Mitomycin C-Activity Effected by Vitamins B1, C, E and β-Carotene under Irradiation with γ-Rays

2003 ◽  
Vol 58 (3-4) ◽  
pp. 244-248 ◽  
Author(s):  
Edith Heinrich ◽  
Nikola Getoff

Vitamin B1 (thiamine) can essentially effect the activity of mitomycin C (MMC), added individually or in combination with antioxidant vitamins (C, E-acetate, β-carotene) as found in experiments in vitro (Escherichia coli bacteria, AB 1157) under irradiation with γ-rays. The environment plays a crucial role. In airfree media vitamin B1 leads to a 2-fold increase of the MMC-efficiency, but adding vitamin C it decreases. In the presence of all vitamins (B1, C, E-ac., and β-carotene) the MMC-action increases about 1.8-fold. In aerated media vitamin B1 causes an about 4-times increase of the MMC-efficiency, but by adding vitamin B1 and C the MMC-activity decreases by a factor of two, whereas in the presence of B1, C, E-ac., and β-carotene it rises again to 2.6-fold. In environment saturated with N2O (conversion of e-aq into OH radicals) a different picture is observed. The presence of vitamin B1 or vitamin B1 + C causes a strong decrease of the MMC-efficiency, but the addition of all vitamins (B1, C, E-ac., and β-car.) leads to a small increase of the cytostatic action. The results demonstrate the influence of vitamin B1 used individually or in combination with other antioxidants on the MMC-efficiency and the strong effect of the environment. The results are of interest for the application of MMC in radiotherapy.

2001 ◽  
Vol 183 (7) ◽  
pp. 2259-2264 ◽  
Author(s):  
Yan Wei ◽  
Amy C. Vollmer ◽  
Robert A. LaRossa

ABSTRACT Mitomycin C (MMC), a DNA-damaging agent, is a potent inducer of the bacterial SOS response; surprisingly, it has not been used to select resistant mutants from wild-type Escherichia coli. MMC resistance is caused by the presence of any of four distinctE. coli genes (mdfA, gyrl, rob, andsdiA) on high-copy-number vectors. mdfAencodes a membrane efflux pump whose overexpression results in broad-spectrum chemical resistance. The gyrI (also called sbmC) gene product inhibits DNA gyrase activity in vitro, while the rob protein appears to function in transcriptional activation of efflux pumps. SdiA is a transcriptional activator of ftsQAZ genes involved in cell division.


2003 ◽  
Vol 374 (3) ◽  
pp. 767-772 ◽  
Author(s):  
Elisabet ROMAN ◽  
Ian ROBERTS ◽  
Kerstin LIDHOLT ◽  
Marion KUSCHE-GULLBERG

The Escherichia coli K5 capsular polysaccharide (glycosaminoglycan) chains are composed of the repeated disaccharide structure: -GlcAβ1,4-GlcNAcα1,4-(where GlcA is glucuronic acid and GlcNAc is N-acetyl-d-glucosamine). The GlcA, present in most glycosaminoglycans, is donated from UDP-GlcA, which, in turn, is generated from UDP-glucose by the enzyme UDP-glucose dehydrogenase (UDPGDH). The formation of UDP-GlcA is critical for the biosynthesis of glycosaminoglycans. To investigate the role of UDPGDH in glycosaminoglycan biosynthesis, we used K5 polysaccharide biosynthesis as a model. E. coli was transformed with the complete gene cluster for K5 polysaccharide production. Additional transformation with an extra copy of UDPGDH resulted in an approx. 15-fold increase in the in vitro UDPGDH enzyme activity compared with the strain lacking extra UDPGDH. UDP-GlcA levels were increased 3-fold in overexpressing strains. However, metabolic labelling with [14C]glucose showed, unexpectedly, that overexpression of UDPGDH lead to decreased formation of K5 polysaccharide. No significant difference in the K5 polysaccharide chain length was observed between control and overexpressing strains, indicating that the decrease in K5-polysaccharide production most probably was due to synthesis of fewer chains. Our results suggest that K5-polysaccharide biosynthesis is strictly regulated such that increasing the amount of available UDP-GlcA results in diminished K5-polysaccharide production.


Author(s):  
SUNARTI M.BIOMED ◽  
DEBORA PANINSARI

Objective: The objective of this study was to discover of the ethanolic extract of Rhinacanthus nasutus (L) Kurz in inhibiting Escherichia coli bacteria using an in vitro method. Methods: This is an experimental study using a laboratory test with Kirby-Bauer or paper disc method by observing and measuring the inhibition zone of the ethanolic extract of R. nasutus against E. coli bacteria with extract concentrations of 15%, 30%, and 60% consisting of control groups and treatment group. The positive control group used chloramphenicol antibiotics and negative control groups used Aquadest. E. coli was incubated at 37°C for 24 h. Then, the plates were incubated for 24 h at 37°C and the diameter of the inhibition zone was observed until the 3rd day with three repetitions. Results: The results of the study showed that the mean inhibition zone of E. coli bacteria was 10.93 mm, 12.09 mm, and 18.90 mm. The results of the Shapiro–Wilk test were p=0.199. The results of the one-way analysis of variance test were p<0.05 and that of the post hoc test indicated a significant value of p<0.05. Based on the results of the research, there were significant differences in the inhibition zone between the control group and the treatment group at a concentration of 15%, 30%, and 60%. Conclusion: R. nasutus extract was effective to inhibit the growth of E. coli bacteria at concentrations of 15%, 30%, and 60%, so R. nasutus is effective as an antimicrobial.


2019 ◽  
Vol 87 (12) ◽  
Author(s):  
Luz A. Fernández-López ◽  
Karla Gil-Becerril ◽  
Silvia Galindo-Gómez ◽  
Teresa Estrada-García ◽  
Cecilia Ximénez ◽  
...  

ABSTRACT Epidemiological studies suggest frequent association of enteropathogenic bacteria with Entamoeba histolytica during symptomatic infection. In this study, we sought to determine if the interaction with enteropathogenic (EPEC) or nonpathogenic Escherichia coli (strain DH5α) could modify the virulence of E. histolytica to cause disease in animal models of amebiasis. In vitro studies showed a 2-fold increase in CaCo2 monolayer destruction when E. histolytica interacted with EPEC but not with E. coli DH5α for 2.5 h. This was associated with increased E. histolytica proteolytic activity as revealed by zymogram analysis and degradation of the E. histolytica CP-A1/5 (EhCP-A1/5) peptide substrate Z-Arg-Arg-pNC and EhCP4 substrate Z-Val-Val-Arg-AMC. Additionally, E. histolytica-EPEC interaction increased EhCP-A1, -A2, -A4, and -A5, Hgl, Apa, and Cox-1 mRNA expression. Despite the marked upregulation of E. histolytica virulence factors, nonsignificant macroscopic differences in amebic liver abscess development were observed at early stages in hamsters inoculated with either E. histolytica-EPEC or E. histolytica-E. coli DH5α. Histopathology of livers of E. histolytica-EPEC-inoculated animals revealed foci of acute inflammation 3 h postinoculation that progressively increased, producing large inflammatory reactions, ischemia, and necrosis with high expression of il-1β, ifn-γ, and tnf-α proinflammatory cytokine genes compared with that in livers of E. histolytica-E. coli DH5α-inoculated animals. In closed colonic loops from mice, intense inflammation was observed with E. histolytica-EPEC manifested by downregulation of Math1 mRNA with a corresponding increase in the expression of Muc2 mucin and proinflammatory cytokine genes il-6, il-12, and mcp-1. These results demonstrate that E. histolytica/EPEC interaction enhanced the expression and production of key molecules associated with E. histolytica virulence, critical in pathogenesis and progression of disease.


Blood ◽  
1994 ◽  
Vol 83 (5) ◽  
pp. 1436-1441 ◽  
Author(s):  
TK Tang ◽  
CH Yeh ◽  
CS Huang ◽  
MJ Huang

We have developed a system to characterize normal and mutated glucose-6- phosphate dehydrogenase (G6PD) enzymes in vitro. Normal or mutant G6PD cDNA was subcloned into a pGEX-3X vector, which allowed production of a functional fusion protein in Escherichia coli. When we compared the recombinant normal enzyme with authentic human G6PD, indistinguishable Km values for glucose-6-phosphate (G6P) and NADP were obtained, and the utilization rates for two substrate analogues (2-deoxy G6P and deamino NADP) also showed no difference between the enzymes. This system was used to assay a biochemically uncharacterized variant, G6PD Taipei (493 A-->wG; 165 Asn-->Asp), plus two other known mutations (487 G-->A; 163 Gly-->Ser and 592 C-->T; 198 Arg-->Cys) that are located close to or within the putative G6P binding domain. Our results show that the G6PD activities of these three mutants were greatly reduced. No significant alteration in G6PD kinetics was observed for both 487 and 493 mutations. However, a drastic reduction in the Km for G6P (4-fold decrease) and tremendous increases in utilization rates of 2-deoxy G6P (32-fold increase) and deamino NADP (6-fold increase) were associated with the 592 mutation. This results suggests that arginine 198 in human G6PD, possibly located within the putative G6P binding domain, may play an important role in binding the substrate G6P. In addition, we and others have recently identified that at least nine different types of mutations are responsible for G6PD deficiency in Chinese. In this report, we also present the occurrence rate of each mutation present in the population of Taiwan.


2021 ◽  
Author(s):  
Yury B Slonimskiy ◽  
Nikita A Egorkin ◽  
Thomas N. Friedrich ◽  
Eugene G. Maksimov ◽  
Nikolai N. Sluchanko

Carotenoids are lipophilic substances with many biological functions, from coloration to photoprotection. Being potent antioxidants, carotenoids have multiple biomedical applications, including the treatment of neurodegenerative disorders and retina degeneration. Nevertheless, the delivery of carotenoids is substantially limited by their poor solubility in the aqueous phase. Natural water-soluble carotenoproteins can facilitate this task, necessitating studies on their ability to uptake and deliver carotenoids. One such promising carotenoprotein, AstaP (Astaxanthin-binding protein), was recently identified in eukaryotic microalgae, but its structure and functional properties remained largely uncharacterized. By using a correctly folded recombinant protein, here we show that AstaP is an efficient carotenoid solubilizer that can stably bind not only astaxanthin but also zeaxanthin, canthaxanthin, and, to a lesser extent, β-carotene, i.e. carotenoids especially valuable to human health. AstaP accepts carotenoids provided as acetone solutions or embedded in membranes, forming carotenoid-protein complexes with an apparent stoichiometry of 1:1. We successfully produced AstaP holoproteins in specific carotenoid-producing strains of Escherichia coli, proving it is amenable to cost-efficient biotechnology processes. Regardless of the carotenoid type, AstaP remains monomeric in both apo- and holoforms, while its rather minimalistic mass (~20 kDa) makes it an especially attractive antioxidant delivery module. In vitro, AstaP transfers different carotenoids to the liposomes and to unrelated proteins from cyanobacteria, which can modulate their photoactivity and/or oligomerization. These findings expand the toolkit of the characterized carotenoid-binding proteins and outline the perspective of the use of AstaP as a unique monomeric antioxidant nanocarrier with an extensive carotenoid-binding repertoire.


Author(s):  
Abdul Wahid Jamaluddin ◽  
Muhammad F. Mursalim ◽  
Andi M. S. Apada

Escherichia coli is a gram negative bacterium which is a normal flora in the digestive tract. In birds, this bacterium causes a disease known as colibasillosis. Antibiotics are generally used, but excessive use will cause residues and antibiotic resistance. To avoid resistance or residue, an alternative treatment is needed. The combination of propolis and ginger extract is very promising to develop because both have a synergistic effect as antimicrobials. The research aims to determine the effect of the combination extract on Escherichia coli bacteria in vitro. We used 8 groups which contain combinations of propolis and ginger extract. We used amoxicillin disk as a positive control, 1% Na CMC as a negative control. The results showed a combination of ginger and propolis extract showed good inhibitory activity against Escherichia coli in all groups> 6mm., and the highest inhibitory activity was K3 (5% propolis combination and 15% ginger extract) with 8.7 mm. The combination of propolis and ginger extract has the potential to be used as an alternative antibiotic to prevent antibiotic resistance from synthetic antibiotics.Keywords: alternative antibiotics, combination extracts, Escherichia coli, ginger, in vitro, propolis


2018 ◽  
Vol 7 (2) ◽  
pp. 144-149
Author(s):  
Susiwati Susiwati

This research aims to determine the inhibition of sapodilla fruit, garlic, andong leaves and pare fruit toward the growth of escherichia coli bacteria. Antimicroba test used paper disc diffusion was in-vitro test. Sapodilla fruit, garlic, andong leaves and pare fruit were extracted by using maceration process. The extracts were tested on the growth of E- coli bacteria.  The highest inhibition zone (6,7mm) was found in andong leaves extract. The highest inhibition zone was 8.3 mm, whereas the inhibition of pare fruit did not not provide the inhibitory zone. It can be concluded that garlic extract, sapodolla extract and decoction of andong leaves have highly inhibitory in vitro. Based on stastistical analysis, there was Significant difference betwen the effectiveness of garlic extract with a decoction of andong leaves but the effectivess of garlic extract with sapodilla extract was not meaningful. Whereas pare fruit did not give any inhibition zones. From the result of this research, the society can be encouraged to consume andong leaves or sapodilla fruit to treat diarrhea. In addition, garlic spices and pare fruit also can be used to overcome diarrhea, which is caused by the bacterium E. coli.


2020 ◽  
Vol 3 (2) ◽  
pp. 241-252
Author(s):  
Christe Mareta Ardika Sari ◽  
◽  
Disa Andriani ◽  
Didik Wahyudi ◽  

Papaya seeds (Carica papaya L.) have antibacterial activity because they contain terpenoid, karpain and flavonoid compounds. Flavonoids have OH groups that can damage bacterial cell walls. The dry powder of papaya seeds was extracted by maceration method using 80% ethanol. The purpose of this study was to determine the optimal combination of HPMC and carbopol concentrations in the hand sanitizer gel of papaya seed ethanol extract which can influence the in vitro inhibition of Escherichia coli bacteria. The data analysis used in this study was one way ANOVA and then continued with the Post Hoc Tests. The results of the study obtained a yield of 6.933%. The optimum formula obtained is RUN 8 with a concentration of HPMC: Carbopol (0.25gram: 0.75gram). The results of antibacterial activity against Escherichia coli bacteria obtained an average of 44.25 mm from the two samples. The statistical results obtained stated that there was no significant difference between the concentration of A and ciprofloxacin as a positive control.


Genetics ◽  
1979 ◽  
Vol 92 (4) ◽  
pp. 1041-1059
Author(s):  
Joan M Henson ◽  
Herman Chu ◽  
Carleen A Irwin ◽  
James R Walker

ABSTRACT Escherichia coli mutants with temperature-sensitive (ts) mutations in dnaX and dnaY genes have been isolated. Based on transduction by phage PI, dnaX and Y have been mapped at minutes 10.4-10.5 and 12.1, respectively, in the sequence dnaX purE dnaY. Both dnaXts36 and YtslO are recessive to wild-type alleles present on episomes. F13 carries both dnaX  + and Y  +; the shorter F210 carries dnaY  +, but not X  +. Lambda transducing phages that carry dnaX  + or Y  + have been isolated, and hybrid plasmids of Col E1 and E. coli DNA from the CLARKE and CARBON (1976) collection also carry portions of the dnaX purE dnaY region. Results obtained with the λ transducing phages and the hybrid plasmids suggest that dnaX is a different gene from the previously characterized dnaZ gene, which is also near minute 10.5.—The dnaXts36 mutant, after a shift to 42°, stopped DNA synthesis gradually, and the total amount of DNA increased two-fold. When this mutant was shifted to M°, the rate of DNA synthesis dropped immediately and the final increment of DNA was only 10% of the initial amount. Replicative DNA synthesis in toluene-treated cells was completely inhibited at 42° and was partially in-hibited even at 30°.—When the dnaYtslO mutant was shifted to 42°, DNA synthesis gradually stopped, and the amount of DNA increased 3.6-fold. At 44°, residual DNA synthesis amounted to a two-fold increase. Replicative DNA synthesis in vitro in toluene-treated cells was inactivated after 20 minutes at 42° or by "preincubation" of cells at 42° before toluene treatment.— The dnaX and dnaY products probably function in polymerization of DNA, although participation also in initiation cannot be excluded.


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