Chromosome Abnormalities and Absolute Telomere Lengths of Leukocytes from Silk Weavers with Emphasis on Potential Genotoxicity and Mutagenicity of Silk Dyes

Document Type: Research Articles

Authors

1 Graduate School, Khon Kaen University, Khon Kaen Province, Thailand.

2 Department of Epidemiology, Faculty of Public Health, Khon Kaen University, Khon Kaen, Thailand.

3 Department of Parasitology and Entomology, Faculty of Public Health, Mahidol University, Bangkok, Thailand.

4 Department of Anatomy, Faculty of Veterinary Medicine, Khon Kaen University, Khon Kaen, Thailand.

5 Department of Clinical Microscopy, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen Province, Thailand.

Abstract

Objectives: This study is aimed to assess the possible genotoxicity and mutagenicity of silk dyes on silk weavers.
Methods: Peripheral blood leukocytes were obtained from 24 silk weavers and 24 age- and sex-matched controls in
northeastern Thailand. After mitogen stimulation in culture, chromosome abnormalities were examined using Giemsa
banding and the absolute telomere length (aTL) was measured with SYBR green qRT-PCR. To confirm genotoxic and
mutagenic effects of silk dyes, leukocytes from one each of healthy male and female volunteers were cultured with
various concentrations of 3 dark red silk dyes under the presence of mitogen. Chromosome abnormalities and the
telomere length were determined as above. Results: The proportion of normal metaphase in the silk weaving workers
was significantly lower than that in controls. The frequency of chromosome aberrations was higher in the silk weavers
than in control group. Polyploidy was detected only in the silk weavers. The aTL was significantly shorter in the silk
weavers than in control group (p < 0.05). When leukocytes from normal volunteers were stimulated with mitogen under
the presence of various concentrations of 3 silk dyes, suppressed the mitotic index (MI) and normal metaphase, whereas
the proportion of prophase and the incomplete chromosome forming increased significantly. All dyes induced polyploidy.
Dye #CA5 induced structural changes in male leukocytes, whereas #30 induced the changes in female leukocytes.
The #CA5 increased aTL of normal leukocytes in a dose-dependent manner. Conclusions: All dyes, especially #CA5,
have high genotoxicity and mutagenicity to induce chromosome aberrations and telomeric instability. Taken all those
results together, regular health checking of silk weavers who have been exposed to those dyes is critically necessary
to prevent various chemical-induced carcinogenesis.

Keywords

Main Subjects