Genotoxicity and cytotoxicity of antineoplastic drugs at environmentally relevant concentrations after long-term exposure

Introduction

5-fluorouracil (5-FU) and methotrexate (MTX) are the antineoplastic drugs most commonly used worldwide. Considered cytotoxic, these pharmaceuticals exhibit low specificity, causing damage not only to cancer cells but also to healthy cells in organisms. After being consumed and metabolized, these drugs are excreted through urine and feces, followed by wastewater treatment. However, conventional treatments do not have the capacity to completely remove these substances, risking their introduction into freshwater systems. This could pose a risk to human health even at low concentrations.

Aims

Thus, the present study aimed to investigate the genotoxicity, cytotoxicity, and mutagenicity of 5-FU and MTX at environmentally relevant concentrations after a long-term exposure, using adult male rats as an experimental model.

Methods

Male Wistar rats (70 days old) were distributed into 4 groups (n = 10/group): control, received only vehicle; MTX, received methotrexate at 10ngL-1; 5-FU received 5-fluorouracil at 10ngL-1; and MTX + 5-FU, received a combination of MTX and 5-FU at 10ngL-1 each. The period of exposure was from postnatal day (PND) 70 to PND 160, through drinking water. After that, the animals were euthanized and the samples (liver, testis, femoral bone marrow, and peripheral blood) were obtained.

Results

Increased DNA fragmentation was observed in the peripheral blood, liver, and testis, altering the parameters of the tail moment and tail intensity in the Comet assay. Besides, the change in the ratio between PCE and NCE indicates bone marrow suppression.

Conclusion

These findings warn the adverse effects for the general population worldwide chronically exposed to these drugs at trace concentration unintentionally.

Oral fish oil positively influences nutritional-inflammatory risk in patients with haematological malignancies during chemotherapy with an impact on long-term survival: a randomised clinical trial

BACKGROUND

Studies suggest that the ingestion of fish oil (FO), a source of the omega-3 polyunsaturated fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), can reduce the deleterious side-effects of chemotherapy. The aim of this randomised clinical trial was to evaluate the effect of supplementation with oral FO for 9 weeks on nutritional parameters and inflammatory nutritional risk in patients with haematological malignancies during the beginning of chemotherapy.

METHODS

Twenty-two patients with leukaemia or lymphoma were randomised to the unsupplemented group (UG) (n = 13) or supplemented group (SG) (n = 9). SG received 2 g/day of fish oil for 9 weeks. Nutritional status, serum acute-phase proteins and plasma fatty acids were evaluated before (T0) and after (T1) the intervention period. Data were analysed using two models; model 1, comprising data from all patients included in the study, and model 2, comprising data from UG patients with no increase in the proportions of EPA and DHA in plasma and data from SG patients showing an at least 100% increase in plasma EPA and DHA.

RESULTS

SG showed an increased plasma proportion of EPA and DHA in both models. In model 2, C-reactive protein (CRP) and CRP/albumin ratio showed larger reductions in the SG. Overall long-term survival in both models (465 days after the start of the chemotherapy) was higher in the group ingesting fish oil (P < 0.05).

CONCLUSIONS

These findings indicate an improved nutritional-inflammatory risk and potential effects on long-term survival in patients with haematological malignancies supplemented with FO during the beginning of chemotherapy.

Flow of essential elements in subcellular fractions during oxidative stress

Essential trace elements are commonly found in altered concentrations in the brains of patients with neurodegenerative diseases. Many studies in trace metal determination and quantification are conducted in tissue, cell culture or whole brain. In the present investigation, we determined by ICP-MS Fe, Cu, Zn, Ca, Se, Co, Cr, Mg, and Mn in organelles (mitochondria, nuclei) and whole motor neuron cell cultured in vitro. We performed experiments using two ways to access oxidative stress: cell treatments with H₂O₂ or Aβ-42 peptide in its oligomeric form. Both treatments caused accumulation of markers of oxidative stress, such as oxidized proteins and lipids, and alteration in DNA. Regarding trace elements, cells treated with H₂O₂ showed higher levels of Zn and lower levels of Ca in nuclei when compared to control cells with no oxidative treatments. On the other hand, cells treated with Aβ-42 peptide in its oligomeric form showed higher levels of Mg, Ca, Fe and Zn in nuclei when compared to control cells. These differences showed that metal flux in cell organelles during an intrinsic external oxidative condition (H₂O₂ treatment) are different from an intrinsic external neurodegenerative treatment.

In vivo genotoxicity of treated water containing the cylindrospermopsin-producer Cylindrospermopsis raciborskii

Cylindrospermopsin (CYN) is an alkaloid commonly produced by some cyanobacteria that has been implicated in outbreaks of human illness. The aim of this study was to investigate the genotoxicity of Cylindrospermopsis raciborskii cellular content (including CYN) and its byproducts resulting from chlorination during water treatment. DNA damage in blood and liver cells was analysed by the comet assay and micronucleus test (MN). Mice were injected intraperitoneally with the following treatments: (a) physiological saline, (b) treated water, (c) treated water plus C. raciborskii extract (CYN producer strain, CYPO-011 K), (d) C. raciborskii extract (CYN producer strain, CYPO-011 K), (e) C. raciborskii extract (CYN non producer strain), and (f) treated water plus C. raciborskii extract (CYN non producer strain) extract. After 48 h, samples were taken to perform tests (blood and liver cells to the comet assay and bone marrow to MN test). The CYPO-011 K had a genotoxic and mutagenic effects on liver and bone marrow cells. The group that received chlorine-treated water plus CYPO-011 K also exhibited genotoxic effects in the liver, as well as in the blood, and a mutagenic effect in blood marrow cells. The results emphasise the need of improving CYN monitoring in waters bodies in order to reduce the risk of human exposure.

Electromyographic analysis of masseter and temporal muscles, bite force, masticatory efficiency in medicated individuals with schizophrenia and mood disorders compared with healthy controls

This study aimed to comparatively analyse the electromyographic activity of the masseter and temporal muscles at rest and during mandible postural clinical conditions (right and left laterality, protrusion and maximum voluntary contraction), right and left maximum molar bite forces and the masticatory efficiency of individuals with schizophrenia or mood disorders - all medicated (medicated groups) compared with control group (healthy volunteers) via electromyography. Individuals were distributed into three groups: Group I (Schizophrenia - 20 individuals), Group II (mood disorders - 20 individuals) and Group III (Control - 40 individuals). Basically, the results were only statistically significant for the clinical mandible conditions and bite force. The most unsatisfactory results were observed in the medicated groups in relation to the control group. The group with mood disorders obtained the most unsatisfactory results compared with the group with schizophrenia. It was suggested by these observations that the association of mood disorders and schizophrenia with medication has negatively affected the stomatognathic system in relation to controls when the electromyography and bite force were used for the analysis.

Rosmarinic acid as a protective agent against genotoxicity of ethanol in mice

The aim of the present work was to study the protective effects of rosmarinic acid against ethanol-induced DNA damage in mice. The antigenotoxic capacity of rosmarinic acid (100 mg/kg) was tested using pre-, co- and post-treatment with ethanol (5 g/kg). Peripheral blood (1 and 24 h) and brain cells (24 h) were evaluated using the comet assay and bone marrow was analyzed using the micronucleus assay (24 h). The results were compared to data of TBARS, enzymes with antioxidant activity, and DCFH-DA test. Peripheral blood and brain cells show that mean damage index (DI) and damage frequency (DF) values of ethanol with pre-treatment with rosmarinic acid group were significantly lower than in the ethanol group. In brain cells all different treatments with ethanol and rosmarinic acid showed significant decrease in DI and DF mean values when compared to ethanol group and negative control. No significant differences were observed in micronucleus frequency, activity of antioxidant enzymes and TBARS between groups. The DCFH-DA test show a reduction of 18% of fluorescence intensity when compare with ethanol group. The results show that rosmarinic acid could decrease the levels of DNA damage induced by ethanol, for both tissues and treatment periods.

The effect of dietary supplementation with 9-cis:12-trans and 10-trans:12-cis conjugated linoleic acid (CLA) for nine months on serum cholesterol, lymphocyte proliferation and polymorphonuclear cells function in Beagle dogs

Conjugated linoleic acids (CLA), 9-cis:11-trans and 10-trans:12-cis, have been shown to be able to modify some immune cells parameters and plasma lipids in a variety of experiment models. Since lymphocytes and polymorphonuclear cells (PMNC) have a large spectrum functions in the immune response, the knowledge in this field has to be expanded. Beagle dogs were fed a control diet or a CLA supplemented diet for nine months. Blood was collected for biochemical analysis and lymphocyte and PMNC isolation. PMNC were assayed for lysosome content, phagocytic activity and superoxide anion production. A lymphocyte proliferation capacity assay was done. The CLA fed dogs had a 34% reduction in total cholesterol (P < 0.05), 28% in LDL (P < 0.05) and 28% non-HDL-cholesterol (P < 0.05). Neither of the PMNC parameters evaluated demonstrated significant alteration. Lymphocytes from CLA group increased by 45% their mitotic capacity (P < 0.05). Our study demonstrates that CLA can successfully modify the lipid profile of dogs (monogastrics) when fed at reasonable levels, but did not significantly alter inflammatory function as would generally predicted. Further, we had some indication that CLA modulated T cell responsiveness.

Patterns of anti-tuberculosis drug resistance among HIV-infected patients in Maputo, Mozambique, 2002-2003

SETTING

Two tuberculosis (TB) reference hospitals in Maputo, Mozambique.

OBJECTIVES

To assess the pattern of TB drug resistance and its risk factors in human immunodeficiency virus (HIV) patients.

DESIGN

Adult HIV-positive patients with TB diagnosed by culture of sputum or bronchial washing were enrolled during 2002-2003. Cultures of 111 patients were tested for rifampicin, isoniazid, streptomycin and ethambutol sensitivity. Chest X-ray, haemoglobin (Hb), total lymphocyte and CD4 counts were also performed.

RESULTS

Overall resistance to any drugs was found in 18% and multidrug-resistant TB (MDR-TB) in 9%. New cases of TB accounted for 62% of the studied group. Drug resistance in this subgroup was 13% compared with 26.3% in the previously treated subgroup, and MDR-TB was 5.8% vs. 15.8%. All patients presented Hb levels < 9 g/dl and total lymphocyte counts < 1200/microl. CD4 counts were significantly low in the drug resistance subgroup, with levels mostly < 100/microl. Cavities on X-ray were seen only in drug-sensitive patients. No risk factors for drug resistance were detected.

CONCLUSIONS

Overall observed drug resistance was 18%, and MDR-TB 9%. Previously treated patients had high drug resistance (26.3%) and MDR-TB (15.8%).