Potential toxicity of leachate from the municipal landfill in view of the possibility of their migration to the environment through infiltration into groundwater

Leachate from landfills is a product of complex biological and physicochemical processes occurring during waste storage. In the present study, the toxicity of landfill leachate (LL) to human and bacterial cells was investigated for better understanding of LL environmental toxicity. Studies regarding LL physicochemical properties and cytotoxicity analysis were conducted. In Escherichia coli, Pseudomonas fluorescens, Bacillus subtilis, fibroblasts and melanoma A-375 cells, cell viability assays were applied. For the determination of LL antibacterial activity, twofold dilution series of LL were prepared in the range from 50% to 0.1% (50%, 25%, 12.5%, 6.25%, 3.13%, 1.56%, 0.78%, 0.39%, 0.2%, 0.1%). Human cells viability was examined at LL concentrations of 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 5%, 10%, 15%, 20% and 30%. ROS (reactive oxygen species) content and apoptosis level were also measured in bacterial and human cells under the influence of LL. Unexpectedly obtained results indicate stimulation of bacterial viability by LL. Fibroblasts under the influence of LL showed decrease in their viability and increase in apoptosis level and A-375 melanoma cells showed an increase in relative viability and decrease in apoptosis. ROS level in bacterial cells was elevated in higher LL concentrations and decreased in lower LL concentrations. In human cells, ROS content was rather high in both tested cell lines. Presented results indicate cytotoxic potential of analyzed LL and the necessity of LL monitoring because it may pose a health hazard for exposed human populations and the whole human environment.

58 Reduced nutrient availability during invitro culture improves embryo production and morphological quality and alters metabolic status of bovine embryos

Invitro production (IVP) of embryos is designed to reproduce an environment that resembles the female reproductive tract. However, the system does not perform optimally in terms of quality and embryo production. A major setback lies in the loss of dynamics observed in a static invitro system, which might affect the availability of substrates that reach the embryo. A reduction in the amount of nutrients in media has been used as an approach to improve IVP (Ermisch et al. 2020 Sci. Rep. 10, 9263; https://doi.org/10.1038/s41598-020-66019-4). The present study aimed at describing a defined sequential medium (embryonic culture supplementation, ECS) and to investigate the effect of reducing nutrient availability on embryo production, quality, and metabolism. ECS was developed in our laboratory and is a serum-free, salt-based culture medium supplemented with the amount of energy substrates and amino acids found in bovine oviduct (Ov) and uterus (Ut) fluids as previously described (Hugentobler et al. 2007Mol. Reprod. Dev. 74, 445–454; https://doi.org/10.1002/mrd.20607; Hugentobler et al. 2008Mol. Reprod. Dev. 75, 496–503; https://doi.org/10.1002/mrd.20760). Embryos were cultured according to the following ECS supplementation: ECS100 (supplemented with 8mg mL−1 bovine serum albumin and 100% of the energy substrates and amino acids concentrations of the Ov and Ut fluids) and ECS50 (half dilution of ECS100). Bovine oocytes from abattoir ovaries were submitted to IVP using standard protocols. On Day 0 of invitro culture, presumptive zygotes were randomly divided into groups ECS100-Ov or ECS50-Ov. On Day 4, embryos were respectively transferred to ECS100-Ut and ECS50-Ut. Expanded blastocysts were collected on Day 7 to assess embryo production, morphology (total cell number by Hoescht 33342 staining; inner cell mass and trophectoderm cells by CDX2 immunostaining), and metabolic status (mitochondrial activity and reactive oxygen species content by MitotrackerTM RedCMXRos and CellROXTM Green staining, ThermoFisher Scientific; NADH and FAD+ by autofluorescence). Data were analysed by Student’s t-test (a=4%). Although cleavage rates were similar between ECS50 and ECS100 (78.13±3.73 vs. 79.70±4.18; P=0.788), blastocyst rates were positively influenced by the reduction in concentration (28.88±1.74 vs. 16.73±2.41; P=0.004). This difference likely comes from a blockage at the morula stage in group ECS100, because the conversion from morula to blastocyst was 20% lower in this group (57.73±3.81 vs. 38.15±3.45; P=0.008). In terms of morphology, blastocysts produced in ECS50 had a higher number of cells (152.4±9.61 vs. 118.3±7.22; P=0.036), which is explained by the higher number of trophectoderm cells. Finally, metabolic status was affected by nutrient reduction: embryos from ECS50 had higher mitochondrial activity, reactive oxygen species content (P<0.0001), and lower NADH (P=0.01), suggesting higher oxidative phosphorylation to produce energy, as expected at this stage. In conclusion, ECS is a functional medium, and a reduced nutrient concentration (ECS50) improves embryo production, morphological quality, and metabolic status of blastocysts, suggesting that culture conditions must be adapted to the invitro system rather than resembling invivo conditions. This research was funded by FAPESP (2016/00350-0, 2017/18384-0).

THE VALUE OF BASAL EXPRESSION LEVEL OF HEMOXYGENASE-1 FOR SENSITIVITY OF HUMAN MELANOMA CELLS TO OXIDATIVE STRESS IN VITRO

Introduction. The molecular basis of radio- and photodynamic therapy (PDT), the mechanism of action of a number of antitumor chemotherapy drugs is oxidative stress (OS). The enzyme hemoxygenase-I (НO-1), a molecular marker of OS, is a key participant in the system of protection and adaptation of tumor cells under stress.Objective. To find out whether the sensitivity of human melanoma tumor cells to OS depends on the basal and modulator-induced levels of НO-1 expressionMaterial and methods. Human melanoma cell lines were used in the study. The expression of mRNA НO-1 in cells was studied by real-time RT-PCR, the reactive oxygen species content in cells – by flow cytometry and the cytotoxicity of drugs – by MTT assay.Results. According to our data, human melanoma cells have different basal levels of HO-1 transcription: high (3.0–3.5 o. u.) in lines MelIL, MelP, medium (1.5 o. u.) in lines MeWo, MelZ, MelIbr and low (0.5 o. e.) – MelMe, A375).There is no direct correlation between the level of basal cell expression of HO-1 and their sensitivity to the OS inducer – Н2О2. The hemin-induced increase in HO-1 expression in cells is accompanied by doubled resistance to Н2О2. It was found that HO-1 repression in the presence of apigenin was registered in melanoma cells with different basal levels, but sensitization to Н2О2 (2–4 times) was observed only for cells with medium (MeWo) and low (A375) levels of basal HO-1 expression. It was found that the decrease in basal expression of HO-1 induced by apigenin is accompanied by an increase in the reactive oxygen species content in cells.Conclusions. The results of our research allow us to recommend natural flavon apigenin, a modulator of HO-1 expression, for inclusion in the chemotherapy and PDT regimens to increase the effectiveness of human melanoma treatment.

Expression of the Tyrosine Hydroxylase Gene from Rat Leads to Oxidative Stress in Potato Plants

Catecholamines are biogenic aromatic amines common among both animals and plants. In animals, they are synthesized via tyrosine hydroxylation, while both hydroxylation or decarboxylation of tyrosine are possible in plants, depending on the species, though no tyrosine hydroxylase—a counterpart of the animal enzyme—has been identified yet. It is known that in potato plants, it is the decarboxylation of tyrosine that leads to catecholamine production. In this paper, we present the effects of the induction of an alternative route of catecholamine production by introducing the tyrosine hydroxylase gene from rat. We demonstrate that an animal system can be used by the plant. However, it does not function to synthesize catecholamines. Instead, it leads to elevated reactive oxygen species content and a constant stress condition in the plant, which responds with elevated antioxidant levels and improved resistance to infection.

Expression of tyrosine hydroxylase gene from rat leads to oxidative stress in potato plants

Catecholamines are biogenic aromatic amines common among both animals and plants. In animals they are synthesized via tyrosine hydroxylation, while in plants, both hydroxylation or decarboxylation of tyrosine are possible, depending on the species, though no tyrosine hydroxylase – a counterpart of animal enzyme has been identified yet. It is known that in potato plants it is the decarboxylation of tyrosine that leads to catecholamine production. In this paper we present the effects of induction of an alternative route of catecholamine production by introducing tyrosine hydroxylase gene from rat. We demonstrate that an animal system can be used by the plant, however, it does not function to synthesize catecholamines. Instead it leads to elevated reactive oxygen species content and constant stress condition to the plant which responds with elevated antioxidant level and further with improved resistance to infection.One sentence summaryIntroduction of rat tyrosine hydroxylase gene to potato disturbs catecholamine synthesis, causes oxidative stress and activates antioxidant response.

The effect of elicitors of bacterial origin on the functioning of the protective system of potato (Solanum Tuberosum L.) seedlings infected with X-virus

The reactive oxygen species content, the activity of phenolic peroxidase, and the expression levels of genes encoding certain defense proteins were studied in potato seedlings grown on a substrate with the addition of a preparation based on B. subtilis and infected with potato virus Х. The accumulation of reactive oxygen species and the induction of the defense system components in potato leaves treated with this preparation and infected are shown. Less viral material was detected in experimental samples of potato seedlings compared with control untreated with B. subtilis.

Pearl extract protects HaCaT cells from UV radiation-induced apoptosis through mitochondrial pathway regulation

Background: Previous studies have demonstrated that pearl extract (PE) promotes wound healing and skin whitening. However, it remains unclear whether PE can inhibit ultraviolet (UV)-photodamage in HaCaT cells. In this study, an in vitro photoaging cell model was established to observe the effect of PE on UV-induced damage and the apoptosis of HaCaT cells. The aim of this study was to provide a reference for the future development of natural sunscreens.Results: PE concentrations of 0.1 and 1 μg/mL were considered the most effective and safe concentrations. Compared to that in the control group, superoxide dismutase and glutathione peroxidase activity in the photoaging group was significantly reduced, whereas malondialdehyde and reactive oxygen species content, along with tumour necrosis factor-alpha (TNF-α) and interleukin (IL)-10 mRNA and protein levels, were markedly increased. In contrast, Bcl-2 protein expression was significantly decreased, whereas caspase-3, caspase-9, and Bax protein expression levels were significantly increased. Compared to that in the photoaging group, HaCaT cell proliferation was significantly increased in the PE group. Both PE concentrations significantly increased superoxide dismutase and glutathione peroxidase activity in cells, reduced malondialdehyde and reactive oxygen species content, decreased TNF-α and IL-10 mRNA expression in cells, and reduced TNF-α and IL-10 protein levels in the supernatant. Additionally, Bcl-2 protein expression levels were significantly increased, whereas caspase-3, caspase-9, and Bax protein expression levels were significantly reduced by PE treatment.Conclusions: PE can inhibit UV-induced apoptosis by inhibiting mitochondria-mediated apoptosis and regulating TNF-α and IL-10 expression.

Bacterial Disinfection by CuFe2O4 Nanoparticles Enhanced by NH2OH: A Mechanistic Study

Many disinfection technologies have emerged recently in water treatment industry, which are designed to inactivate water pathogens with extraordinary efficiency and minimum side effects and costs. Current disinfection processes, including chlorination, ozonation, UV irradiation, and so on, have their inherent drawbacks, and have been proven ineffective under certain scenarios. Bacterial inactivation by noble metals has been traditionally used, and copper is an ideal candidate as a bactericidal agent owing to its high abundance and low cost. Building on previous findings, we explored the bactericidal efficiency of Cu(I) and attempted to develop it into a novel water disinfection platform. Nanosized copper ferrite was synthesized, and it was reduced by hydroxylamine to form surface bound Cu(I) species. Our results showed that the generated Cu(I) on copper ferrite surface could inactivate E. coli at a much higher efficiency than Cu(II) species. Elevated reactive oxygen species’ content inside the cell primarily accounted for the strong bactericidal role of Cu(I), which may eventually lead to enhanced oxidative stress towards cell membrane, DNA, and functional proteins. The developed platform in this study is promising to be integrated into current water treatment industry.

Pearl extract protects HaCaT cells from UV radiation-induced apoptosis through mitochondrial pathway regulation

Background: Previous studies demonstrated that pearl extract (PE) promotes wound healing and skin whitening. However, whether PE can inhibit ultraviolet (UV) photodamage in HaCaT cells remains unclear. In this study, an in vitro photoaging cell model was established to observe the effect of PE on UV-induced damage and apoptosis of HaCaT cells. The aim was to provide a reference for future development of natural sunscreen agents. Results: PE concentrations of 0.1 and 1 μg/mL were considered as the most effective and safe concentrations. Compared to the control group, superoxide dismutase and glutathione peroxidase activities in the photoaging group were significantly reduced, while malondialdehyde and reactive oxygen species content, along with tumor necrosis factor-alpha (TNF-a) and interleukin (IL)-10 mRNA and protein levels were markedly increased. In contrast, Bcl-2 protein expression was significantly decreased, while caspase-3, caspase-9, and Bax protein expression levels were significantly increased. Compared to the photoaging group, HaCaT cell proliferation was significantly increased in the PE group. Both PE concentrations significantly increased superoxide dismutase and glutathione peroxidase activities in cells, reduced malondialdehyde and reactive oxygen species content, decreased TNF-a and IL-10 mRNA expression in cells, and reduced TNF-a and IL-10 protein levels in the supernatant. Additionally, Bcl-2 protein expression levels were significantly increased, while caspase-3, caspase-9, and Bax protein expression levels were significantly reduced by PE treatment. Conclusions: PE can inhibit UV-induced apoptosis by inhibiting mitochondria-mediated apoptosis and regulating TNF-a and IL-10 expression.