Assessment of genotoxicity of pyrethrin in cultured human lymphocytes

Assessment of the genotoxic effects of antihypertensive drug active ingredient indapamide in human lymphocytes

Hypertension is the most common cardiovascular disease and is also known as high blood pressure. The large majority of hypertensive patients need long-term administration of antihypertensive agents. Indapamide is an orally administered diuretic antihypertensive drug. The present work aimed to assess the possible genotoxic effects of indapamide using four different assays: chromosomal aberration (CA), sister chromatid exchange (SCE), micronucleus (MN), and comet. Lymphocytes from three different donors were exposed to 18.75, 37.50, 75.00, and 100.00 μg/ml indapamide. Additionally, a negative, a positive (mitomycin C = MMC, 0.20 μg/ml), and a solvent control (5.4 μl/ml methanol) were also applied. As a result, it was seen that indapamide did not cause a significant change in CAs and MN frequencies compared to the control. It caused significant damage only at the highest concentration in the comet assay. Similarly, while it did not affect the number of SCEs in the 24-h treatment, it increased the SCE frequency at the two highest concentrations in the 48-h. Mitotic index (MI) decreased at almost all concentrations. Considering all these results, this study revealed that indapamide did not have a significant genotoxic effect in these conditions. To the best of our knowledge, this is the first investigation about the genotoxic effect of indapamide in human lymphocytes in vitro.

Genotoxicity of nedaplatin in cultured lymphocytes: modulation by vitamin E

Nedaplatin is a chemotherapeutic agent used widely in cancer therapy. Nedaplatin has been shown to cause DNA damage to cells via the induction of oxidative stress. Vitamin E (Vit E) has an anti-mutagenic activity that can protect cells from DNA damaging agents. The objective of this study is to examine the genotoxic and cytotoxic effects of nedaplatin in human cultured lymphocytes. In addition, modulation of such effects by Vit E was also examined. The frequencies of sister chromatid exchange (SCE) and chromosomal aberrations (CAs) were used as an indicator for genotoxicity. The mitotic and proliferative indices were used to examine the cytotoxic effects of nedaplatin. The results showed that nedaplatin significantly elevated SCE and CA frequencies in human lymphocytes (p ˂ 0.01). The increases in the frequencies of SCE and CA caused by nedaplatin were lowered by pretreatment treatment with Vit E (p < 0.05). Nedaplatin significantly lowered mitotic index but Vit E pretreatment did not modulate this effect. These results suggest that Vit E has the potential to ameliorate the genotoxicity of nedaplatin in cultured lymphocytes.

Ameliorative potential of vitamin C and E against Roundup-glyphosate induced genotoxicity triggering apoptosis in caprine granulosa cells

The present study was aimed to investigate the genotoxic and apoptotic effects of glyphosate (GLP) in Roundup formulation along with mitigation of two potent antioxidants that is, vitamin C and E in caprine granulosa cells in vitro. The entire work was done in a dose and time dependent manner where different concentrations of GLP (0.1, 2.0, and 4.0 mg/ml) in Roundup and antioxidants (0.5 and 1.0 mM) were employed to culture of granulosa cells for exposure durations of 24, 48, and 72 h. Analysis of GLP-induced geno-toxicity was accomplished by using single cell gel electrophoresis (comet assay) assay. Results have shown increased incidences of DNA fragmentation, evidenced by presence of different types of comets (Type 1-Type 4) in Roundup-GLP- exposed groups in contrast to the control group (Type 0 comet). However, mitigation by both vitamin C and E was significant (p < .05) in combating the GLP-induced genotoxicity in granulosa cells in a concentration- and time-dependent manner. The results of our study provide a clear indication of the ameliorative actions of vitamin C and E against Roundup-GLP-induced genotoxicity that instigate apoptosis in ovarian granulosa cells of caprine.

The fate of biocontrol agents under the European phytopharmaceutical regulation: how this regulation hinders the approval of botanicals as new active substances

The use of biocontrol agents (BCAs) is growing across the world and in Europe in particular, where novel ways of farming are highly encouraged and implemented. However, although the social pressure is high to increase the number of BCAs in use within the EU, the European plant protection products (PPP) regulation (EC) N° 1107/2009 does not define clearly what BCAs are. Therefore, problems and drawbacks are observed throughout the whole authorisation process. Consequently, this situation impedes drastically the rapid implementation of botanical BCAs and their subsequent use in the field. Previous studies described in detail the fate of BCAs and the current administrative process that leads to their approval. Drawbacks are described for GMOs but surprisingly scarcely for pesticides. Therefore, the present study pinpoints the drawbacks of the approval process of botanical BCAs. To achieve this goal, a comparative study of 5 substances (4 of plant origin and 1 chemical) was performed. This study clearly reveals the present weaknesses and loopholes in the European PPP regulation process. The results of the present study may be useful to initiate and promote a major change in the evaluation and the regulation process of BCAs. This should allow designing a novel and innovative framework enabling the development of future plant protection products according to the sustainable use of pesticides, described in the corresponding (EC) Directive N° 128/2009 (SUD). This work targets farmers, policy makers, NGOs and scientists interested in issues related to this topic.

Genotoxicity of cisplatin and carboplatin in cultured human lymphocytes: a comparative study

Cisplatin and carboplatin are integral parts of many antineoplastic management regimens. Both platinum analogues are potent DNA alkylating agents that robustly induce genomic instability and promote apoptosis in tumor cells. Although the mechanism of action of both drugs is similar, cisplatin appears to be more cytotoxic. In this study, the genotoxic potential of cisplatin and carboplatin was compared using chromosomal aberrations (CAs) and sister-chromatid exchange (SCE) assays in cultured human lymphocytes. Results showed that cisplatin and carboplatin induced a significant increase in CAs and SCEs compared to the control group (p<0.01). Levels of induced CAs were similar in both drugs; however, the magnitude of SCEs induced by cisplatin was significantly higher than that induced by carboplatin (p<0.01). With respect to the mitotic and proliferative indices, both cisplatin and carboplatin significantly decreased mitotic index (p<0.01) without affecting the proliferative index (p>0.05). In conclusion, cisplatin was found to be more genotoxic than carboplatin in the SCE assay in cultured human lymphocytes, and that might explain the higher cytotoxicity of cisplatin.

In vitro genotoxicity assessment of monopotassium glutamate and magnesium diglutamate

Food additives are approved chemicals used for various purposes in foods; to provide nutritional safety, increase flavor, extend shelf life, reduce nutrient losses etc. In this study, the in vitro genotoxic effects of flavor enhancers, Monopotassium glutamate (MPG) and Magnesium diglutamate (MDG) were investigated in human peripheral blood lymphocytes by using chromosome aberrations (CAs), sister chromatid exchanges (SCEs), cytokinesis-block micronucleus cytome (CBMN-Cyt), and comet assays. Four concentrations of MPG (125, 250, 500, and 1000 μg/mL) and MDG (93.75, 187.5, 375, and 750 μg/mL) were used. Both food additives significantly reduced mitotic index and increased the frequency of CAs at high concentrations. MPG and MDG (except 93.75 μg/mL) significantly increased SCEs/Cell in concentration-dependent manner. In the CBMN-Cyt test, both MPG and MDG increased the formation of micronucleus, nuclear buds, and nucleoplasmic bridges compared to control in a concentration-dependent manner. However, these increases were statistically significant at higher concentrations. MPG (at 500 and 1000 μg/mL) and MDG (except 93.75 μg/mL) significantly increased DNA damages observed by comet assay. It is concluded from these results that MPG and MDG have clastogenic, mutagenic, aneugenic, and cytotoxic effects, particularly at high concentrations in human lymphocytes in vitro.

Assessment of Genotoxicity of Levosimendan in Human Cultured Lymphocytes

BACKGROUND AND OBJECTIVE

Levosimendan is a positive inotropic and a vasodilator agent with pleotropic characteristics that include antioxidation, anti-inflammation and smooth muscle vasodilation.

METHODS

In this study, the effects of levosimendan (0, 0.1, 1, 10, and 20 µg/ml) on oxidative DNA damage and sister-chromatid exchanges (SCEs) were evaluated in human cultured lymphocytes.

RESULTS

The results showed that levosimendan increased the frequency of SCEs in all examined concentrations (P<0.01) except for 0.1 µg/ml. On the other hand, levosimendan did not induce oxidative DNA damage as measured by the 8-OHdG biomarker (P > 0.05). In addition, neither mitotic arrest nor proliferation index was affected by levosimendan at all examined doses (P > 0.05).

CONCLUSION

In conclusion, levosimendan might be associated with increases in sister-chromatid exchanges in cultured human lymphocytes. In vivo studies are required to confirm the present findings.

Effective attenuation of glyphosate-induced oxidative stress and granulosa cell apoptosis by vitamins C and E in caprines

Pesticides are known to cause a wide range of reproductive problems that possess degenerative effects on mammalian fertility. Glyphosate (GLP), a broad-spectrum organophosphate herbicide, is known to be a potent mammalian toxicant. The present study aims at assessing the GLP-induced (0.1, 2.0, and 4.0 mg/ml) granulosa cells toxicity and evaluating the mitigating effects of vitamins C and E (0.5 mM and 1.0 mM) in healthy caprine antral follicles, cultured in vitro in a dose- and time-dependent manner (24, 48, and 72 hr) and subjected to various cytotoxic and geno-toxic analysis, namely, classic histology, EB/AO differential staining, oxidative stress parameters, and antioxidant enzymatic activity. The histomorphological analysis and EB/AO staining elucidated increase in the incidence of apoptotic attributes within granulosa cells with increasing dose and duration of the GLP treatment. The highest apoptotic frequency was observed at 4.0 mg/ml GLP after 72-hr exposure duration in comparison with the control. GLP exposure also led to a significant decline in the antioxidant enzymes' activity, namely, SOD, catalase, and GST along with enhanced lipid peroxidation and reduced FRAP activity in a dose- and time-dependent manner. Vitamins C and E supplementation decreased oxidative stress-mediated granulosa cells apoptosis, suggesting its efficiency to diminish GLP-mediated GCs cytotoxicity and thereby, preventing associated fertility disorders.

Carbon Dioxide, Odorants, Heat and Visible Cues Affect Wild Mosquito Landing in Open Spaces

CO₂ and other chemicals affect mosquito blood meal seeking behavior. Heat, humidity and black color can also serve as orientation cues. However mosquito attraction does not necessarily mean that it will land. The sequence of the cues used for mosquito landing is unclear. We performed a field study with wild mosquitoes in an open space and found that no chemicals (except pyrethrins) could completely prevent mosquitoes from landing. CO₂ mimics cyclopentanone and pyridine attracted mosquitoes but did not lead to landing. No mosquito was caught in the absence of heat, although in the presence of CO₂. Mosquito females commonly explore visible black objects by eyes, which is independent of infrared radiation. Humidification around the heat source may increase the detection distance but it did not affect mosquito landing. If a black object was located distant from the CO₂ and heat, mosquitoes still explored the heat source. Relative to CO₂ and heat, odorants, humidity and black color show lesser effects on mosquito landing.

Vitamin B12 protects against DNA damage induced by hydrochlorothiazide

DNA damage induced by hydrochlorothiazide was previously reported in cultured human lymphocytes. In this study, we aimed to investigate the harmful effects of hydrochlorothiazide on DNA by measuring the spontaneous frequency of sister chromatid exchanges (SCEs) in cultured human lymphocytes. We also aimed to investigate the possible protection of that damage by vitamin B12. The results showed that hydrochlorothiazide (5 µg/mL) significantly increased the frequency of sister chromatid exchanges (P < 0.001) in human lymphocytes in comparison with control. Additionally, the frequency of hydrochlorothiazide-induced SCEs was significantly decreased by co-treatment with vitamin B12 at concentration of 13.5 µg/mL (P < 0.001). In conclusion, hydrochlorothiazide is genotoxic to human lymphocytes and its toxicity is reduced by vitamin B12.