ABSTRACT
The isoflavone irilone is found in human plasma after ingestion of red clover-based dietary supplements, but information allowing safety assessment is rare. Here, data in support of the mutagenic potential of irilone in cultured V79 cells [1] are presented. These data include (i) a quantitative assessment of irilone in the culture medium during the cell culture experiments, (ii) changes in the mutation spectrum in cDNA of the hypoxanthine-guanine phosphoribosyltransferase locus of irilone-treated V79 cells, (iii) occurrence of karyorrhexis and apoptosis as well as (iv) number of micronucleated cells containing whole chromosomes or chromosomal fragments. Also exemplary micrographs, used for the fluorescence microscopic assessment of (iii) and (iv) are presented.
ABSTRACT
After consumption of red clover-based dietary supplements, plasma concentrations of the isoflavone irilone (IRI) equal that of the well-investigated daidzein. Since some isoflavones are genotoxic, the potential of IRI to induce mutations was investigated. Gene mutations were determined by hypoxanthine-guanine phosphoribosyltransferase (HPRT) assay and sequencing of mutant cDNA, chromosome and genome mutations by micronucleus assay complemented by immunochemical staining of centromere proteins and microtubules in cultured V79 cells. Cell proliferation was monitored by electronic cell counting, flow cytometry and fluorescence microscopy. IRI did not affect the mutant frequency in the Hprt locus but altered the mutation spectrum by increasing the proportion of deletions and decreasing that of base pair substitutions. Induction of chromosome mutations was supported by a slight but significant increase in the number of micronucleated cells containing chromosomal fragments despite activation of three cell cycle checkpoints possibly interfering with micronuclei formation. Moreover, IRI exhibited a strong aneugenic potential characterized by disrupted mitotic spindles, mitotic arrest, and asymmetrical cell divisions leading to chromosome loss, nuclear fragmentation as well as mitotic catastrophe. Thus, IRI might be another isoflavone to be taken into account in safety assessment of dietary supplements.
Subject(s)
Dietary Supplements/toxicity , Fibroblasts/drug effects , Hypoxanthine Phosphoribosyltransferase/genetics , Isoflavones/toxicity , Mutagenicity Tests , Mutagens/toxicity , Mutation , Animals , Cell Cycle Checkpoints/drug effects , Cell Line , Cell Proliferation/drug effects , Centromere/drug effects , Centromere/metabolism , Cricetulus , DNA Mutational Analysis , Dose-Response Relationship, Drug , Fibroblasts/enzymology , Fibroblasts/pathology , Micronuclei, Chromosome-Defective/chemically induced , Micronucleus Tests , Microtubules/drug effects , Microtubules/metabolism , Mutagenicity Tests/methods , Risk Assessment , Time FactorsABSTRACT
Screening of various bisquaternary bisnaphthalimides against a variety of human pathogens revealed one compound, designated MT02, with strong inhibitory effects against Gram-positive bacteria. The MICs ranged from 0.31 µg/ml against community-acquired methicillin-resistant Staphylococcus aureus (MRSA) lineage USA300 to 20 µg/ml against Streptococcus pneumoniae. Radioactive whole-cell labeling experiments indicated a strong impact of MT02 on bacterial DNA replication. DNA microarray studies generated a transcriptional signature characterized by stronger expression of genes involved in DNA metabolism, DNA replication, SOS response, and transport of positively charged compounds. Furthermore, surface plasmon resonance and gel retardation experiments demonstrated direct binding of MT02 to DNA in a concentration-dependent, reversible, and non-sequence-specific manner. The data presented suggest that the bisquaternary bisnaphthalimide MT02 exerts anti-Gram-positive activity by binding to DNA and thereby preventing appropriate DNA replication.
Subject(s)
Anti-Bacterial Agents/pharmacology , Bacterial Proteins/drug effects , Intercalating Agents/pharmacology , Anti-Bacterial Agents/chemistry , Bacterial Proteins/genetics , Cell Line , Cell Line, Tumor , Cell Proliferation/drug effects , Humans , Intercalating Agents/chemistry , Microbial Sensitivity Tests , Molecular Structure , Oligonucleotide Array Sequence Analysis , Staphylococcus aureus/geneticsABSTRACT
BACKGROUND: Traditionally, the purpose of routine postoperative surveillance has been to detect postoperative complications. The literature reports well-documented, procedure-specific postoperative complication rates. However, there are no reports detailing the prevalence of postoperative complications in general surgical ward settings, where nurses care for patients following a variety of surgical procedures. AIMS: This paper reports an audit of the frequency and type of postoperative complications in a general surgical population occurring in the first 24 hours postoperatively. METHOD: A patient record audit was undertaken for all postoperative patients who returned to two general surgical wards. This was conducted sequentially, involving a 4 week data collection phase in each participating ward during 2001. RESULTS: The audit sample comprised 144 patient records with an average patient age of 54 years. Statistically significant results included the rate of postoperative nausea and vomiting of 37.5% (n = 54), and 17% (n = 25) of patients experiencing another 'clinical event'. LIMITATIONS: The findings reflect only those complications recorded/documented in postoperative patients' records, and cannot be generalized beyond the sample and setting. CONCLUSIONS: Postoperative patients cared for on general surgical wards experienced a high level of nausea and vomiting, while the occurrence of life-threatening complications was small.
