carbon source were compared among various strains.Cellulase activity (C1 and Cx enzymes; cellulose and carboxymethylcellulose as substrates, respectively) in the filtrate of germinating conidiospores was detected in the pathogenic T–l (Ken 53–33) strain as well as nonpathogenic 0 (THU 3 × 1) strain of P. oryzae. The activity was higher in the former than the latter strains. Cellulase activity (Cx enzyme) in the filtrate of growing mycelia was detected in the four strains used, T–l (Ken 53–33), C–3 (N 87), N–1 (H373), and 0 (THU 3 × 1). Cellulase activity (Cx enzyme) in the filtrate of mycelia was optimal at pH 5.0 and 40°C, and stable up to 40°C. Their properties did not differ significantly except for the pH-activity curve at alkaline side among various strains; but cellulase activity (C1 enzyme) was found to be correlated with their pathogenicity except for the case of C–3 strain. 相似文献
8.
Regulation of gamma-aminobutyric acid degradation in Escherichia coli by nitrogen metabolism enzymes. 总被引:4,自引:4,他引:0
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The possible role of glutamate dehydrogenase, glutamate synthase, and glutamine synthetase in the regulation of enzyme formation in the gamma-aminobutyric acid (GABA) catabolic pathway of Escherichia coli K-12 was investigated. Evidence is presented indicating that glutamine synthetase acts as a positive regulator in the E. coli GABA control system. Mutations impairing glutamate synthase activity prevent the depression of the enzymes of the GABA pathway in ammonia-limited glucose media. However, mutations resulting in constitutive synthesis of glutamine synthetase (GlnC) restore the ability of the glutamate synthase-less mutants to grow in glucose-GABA media and result in depressed synthesis of the GABA enzymes. It is suggested that the loss of glutamate synthesis activity affects the GABA control system indirectly by lowering glutamine synthetase levels. 相似文献
9.
Besnard T Renée N Etienne-Grimaldi MC François E Milano G 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2008,870(1):117-120
The 5FU prodrug capecitabine undergoes a 3-step enzymatic conversion, including the conversion of 5'DFRC into 5'DFUR by cytidine deaminase (CDA). The presence of CDA activity in blood led us to analyze the possible ex vivo conversion of 5'DFCR into 5'DFUR in blood samples. We thus examined the impact of the addition of a CDA inhibitor (tetrahydrouridine (THU) 1 microM final) in blood. Blood samples from 3 healthy volunteers were taken on tubes containing or not THU. Blood was spiked with 5'DFCR (20 microM final) (T0) and was maintained at room temperature for 2 h. Plasma concentrations of 5'DFRC and 5'DFUR were analyzed with an optimized HPLC assay. In the absence of THU, 5'DFUR was detectable as early as T0. The percent of 5'DFUR produced relative to 5'DFCR increased over time, up to 7.7 % at 2h. In contrast, the presence of THU totally prevents the formation of 5'DFUR. The impact of THU for preventing the conversion of 5'DFCR was confirmed by the analysis of blood samples from 2 capecitabine-treated patients. Addition of THU in the sampling-tube before the introduction of blood is thus strongly recommended in order to guarantee accurate conditions for reliable measurement of capecitabine metabolites in plasma, and thus faithful pharmacokinetic data. 相似文献
10.
Tetrahydrouridine specifically facilitates deoxycytidine incorporation into herpes simplex virus DNA. 总被引:1,自引:0,他引:1
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As reported by Jamieson and Subak-Sharpe (J. Gen. Virol. 31:303-313, 1976), exogenous deoxycytidine is very poorly incorporated into herpes simplex virus DNA. Here it is shown that this incorporation was dramatically increased in the presence of tetrahydrouridine (THU), a specific inhibitor of cytidine-deoxycytidine deaminase. Thus, the exclusion of deoxycytidine from herpes simplex virus DNA probably results from massive degradation by the deaminase, which is consistent with the observation that in the absence of THU, most of the nucleotides formed from exogenous deoxycytidine are dUMP. The effect of tHU upon deoxycytidine incorporation was specific for herpes simplex virus-infected cells; THU did not increase deoxycytidine incorporation into DNA of uninfected cells. Therefore, one might expect THU to enhance the antiviral activity of 1-beta-D-arabinofuranasylcytosine since this analog is also readily deaminated. However, THU increased both the antiviral activity and the cell toxicity only slightly and to about the same extent. Therefore, the metabolism of 1-beta-D-arabnofuranosylcytosine is different from that of deoxycytidine in herpes simplex virus-infected cells. 相似文献
11.
DGAT enzymes are required for triacylglycerol synthesis and lipid droplets in adipocytes 总被引:1,自引:0,他引:1
Harris CA Haas JT Streeper RS Stone SJ Kumari M Yang K Han X Brownell N Gross RW Zechner R Farese RV 《Journal of lipid research》2011,52(4):657-667
The total contribution of the acyl CoA:diacylglycerol acyltransferase (DGAT) enzymes, DGAT1 and DGAT2, to mammalian triacylglycerol (TG) synthesis has not been determined. Similarly, whether DGAT enzymes are required for lipid droplet (LD) formation is unknown. In this study, we examined the requirement for DGAT enzymes in TG synthesis and LDs in differentiated adipocytes with genetic deletions of DGAT1 and DGAT2. Adipocytes with a single deletion of either enzyme were capable of TG synthesis and LD formation. In contrast, adipocytes with deletions of both DGATs were severely lacking in TG and did not have LDs, indicating that DGAT1 and DGAT2 account for nearly all TG synthesis in adipocytes and appear to be required for LD formation during adipogenesis. DGAT enzymes were not absolutely required for LD formation in mammalian cells, however; macrophages deficient in both DGAT enzymes were able to form LDs when incubated with cholesterol-rich lipoproteins. Although adipocytes lacking both DGATs had no TG or LDs, they were fully differentiated by multiple criteria. Our findings show that DGAT1 and DGAT2 account for the vast majority of TG synthesis in mice, and DGAT function is required for LDs in adipocytes, but not in all cell types. 相似文献
12.
13.
The CCA-adding enzymes [ATP(CTP):tRNA nucleotidyl transferases], which catalyze synthesis of the conserved CCA sequence to the tRNA 3' end, are divided into two classes. Recent studies show that the class II Escherichia coli CCA-adding enzyme synthesizes poly(C) when incubated with CTP alone, but switches to synthesize CCA when incubated with both CTP and ATP. Because the poly(C) activity can shed important light on the mechanism of the untemplated synthesis of CCA, it is important to determine if this activity is also present in the class I CCA enzymes, which differ from the class II enzymes by significant sequence divergence. We show here that two members of the class I family, the archaeal Sulfolobus shibatae and Methanococcus jannaschii CCA-adding enzymes, are also capable of poly(C) synthesis. These two class I enzymes catalyze poly(C) synthesis and display a response of kinetic parameters to the presence of ATP similar to that of the class II E. coli enzyme. Thus, despite extensive sequence diversification, members of both classes employ common strategies of nucleotide addition, suggesting conservation of a mechanism in the development of specificity for CCA. For the E. coli enzyme, discrimination of poly(C) from CCA synthesis in the intact tRNA and in the acceptor-TPsiC domain is achieved by the same kinetic strategy, and a mutation that preferentially affects addition of A76 but not poly(C) has been identified. Additionally, we show that enzymes of both classes exhibit a processing activity that removes nucleotides in the 3' to 5' direction to as far as position 74. 相似文献
14.
Regulatory roles of nicotinamide nucleotides and three key enzymes, beta-ketothiolase (KT), NADPH-dependent acetoacetyl-CoA reductase (AAR), and citrate synthase (CS), on poly(3-hydroxybutyrate) (PHB) synthesis in recombinant Escherichia coli harboring a plasmid containing the Alcaligenes eutrophus polyhydroxyalkanoate (PHA) biosynthesis genes were examined. Cells were grown in various media and were subsequently compared for PHB concentration, PHB content, the activities of the key enzymes, and the levels of nicotinamide nucleotides. Cells of recombinant E. coli accumulated the largest amount of PHB in LB+glucose medium among those tested. PHB synthesis was not enhanced by limiting inorganic ions. The activity of CS, which competes with KT for acetyl-CoA, was lower when cells were grown in LB+glucose compared with other media. The NADPH level and the NADPH/NADP ratio were high in LB+glucose. Examination of the time profiles of the specific PHB synthesis rate, key enzyme activities, and the levels of nicotinamide nucleotides showed that PHB synthesis is most significantly affected by the NADPH level. Even though the NADH level and the NADH/NAD ratio were also high during the synthesis of PHB, no direct evidence of their positive effect on PHB synthesis was found. Low activity of CS was beneficial for PHB synthesis due to the availability of more acetyl-CoA to PHB biosynthetic pathway. In recombinant E. coli, the level of NADPH and/or the NADPH/NADP ratio seem to be the most critical factor regulating the activity of AAR and, subsequently, PHB synthesis. (c) 1996 John Wiley & Sons, Inc. 相似文献
15.
Tetrahydrouridine (THU) is a well characterized and potent inhibitor of cytidine deaminase (CDA). Highly expressed CDA catalyzes and inactivates cytidine analogues, ultimately contributing to increased gemcitabine resistance. Therefore, a combination therapy of THU and gemcitabine is considered to be a potential and promising treatment for tumors with highly expressed CDA. In this study, we found that THU has an alternative mechanism for inhibiting cell growth which is independent of CDA expression. Three different carcinoma cell lines (MIAPaCa-2, H441, and H1299) exhibited decreased cell proliferation after sole administration of THU, while being unaffected by knocking down CDA. To investigate the mechanism of THU-induced cell growth inhibition, cell cycle analysis using flow cytometry was performed. This analysis revealed that THU caused an increased rate of G1-phase occurrence while S-phase occurrence was diminished. Similarly, Ki-67 staining further supported that THU reduces cell proliferation. We also found that THU regulates cell cycle progression at the G1/S checkpoint by suppressing E2F1. As a result, a combination regimen of THU and gemcitabine might be a more effective therapy than previously believed for pancreatic carcinoma since THU works as a CDA inhibitor, as well as an inhibitor of cell growth in some types of pancreatic carcinoma cells. 相似文献
16.
Synthetic Capabilities of Plasmolyzed Cells and Spheroplasts of Escherichia coli 总被引:2,自引:2,他引:0
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Kenneth E. Rubenstein Margit M. K. Nass Seymour S. Cohen 《Journal of bacteriology》1970,104(1):443-452
Effects of plasmolysis and spheroplast formation on deoxyribonucleic acid (DNA), ribonucleic acid (RNA), protein, and phospholipid synthesis by Escherichia coli strain THU were studied. RNA and protein synthesis were severely diminished. DNA and phospholipid synthesis were inhibited, but less so; they could be partly restored. DNA synthesis could be restored by replacing thymine in the medium with thymidine, and phospholipid synthesis, by adding back small quantities of soluble cell extract. Plasmolysis effected marked reductions in rates of growth and macro-molecule synthesis, and temporarily reduced culture viability. Plasmolysis also caused an anomalous stimulation of phospholipid synthesis. Spheroplasts and plasmolyzed cells synthesized small amounts of ribosomal RNA that sedimented normally. However, this ribosomal RNA was very inefficiently packaged to ribosome subunits. Spheroplasts were unable to carry out induced synthesis of beta-galactosidase, and plasmolyzed cells were delayed in this function. Radioautographs examined in an electron microscope showed that DNA synthesis in plasmolyzed cells and spheroplasts was performed by a substantial fraction of the culture populations. That DNA and membrane were associated in the spheroplasts used in this study was suggested by formation of M-bands containing membrane and most of the cell's DNA. The results are discussed in terms of alterations of membrane structure and conformation attending plasmolysis and spheroplasting. 相似文献
17.
耐辐射球菌pprI在大肠杆菌中表达增强细胞抗氧化能力的研究 总被引:4,自引:0,他引:4
将耐辐射球菌(Deinococcus radiodurans)与DNA修复有关的开关基因—pprI通过穿梭质粒pRADZ3导入大肠杆菌TG1中,使其在正常培养条件下(不需诱导剂)表达PprI蛋白,并通过Western blot证实该基因在TG1中可稳定表达。与转化了空白质粒pRADZ3 TG1对照,观察了改造后的两种大肠杆菌在有H2O2氧化压力下的存活率和大肠杆菌中两种过氧化氢酶(KatE, KatG)的活性表达差异。结果表明,无论在指数生长期还是稳定生长期,能表达PprI蛋白的大肠杆菌比对照的存活率要高出10%左右;非变性电泳结果表明,耐辐射球菌pprI 在大肠杆菌中的表达使得KatE活性在指数生长期与稳定生长期分别增加1.5~2倍和2.5~3倍。证明耐辐射球菌pprI 在大肠杆菌中的表达能够增强细胞抗氧化能力。 相似文献
18.
Increased very low density lipoprotein secretion and gonadal fat mass in mice overexpressing liver DGAT1 总被引:4,自引:0,他引:4
Yamazaki T Sasaki E Kakinuma C Yano T Miura S Ezaki O 《The Journal of biological chemistry》2005,280(22):21506-21514
Acyl-CoA:diacylglycerol acyltransferases (DGATs) catalyze the last step in triglyceride (TG) synthesis. The genes for two DGAT enzymes, DGAT1 and DGAT2, have been identified. To examine the roles of liver DGAT1 and DGAT2 in TG synthesis and very low density lipoprotein (VLDL) secretion, liver DGAT1- and DGAT2-overexpressing mice were created by adenovirus-mediated gene transfection. DGAT1-overexpressing mice had markedly increased DGAT activity in the presence of the permeabilizing agent alamethicin. This suggests that DGAT1 possesses latent DGAT activity on the lumen of the endoplasmic reticulum. DGAT1-overexpressing mice showed increased VLDL secretion, resulting in increased gonadal (epididymal or parametrial) fat mass but not subcutaneous fat mass. The VLDL-mediated increase in gonadal fat mass might be due to the 4-fold greater expression of the VLDL receptor protein in gonadal fat than in subcutaneous fat. DGAT2-overexpressing mice had increased liver TG content, but VLDL secretion was not affected. These results indicate that DGAT1 but not DGAT2 has a role in VLDL synthesis and that increased plasma VLDL concentrations may promote obesity, whereas increased DGAT2 activity has a role in steatosis. 相似文献
19.
用聚合酶链反应(PCR)以大肠杆菌JM83基因组DNA为模板,扩增了精氨酰-tRNA合成酶(ArgRS)基因。将该基因重组到载体pUC18上转化到大肠杆菌TG1中,得到在转化子中ArgRS的高表达。粗抽液中ArgRS的氨酰化活力,TG1和TG1转化子分别为1.65U/mg和210U/mg,后者为前者的127倍。DNA顺序测定表明,与从大肠杆菌JA200中克隆到的ArgRS基因相比913位碱基为A而不为C,这种变化使ArgRS的305位氨基酸残基由Gln变为Lys,但这种改变不影响酶的活力。 相似文献
20.
Magdalena K?dzierska Rafa? G?owacki Urszula Czernek Katarzyna Szyd?owska-Pazera Piotr Potemski Janusz Piekarski Arkadiusz Jeziorski Beata Olas 《Molecular and cellular biochemistry》2013,372(1-2):47-55
Different low-molecular-weight thiols, including glutathione, cysteine, and cysteinylglycine are physiological free radical scavengers. On the other hand, homocysteine may play a role as an oxidant. The aim of our present study was to establish in vitro the effects of the commercial extract of Aronia melanocarpa (Aronox?) on the amount of selected low-molecular-weight thiols and the activity of antioxidative enzymes (superoxide dismutase, glutathione peroxidase, and glutathione reductase) in plasma obtained from patients with invasive breast cancer during different phases of treatment [before or after the surgery and patients after different phases of chemotherapy (doxorubicin and cyclophosphamide)] and from healthy subjects. Patients were hospitalized in Department of Oncological Surgery and Department of Chemotherapy, Medical University of Lodz, Poland. The level of low-molecular-weight thiols was determined by high-performance liquid chromatography. We observed that in the presence of the Aronia extract changes in amount of thiols in plasma from breast cancer patients (at all tested groups) were significantly reduced. Our results showed that tested commercial extract reduced modifications of antioxidative enzymes activity in plasma from patients during different phases of treatment, but this effect was not statistical significant. Our results suggest that the Aronia extract supplementation in breast cancer patients has a beneficial effect on thiols concentration in plasma. Plasma, as reported in this work, could be used as an experimental model to evaluate the beneficial action of plant supplements, including phenolic extracts on thiols or other molecules during different phases of treatment. 相似文献