Genotoxicity studies on the removal of a direct textile dye by a fungal strain, in vivo, using micronucleus and RAPD-PCR techniques on male rats

The genotoxicity of the azo dye 'Direct Violet' and the removal of this dye by Aspergillus niger strain at different conditions have been investigated in male rats. Two genotoxicity techniques, namely bone marrow micronucleus assay and RAPD fingerprinting pattern, were used in this study for the direct dye and its removal by the fungal strain. Sixty male rats were divided into six treatment groups including a control group and other groups which were exposed for 2 or 8 weeks to Direct Violet dye, Direct Violet dye treated with A. niger at pH 2 or pH 9 or without agitation and acrylamide (30 mg/kg b.w.). A potent dose-dependent response was observed following oral gavage of the dye up to 1000 mg kg(-1), after which significant toxicity to the erythroid compartment was observed. Acrylamide and Direct Violet treatments increased the number of micronucleated polychromatic erythrocytes (MnPCEs) with respect to the controls. This increase was statistically significant in the two time intervals (2 and 8 weeks treatment, P < 0.0001). Fungi treatments at pH 2 and without agitation were able to reduce the number of MnPCEs induced by Direct Violet administration in all duration groups. Fungi treatment at pH 9 was only able to inhibit the genotoxicity of Direct Violet after 8 weeks treatment. The RAPD fingerprinting pattern indicated that most DNA of the samples treated with dye alone or acrylamide revealed polymorphic bands including the appearance and disappearance of the bands, which did not appear in the DNA samples of normal or fungi protected rats. The implications of these findings for the health and safety of occupationally exposed workers are discussed.     

Long-term exposure of male rats to low-dose ethinylestradiol (EE2) in drinking water: effects on ponderal growth and on litter size of their progeny

Male rats were exposed to 17-ethinylestradiol (EE2) in their drinking water either at concentrations of 1–1000 ng/mL (1 ppb to 1 ppm) for 3 weeks immediately after weaning from post-natal day 22 (PND 22) to PND 43 or at a concentration of 10 ng/mL from PND 5 onwards. Although given temporarily between PND 22 and PND 43, the 0.1 and 1 ppm doses of EE2 were found to significantly affect the ponderal growth of the animals. No male was found to be sterile neither in both exposed groups nor in control groups. Nevertheless, the males exposed to 10 ng/mL EE2 in drinking water from PND 5 onwards conceived a significantly higher proportion (25%) of small litters (one to five pups) than control males (0–3%). When exposed to 1 μg/mL EE2 but only from PND 22 to PND 43, the males produced an intermediate proportion (15%) of small litters in their progeny but this might be consecutive to the observed retardation in weight gain.     

Developmental toxicity and psychotoxicity of FD and C red dye no. 40 (Allura red AC) in rats

Adult Sprague-Dawley rats were fed diets containing FD and C red dye No. 40 for 2 weeks and were then bred. The diets were continued for the females throughout gestation and lactation and were provided continuously to their offspring thereafter. The treatment groups were: FD and C red dye No. 40 as 0.0, 2.5, 5.0 or 10.0% of the diet, and a positive control group treated with the toxin hydroxyurea on days 2–10 of life with 50 mg/kg/day given s.c. as a positive control group. Parental animals were evaluated for weight and food consumption, and females for reproductive success. The offspring were assessed on a series of tests using the Cincinnati Psychoteratogenicity Screening Test Battery. Additional measures were weight, food consumption, physical landmarks of development, and brain weight. Red-40 significantly reduced reproductive success, parental and offspring weight, brain weight, survival, and female vaginal patency development. Behaviorally, R40 produced substantially decreased running wheel activity, and slightly increased postweaning open-field rearing activity. Overall, R40 produced evidence of both physical and behavioral toxicity in developing rats at doses of up to 10% of the diet.     

Adverse effects of butyl benzyl phthalate on the reproductive and hematopoietic systems of male rats

A 14-day dietary study was conducted in adult, male, Fischer 344 rats at levels of 0.0, 0.625, 1.25, 2.5 and 5.0% butyl benzyl phthalate (BBP) to evaluate potential effects of this plasticizer on the male reproductive and hematopoietic systems. Total body, thymus, testis, epididymis, prostate and seminal vesicle weights were reduced in the 2.5% and 5% BBP dose groups, while pituitary weight was unaffected. Histological evaluations revealed dose-dependent atrophy of the testis, prostate and seminal vesicles at 2.5% and 5%, atrophy of the thymus and epididymis at 5%, and the presence of immature sperm cells in the tubular lumens and necrosis of the tubular epithelium in the epididymis at 2.5% and 5% BBP. Plasma testosterone concentration was decreased at 5%, while follicle stimulating hormone (FSH) and luteinizing hormone (LH) concentrations were increased at 2.5% and 5.0% BBP. The circulating components of blood, and clotting times (prothrombin time, activated partial thromboplastin time), were unaffected although bone marrow cellularity was reduced at 2.5% and 5%. Changes in non-reproductive organs included enlargement of liver and kidneys, thymic atrophy and associated morphological abnormalities in these organs. These data indicate a direct toxic effect of BBP on the testis with secondary effects on other reproductive organs. Pituitary and hypothalamic responses did not appear to be affected. The reduced bone marrow cellularities suggest that prolonged exposures to BBP could affect circulating blood components or compromise clotting ability.