Maha A. Fahmy

In vivo and in vitro studies on the genotoxicity of cadmium chloride in mice.

The genotoxic effect of cadmium chloride was evaluated in chromosomes of experimental mice using in vivo and in vitro studies. In vivo the induction of micronuclei, sister chromatid exchange in mouse bone marrow and chromosomal aberrations in both somatic and germ cells was investigated. Doses 1.9, 5.7 and 7.6 mg kg−1 body wt. (single i.p. treatment) induced a significant and dose‐dependent increase in the percentage of polychromatic erythrocytes with micronuclei. Such a percentage reached 2.1% with the highest tested dose, compared with 0.57% for the control (non‐treated) and 2.2% for mitomycin c as the positive control. The dose of 1.9 mg kg−1 body wt. had no significant effect with respect to sister chromatid exchange (SCE) but the doses of 5.7 and 7.6 mg kg−1body wt. increased the frequency of SCEs significantly. The frequency of SCE reached 7.35 ± 0.26 per cell after treatment with the highest tested dose, which is a less than twofold increase compared with the control frequency of 4.6 ± 0.42 per cell. However mitomycin c induced a much higher effect (12.1 ± 0.73). Cadmium chloride also induced a significant increase in the percentage of chromosomal aberrations in mouse bone marrow at the doses of 5.7 and 9.5 mg kg−1 body wt. (single i.p. treatment). The effect is a function of cadmium chloride concentration. Moreover, cadmium chloride induced its maximum effect concerning the induction of chromosomal aberrations in mouse bone marrow cells 24 h after treatment, compared with 12 and 48 h.

Cytogenetic studies on the effect of feeding mice with stored wheat grains treated with malathion.

The cytogenetic effect of malathion residues in wheat grains stored for different periods of time (4, 12, 24 weeks) was evaluated in Swiss mice. The studies included: (1) chromosomal aberrations analysis in bone-marrow and spermatocyte cells; (2) chromosomal aberrations and sister chromatid exchange (SCE) analysis in spleen cell culture from mice fed with stored wheat grains. The tested doses were 8.36 (applied dose), 25.08 and 41.80 mg malathion kg(-1) wheat grains. The results demonstrated that the cytogenetic effect induced in different mouse tissues by malathion residues was dose-dependent and increased with increasing of both feeding and storage periods. Feeding mice with wheat grains stored for 4 weeks had a non-significant effect with respect to the induction of chromosomal aberrations or SCEs. Significant chromosome damage and increase of SCEs were observed in mice fed with wheat grains stored for 12 weeks. The maximum effect was recorded in mice fed for 12 weeks with the grains treated with the highest tested dose and stored for 24 weeks. However, mitomycin C i.p.-injected in mice at 1 mg kg(-1) body weight (b.w.) (positive control) induced a higher effect. The percentage of chromosome aberrations reached 13.60+/-0.98, 13.60+/-0.77 and 11.73+/-0.98 (P<0.01) in bone-marrow, cultured spleen cells and spermatocytes, respectively. The significant increase of abnormalities in spermatocytes was seen for univalent formation only, predominantly of the sex chromosomes. The frequency of SCEs was 10.76+/-0.62 per cell (P<0.01) in cultured spleen cells compared with 5.46+/-0.45 per cell for control and 14.66+/-0.54 per cell for the positive control. The obtained results indicate that malathion residues in stored wheat grains have potential genotoxic effect in mice under the conditions tested.

Studies on the genotoxic effect of beryllium chloride and the possible protective role of selenium/vitamins A, C and E

The genotoxic potential of beryllium chloride (BeCl2) was evaluated in vivo in mice using different endpoints. Chromosomal aberrations in bone marrow cells and in spermatocytes as well as sperm abnormalities were determined in the tested mice. The protective role of an orally administered drug consisting of selenium and vitamins A, C and E (selenium-ACE) was also studied. For analysis of chromosomal aberrations, both single and repeated oral treatments for a period of 3 weeks were performed. The doses used were 93.75, 187.50, 375, and 750 mg BeCl2/kg bw, which corresponds to 1/16, 1/8, 1/4, and 1/2 of the experimental LD50. BeCl2 induced a statistically significant increase in the percentage of chromosomal aberrations in both somatic and germ cells, with a dose- and time-response. The percentage of induced chromosomal aberrations was significantly reduced in all BeCl2-treated groups after oral administration of selenium-ACE. Beryllium chloride also induced a significant increase in the percentage of abnormal sperm. This percentage reached values of 9.62 +/- 0.32 and 5.56 +/- 0.31 in mice treated with the highest test dose of BeCl2 and with BeCl2+selenium-ACE, respectively, compared with 1.96 +/- 0.14 for the control. In conclusion, the results demonstrate the genotoxic effect of beryllium chloride and confirm the protective role of selenium-ACE against the genotoxicity of beryllium chloride.

Cytogenetic Effect of Some Insecticides in Mouse Spleen

Several insecticides were tested for their ability to induce chromosomal aberrations in mouse spleen. They were injected i.p. in doses representing approximately 1/8–1/10 of the respective ld50 values. Doses were: DDT, 5.5 mg kg−1 body wt.; malathion, 30 mg kg−1 body wt.; Dursban, 4 mg kg−1 body wt.; Sevin, 7 mg kg−1 body wt.; and Lannate, 1 mg kg−1 body wt. ‘Mitomycin C’ at a dose of 1 mg kg−1 body wt. was used as a positive control. Mice were sacrificed 6, 24 and 48 h after treatment. DDT, malathion, dursban and lannate caused maximum chromosomal aberrations 24 h after injection, whereas Sevin induced its maximum effect 6 h after the treatment. All the insecticides induced statistically significant chromosomal aberrations even after excluding the number of metaphases with gaps. The results indicate genotoxicity in mouse spleen cells.

Genotoxicity evaluation of buprofezin, petroleum oil and profenofos in somatic and germ cells of male mice.

The two pest control agents, buprofezin and petroleum oil (Super Royal), were tested to evaluate their potential mutagenicity, in comparison with the organophosphorus insecticide profenofos. Chromosomal aberration analysis was used in both somatic and germ cells of male mice. Single oral treatment at three different dose levels (1/16, 1/8 and 1/4 LD 50) for each insecticide induced an increase in the percentage of chromosomal aberrations in bone‐marrow cells 24 h post‐treatment, indicating a dose‐dependent relationship. The percentage of chromosomal aberrations reached 23 ± 0.73, 10.5 ± 0.64 and 15 ± 1.4 after treatment with the highest tested dose of profenofos, buprofezin and Super Royal, respectively. Such percentages did not exceed the corresponding value of the positive control, mitomycin C (29.2 ± 0.69).

The modifying effect of selenium and vitamins A, C, and E on the genotoxicity induced by sunset yellow in male mice.

The use of food additives in various products is growing up. It has attracted the attention towards the possible correlation between the mutagenic potential of food additives and various human diseases. This work evaluated the protective role of selenium and vitamins A, C and E (selenium ACE)(1) against the genotoxic effects induced by a synthetic food additive, sunset yellow, in mice. Six groups were studied including two control groups (negative and positive control), two groups are given single dose of sunset yellow (either 0.325, 0.65 or 1.3mg/kg body weight(2) alone or with selenium ACE) and two groups are given sunset yellow daily for 1, 2 or 3 weeks (0.325mg/kg b.wt./day alone or with selenium ACE), respectively. The study examined the induction of sister chromatid exchanges (SCEs)(3) in bone-marrow cells, chromosomal aberration in somatic (bone-marrow) and germ cells (spermatocytes) after single and repeated oral treatment, and the induction of morphological sperm abnormalities. The results showed that sunset yellow had genotoxic effects as indicated by increased frequency of SCEs, by chromosomal aberrations in both somatic and germ cells, and by increased morphological sperm abnormalities and DNA fragmentation. The results also indicated that the oral administration of selenium ACE significantly reduced the genotoxic effects of sunset yellow, a result that may support the use of antioxidants as chemopreventive agents in many applications.

The protective role of thiola and soybean seeds against the genotoxicity induced by potassium dichromate in mice

The genotoxic potential of potassium dichromate (K(2)Cr(2)O(7)) was evaluated in vivo in mice using different mutagenic end points. Chromosomal aberrations in bone-marrow and spermatocytes as well as sperm abnormalities in the tested mice were determined. The doses used were 3, 6, 12 mg K(2)Cr(2)O(7)kg(-1) body weight which correspond to 1/16, 1/8, 1/4 the experimental LD(50), respectively. The protective roles of i.p. injection with thiola (a synthetic sulfhydryl compound) at 20 mg kg(-1) body weight and feeding treatment with soybean seeds (30% of the diet) were also studied. For chromosomal aberration analysis, subacute treatment for a period of 3 weeks were performed. All the tested doses of K(2)Cr(2)O(7) induced a statistically significant increase in the percentage of chromosomal aberrations in both somatic and germ cells with dose and time relationships. The percentage of the induced chromosomal aberrations was significantly minimized in all groups of mice i.p. treated with thiola or fed soybean seeds during the period of treatment. Potassium dichromate also induced a significant increase (P<0.01) in the percentage of abnormal sperms at the doses 6 and 12 mg kg(-1) body weight. Such percentage reached 7.52+/-0.45, 5.50+/-0.53 and 4.28+/-0.45 in mice treated with the highest tested dose of K(2)Cr(2)O(7), K(2)Cr(2)O(7) and thiola; K(2)Cr(2)O(7) and soybean, respectively compared with 2.14+/-0.33 for the control. In conclusion, the results demonstrate the genotoxic effect of potassium dichromate in mice. The results also confirm the protective role of thiola and soybean seeds against the genotoxicity of potassium dichromate.

A mixture of honey bee products ameliorates the genotoxic side effects of cyclophosphamide

Abstract Objective To evaluate the protective role of a mixture of honey bee products (honey, royal jelly and pollen grains) against the genotoxicity induced by the anticancer drug cyclophosphamide (CP). Methods The study included chromosomal aberration analysis in mice bone marrow cells, induction of morphological sperm abnormalities, DNA fragmentation and histopathological changes induced in liver cells of mice. CP was injected intraperitoneally at the dose of 20 mg/kg body weight. The mixture of honey bee products was administrated orally for different periods of time 5, 10 and 15 days with a dose exactly equivalent to the daily intake of human beings. Results The results revealed that honey mixture ameliorated the genotoxic side effects of CP. For chromosomal aberrations the percentage reached 25.20 ± 1.30 for CP treated group, while it reached half of that value 12.30 ± 0.54 in CP-group pretreated with honey mixture for 15 days. Breaks, fragments and multiple aberrations were the most pronounced types of aberrations induced after CP treatment and honey mixture reduced these types of abnormalities. CP induced significant percentage of sperm abnormalities 8.52 ± 0.17 compared to control 3.10 ± 0.10. The percentage of sperm abnormalities reached nearly to the control value in CP- mice treated with honey mixture for 15 days. Honey also reduced the incidence of liver DNA damage induced by CP. The results also indicated that CP had a marked damaging effect on liver tissue including severe dilatation, congestion of main blood vessels and massive infiltration of inflammatory cells with irregular general pattern of the tissue. These effects were greatly ameliorated by using oral administration of honey mixture for different periods of time. Conclusions The results concluded that honey bee mixture can be used as chemopreventive agent for minimizing the genotoxic side effects of the anticancer drug CP and open the field for its use in many applications.

Cytogenetic effect of griseofulvin in mouse spermatocytes

The genotoxic effects of griseofulvin (GF) in mouse primary spermatocytes at diakinesis metaphase I of meiosis were investigated. Griseofulvin was administered orally as a single dose of 500, 1000, 1500 and 2000 mg kg−1 body wt. and a multiple treatment with a daily dose of 1000 mg kg−1 body wt. for three and five successive doses. Both single and multiple treatment induced a statistically significant increase in the percentage of chromosomal aberrations which have a dose and time‐dependent relationship. The frequency of chromosomal aberrations peaked 6 and 12 h post treatment; with the highest dose of the drug it reached 27.8% ± 0.87 and 27.66% ± 0.48 6 and 12 h respectively, compared with 5.6% ± 0.39 and 5.2% ± 0.48 for the control.

Molecular and cytogenetic evaluation for potential genotoxicity of hydrocortisone

Abstract Objective To assess the risk of hydrocortisone sodium succinate through different end points of genotoxicity. Methods The study examined the induction of chromosomal aberrations in bone marrow cells, morphological sperm abnormalities, the effect on dominant lethal gene and protein synthesis. Hydrocortisone was given intraperitoneally at three dose levels 26, 39 and 52 mg/kg body weight which was equivalent to the therapeutic doses in man. Results The results showed that single dose treatment with different doses had no effect on chromosomal aberrations. The dose of 52 mg/kg body weight induced significant percentage of chromosomal aberrations in bone marrow cells after repeated treatment for 7 and 14 days. Significant effect of morphological sperm abnormalities was demonstrated only after treatment with the dose of 52 mg/kg body weight. For examining the dominant lethal mutation, male mice were injected with dose of 39 mg/kg body weight for 5 consecutive days. Mating between treated males and virgin untreated females were performed at different time intervals. The results showed that the percentage of fertile mating at 1–7 and 8–14 days reduced to 50% and 60% respectively compared with control group while no effect was recorded at 15–21 days. The percentage of dominant lethal mutation reached 0.32%, 4.4% and 0% in mating intervals respectively indicating pronounced effect of hydrocortisone at the interval 8–14 days which represented by the late spermatids. The results also showed that the repeated treatment with the dose of 52 mg/kg body weight inhibited protein synthesis which contributed to the cytotoxic effect of the drug. Conclusions It is concluded that long term treatment with large doses of hydrocortisone may have genotoxic effect.