Cytotoxic Effects of Alcohol Extracts from a Plastic Wrap (Polyvinylidene Chloride) on Human Cultured Liver Cells and Mouse Primary Cultured Liver Cells.

An increasing accumulation of microplastics and further degraded nanoplastics in our environment is suspected to have harmful effects on humans and animals. To clarify this problem, we tested the cytotoxicity of two types of plastic wrap on human cultured liver cells and mouse primary cultured liver cells. Alcohol extracts from plastic wrap, i.

Chloroethylating anticancer drug-induced mutagenesis and its repair in .

Background: Chloroethylnitrosourea (CENU) derivatives, such as nimustine (ACNU) and carmustine (BCNU), are employed in brain tumor chemotherapy due to their ability to cross the blood-brain barrier. They are thought to suppress tumor development through DNA chloroethylation, followed by the formation of interstrand cross-links (ICLs) that efficiently block replication and transcription. However, the alkylation of DNA and ICLs may trigger genotoxicity, leading to tumor formation as a side effect of the chemotherapeutic treatment.

UV-irradiated 2-methyl-4'-(methylthio)-2-morpholinopropiophenone-containing injection solution produced frameshift mutations in the Ames mutagenicity assay.

In previous studies, we detected the photoinitiators 1-hydroxycyclohexyl phenyl ketone (1-HCHPK), methyl 2-benzoylbenzoate (MBB), and 2-methyl-4'-(methylthio)-2-morpholinopropiophenone (MTMP) in intravenous injection solutions. In addition, we reported that 1-HCHPK, MBB, and MTMP exhibited cytotoxicity towards normal human peripheral blood mononuclear cells. A previous in vitro study reported that a free-radical photoinitiator introduced covalently bound purine residues into DNA.

E. coli mismatch repair enhances AT-to-GC mutagenesis caused by alkylating agents.

Alkylating agents are known to induce the formation of O-alkylguanine (O-alkG) and O-alkylthymine (O-alkT) in DNA. These lesions have been widely investigated as major sources of mutations. We previously showed that mismatch repair (MMR) facilitates the suppression of GC-to-AT mutations caused by O-methylguanine more efficiently than the suppression of GC-to-AT mutations caused by O-ethylguanine.

Indolo[3,2-b]quinoline Derivatives Suppressed the Hemolytic Activity of Beta-Pore Forming Toxins, Aerolysin-Like Hemolysin Produced by Aeromonas sobria and Alpha-Hemolysin Produced by Staphylococcus aureus.

In an attempt to discover inhibitory compounds against pore-forming toxins, some of the major toxins produced by bacteria, we herein examined the effects of four kinds of indolo[3,2-b]quinoline derivatives on hemolysis induced by the aerolysin-like hemolysin (ALH) of Aeromonas sobria and also by the alpha-hemolysin of Staphylococcus aureus. The results showed that hemolysis induced by ALH was significantly reduced by every derivative, while that induced by alpha-hemolysis was significantly reduced by three out of the four derivatives. However, the degrees of reduction induced by these derivatives were not uniform.

Properties of hemolysin and protease produced by Aeromonas trota.

We examined the properties of exotoxins produced by Aeromonas trota (A. enteropelogenes), one of the diarrheagenic species of Aeromonadaceae. Nine of 19 A.

Spermidine-analogous triamines suppressed the growth of Candida albicans.

We examined the antifungal activity of various synthetic triamines on several fungi. Among various triamines having a general structure H2N(CH2)aNH(CH2)bNH2 (a=2-5, b=3-8), some triamines (a=4 or 5) showed inhibitory effect on the growth of Candida albicans and C. tropicalis.

Analysis of carboxy terminal domain of metalloprotease of elastolytic Aeromonas hydrophila.

We examined the ability of Aeromonas hydrophila to lyse elastin. Eight of 13 strains showed elastolytic activity on agar medium containing elastin and 5 strains did not. In order to examine the involvement of the metalloprotease of A.

Distinct pathways for repairing mutagenic lesions induced by methylating and ethylating agents.

DNA alkylation damage can be repaired by nucleotide excision repair (NER), base excision repair (BER) or by direct removal of alkyl groups from modified bases by O(6)-alkylguanine DNA alkyltransferase (AGT; E.C. 2.

Production and properties of lipase of Aeromonas sobria.

Aeromonas have been isolated from a wide variety of aquatic environments. However the number of Aeromonas in sea water is extremely small compared to that in fresh water. In in vitro culture, Aeromonas can grow in mediums containing NaCl at a concentration of 3.

Inhibition of biosynthesis of metalloprotease of Aeromonas sobria by sodium chloride in the medium.

The present authors have previously shown that the serine protease activity of Aeromonas sobria is markedly decreased when A. sobria is cultured in medium containing 3.0% sodium chloride (NaCl, concentration almost equivalent to sea water salinity), and that this occurs because, although the synthesis of ASP is not disturbed by the salt in the medium, the maturation pathway of serine protease of A.

Maturation pathway of metalloprotease produced by Aeromonas sobria.

Previously, we cloned the metalloprotease gene of Aeromonas sobria (amp) and determined its nucleotide sequence (GenBank accession number DQ784565). The protease is composed of 591 amino acid residues. In this study, we purified the mature metalloprotease from the culture supernatant of A.

Influence of neighbouring base sequences on the mutagenesis induced by 7,8-dihydro-8-oxoguanine in yeast.

We have analysed the influence of neighbouring base sequences on the mutagenesis induced by 7,8-dihydro-8-oxoguanine (8-oxoG or G(o)), a typical oxidative lesion of DNA, using the yeast oligonucleotide transformation technique. Two oligonucleotides, oligo-CCG(o) and oligo-CGG(o), each possessing a single 8-oxoG residue and represented by the sequences 5'-CCG(o)-3' and 5'-CGG(o)-3', respectively, were introduced into a chromosome of Saccharomyces cerevisiae and their mutagenic potentials were compared. In a wild-type strain, 8-oxoG showed very weak mutagenic potential in both cases.

Binding of MutS protein to oligonucleotides containing a methylated or an ethylated guanine residue, and correlation with mutation frequency.

The MutS-based mismatch repair (MMR) system has been conserved from prokaryotes to humans, and plays important roles in maintaining the high fidelity of genomic DNA. MutS protein recognizes several different types of modified base pairs, including methylated guanine-containing base pairs. Here, we looked at the relationship between recognition and the effects of methylating versus ethylating agents on mutagenesis, using a MutS-deficient strain of E.

Enhancement of phase II enzyme activity by purpurin resulting in the suppression of MeIQx-DNA-adduct formation in mice.

We previously demonstrated using a bacterial system that the antigenotoxic activity of the anthraquinone compounds purpurin and alizarin was due to the suppression of microsomal enzyme activity involved in the activation of mutagens. In the present study we determined the effect of purpurin and alizarin on (i) MeIQx-DNA-adduct formation in mouse tissues and (ii) the activity of phases I and II enzymes in liver fractions, the liver being the target tissue of MeIQx. The amount of MeIQx-DNA adduct formed was determined using 32P-postlabeling methods.

Involvement of the drug efflux protein TolC in mutagenicity induced by MNNG or Trp-P-2.

In the development of mutation assay systems, a number of approaches have been performed with a particular view to improve sensitivity. The inhibition of mutagen-efflux from tester bacteria might lead to increased mutagenic activity as the concentration of mutagen increases inside the cell. In this study, we constructed a series of Escherichia coli CC strains lacking the TolC protein to determine if mutation is actually enhanced by the inhibition of mutagen reflux.

Novel antimutagenic factors derived from the edible mushroom Agrocybe cylindracea.

Studies have shown that certain foods contain compounds with antigenotoxic activities. Here, we ask if dried powders and/or extracts from three edible mushrooms, Agrocybe cylindracea, Lentinula edodes and Pleurotus ostreatus, have a mitigating effect on genotoxicity. We used two in vivo assays: the Drosophila DNA repair test and the Drosophila wing spot test (also known as SMART) which measures somatic mutation and recombination.