Detection of Cytogenetic Effects in Peripheral Lymphocytes of Students Exposed to Formaldehyde with Cytokinesis-Blocked Micronucleus Assay

Cytokinesis-blocked micronucleus assay was applied as a biological dosimeter to detect abnormalities in human peripheral lymphocytes of thirteen students exposed to formaldehyde (FA) during a 12-week (10 h per week) anatomy class. Breathing-zone air samples colleeted during dissection procedures showed a mean concentration of 2. 37 ppm (3. 17mg/m3 ). Ten students from the same school but without FA exposure served as controls. Chromosome aberrations (CA) and sister chromatid exchanges (SCE) were detected in both groups. The micronuclei (MN) rate (6. 38 ± 2. 50‰ ) and CA rate (5. 92 ±2. 40‰ ) in the FA-exposed group showed a significant increase (P< 0. 01 ) when compared with those of the controls (3. 15 ±1. 46‰and 3. 40 ± 1. 57 % respectively). A correlation between MN and CA in individuals was observed. SCE in the exmpd group were also increased (P< 0. 05), but not so greatly as MN or CA. The results indicated that FA might damage the chromosomes of human lymphocytes.

The Cytokinesis-Block Micronucleus Assay on Peripheral Blood Lymphocytes as a Prospective Biological Test-System to Estimate the Influence of Radon on the Human Organism: Recent Progress and Future Prospects

This paper discusses the problem of assessing the negative after-effects of low doses of ionising radiation exposure in humans. Radon and its decay daughter products are the most widespread source of such irradiation. Miners (in both uranium and non-uranium mines) as well as laypeople in domestic life may be exposed to radon, making the problem of assessing the cytogenetic effects of exposure extremely crucial. One of the more promising test systems to assess the effect of radon is the cytokinesis-block micronucleus assay (CBMN) on peripheral blood lymphocytes, which has a number of advantages over other cytogenetic techniques. Recent progress and future prospects of this cytogenetic method are discussed here.

Comet assay and cytokinesis-blocked micronucleus test for monitoring the genotoxic effects of X-ray radiation in humans

Obejctive To assess the genotoxic effects of X ray radiation on human populations Methods The single cell gel electrophoresis (SCGE) and cytokinesis blocked micronucleus (CBMN) test were applied as biological dosimeters to detect DNA damage and abnormalities in human peripheral lymphocytes of subpopulation exposed to X ray radiation The subjects were divided into four groups: 12 radiation patients; 13 intervention radiation therapy doctors; 32 radiation diagnostians; 28 controls Results The average comet lengths of the four groups were 128 17±4 49?μm, 88 09±5 39?μm, 72 68±2 57?μm and 32 87±0 57?μm, respectively The difference in average comet length between any two groups was highly significant ( P <0 01) The average micronucleated cell (MNC) rates (‰) of the four groups were 12 33±0 85, 9 75±1 02, 8 48±0 66 and 3 18±0 36, respectively The difference of MNC rates of Group 1 vs 3, 1 vs 4, 2 vs 4 and 3 vs 4 was highly significant ( P <0 01), and the difference of Group 1 vs 2 was significant ( P <0 05), but there was no difference of MNC rate in Group 2 vs 3 ( P >0 05) Conclusions This study showed that both the comet assay and the CBMN test could be used to monitor populations exposed to X ray radiation, but the comet assay seems to be more sensitive than the CBMN test

Genotoxicity of Synthetic Food Colorants

A study was conducted to evaluate the genotoxicity, if any, of the permitted synthetic food colorants used in India. Eight synthetic food colorants namely Erythrosine （E 127）, Tartrazine （E 102）, Ponceau 4R （E 124）, Sunset Yellow FCF （E 110）, Brilliant Blue FCF （E133）, Fast Green FCF （E143）, Carmoisine （E122） and Indigo Carmine （E132） and their combination are used in sweets namely Ladu, Jilebi and Halwa in Calicut and suburban areas of Kerala, in India. The genotoxicity of the colorants alone and in combinations at different concentrations were evaluated by Cytokinesis Block Micronucleus （CBMN） Assay. It was observed that all the above colorants and their combinations could cause genotoxicity to human lymphocytes even at the permissible concentration of 100 ppm as per PFA （Prevention of Food Adulteration） Act of India. The toxicity varied from dye to dye and was proportional to their concentration. Combination of colors showed more toxicity than the individual components. Toxicity could be reduced drastically by reducing the concentration of the dyes at least 50% below the permissible limit. Permitted synthetic food colorants even at the permissible limit should be used with caution. This study demonstrated the need for redefining the permissible limit of the food colorants based on Admissible Daily Intake （ADI） as being practiced in developed countries.

Phyllanthus emblica Linn.fruit extract potentiates the anticancer efficacy of mitomycin C and cisplatin and reduces their genotoxicity to normal cells in vitro

Objective： Fruit of Phyllanthus emblica Linn. （PE） is widely consumed as a functional food and used as a folk medicine due to its remarkable nutritional and pharmacological effects. Mitomycin C （MMC） and cisplatin （cDDP） are the most widely used forms of chemotherapeutic drug, but their clinical use is limited by their genotoxicity to normal cells. We aimed to determine whether PE has potential to reduce the genotoxicity, while improving the anticancer effect, of MMC and cDDP. Methods： Cell proliferation was evaluated using the trypan blue exclusion assay and colony-forming assay. Genomic instability （GIN） was measured using the cytokinesis-block micronucieus assay. Results： Co-treatment （72 h） with PE at 20-320 μg/ml significantly enhanced the efficacy of MMC （0.05 μg/ml） and cDDP （1 μg/ml） against Colo205 colorectal cancer cells （P〈0.05）, and at 80-320 μg/ml significantly decreased MMC- and cDDP-induced GIN and multinucleation in normal colonic NCM460 cells （P〈0.05）. PE significantly decreased the mitotic index （P〈0.01）, blocked mitotic progression （P〈0.05）, and promoted apoptosis （P〈0.01） in MMC- and cDDP-treated NCM460 cells, suggesting that PE-mediated inhibition of mitosis and induction of apoptosis may limit the division and survival of highly damaged cells. Also, PE was found to inhibit the clonal expansion of MMC- and cDDP-treated NCM460 cells （P〈0.05） and decrease the heterogeneity of the surviving clones. Conclusions： PE potentiates the anticancer efficacy of MMC and cDDP, while preventing their genotoxicity and inhibiting clonal expansions of unstable genomes in normal cells. These data suggest that PE has the potential to reduce the risk of secondary cancers induced by chemotherapeutics.