Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.23.17 (PCE)
 1,301 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The objective of the present study was to investigate the potential of nicotine to induce micronucleated polychromatic erythrocytes (MNPCE) in bone marrow of male and female mice. Cyclophosphamide at 40mg/kg was used as positive control clastogen. Single doses of 4, 8 or 16mg/kg nicotine were given via oral intubation and bone marrow was sampled at 18, 24, 30, 36 and 48h after treatment. Cyclophosphamide yielded the expected positive results. Despite the evident signs of acute toxicity shown by the animals, mainly at the 8 and 16mg/kg doses of nicotine, and the reduction in the % PCE, the results show that the MNPCE frequency in male and female mice was not affected by treatment with any of the selected doses of nicotine, in either of the sampling times 18 or 24h. However, at 30 and 36h after treatment, the MNPCE showed significant increases in both genders after doses of 8 and 16mg/kg. A sex-dependent response was recorded, with males having more MNPCE than females after treatment with 8 or 16mg/kg nicotine and sampling at 30h. However, at 36h more MNPCE were induced in females than in males, suggesting different degrees of dose interaction in the sexes under the conditions of the assay. The response was directly correlated with bone-marrow toxicity, as greater bone-marrow suppression was noted in females than in males when 36h samples were examined. By 48h recovery was observed even though the cytotoxicity was high. These findings suggest that nicotine at high doses and after prolonged time intervals is genotoxic and cytotoxic for mouse bone marrow.
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PMID:The genotoxic and cytotoxic effects of nicotine in the mouse bone marrow. 1754 74

Malaria has been reported to modulate the activity of cytochrome-P450 enzymes (CYP). Since CYPs are involved both in the activation and detoxication of xenobiotics, we investigated whether malaria would modify the effects of chemical carcinogens in the bone-marrow micronucleus assay. Female C57BL6 mice were infected with Plasmodium berghei (ANKA) and treated (ip route) with cyclophosphamide (CPA, 25 mg/kg body weight), 7,12-dimethylbenz[a]anthracene (DMBA, 50mg/kg body weight) or ethyl methanesulfonate (EMS, 150 mg/kg body weight), on post-infection days 9-12 when parasitemia was > or =9% of RBC. Controls were age-paired non-infected mice. Bone marrows were sampled at 24 and 48 h (CPA), 24 h (EMS) or 48 h (DMBA) after treatment. The background incidence of polychromatic erythrocytes with micronuclei (MN-PCE) in malaria-infected mice was approximately twofold the background incidence in non-infected controls. Effects of indirect clastogens (CPA and DMBA) in the micronucleus assay were attenuated while the effect of EMS, a direct clastogen, was enhanced by infection. In a separate experiment, malaria was shown to decrease activities of ethoxy-(EROD, a marker for CYP1A) and benzyloxy-(BROD, CYP2B) resorufin-O-dealkylases in liver microsomes. The foregoing findings are consistent with the hypothesis that malaria-caused attenuation of genotoxicity arose from a down modulation of CYP isoforms that convert CPA (CYP2B) and DMBA (CYP1A) into their active metabolites.
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PMID:Malaria infection modulates effects of genotoxic chemicals in the mouse bone-marrow micronucleus test. 1785 Nov 16

Gmelina arborea Roxb (family Verbenaceae) commonly known as 'Gambhari' tree, the various parts of the plants are widely used in diarrhoea, anti-pyretic, thirst, anemia, leprosy, ulcers, consumption, strangury, vaginal discharges. We tested the genotoxic potential of G. arborea in bone marrow cells obtained from Swiss albino mice using micronuclei formation as the toxicological endpoints. Aqueous extract of G. arborea (AEGA) was tested at the dose of 286 & 667 mg/kg body weight (b. w.). Cyclophosphamide (CPZ) 25 mg/kg b. w. was used as positive control in micronucleus test. The AEGA significantly increased the % micronucleated polychrometics at doses of 286mg/kg and 667mg/kg, after 24, 48 72h time interval. And also decreased the PCE/NCE ratio after 24, 48 and 72 h as compared to solvent control group. In this study, we investigated the effect of G. arborea on mammalian bone marrow cells using micronuclei formation to assess the genotoxicity of the herb.
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PMID:In vivo rodent micronucleus assay of gmelina arborea roxb (gambhari) extract. 2224 28