Modulating effect of simvastatin on the DNA damage induced by doxorubicin in somatic cells of Drosophila melanogaster

Influence of Body Mass Index and Duration of Disease on Chromosome Damage in Lymphocytes of Patients with Diabetes

It is well-established that patients with diabetes mellitus (DM) have a higher incidence of several types of cancer. The precise mechanisms of this association are still unknown, but obesity and chronic inflammation-induced reactive oxygen species (ROS) are thought to be the main risk factors. ROS may produce different DNA damage, which could eventually lead to cancer. The main objective of this study was to evaluate the relation of chromosome aberrations (CA) with disease status, demographics, and clinical parameters in 33 subjects with type 1 DM (T1DM), 22 subjects with type 2 DM (T2DM), and 21 controls. CAs were analyzed in cultured peripheral blood lymphocytes and subdivided into chromatid (CTA)- and chromosome (CSA)-type aberrations. Compared with controls, higher levels of CTAs and CSAs were observed in T1DM (p = 0.0053 and p = 0.0203, respectively) and T2DM (p = 0.0133 and p = 0.00002, respectively). While there was no difference in CTAs between T1DM and T2DM, CSAs were higher in T2DM (p = 0.0173). A significant positive association between CTAs and disease duration (rs = 0.2938, p = 0.0099) and between CSAs and disease duration (rs = 0.4306, p = 0.0001), age (rs = 0.3932, p = 0.0004), and body mass index (BMI) (rs = 0.3502, p = 0.0019) was revealed. After multiple regression analysis, duration of disease remained significant for CTA, CSA, and CAs (p = 0.0042, p = 0.00003, and p = 0.00002, respectively). For CSA, BMI and the use of statins were the other important confounding variables (p = 0.0105 and p = 0.0763). Thus, this study demonstrated that both T1DM and T2DM patients had a higher number of all types of aberrations than controls, which increases with the prolonged disease duration. Higher BMI was associated with a higher frequency of CSA. The use of statins might be beneficial for reducing chromosome damage, but further investigations are needed to confirm this association.

Arrabidaea chica chloroform extract modulates estrogen and androgen receptors on luminal breast cancer cells

BACKGROUND

Breast Cancer (BC) is the most common cancer in women worldwide and, although 70% of patients are responsive to selective Estrogen Receptor (ER) modulators such as Tamoxifen (Tam), patients' survival is comprised by resistance to endocrine therapy. Brazilian flora, especially the Amazon biome, is one of the richest global sources of native species with potentially bioactive compounds. Arrabidaea chica is a plant native to the Amazon that has been used in the treatment of different diseases. However, its action on BC remains unclear.

METHODS

Herein the biological effects of the chloroform extract of A. chica (CEAC) were evaluated on BC cells and in in vivo model. After confirmation of CEAC antioxidant capacity, cells were treated with CEAC and Tam, alone and with CEAC+Tam. The cell viability was evaluated by MTT and hormone receptor transcripts levels were assessed (ESR1, ESR2 and AR). Finally, anticarcinogenicity of CEAC was recorded in Drosophila melanogaster through Epithelial Tumor Test (ETT).

RESULTS

The study confirmed the antioxidant activity of CEAC. CEAC was selective for MCF-7, downregulating ESR2 and AR transcripts and upregulating ESR2 expression. The modulatory effects of CEAC on ERs did not differ between cells treated with Tam and with CEAC+Tam. Interestingly, previous treatment with CEAC, followed by treatment with Tam promoted a significant decrease in cell viability. The extract also presented anticarcinogenic effect in in vivo assay.

CONCLUSION

The bioassays on breast tumor cells demonstrated the antiproliferative activity of the extract, which modulated the expression of hormone receptors and sensitized luminal tumor cells to Tam. These results suggest that CEAC could be a complementary treatment for BC.

Phytochemical prospecting, isolation, and protective effect of the ethanolic extract of the leaves of Jatropha mollissima (Pohl) Baill

Jatropha mollissima is used in folk medicine as antimicrobial, antiparasitic, and larvicidal. However, few toxicogenetic studies have been carried out. Therefore, the aim of this study was to determine the phytochemical profile of ethanolic leaf extract of J. mollissima (EEJM) as well as potential cytotoxic, mutagenic, and antimutagenic properties. The EEJM was subjected to successive fractionation for the isolation of secondary metabolites, and five concentrations (0.01; 0.1; 1; 10 and 100 mg/ml) of extract were investigated using Allium cepa assay and the Somatic Mutation and Recombination (SMART) test. The mitotic index and % damage reduction were analyzed for A. cepa and the frequency of mutant hair for SMART. The presence of coumarins, alkaloids, flavonoids, saponins, and tannins was detected, while spinasterol and n-triacontane were the isolates identified for the first time for this species. EEJM did not exhibit cytotoxicity and was not mutagenic at 1 or 10 mg/ml using A. cepa and all concentrations of EEJM were not mutagenic in the SMART test. A cytoprotective effect was found at all concentrations. At 1 or 10 mg/ml EEJM exhibited antimutagenicity in A. cepa. In SMART, the protective effect was observed at 0.1 to 100 mg/ml EEJM. Our results demonstrate the important chemopreventive activity of EEJM, a desired quality in the search for natural anticarcinogenic compounds.

Modulating effect of vitamin D3 on the mutagenicity and carcinogenicity of doxorubicin in Drosophila melanogaster and in silico studies

Vitamin D3 (VD3) deficiency increases DNA damage, while supplementation may exert a pro-oxidant activity, prevent viral infections and formation of tumors. The aim of this study was to investigate the mutagenicity and carcinogenicity of VD3 alone or in combination with doxorubicin (DXR) using the Somatic Mutation and Recombination Test and the Epithelial Tumor Test, both in Drosophila melanogaster. For better understanding of the molecular interactions of VD3 and receptors, in silico analysis were performed with molecular docking associated with molecular dynamics. Findings revealed that VD3 alone did not increase the frequency of mutant spots, but reduced the frequency of mutant spots when co-administered with DXR. In addition, VD3 did not alter the recombinogenic effect of DXR in both ST and HB crosses. VD3 alone did not increase the total frequency of tumor, but significantly reduced the total frequency of tumor when co-administered with DXR. Molecular modeling and molecular dynamics between calcitriol and Ecdysone Receptor (EcR) showed a stable interaction, indicating the possibility of signal transduction between VD3 and EcR. In conclusion, under these experimental conditions, VD3 has modulatory effects on the mutagenicity and carcinogenicity induced by DXR in somatic cells of D. melanogaster and exhibited satisfactory interactions with the EcR.

Ethanolic Extracts from Azadirachta indica Leaves Modulate Transcriptional Levels of Hormone Receptor Variant in Breast Cancer Cell Lines

Breast Cancer (BC) encompasses numerous entities with different biological and behavioral characteristics, favored by tumor molecular complexity. Azadirachta indica (neem) presents phenolic compounds, indicating its potential as an antineoplastic compound. The present study aimed to evaluate the cellular response of MCF10, MCF7, and MDA-MB-231 breast cell lines to ethanolic extracts of neem leaves (EENL) obtained by dichloromethane (DCM) and ethyl acetate (EA) solvent. Extracts’ antiproliferative activities were evaluated against MCF 10A, MCF7, and MDA-MB-231 for 24 and 48 h using MTT assay. ESR1, ESR2, AR, AR-V1, AR-V4, and AR-V7 transcripts were quantified through qPCR for 0.03125 μg/mL of DCM and 1.0 μg/mL for EA for 48 h. The EENL was tested on Drosophila melanogaster as a sole treatment and then also together with doxorubicin. Antiproliferative effect on tumor cell lines without affecting MCF 10A were 1.0 µg/mL (P < 0.001) for EA, and 0.03125 µg/mL (P < 0.0001) for DCM, both after 48 h. Transcriptional levels of AR-V7 increased after treatment. In vivo assays demonstrated that EENL induced fewer tumors at a higher concentration with doxorubicin (DXR). The behavior of AR-V7 in the MDA-MB-231 tumor lineage indicates new pathways involved in tumor biology and this may have therapeutic value for cancer.

Protective effect of aspirin against mitomycin C-induced carcinogenicity, assessed by the test for detection of epithelial tumor clones (warts) in Drosophila melanogaster

The present study assessed the protective effect of aspirin against carcinogenicity induced by mitomycin C (MMC) by the test for detection of warts/epithelial tumor clones in Drosophila melanogaster. Larvae were treated with different concentrations of aspirin alone (10, 20 or 40 mg/mL) or aspirin in association with MMC. MMC and ultrapure water were employed as the positive and negative control, respectively. Antioxidant activity was determined using the DPPH method. For performing cytotoxicity assay on HeLa cells, the aspirin concentrations used ranged from 200 mmol/L to 3,125 mmol/L. For assessment of apoptosis and necrosis, cells were incubated for 24 h with complete medium in the absence (control group) or presence of aspirin (12.5 mmol/L and 25 mmol/L). The results obtained in the assessment of the possible carcinogenic effects of aspirin at the three concentrations tested indicate no statistically significant increase in tumor frequency compared to the negative control. The anticarcinogenic activity assessment, where the larvae of D. melanogaster were previously induced to tumor formation by MMC and later treated with aspirin, showed a statistically significant reduction in the number of tumors compared to the positive control. Antioxidant activity across the three aspirin concentrations (10, 20 or 40 mg/mL) ranged from 20.81% to 26.5%. It was observed that aspirin reduced growth viability of HeLa cells in a concentration-dependent manner in comparison with the control. These results indicate that aspirin did not induce tumors in Drosophila and reduced MMC-induced carcinogenicity. The antioxidant activity and apoptosis induction appear to be the main mechanisms involved in reducing the frequency of tumors.

Modulating effect of losartan potassium on the mutagenicity and recombinogenicity of doxorubicin in somatic cells of Drosophila melanogaster

Losartan potassium is an antihypertensive drug in the angiotensin II receptor antagonist (ARA) class. Some studies claim that, in addition to regulating blood pressure, this class of drug has anticancer properties. The objective of this study was to evaluate the genotoxic and antigenotoxic potential of losartan potassium using the SMART (Somatic Mutation and Recombination Test) assay on the somatic cells of Drosophila melanogaster, as well as the possible modulating effects of this drug, when associated with doxorubicin (DXR). Third instar larvae, descendents of standard and high bioactivation (ST and HB) crosses, were chronically treated with different concentrations of losartan potassium (0.25; 0.5; 1; 2; and 4 mM) alone or in association (co-treatment) with doxorubicin (DXR 0.125 mg/mL). The results showed an absence of a mutagenic effect of losartan potassium. In the co-treatment of losartan with DXR, the results showed that losartan is capable of reducing the number of mutant spots induced by DXR without altering the recombinogenic effect of the chemotherapeutic agent. Antiproliferative action appears to be the main mechanism involved in reducing the frequency of mutant spots and consequent modulation of alterations induced by DXR, although this parameter has not been directly assessed in this study.