Adverse Effects of Non-Metallic Nanoparticles in the Central Nervous System.

The interest in nanoparticles (NPs) and their effects on living organisms has been continuously growing in the last decades. A special interest is focused on the effects of NPs on the central nervous system (CNS), which seems to be the most vulnerable to their adverse effects. Non-metallic NPs seem to be less toxic than metallic ones; thus, the application of non-metallic NPs in medicine and industry is growing very fast. Hence, a closer look at the impact of non-metallic NPs on neural tissue is necessary, especially in the context of the increasing prevalence of neurodegenerative diseases. In this review, we summarize the current knowledge of the in vitro and in vivo neurotoxicity of non-metallic NPs, as well as the mechanisms associated with negative or positive effects of non-metallic NPs on the CNS.

Exposure to Chlorpyrifos Alters Proliferation, Differentiation and Fatty Acid Uptake in 3T3-L1 Cells.

Organophosphorus pesticides (OPs) are important factors in the etiology of many diseases, including obesity and type 2 diabetes mellitus. The aim of this study was to investigate the effect of a representative of OPs, chlorpyrifos (CPF), on viability, proliferation, differentiation, and fatty acid uptake in 3T3-L1 cells. The effect of CPF exposure on preadipocyte proliferation was examined by the MTT, NR, and BrdU assays. The impact of CPF exposure on the differentiation of preadipocytes into mature adipocytes was evaluated by Oil Red O staining and RT-qPCR. The effect of CPF on free fatty acid uptake in adipocytes was assessed with the fluorescent dye BODIPY. Our experiments demonstrated that exposure to CPF decreased the viability of 3T3-L1 cells; however, it was increased when the cells were exposed to low concentrations of the pesticide. Exposure to CPF inhibited the proliferation and differentiation of 3T3-L1 preadipocytes. CPF exposure resulted in decreased lipid accumulation, accompanied by down-regulation of the two key transcription factors in adipogenesis: C/EBPα and PPARγ. Exposure to CPF increased basal free fatty acid uptake in fully differentiated adipocytes but decreased this uptake when CPF was added during the differentiation process. Increased free fatty acid accumulation in fully differentiated adipocytes may suggest that CPF leads to adipocyte hypertrophy, one of the mechanisms leading to obesity, particularly in adults. It can therefore be concluded that CPF may disturb the activity of preadipocytes and adipocytes, although the role of this pesticide in the development of obesity requires further research.

Lifestyle, Eating Habits, and Health Behaviors Among Dietary Supplement Users in Three European Countries.

Dietary supplements (DS) are used by about 30-50% of adults in developed countries. However, only a few studies have compared the characteristics of DS users in different nations. This study aimed to identify and compare selected health-related behaviors of DS users from three European countries. A total of 3,588 adults (32.08 ± 8.04 years) from Poland (1,030 females, 287 males), Germany (994 females, 190 males), and the United Kingdom (911 females, 176 males) were included in the analysis. The study was based on a self-administered survey consisting of 70 questions regarding baseline characteristics, lifestyle, eating, and health habits. The associations of the obtained results were compared using the Kruskal-Wallis test, Pearson Chi-Square test, and Cramer's V value. The highest percentage of DS users (56.98%, n = 2,044) had a correct body weight, while higher body weight values were observed in 39.19% (n = 1,406). In terms of lifestyle, statistically significant differences (p < 0.05) were noted for alcohol consumption and the level of physical activity. Fruit and vegetables were most often consumed a few times a weeks (34.67%, n = 1,244). A similar result was observed for the consumption of whole grain (37.76%, n = 1,355), dairy (39.99%, n = 1,435), eggs (49.67%, n = 1,782), and meat (51.45%, n = 1,846). Most DS users did not have a chronic disease (66.72%, n = 2,394). Among the other conditions, a frequent occurrence (a few times a weeks) of gastrointestinal problems (28.29%, n = 1,015) and concentration disorders (29.15%, n = 1,046) was noted. Cramer's V values (<0.3) indicated a weak (but significant p < 0.05) relationship between the country of residence and most of the analyzed variables. In conclusion, DS users were characterized by a healthy lifestyle with appropriate behaviors but not healthy eating habits.

Chlorpyrifos alters expression of enzymes involved in vitamin D3 synthesis in skin cells.

Skin acts as a mechanical barrier between human body and environment. Epidermal cells are regularly exposed to many physiological and environmental stressors, such as pesticides, like chlorpyrifos (CPS). It is recognised that CPS may affect metabolism of other exo- and endogenous substances by affecting enzyme activity and expression. This study aims to investigate the effect of CPS on expression of CYP27A1, CYP27B1 and CYP24A1, the enzymes involved in synthesis and metabolism of vitamin D3, in human keratinocytes HaCaT and human fibroblasts BJ. Synthesis of vitamin D3 in cells was initiated by irradiating with UVB. Expression of CYP27A1, CYP27B1 and CYP24A1 was evaluated by RT-qPCR and Western blot. Our experiments revealed that expression of all tested cytochrome P450 isoforms in cells exposed to CPS changed significantly. Exposure of HaCaT keratinocytes to CPS decreased CYP27A1 mRNA levels, but increased CYP27B1 and CYP24A1 mRNA levels. This was confirmed at the protein level, except for the CYP27A1 expression. Outcome for the BJ cells was however less conclusive. Though exposure to CPS decreased CYP27A1 and CYP27B1 mRNA levels, at protein level increasing concentration of CPS and UVB intensity induced expression of CYP27A1 and CYP24A1. The expression of CYP27B1 isoform decreased in line with mRNA level. Nevertheless, it can be concluded that CPS may therefore interrupt vitamin D3 metabolism in skin cells, but further studies are required to better understand such mechanisms.

Nuclear Factor kappa B activation by Ag, Au nanoparticles, CdTe quantum dots or their binary mixtures in HepG2 cells.

INTRODUCTION AND OBJECTIVE: Nuclear factor kappa B (NF-κB) signalling pathway plays a central role in the regulation of cellular response to stress. The aim of the study was to investigate the ability of silver nanoparticles (AgNPs), gold nanoparticles (AuNPs), CdTe quantum dots (CdTeQDs) or their binary mixtures to stimulate NF-κB binding in HepG2 cells. A dual luciferase reporter system was used to investigate NF-κB binding. MATERIAL AND METHODS: Cells were transiently transfected with a firefly luciferase reporter system and Renilla luciferase expression plasmid as a transfection efficiency control. Twenty- four hours after transfection, the cells were treated with nanoparticles (10 µg/cm3 AgNPs, 10 µg/cm3 AuNPs, 3 µg/cm3 CdTeQDs) or with 10 ng/cm3 TNFα as a positive control. Six hours later, the cells were lysed and the activities of the luminescence of firefly and Renilla luciferases were measured using the Dual-Luciferase Reporter Assay System. RESULTS: AuNPs and CdTeQDs alone significantly inhibited NF-κB binding activity. Co-treatment with AgNPs and CdTeQDs resulted in an additive effect, whereas the presence of AgNPs diminished the inhibitory effect of AuNPs. Interestingly, significant antagonism was observed between AuNPs and CdTeQDs, suggesting a similar mode of action. CONCLUSIONS: Comparison of the NF-κB binding activity induced by the mixtures of NPs suggests that in some cases NF-κB binding activity might differ from that observed for the NPs alone.

Susceptibility of HepG2 Cells to Silver Nanoparticles in Combination with other Metal/Metal Oxide Nanoparticles.

The fast-growing use of nanomaterials in everyday life raises the question about the safety of their use. Unfortunately, the risks associated with the use of nanoparticles (NPs) have not yet been fully assessed. The majority of studies conducted so far at the molecular and cellular level have focused on a single-type exposure, assuming that NPs act as the only factor. In the natural environment, however, we are likely exposed to a mixture of nanoparticles, whose interactions may modulate their impact on living organisms. This study aimed to evaluate the toxicological effects caused by in vitro exposure of HepG2 cells to AgNPs in combination with AuNPs, CdTe quantum dot (QD) NPs, TiO2NPs, or SiO2NPs. The results showed that the toxicity of nanoparticle binary mixtures depended on the type and ratio of NPs used. In general, the toxicity of binary mixtures of NPs was lower than the sum of toxicities of NPs alone (protective effect).

Two Sides to the Same Coin-Cytotoxicity vs. Potential Metastatic Activity of AgNPs Relative to Triple-Negative Human Breast Cancer MDA-MB-436 Cells.

Silver nanoparticles (AgNPs) are used in many fields of industry and medicine. Despite the well-established antimicrobial activity, AgNPs are foreseen to be used as anticancer drugs due to the unusual feature-inability to induce drug resistance in cancer cells. The aim of the study was to assess biological activity of AgNPs against MDA-MB-436 cells. The cells were derived from triple-negative breast cancer, a type of breast cancer with poor prognosis and is particularly difficult to cure. AgNPs were toxic to MDA-MB-436 cells and the probable mechanism of toxicity was the induction of oxidative stress. These promising effects, giving the opportunity to use AgNPs as an anti-cancer agent should, however, be treated with caution in the light of further results. Namely, the treatment of MDA-MB-436 cells with AgNPs was associated with the increased secretion of several cytokines and chemokines, which were important in breast cancer metastasis. Finally, changes in the actin cytoskeleton of MDA-MB-436 cells under the influence of AgNPs treatment were also observed.

Organophosphorus pesticides can influence the development of obesity and type 2 diabetes with concomitant metabolic changes.

Widespread use and the bioaccumulation of pesticides in the environment lead to the contamination of air, water, soil and agricultural resources. A huge body of evidence points to the association between the pesticide exposure and increase in the incidence of chronic diseases, e.g. cancer, birth defects, reproductive disorders, neurodegenerative, cardiovascular and respiratory diseases, developmental disorders, metabolic disorders, chronic renal disorders or autoimmune diseases. Organophosphorus compounds are among the most widely used pesticides. A growing body of evidence is suggesting the potential interdependence between the organophosphorus pesticides (OPs) exposure and risk of obesity and type 2 diabetes mellitus (T2DM). This article reviews the current literature to highlight the latest in vitro and in vivo evidences on the possible influence of OPs on obesity and T2DM development, as well as epidemiological evidence for the metabolic toxicity of OPs in humans. The article also draws attention to the influence of maternal OPs exposure on offspring. Summarized studies suggest that OPs exposure is associated with metabolic changes linked with obesity and T2DM indicated that such exposures may increase risk or vulnerability to other contributory components.

Assessment of DNA damage in Polish children environmentally exposed to pesticides.

Exposure to pesticides leads to complex, long-lasting adverse effects on human health, and poses a substantial risk to those living in areas devoted to agriculture. Children are particularly vulnerable to the pesticide exposure, due to the developmental, dietary and physiological factors. Small body mass and typical exploratory behavior result in increased risk of intoxication. Thus, even exposure to low concentrations of pesticides, if of sufficient duration, may lead to permanent health disorders and limit their harmonious development. In this study 108 children, living in areas of an intense pesticide use and a control group (n = 92) of children from an agrotouristic area were investigated, whether DNA damage increased due to prolonged pesticide exposure. A presence of DNA breaks and oxidative damage to DNA bases, characterized as Fpg-sensitive sites, were detected by comet assay. Micronuclei (MN) formation was evaluated by cytokinesis-block MN assay. The exposure of children to pesticides resulted in increased number of MN in peripheral blood lymphocytes (P = 0.016), increased DNA strand breaks level (P = 0.002) and oxidative damage to DNA (P < 0.001). Negative correlation was demonstrated between the level of DNA strand breaks and acetylcholinesterase (AChE) activity in exposed group. In conclusion, despite just environmental pesticide exposure in the test group of children, significant biological effects were detected.

Chlorpyrifos stimulates expression of vitamin D3 receptor in skin cells irradiated with UVB.

Skin, the organ responsible for vitamin D synthesis, is fully exposed to many xenobiotics, e.g. polycyclic aromatic hydrocarbons and pesticides. A broad spectrum organophosphorus insecticides (OP's), such as chlorpyrifos (CPS), are commonly used in agriculture and to control domestic insects. Thus, the aim of this study was to investigate the effect of chlorpyrifos, on the expression of vitamin D3 receptor (VDR) in human keratinocytes cell line HaCaT and fibroblasts cell line BJ. The impact of CPS and UVB radiation on cell viability were examined by Neutral Red assay. The effect of CPS on VDR expression was evaluated by RT-qPCR and flow cytometry (FC). The presented study demonstrated that exposure to CPS and UVB significantly affects the viability of HaCaT and BJ cells lines. Results also revealed that exposure to CPS induced the expression at mRNA and protein level of VDR nuclear receptor in both cell lines exposed to UVB. In HaCaT incubated with 250 µM CPS and 15 mJ/cm2 UVB, the relative VDR expression was ∼2-fold higher; whereas in BJ incubated with 250 µM CPS and 20 mJ/cm2, UVB was∼3-fold higher. Results from FC confirmed this result, as VDR expression increased by ~250% in HaCaT incubated with 250 µM CPS and 20 mJ/cm2 UVB, and in BJ incubated with 250 µM CPS, and 20 mJ/cm2 UVB cells VDR expression increased by ~190%, compared with control. It can therefore be concluded that OPs pesticide might interfere with vitamin D3 metabolism in skin cells.