Genotoxic markers in patients with diabetes mellitus (Literature review)

This paper considers studies aimed at identifying markers of genotoxicity (chromosomal aberrations, micronuclei, and DNA damage assessed by the DNA comet assay) in patients with both gestational diabetes mellitus (GDM) and diabetes type 1 and 2 (T1DM and T2DM, respectively), as well as possible changes in the levels of these genotoxic markers under the influence of medicines and nutritions. Patients with T2DM are characterized by an increased level of genotoxicity markers. The results of genotoxicity markers in patients with T1DM and GDM studies are contradictory, however, they indicate the presence of an increased genotoxic load rather than its absence. The levels of genotoxic damage in diabetic patients may be reduced by physical exercises, diet, and/or hypoglycemic drugs. Metformin, Afobazole and Noopept are recommended for experimental and clinical studies as possible drug candidates that reduce the levels of genotoxic biomarkers in diabetic patients.

Reproductive Toxicity of Theobroma cacao: Increase in Survival Index, Nongenotoxic, and Proimplantation Potential

Unsweetened natural cocoa (UNCP) was evaluated for reproductive toxicity in rats. A preliminary genotoxic potential was evaluated by the DNA comet assay test using C57Bl/6 mice. Both therapeutic dose (TD; 900 mg/kg) and high dose (HD; 9000 mg/kg) of UNCP were used. White Wistar rats were used in two experimental groups. The females received UNCP 15 days before crossing with untreated males. The males received UNCP for 48 days before mating with untreated females. Subacute toxicity was observed during a 14-day oral administration of UNCP. Results show that a high tail DNA% was observed with methyl mesylate administration in all tissues analysed. The lowest tail DNA% value was observed in the liver (1.64 ± 0.26) and kidney (1.63 ± 0.30) during UNCP (TD) administration. UNCP did not induce observable physical congenital malformations on the pubs of treated female and male rats, lacks genotoxic potential, and did not adversely affect pregnancy index, pub weights, and survival index, but UNCP exhibited proimplantation potential ( p > 0.05 ).

Gamma-hexalactone flavoring causes DNA lesion and modulates cytokines secretion at non-cytotoxic concentrations

Background The γ-hexalactone is a flavoring agent for alcoholic beverages, teas, breads, dairy products, coffees, buttery products among others. It presents low molecular weight and exhibits sweet fruity aroma with nuances of nuts. As far as we know, both literature and government regulations have gaps regarding the safe use of the γ-hexalactone. In this context, the main objective of this work was to evaluate the effects of γ-hexalactone through in silico and in vitro approaches. Methods The in silico analysis was performed through four free online platforms (admetSAR, Osiris Property Explorer®, pkCSM platform and PreADMET) and consisted of comparative structural analysis with substances present in databases. The computational prediction was performed in the sense of complement and guide the in vitro tests. Regarding in vitro investigations, screening of cytotoxicity (assessed by cell proliferation and viability parameters) in lymphocytes exposed to γ-hexalactone for 72 h were carried out previously to determine non-cytotoxic concentrations. Following this screening, concentrations of 5.15, 0.515, and 0.0515 μM were selected for the study of the respective potentials: genotoxic (assessed by DNA comet assay), chromosomal mutation (analysis of micronucleus frequency) and immunomodulatory (cytokine quantification using ELISA immunoassay). The results of in vitro assays were compared by one-way analysis of variance (ANOVA), followed by Bonferroni’s post hoc test, conducted by statistic software. Results The platform PreADMET pointed out that γ-hexalactone is potentially mutagenic and carcinogenic. The comet assay data corroborate with these results demonstrating that γ-hexalactone at 5.15 μM caused lymphocytes DNA damage. In relation to cytokine secretion, the results indicate that lymphocytes were activated by γ-hexalactone at non-cytotoxic concentrations, involving an increase in the IL-1 levels in all tested concentrations, ranging from approximately 56 to 93%. The γ-hexalactone only at 5.15 μM induced increase in the levels of IL-6 (~ 60%), TNF-α (~ 68%) and IFN-γ (~ 29%), but decreased IL-10 (~ 46%) in comparison with the negative control (p < 0.05). No change was observed in total lymphocytes or in cell viability at the concentrations tested. Conclusions In summary, the γ-hexalactone demonstrated immunomodulatory and genotoxic effects at non-cytotoxic concentrations in healthy lymphocytes.

Effects of Polar Steroids from the Starfish Patiria (=Asterina) pectinifera in Combination with X-Ray Radiation on Colony Formation and Apoptosis Induction of Human Colorectal Carcinoma Cells

Despite significant advances in the understanding, prevention, and treatment of cancer, the disease continues to affect millions of people worldwide. Chemoradiation therapy is a rational approach that has already proven beneficial for several malignancies. However, the existence of toxicity to normal tissue is a serious limitation of this treatment modality. The aim of the present study is to investigate the ability of polar steroids from starfish Patiria (=Asterina) pectinifera to enhance the efficacy of radiation therapy in colorectal carcinoma cells. The cytotoxic activity of polar steroids and X-ray radiation against DLD-1, HCT 116, and HT-29 cells was determined by an MTS assay. The effect of compounds, X-ray, and their combination on colony formation was studied using the soft agar method. The molecular mechanism of the radiosensitizing activity of asterosaponin P1 was elucidated by western blotting and the DNA comet assay. Polar steroids inhibited colony formation in the tested cells, and to a greater extent in HT-29 cells. Asterosaponin P1 enhanced the efficacy of radiation and, as a result, reduced the number and size of the colonies of colorectal cancer cells. The radiosensitizing activity of asterosaponin P1 was realized by apoptosis induction through the regulation of anti- and pro-apoptotic protein expression followed by caspase activation and DNA degradation.

Studi Awal Pengaruh Radiasi Terhadap Pekerja Radiasi Menggunakan Metode Comet Assay

Telah dilakukan studi awal pengaruh radiasi terhadap pekerja radiasi menggunakan metode comet assay. Pengambilan data dosis radiasi dilakukan pada hasil pembacaan laju dosis radiasi terhadap pekerja radiasi menggunakan film badge di Instalasi Radiologi RS Dr. Reksodiwiryo Padang, sedangkan pemeriksaan DNA sel limfosit dilakukan di Laboratorium Biomolekuler PTKMR BATAN. Pemeriksaan DNA sel limfosit dilakukan pada 50 sel sampel darah dari tiga orang pekerja radiasi dan tiga orang normal sebagai sampel kontrol, menggunakan mikroskop fluorescent dan CASP LAP comet assay software. Hasil pembacaan dosis radiasi menunjukkan bahwa laju dosis radiasi yang diterima pekerja radiasi yaitu 1,2 mSv/tahun. Hasil ini masih berada di bawah NBD berdasarkan Perka BAPETEN No 4 Tahun 2013. Pemeriksaan DNA sel limfosit menunjukkan nilai rata-rata tail length (TL) sampel pekerja radiasi lebih tinggi dibandingkan dengan sampel kontrol. Berdasarkan nilai TL tersebut belum bisa diketahui tingkat keparahan suatu kerusakan DNA.Kata kunci : laju dosis radiasi, NBD, kerusakan DNA , comet assay, limfosit, tail length

Human adipose-derived stem cells obtained from lipoaspirates are highly susceptible to hydrogen peroxide mediated cytogenotoxicity

There is evidence that H2O2 can induce the proliferation, migration, and regeneration of stem cells, as well as that of adipose-derived stem cells (ASCs). This could be useful to expand the possible uses of ASCs in therapeutic applications. However, the safety profile of H2O2 use in stem cells is not clear yet. Therefore, the present study evaluated the acute cytotoxic, oxidative and genotoxic effects of different concentrations of H2O2 on ASCs obtained from human lipoaspirates. The ASCs were treated with 1–1000 μM H2O2 for two hours. Cell viability was evaluated by double-strand DNA determination. Apoptosis induction was analyzed measuring active levels of caspases 1, 3 and 8. Biochemical oxidative stress markers were analyzed and genotoxic effects were assessed by DNA comet assay. All H2O2 concentrations increased ASC mortality rates with approximately 100% mortality achieved at ≥ 200 μM. Active caspases 1, 3 and 8, oxidative stress, as well as oxidative damage as assessed by lipid peroxidation increased dose‐dependently. There was also an approximate 50% increase in catalase levels in cells exposed to all H2O2 tested concentrations. H2O2 concentrations of ≥ 10 μM were genotoxic. These results suggest that ASCs are highly sensitive to H2O2 exposition. In addition, DNA damage in the surviving cells may affect their proliferative and differentiation capacity, as well as their safety profile for therapeutic use.

Evaluation of DNA damage by Comet Assay in populations of endemic Beyşehir frog Pelophylax caralitanus (Arıkan,1988)

In study this, the level of DNA damage in three populations of endemic Beyşehir frog (Pelophylax caralitanus) inhabiting on Lakes of Karamık, Eber and Beyşehir with different anthropogenic pollution was assessed by using the DNA Comet Assay technique. Frog erythrocytes cells were used for the analysis. Seven adult individuals were collected from each biotope containing minimum 100 cells were analysed. While the results showing a significant increase in the DNA comet index in the contaminated zone [(Eber Lake= Idc=0.22±0.015), (p<0.05)], the majority of the cells did not contain any DNA damage in the clean zone (Karamık Lake, Idc=0.08±0.001). The obtained data demonstrated t that the endemic Beyşehir frog could serve as a useful flag species in an indicator of anthropogenic impact on ecosystems.