ABSTRACT
Abstract The purpose of the current work was to assess a possible role of cytochrome P450 1A2 (CYP1A2) and N-acetyltransferase 2 (NAT2) in the metabolic activation of 2,6-dimethylaniline (2,6-DMA) and also clarify the function of DNA repair in affecting the ultimate mutagenic potency. Two cell lines, nucleotide excision repair (NER)-deficient 5P3NAT2 and proficient 5P3NAT2R9 both expressing CYP1A2 and NAT2, were treated with 2,6-DMA for 48 h or its metabolites for 1 h. Cell survival determined by trypan blue exclusion and MTT assays, and 8-azaadenine-resistant mutants at the adenine phosphoribosyltransferase (aprt) gene locus were evaluated. 5P3NAT2 and 5P3NAT2R9 cells treated with 2,6-DMA and its metabolites showed a dose-dependent increase in cytotoxicity and mutant fraction; N-OH-2,6-DMA and 2,6-DMAP in serum-free α-minimal essential medium (MEM) are more potent than 2,6-DMA in complete MEM. 5P3NAT2 cells was more sensitive to the cytotoxic and mutagenic action than 5P3NAT2R9 cells. H2DCFH-DA assay showed dose-dependent ROS production under 2,6- DMAP treatment. These findings indicate that the genotoxic effects of 2,6-DMA are mediated by CYP1A2 activation via N-hydroxylation and the subsequent esterification by the phase II conjugation enzyme NAT2, and through the generation of ROS by hydroxylamine and/or aminophenol metabolites. NER status is also an important contributor
Subject(s)
Cells/classification , Cytochrome P-450 CYP1A2/analysis , Genotoxicity , Cell Line/classification , Hydroxylamine/agonists , DNA RepairABSTRACT
Mistletoes are evergreen and semi parasitic plant growing on a variety of trees and shrubs. They have been used in the treatment and management of many diseases for many years, both traditional and complementary medicine such as diarrhea, cough, diabetes, hypertension and cancer. The purpose of this study was to determine the antimicrobial activity of Korean camellia mistletoe (Korthalsella japonica (Thunb.) Engl.) depending on the harvest time (August and November 2015) and solvent (100% methanol and 70% ethanol). Antimicrobial activity of methanol and ethanol extracts was subject to screening against two gram positive (S. epidermidis and B. subtilis subsps.) and negative bacillus (K. pneumonia and E. coli) by using disc diffusion method and measured by the size of clear zone (diameter, mm). The results showed that methanol extract was slight effective in 15 mg/disc concentration on all strains regardless of harvest time, while ethanol extract has no certain antimicrobial effect on both gram positive and negative bacillus. The results obtained in this study suggested that the extracts have low potential for use in the treatment of diseases caused by these test organisms and futher studies are necessary to evaluate the anti-bacterial efficiency of Korean camellia mistletoe against different bacterial strains.