An evaluation of a hepatotoxicity risk induced by the microplastic polymethyl methacrylate (PMMA) using HepG2/THP-1 co-culture model

Inappropriate disposal of plastic wastes and their durability in nature cause uncontrolled accumulation of plastic in land/marine ecosystems, also causing destructive effects by bioaccumulating along the food chain. Microplastics may cause chronic inflammation in relation to their permanent structures, especially through oxidative stress and cytotoxic cellular damage, which could increase the risk of cancer development. The accumulation of microplastics in the liver is a major concern, and therefore, the identification of the mechanisms of their hepatotoxic effects is of great importance. Polymethyl methacrylate (PMMA) is a widely used thermoplastic. It has been determined that PMMA disrupts lipid metabolism in the liver in various aquatic organisms and causes reproductive and developmental toxicity. PMMA-induced hepatotoxic effects in humans have not yet been clarified. In our study, the toxic effects of PMMA (in the range of 3-10 μm) on the human liver were investigated using the HepG2/THP-1 macrophage co-culture model, which is a sensitive immune-mediated liver injury model. Cellular uptake of micro-sized PMMA in the cells was done by transmission electron microscopy. Determination of its effects on cell viability and inflammatory response, oxidative stress, along with gene and protein expression levels that play a role in the mechanism pathways underlying the effects were investigated. The results concluded that inflammation, oxidative stress, and disruptions in lipid metabolism should be the focus of attention as important underlying causes of PMMA-induced hepatotoxicity. Our study, which points out the potential adverse effects of microplastics on human health, supports the literature information on the subject.

The cyclin-dependent kinase inhibitor abemaciclib-induced hepatotoxicity: Insight on the molecular mechanisms in HepG2/THP-1 co-culture model

Drug-induced liver injury (DILI) is one of the widespread causes of liver injury and immune system plays important role. Abemaciclib (ABE) is a cyclin-dependent kinase inhibitor used as monotherapy or combination therapy in the treatment of breast cancer. Like other kinase inhibitors, the underlying mechanisms of ABE-induced hepatotoxicity are not completely known yet. In the current study, hepatotoxicity of ABE was evaluated with HepG2/THP-1 co-culture model which has been developed in recent years for the evaluation of DILI potential. Following ABE treatment, oxidative stress, mitochondrial damage, cytokine secretion levels, apoptotic/necrotic cell death were determined. According to our results, ROS production along with GSH depletion was observed in HepG2 cells after ABE treatment. ABE promoted secretion of pro-inflammatory mediators (TNF-α and MCP-1) and declined anti-inflammatory cytokine IL-10 release. Besides, NFKβ and JNK1 protein expression levels increased following ABE treatment. ABE enhanced intracellular calcium levels, induced early apoptotic and necrotic cell deaths in HepG2 cells. Furthermore, the changes in some mitochondrial parameters including a reducement in intracellular ATP levels and complex V activity; hyperpolarized mitochondrial membrane potential and enhanced mitochondrial ROS levels were observed, whereas mitochondrial mass did not show any differences after ABE treatments. Therefore, ABE-induced hepatotoxic effects is probably via oxidative stress, inflammatory response and necrotic cell death rather than direct mitochondrial toxicity. In conclusion; the study makes a significant contribution to strengthening the infrastructure we have on in vitro toxicity mechanism evaluations, which are the basis of preclinical toxicity studies.

Ripretinib induced skeletal muscle toxicity through mitochondrial impairment in C2C12 myotubes

Ripretinib is a multikinase inhibitor drug approved in 2020 by the FDA and in 2021 by EMA for use in the treatment of advanced gastrointestinal stromal tumors (GIST) which have not adequately responded to previous treatments with kinase inhibitors. The most common side effects of the drug are myalgia and fatigue, which likely causes interruption of the treatment or reduction of the dose. Skeletal muscle cells highly depend on ATP to perform their functions and mitochondrial damage may play a role in skeletal muscle toxicity induced by kinase inhibitors. However, the molecular mechanism has not been clearly identified in the literature yet. In this study, it has been aimed to elucidate the role of mitochondria in the toxic effect of ripretinib on skeletal muscle using the mouse C2C12 myoblast-derived myotubes. The myotubes were exposed to ripretinib at the range of 1-20 μM concentrations for 24 h. To determine the potential role of mitochondrial impairment in ripretinib-induced skeletal muscle toxicity, intracellular ATP level, mitochondrial membrane potential (MMP), mitochondrial ROS production (mtROS), mitochondrial DNA (mtDNA) copy number, and mitochondrial mass were examined after ripretinib treatment. Furthermore, changes in PGC 1α/NRF 1/NRF 2 expression levels that play a role in mitochondrial biogenesis and mitophagy were investigated. Additionally, the mitochondrial electron transport chain (ETC) enzyme activities were evaluated. Lastly, a molecular docking study was done to see ripretinib's possible interaction with DNA polymerase gamma (POLG) which is important for DNA replication in the mitochondria. According to the findings, ripretinib decreases the ATP level and mtDNA copy number, induces loss of MMP, and reduces mitochondrial mass. The activities of the ETC complexes were inhibited with ripretinib exposure which is in line with the observed ATP depletion and MMP loss. The molecular docking study revealed that ripretinib has inhibitory potential against POLG which supports the observed inhibition of mtDNA. The expression of PGC 1α was reduced in the nuclear fraction indicating that PGC-1α was not activated since the NRF 1 expression was reduced and NRF 2 level did not show significant change. Consequently, mtROS production increased in all treatment groups and mitophagy-related gene expressions and Parkin protein expression level were up-regulated at high doses. In conclusion, mitochondrial damage/loss can be one of the underlying causes of ripretinib-induced skeletal muscle toxicity. However, further studies are needed to confirm the results in vivo.

UR-144, synthetic cannabinoid receptor agonist, induced cardiomyoblast toxicity mechanism comprises cytoplasmic Ca2+ and DAPK1 related autophagy and necrosis

UR-144, a cannabinoid receptor agonist, is widely used alone or in combination with other synthetic cannabinoids (SCs) all over the world. At overdose, cardiovascular symptoms have been reported and the underlying molecular mechanisms of these adverse effects are not known. It is highly important to clarify the toxic effects of UR-144 for the treatment of poisoning. In the present study, the molecular mechanism of cytotoxic effects of UR-144 is evaluated on a cardiomyoblastic cell line using WST-1 and LDH assays. Apoptosis/necrosis, autophagy, and ROS (reactive oxygen species) levels were determined using flow cytometry. Cytoplasmic Ca²⁺ levels were measured by using a fluorogenic calcium-binding dye. Released and cytoplasmic troponin T levels, a specific marker of cardiotoxicity, were examined with western blot. For the evaluation of the role of DAPK1, on UR-144-induced cell death, DAPK1 activity and DAPK1 protein level were investigated. Its cytotoxic effects increased in a dose-dependent manner for WST-1 and LDH assays, while membrane damage, one of the signs of necrotic cell death, was more remarkable than damage to mitochondria. Cytoplasmic Ca²⁺ levels rose after high-dose UR-144 treatment and inhibition of DAPK1 activity ameliorated UR-144-induced cytotoxicity. Released troponin T significantly increased at a dose of 200 µM. ROS and total antioxidant capacity of cells were both reduced following high dose UR-144 treatment. The results indicated that UR-144-induced autophagic and necrotic cell death might be a consequence of elevated cytoplasmic Ca²⁺ levels and DAPK1 activation. However, in vivo/clinical studies are needed to identify molecular mechanisms of cardiotoxic effects of UR-144.

Zoledronic acid-induced oxidative damage and endoplasmic reticulum stress-mediated apoptosis in human embryonic kidney (HEK-293) cells

Zoledronic acid, a nitrogen-containing bisphosphonate drug, is used for the treatment of osteoporosis, Paget's disease of bone, and tumor-induced osteolysis. Zoledronic acid has also gained a place in cancer treatment due to its cytotoxic and antiproliferative effects in many cancer cells. Although zoledronic acid is considered safe, kidney damage is still one of the concerns in therapeutic doses. In the study, the aim was to assess the nephrotoxic profiles of zoledronic acid in the human embryonic kidney (HEK-293) cells. Cytotoxicity evaluation was performed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) and neutral red uptake tests, while oxidative stress was performed by reactive oxygen species (ROS) production via flow cytometry, and the incomprehensible evaluation of ROS-related genes by RT-PCR and apoptosis was performed with Annexin-PI analysis in flow cytometry. The obtained result showed that zoledronic acid inhibited cell viability (IC₅₀ values were determined as 273.16  by MTT) and cell proliferation in a concentration-dependent manner, induced ROS production, caused glutathione depletion, and increased oxidative stress index and endoplasmic reticulum (ER) stress, indicating severe cellular stress. The expression levels of oxidative damage (L-fabp, α-GST, Nrf2, and HMOX1), ER stress (CASP4, IRE1-α, GADD153, and GRP78), and apoptosis (Bcl-2, Bax, Cyt-c, p53, CASP9, CASP3, NF-κB, TNF-α, and JNK) related genes were altered as well as IRE1-α protein levels. Herein, we were the first to show that increased oxidative stress and ER stress resulting in apoptosis are the key molecular pathways in zoledronic acid-induced nephrotoxicity equivalent to clinically administered concentrations.

Determination of Perflourooctanoic Acid Toxicity in a Human Hepatocarcinoma Cell Line

BACKGROUND

Perfluorooctanoic acid (PFOA) is used in different industrial and commercial products. Research shows the presence of PFOA in home dusts, tap and surface water, and in biological samples. The International Agency for Research on Cancer (IARC) has classified PFOA as a possible carcinogen for humans. The liver is thought to be a target organ of PFOA accumulation and toxicity.

OBJECTIVE

Some studies have found toxic effects on the liver and related mechanisms; however, more studies are needed to better understand PFOA - induced hepatotoxicity.

METHODS

In the present study, a human hepatocarcinoma cell line was exposed to PFOA for 24 hours and cell viability, apoptosis, the oxidative system and immune response were evaluated.

RESULTS

While apoptosis was the main cell death pathway at low concentration (86.5%), the necrotic cell fraction increased with higher concentrations (46.7%). Significant changes in the reactive oxygen species (5.3-folds) glutathione (GSH) (1.7-folds) and catalase (CAT) (1.4-folds) levels were observed, as well as changes to interleukin-6 (≤1.8-fold) and interleukin-8 levels (35-40%).

CONCLUSIONS

In light of the data, PFOA is potentially hepatotoxic through the investigated pathways. The results represent a background for future in vivo mechanistic studies.

COMPETING INTERESTS

The authors declare no competing financial interests.

Cellular Stress Pathways Are Linked to Acetamiprid-Induced Apoptosis in SH-SY5Y Neural Cells

Simple Summary

Neonicotinoids constitute more than one-quarter of the insecticides on the market. Acetamiprid, a widely used neonicotinoid, has been found to be linked with neurological symptoms and there is an urge to understand its molecular mechanisms. It decreased cellular viability in millimole concentrations after 24 h in SH-SY5Y neural cells. Additionally, it increased reactive oxygen species, intracellular calcium and endoplasmic reticulum stress. Since overwhelmed cellular stress can destroy cellular structures and cause cell death, we also evaluated cellular death mechanisms. Acetamiprid induced apoptosis rather than necrosis indicating that cells undergo suicide initiated by self-generated death signals. Even though acetamiprid is considered to be a safe option in the struggle against harmful agricultural insects, these results suggest that the widespread use should be taken under strict control in order not to cause damage to the mammals.

Abstract

Acetamiprid (ACE), a commonly used neonicotinoid insecticide, is correlated with neurological symptoms, immunotoxicity and hepatotoxicity. Cellular stress and damage could play an important role in ACE-induced neurotoxicity; however, its mechanism has not been fully understood. We evaluated the effects of ACE on oxidative stress, endoplasmic reticulum (ER) stress, cellular death, mRNA expression levels of related genes and protein expressions of related molecular mechanisms in SH-SY5Y human neuroblastoma cells. The half maximal inhibition of enzyme activity (IC₅₀) value of ACE was determined as 4.26 mM after 24 h of treatment by MTT assay. We revealed an increase in reactive oxygen species (ROS) production and calcium release. Significant increases were measured in inositol-requiring enzyme 1-alpha (IRE1-α) and binding immunoglobulin protein 90 (GRP90) levels as well as mRNA expression levels of caspase 3, 4 and 9 genes indicating enhanced ER stress. Apoptosis and ER stress-related genes were significantly upregulated at ≥2 mM. Indeed, ACE caused apoptosis and necroptosis while necrosis was not observed. There was a significant increase in the protein level of mitogen-activated protein kinase-8 (MAPK8) at 4 mM of ACE while no change was seen for nuclear factor kappa-B (NF-κB) and tumor necrosis factor-alpha (TNF-α). In conclusion, increased cellular stress markers could be proposed as an underlying mechanism of ACE-induced cell death in neural cells.

Acetamiprid-induced Cyto- and Genotoxicity in the AR42J Pancreatic Cell Line

Objectives

Neonicotinoid insecticides, 30% of insecticides marketed worldwide, have selective toxicity on insects through α4p2 nicotinic acetylcholine receptors. Although it is known that acetamiprid exerts toxicity on several organ systems, its toxic effects on the pancreas and its mechanism of action have not been clarified yet. Therefore, in the present study, the cytotoxic and genotoxic potentials of acetamiprid on the AR42J pancreatic cell line were evaluated.

Materials and Methods

The (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) (MTT) assay and comet assay were conducted for the cyto- and genotoxicity evaluations, respectively. Reactive oxygen species (ROS) production was assessed by flow cytometry and glutathione (GSH) levels were determined by ELISA for oxidative damage potential, which is thought to be an underlying mechanism of cyto-/genotoxic effects.

Results

To reveal the dose-response relationship the concentration range of 1-6 mM was selected for the assays. Cell viability decreased in a dose-dependent manner and the inhibitory concentration 50 value was calculated as 12.61 mM by the MTT assay. Acetamiprid induced DNA damage in all concentrations tested in a dose-depending manner. The mean tail intensity values were 3.84 and ≤32.96 for the control and exposure groups, respectively. There was no significant difference for ROS production; however, the GSH level was reduced at the highest concentration.

Conclusion

It is thought that the present study will contribute to the literature due to the lack of data on the potential toxic effects of acetamiprid on the pancreas. To better understand acetamiprid toxicity, further studies including a wide range of mechanistic parameters are needed.

Cytotoxic, Genotoxic, and Apoptotic Effects of Nickel Oxide Nanoparticles in Intestinal Epithelial Cells

Objectives

The superior properties of nickel oxide-nanoparticles (NiO-NPs) have led to their wide use in various fields. However, there is little comprehensive knowledge about their toxicity, especially after oral exposure. The toxic effect of NiO-NPs of mean size 15.0 nm was investigated in Caco-2 (human intestinal epithelial) cells as no study has been performed on their intestinal toxicity.

Materials and Methods

Following identification of their particle size distribution and cellular uptake potential, the risk of exposure to NiO-NPs was evaluated by cellular morphologic changes, cyto- and genotoxic potentials, oxidative damage, and apoptotic induction.

Results

NiO-NPs induced a 50% reduction in cell viability at 351.6 μg/mL and caused DNA damage and oxidative damage at 30-150 μg/mL. It appears that apoptosis might be a main cell death mechanism in NiO-NP-exposed intestinal cells.

Conclusion

NiO-NPs might be hazardous to the gastrointestinal system. The results should raise concerns about using NiO-NPs in food-contact appliances and about NiO-NP-containing wastes. Further in vivo and in vitro research should be conducted to explain the specific toxicity mechanism of these particles and reduce their risk to humans.

The Role of PON1 Variants in Disease Susceptibility in a Turkish Population

Paraoxonase 1 (PON1) enzyme plays a major role in antioxidant defense and protects the cells against reactive species. The most common PON1 Q192R and L55M polymorphisms are responsible for a wide variation of PON1 activity, which showed an up to 13-fold interindividual variation among the same genotype. PON1 genotypes were evaluated with the development of pancreatitis, colorectal cancer, and hypothyroidism in a hospital-based, case-control study. Individuals with rs662 G allele had a two-fold risk of developing hypothyroidism. A weak association was found between rs854560 T allele and pancreatitis. The results were preliminary. Further studies with a larger number and detailed biochemical parameters are needed.

Does pendimethalin develop in pancreatic cancer induced inflammation?

Pendimethalin, one of the dinitroaniline group herbicides, is applied for controlling weeds in cereals, legumes and vegetable crops, and has been classified as possible human carcinogen. It is indicated that pendimethalin should arise risks of developing some cancer types; however, there is no data on the effects of pendimethalin on pancreatic cancer-induced inflammation. Injuries resulting from by acute pancreatitis attacks and inflammation are significant factors in the development of pancreatic cancer. Therefore, we investigated whether pendimethalin triggers inflammation as a mechanism of pancreatic cancer development. Parameters related to pancreatic activation, oxidative stress, and inflammation were measured in the human pancreatic (PANC-1) cell line. In the range of 0-100 μM, the levels of chymotrypsin decreased. It should be indicated that the reason for the decrease in chymotrypsin may be the high rates of cell death (20%) observed in the high concentration levels. We observed that pendimethalin significantly induced oxidative damage, while levels of interleukin-6 (IL-6) and interleukin-8 (IL-8) did not change. The obtained results may draw attention to the usage and possible toxic effect of pendimethalin due to oxidative damage induction; however, detailed inflammation mechanisms and other cancer pathways should be investigated.

Reproductive effects of subchronic exposure to acetamiprid in male rats

Acetamiprid, a selective agonist of nicotinic acetylcholine recetors, is one of the most widely used neonicotinoids. There is limited data about toxicity of acetamiprid on male reproductive system. Therefore, the study aimed to investigate the reproductive toxic potential of acetamiprid in male rats orally treated with acetamiprid with low (12.5 mg/kg) medium (25 mg/kg) or high dose (35 mg/kg) for 90 days. According to our results, sperm concentration and plasma testosterone levels decreased in dose dependent manner. Gonadotropin-releasing hormone (GnRH), follicle-stimulating hormeone (FSH), luteinizing hormone (LH) levels increased at low and medium dose groups and acetamiprid caused lipid peroxidation and glutathione (GSH) depletion in the testes. Histologic examinations revealed that acetamiprid induced apoptosis in medium and high dose groups and proliferation index dramatically decreased in high dose group. In conclusion, acetamiprid caused toxicity on male reproductive system in the high dose. The mechanism of the toxic effect may be associated with oxidative stress, hormonal disruptions and apoptosis.

Cupric Oxide Nanoparticles Induce Cellular Toxicity in Liver and Intestine Cell Lines

Purpose: The wide application of cupric oxide nanoparticles (copper (II) oxide, CuO-NPs) in various fields has increased exposure to the kind of active nanomaterials, which can cause negative effects on human and environment health. Although CuO-NPs were reported to be harmful to human, there is still a lack information related to their toxic potentials. In the present study, the toxic potentials of CuO-NPs were evaluated in the liver (HepG2 hepatocarcinoma) and intestine (Caco-2 colorectal adenocarcinoma) cells. Methods: After the characterization of particles, cellular uptake and morphological changes were determined. The potential of cytotoxic, genotoxic, oxidative and apoptotic damage was investigated with several in vitro assays. Results: The average size of the nanoparticles was 34.9 nm, about 2%-5% of the exposure dose was detected in the cells and mainly accumulated in different organelles, causing oxidative stress, cell damages, and death. The IC50 values were 10.90 and 10.04 µg/mL by MTT assay, and 12.19 and 12.06 µg/mL by neutral red uptake (NRU) assay, in HepG2 and Caco-2 cells respectively. Apoptosis assumes to the main cell death pathway; the apoptosis percentages were 52.9% in HepG2 and 45.5% in Caco-2 cells. Comet assay result shows that the highest exposure concentration (20 µg/mL) causes tail intensities about 9.6 and 41.8%, in HepG2 and Caco-2 cells, respectively. Conclusion: CuO-NPs were found to cause significant cytotoxicity, genotoxicity, and oxidative and apoptotic effects in both cell lines. Indeed, CuO-NPs could be dangerous to human health even if their toxic mechanisms should be elucidated with further studies.

Toxic effects of subchronic oral acetamiprid exposure in rats

Acetamiprid, a selective agonist of type-2 nicotinic acetylcholine receptors, is one of the most widely used neonicotinoids. The hepato- and nephrotoxic potential of acetamiprid has not been clarified although it is known to be toxic to other several organ systems, including the nervous, respiratory and immune systems. The present study aimed to investigate acetamiprid liver and kidney toxicity in male rats after a 90-day subchronic exposure to 12.5, 25 and 35 mg/kg. The biochemical and oxidative damage parameters were determined in the plasma and tissue samples as well as histopathological evaluation in the liver and kidney tissues. Acetamiprid caused oxidative damage and affected the liver, denoted by injury markers including the levels of cholesterol, and alanine aminotransferase and aspartate aminotransferase enzymes. There was also a decrease in plasma urea, uric acid and creatinine levels, all of which might result from liver injury. Additionally, acetamiprid was more toxic to the liver than the kidney according to the histopathological examinations. In conclusion, acetamiprid exhibited hepatotoxic potential at all treatment doses on male Sprague Dawley rats.

Gliclazide alone or in combination with atorvastatin ameliorated reproductive damage in streptozotocin-induced type 2 diabetic male rats

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High-fat diet/STZ-induced T2DM caused severe damage in rat male reproductive system.

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ATV treatment slightly improved the reproductive functions.

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GLZ treatment strongly ameliorated spermatogenesis as well as testicular structure.

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ATV/GLZ combination treatment improved sperm morphology and testes structure.

Objectives

Type 2 diabetes (T2DM) is one of the most serious challenges of the 21th century with life-threatening complications and excessive health care costs. In diabetic patients, the main goal in T2DM treatment is the regulation of both blood glucose and lipid levels. For that, Gliclazide (GLZ), an oral antidiabetic, and Atorvastatin (ATV), a lipid lowering agent, are widely used drugs as combination. Diabetes has been reported severe impacts on male reproductive system; however, data obtained about ATV and GLZ treatment alone or in combination are conflicted or insufficient. Herein the effects of ATV and GLZ on male reproductive system in type 2 diabetic male rats have been investigated in the present study.

Methods

T2DM was induced by high-fat diet and single injection of streptozotocin (STZ) (35 mg/kg) in young adult male Sprague-Dawley rats. The diabetic rats were given ATV (10 mg/kg), GLZ (10 mg/kg) and ATV/GLZ (1:1, 10 mg/kg) combination by oral gavage for 28 days. The hormone levels were determined in the cardiac blood samples; and the histopathological and ultrastructural analyses were conducted in the testicular tissues and epididymal sperms.

Results

It was observed that diabetes had severe effects on testicular tissue and spermatogenesis. ATV treatment did not affect sperm count and testes structure (p > 0.05), however ameliorated sperm morphology (p < 0.05). GLZ treatment increased sperm count, and improved sperm morphology, testes structure and spermatogenesis (p < 0.05). ATV/GLZ combination treatment enhanced sperm morphology and improved testicular structure (p < 0.05) while did not affect sperm count (p > 0.05).

Conclusion

GLZ treatment regenerated testicular damage and sperm parameters whether alone or in combination with ATV in diabetic rats without affecting hypothalamic-pituitary-gonadal axis.

P-glycoprotein polymorphism and levothyroxine bioavailability in hypothyroid patients

Objectives

P-glycoprotein (P-gp) contributes to the disposition of a wide variety of drugs; therefore, single nucleotide polymorphisms (SNPs) in the P-gp coding gene might affect its activity. It is well known that personalized medicine, instead of empirical treatment, is a clinically important approach for enhancing responses among patients. Indeed, there is a need to evaluate the association between SNPs of P-gp encoded multidrug resistance genes (MDR1, ABCB1), and the dosage requirements of these drugs. In the present study, we evaluated the association between the dosage of Levothyroxine (L-T4) and three common SNPs (C1236T, G2677T/A and C3435T).

Methods

Genotyping was done using a real-time PCR platform with DNA samples isolated from the venous blood of ninety post thyroidectomy hypothyroid patients. Thyroid hormone levels were measured as routine biochemistry laboratories in the Medical School of Istanbul University.

Results

In the genotype analysis, the minor allele frequencies were 0.48 for C1236T, 0.51 for G2677T/A, and 0.51 for C3435T. In the haplotype-based analysis, T₁₂₃₆T₂₆₇₇T₃₄₃₅ and C₁₂₃₆G₂₆₇₇C₃₄₃₅ were observed as major haplotypes (50.2 and 32.6%, respectively), in agreement with previous studies. The administered dose of L-T4 to achieve physiological thyroid hormone levels was found to be similar in all genotypes and haplotypes, indicating that there is no significant association between MDR1 polymorphisms and L-T4 doses.

Conclusion

Because of conflicted previous reports about the genetic contribution of MDR1 polymorphisms to drug disposition, further studies with large numbers of participants are required to clarify this influence.

In Vitro Evaluation of the Toxicity of Cobalt Ferrite Nanoparticles in Kidney Cell

Objectives

The remarkable properties of hard magnetic cobalt ferrite nanoparticles (CoFe₂O₄-NPs) and their physicochemical stability lead to various applications in different industrial and medical fields. Although CoFe₂O₄-NPs have been reported to cause toxic effects, there is a serious lack of information concerning their effects on the kidneys. In this study, it was aimed to investigate the toxic effects of CoFe₂O₄-NPs on NRK-52E kidney cells.

Materials and Methods

The particle characterisation and cellular uptake were determined using transmission electron microscopy, dynamic light scattering and inductively coupled plasma-mass spectrometry. Then, the cytotoxicity was evaluated by MTT and neutral red uptake assays, the genotoxicity by comet assay, and the apoptotic potentials by Annexin V-FITC apoptosis detection assay with propidium iodide.

Results

After 24 h exposure to CoFe₂O₄-NPs (39±17 nm), it was observed they did not affect the cell viability at concentration ranging from 100 to 1000 µg/mL, but significantly induced DNA damage at concentration ≤100 µg/mL. No apoptotic or necrotic effect was observed in the exposed cells.

Conclusion

According to the results obtained, CoFe₂O₄-NPs are promising for safe use in various applications. However, further in vivo studies are needed to fully understand their mechanisms of action.

Nickel Oxide Nanoparticles Induce Oxidative DNA Damage and Apoptosis in Kidney Cell Line (NRK-52E)

Increasing use of nickel oxide (NiO) nanoparticles in different applications results in high occupational and environmental exposure to them. However, the effect of NiO nanoparticles on human health is still poorly documented. It was aimed to investigate the toxic potentials of NiO nanoparticles on NRK-52E kidney epithelial cells. The following assays were used: the nanoparticle characterization by transmission electron microscopy (TEM) and dynamic light scattering (DLS); the determination of cellular uptake and morphologic changes by TEM and inductively coupled plasma-mass spectrometry (ICP-MS); MTT and neutral red uptake (NRU) assays for cytotoxicity; comet assay for genotoxicity; the determination of malondialdehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG), protein carbonyl (PC) and glutathione (GSH) levels by enzyme-linked immune sorbent assays (ELISA) for the potential of oxidative damage; and Annexin V-FITC apoptosis detection assay with propidium iodide (PI) for apoptosis. The nanoparticles were taken up by the cells and induced dose-dependent DNA damage by comet assay and oxidative damage evidenced by increasing levels of MDA, 8-OHdG, PC and depletion of GSH. At ≥294.0 μg/mL concentration, NiO nanoparticles caused 50% inhibition in cell viability by the cytotoxicity assays. Also, they showed apoptotic/necrotic effects on the cells as well as some morphological changes. We have indicated that their cellular damage effects should raise concern about the safety associated with their applications in consumer products.

In vitro evaluation of cobalt oxide nanoparticle-induced toxicity

Cobalt oxide (Co₃O₄) nanoparticles have applications in nanomedicine and nanotechnology; therefore, any possible adverse effects require thorough investigation. The present study investigated the effects of Co₃O₄ nanoparticles on four different cell lines: liver, HepG2 hepatocellular carcinoma cells; lung, A549 lung carcinoma cells; gastrointestinal, Caco-2 colorectal adenocarcinoma cells; and nervous system, SH-SY5Y neuroblastoma cells. A difference was observed in cell sensitivity toward Co₃O₄ nanoparticles. Co₃O₄ nanoparticles were taken up by all the cell types. However, no cell death was observed in HepG2, Caco-2, or SH-SY5Y cells; only A549 cells showed cytotoxicity at relatively high exposure concentrations. Co₃O₄ nanoparticles did not induce DNA damage or apoptosis in the cell lines tested except in A549. Interestingly, Co₃O₄ nanoparticles induced cellular oxidative damage in all cell types except Caco-2, resulting in increased malondialdehyde and 8-hydroxydeoxyguanosine levels and decreased glutathione levels. According to our results, it could be indicated that high concentrations of Co₃O₄ nanoparticles affected the pulmonary system but were unlikely to affect the liver, nervous system, or gastrointestinal system. Co₃O₄ nanoparticles might be safely used for industrial, commercial, and nanomedical applications if dose rates are adjusted depending on the route of exposure. However, further in vivo and in vitro studies are required to confirm the safety of Co₃O₄ nanoparticles.

Investigation of the toxicity of bismuth oxide nanoparticles in various cell lines

Nanoparticles have been drawn attention in various fields ranging from medicine to industry because of their physicochemical properties and functions, which lead to extensive human exposure to nanoparticles. Bismuth (Bi)-based compounds have been commonly used in the industrial, cosmetic and medical applications. Although the toxicity of Bi-based compounds was studied for years, there is a serious lack of information concerning their toxicity and effects in the nanoscale on human health and environment. Therefore, we aimed to investigate the toxic effects of Bi (III) oxide (Bi₂O₃) nanoparticles in liver (HepG2 hepatocarcinoma cell), kidney (NRK-52E kidney epithelial cell), intestine (Caco-2 colorectal adenocarcinoma cell), and lung (A549 lung carcinoma cell) cell cultures. Bi₂O₃ nanoparticles (∼149.1 nm) were easily taken by all cells and showed cyto- and genotoxic effects. It was observed that the main cell death pathways were apoptosis in HepG2 and NRK-52E cells and necrosis in A549 and Caco-2 cells exposed to Bi₂O₃ nanoparticles. Also, the glutathione (GSH), malondialdehyde (MDA), and 8-hydroxy deoxyguanine (8-OHdG) levels were significantly changed in HepG2, NRK-52E, and Caco-2 cells, except A549 cell. The present study is the first to evaluate the toxicity of Bi₂O₃ nanoparticles in mammalian cells. Bi₂O₃ nanoparticles should be thoroughly assessed for their potential hazardous effects to human health and the results should be supported with in vivo studies to fully understand the mechanism of their toxicity.

In Vitro Toxicological Assessment of Cobalt Ferrite Nanoparticles in Several Mammalian Cell Types

Nanoparticles have been widely used in various fields due to the superior physicochemical properties and functions. As a result, human exposure to nanoparticles increases dramatically. Previous researches have shown that nanoparticles could travel through the respiratory, digestive system, or skin into the blood and then to the secondary organs such as the brain, heart, and liver. Besides, the nanoparticle toxicity is controversial and dependent on the sensitivity of the cell type, route of exposure, and condition, as well as their characteristics. Similarly, cobalt ferrite nanoparticles (CoFe₂O₄-NPs) have been used in different industrial fields, and have also various application possibilities in medical and biomedical fields. CoFe₂O₄-NPs induce toxic responses in various organisms such as human, mice, and algae. However, there is a serious deficit of information concerning their effects on human health and the environment. We aimed to investigate the toxic effects of CoFe₂O₄-NPs on liver (HepG2), colon (Caco-2), lung (A549), and neuron (SH-SY5Y) cells, which reflect different exposure routes in vitro, by using various toxicological endpoints. The cytotoxicity, genotoxicity, oxidative damage, and apoptosis induction of CoFe₂O₄-NPs (39 ± 17 nm) were evaluated. After 24 h, the nanoparticles decreased cell viability at ≤100 μg/mL, while increasing viability at >100 μg/mL. CoFe₂O₄-NPs induced DNA and oxidative damage with increased malondialdehyde (MDA) and 8-hydroxy deoxyguanosine (8-OHdG) levels and decreased glutathione (GSH) levels with no change in protein carbonyl (PC) levels. CoFe₂O₄-NPs had apoptotic effect in HepG2 and Caco-2 cells in a concentration-dependent manner and necrotic effects on SH-SY5Y and A549 cells. Consequently, the adverse effects of CoFe₂O₄-NPs should raise concern about their safety in consumer products.

Characterization and toxicity of hospital wastewaters in Turkey

The aim of the study was to present first preliminary characterization of Turkish hospital wastewaters, their environmental risk, and a method for toxicity assessment. The hospital wastewater samples were collected from two of the largest medical faculty hospitals and a training and research hospital in Istanbul, Turkey. The samples from the selected hospitals were taken as grab samples on March 2014. Overall, 55 substances including pharmaceuticals and their metabolites, pesticides, and corrosion inhibitors were analyzed in all hospital wastewaters. Analysis of toxicity and the antibiotic resistance bacteria were investigated in addition to the chemical analysis in the wastewater of one hospital. Hazard quotients (HQs) and toxic units (TUs) were calculated as basis of the environmental risk assessment. Fourteen pharmaceuticals in hospital wastewater (HWW) were classified as "high risk" with HQ > 10. HQ_HWW values higher than 100 were determined for five antibiotics and one analgesic, namely, ofloxacin, clarithromycin, ciprofloxacin, sulfapyridine, trimethoprim, and diclofenac. Ofloxacin with an HQ_HWW of 9090 was observed to be the most hazardous compound. HQ and TU values of the wastewater treatment plant (WWTP) effluent dropped significantly due to dilution in the sewer. Further elimination by biological degradation or adsorption was observed only in some cases. However, the decreased HQ_WWTPeffluent values do not the change environmental load significantly. Therefore, advanced treatment processes should be applied to remove the persistent compounds. In combination with the results on antibiotic resistance, we would prefer on-site treatment of hospital wastewater. Toxicological assessment was performed using cytotoxic and mutagenic screening tests. The results of the Ames assay showed that the native hospital wastewaters had strongly mutagenic activity with a ≤10-fold increase relative to negative controls. The mutagenic potentials of the samples were generally concentration and metabolic activation dependent. Multiple antibiotic resistances were demonstrated with the tested isolates to ciprofloxacin, trimethoprim, and ceftazidime. This study demonstrates that the hospital wastewaters in Istanbul exhibit strong environmental and toxicological risks, as well as high multiple drug resistance to commonly used antibiotics.

CYP2C9, CYPC19 and CYP2D6 gene profiles and gene susceptibility to drug response and toxicity in Turkish population

Pharmacogenetics is a vast field covering drug discovery research, the genetic basis of pharmacokinetics and dynamics, genetic testing and clinical management in diseases. Pharmacogenetic approach usually focuses on variations of drug transporters, drug targets, drug metabolizing enzymes and other biomarker genes. Cytochrome P450 (CYP) enzymes, an essential source of variability in drug-response, play role in not only phase I-dependent metabolism of xenobiotics but also metabolism of endogenous compounds such as steroids, vitamins and fatty acids. CYP2C9, CYP2C19 and CYP2D6 enzymes being highly polymorphic are responsible for metabolism of a variety of drug groups. In the study, it was determined the genotype and allele frequency of CYP2C9∗2, CYP2C19∗3, CYP2C19∗2, CYP2C19∗3, CYP2C19∗17, CYP2D6∗9 and CYP2D6∗41, very common and functional single-nucleotide polymorphisms (SNPs), in healthy volunteers. The genotype distributions were consistent with the Hardy-Weinberg equilibrium in the population (p > 0.05). It is believed that the determination of polymorphisms in the enzymes may be beneficial in order to prevention or reduction in adverse effects and death. The recessive allele frequencies of CYP2C9∗2, CYP2C19∗3, CYP2C19∗2, CYP2C19∗3, CYP2C19∗17, CYP2D6∗9 and CYP2D6∗41 were 11, 13, 12, 13, 25, 4 and 15%, respectively. According to the obtained results, the carriers of CYP2D6∗9 variant allele should be received higher doses of the drugs metabolizing with this enzyme in Turkish population, while the carriers of other variant alleles do not generally have any requirement of dose regimen.

In Vitro Toxicological Assessment of Magnesium Oxide Nanoparticle Exposure in Several Mammalian Cell Types

Worldwide researchers have rising concerns about magnesium-based materials, especially magnesium oxide (MgO) nanaoparticles, due to increasing usage as promising structural materials in various fields including cancer treatment. However, there is a serious lack of information about their toxicity at the cellular and molecular levels. In this study, the toxic potentials of MgO nanoparticles were investigated on liver (HepG2), kidney (NRK-52E), intestine (Caco-2), and lung (A549) cell lines. For the toxicological assessment, the following assays were used: the particle characterization by transmission electron microscopy, the determination of cellular uptake by inductively coupled plasma-mass spectrometry, MTT and neutral red uptake assays for cytotoxicity, comet assay for genotoxicity, and the determination of malondialdehyde (MDA), 8-hydroxydeoxyguanosine, protein carbonyl, and glutathione levels by enzyme-linked immune sorbent assays for the potential of oxidative damage and annexin V-fluorescein isothiocyanate (FITC) apoptosis detection assay with propidium iodide (PI) for apoptosis. Magnesium oxide nanoparticles were taken up by the cells depending on their concentration and agglomeration/aggregation potentials. Magnesium oxide nanoparticles induced DNA (≤14.27 fold) and oxidative damage. At a concentration of ≥323.39 µg/mL, MgO nanoparticles caused 50% inhibition in cell viability by 2 different cytotoxicity assays. The cell sensitivity to cytotoxic and genotoxic damage induced by MgO nanoparticles was ranked as HepG2 < A549 < Caco-2 < NRK-52E. Although it was observed that MgO nanoparticles induced apoptotic effects on the cells, apoptosis was not the main cell death. DNA damage, cell death, and oxidative damage effects of MgO nanoparticles should raise concern about the safety associated with their applications in consumer products.

The genetic profiles of CYP1A1, CYP1A2 and CYP2E1 enzymes as susceptibility factor in xenobiotic toxicity in Turkish population

Evaluation and sequencing of heritable alterations in the human genome and the large-scale identification of gene polymorphism for understanding the genetic background of individuals in response to potential toxicants are provided by toxicogenetics. Cytochrome P450 (CYP) enzymes play role not only phase I-dependent metabolism of xenobiotics but also metabolism of endogenous compounds. CYP1A1, CYP1A2 and CYP2E1 enzymes, which are in phase I enzymes, are responsible for metabolic activation and detoxification of several chemical compounds. In the present study, it was determined the genotype and allele frequency of CYP1A1∗2A, CYP1A2∗1C, CYP1A2∗1F, CYP2E1 and CYP2E1∗6, very common and functional single-nucleotide polymorphisms (SNPs), in Turkish healthy volunteers. It is believed that the determination of polymorphisms in the enzymes may be beneficial to prevent and reduce and adverse effects and death in response to drugs. The allele frequencies of these genes were 24%, 9%, 33%, 42%, and 12%, respectively. In the present study, the genotype profile of Turkish population was determined about critical enzymes for xenobiotic metabolism. It is suggested that the obtained results might be beneficial in order to dose adjustment of drugs and prevention of adverse reactions, and further investigation about mentioned enzymes and their polymorphisms.

Colloidal nanocarriers for the enhanced cutaneous delivery of naftifine: characterization studies and in vitro and in vivo evaluations

In topical administration of antifungals, the drugs should pass the stratum corneum to reach lower layers of the skin in effective concentrations. Thus, the formulation of antifungal agents into a suitable delivery system is important for the topical treatment of fungal infections. Nanosized colloidal carriers have gained great interest during the recent years to serve as efficient promoters of drug penetration into the skin. Microemulsions are soft colloidal nanosized drug carriers, which are thermodynamically stable and isotropic systems. They have been extensively explored for the enhancement of skin delivery of drugs. This study was carried out to exploit the feasibility of colloidal carriers as to improve skin transport of naftifine, which is an allylamine antifungal drug. The microemulsions were formulated by construction of pseudoternary phase diagrams and composed of oleic acid (oil phase), Kolliphor^® EL or Kolliphor^® RH40 (surfactant), Transcutol^® (cosurfactant), and water (aqueous phase). The plain and drug-loaded microemulsions were characterized in terms of isotropy, particle size and size distribution, pH value, refractive index, viscosity, and conductivity. The in vitro skin uptake of naftifine from microemulsions was studied using tape stripping technique in pig skin. The drug penetrated significantly into stratum corneum from microemulsions compared to its marketed cream (P<0.05). Moreover, the microemulsion formulations led to highly significant amount of naftifine deposition in deeper layers of skin than that of commercial formulation (P<0.001). Microemulsion–skin interaction was confirmed by attenuated total reflectance – Fourier transformed infrared spectroscopy data, in vitro. The results of the in vivo tape stripping experiment showed similar trends as the in vitro skin penetration study. Topical application of the microemulsion on human forearms in vivo enhanced significantly the distribution and the amount of naftifine penetrated into the stratum corneum as compared to the marketed formulation (P<0.05). The relative safety of the microemulsion formulations was demonstrated with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide viability test. This study indicated that the nanosized colloidal carriers developed could be considered as an effective and safe topical delivery system for naftifine.

Telomerase Reverse Transcriptase (TERT) Gene Variations and Susceptibility of Colorectal Cancer

AIM

Colorectal cancer is the third most common cause of cancer-related mortality. Previous studies demonstrated increased telomerase activity in colorectal cancer tissue and suggested a prognostic value for patients with colorectal carcinoma. Telomerase reverse transcriptase (TERT), one of the main functional subunits of the telomerase, is an important factor in modulating telomerase activity, telomere length, and genomic stability. However, there are few studies that have addressed the association between genetic variation at TERT and the risk of colorectal cancer.

METHOD

We evaluated the influence of three common single-nucleotide polymorphisms (SNPs) of the TERT gene (rs2853669, rs2736100, rs2736098) on susceptibility to colorectal cancer in 104 patients and 135 controls in a Turkish population.

RESULTS

We observed that rs2736098 was significantly associated with increased risk of colorectal cancer (OR = 2.53; 95% CI = 1.26-5.10; p = 0.008). On the other hand, rs2736100 and rs2853669 showed no association with colorectal cancer (p ≥ 0.128).

CONCLUSION

These findings are the first results of TERT allele distributions in the Turkish population and also provide increased understanding with respect to colorectal cancer etiology.

Zinc oxide nanoparticles induced cyto- and genotoxicity in kidney epithelial cells

The wide uses of zinc oxide nanoparticles (nano-ZnO) in industrial, cosmetics, medicine, food production and electronics associate with increase in occupational and public exposure. Although, toxicity of nano-ZnO has been extensively studied on many different cell types and animal systems, there is a significant lack of toxicological data focus on nephrotoxic potential of nano-ZnO. In this study, the cyto- and genotoxic effects of nano-ZnO on rat kidney epithelial cells (NRK-52E) were investigated by using different assays. Nano-ZnO (10-50 nm of sizes) were synthesized by sol-gel method. For the cytotoxic effect of nano-ZnO, mean of inhibition concentration (IC50) values in cell line was evaluated by MTT, Trypan Blue (TB) and Neutral Red Uptake (NRU) assays at 25.0-100.0 μg/mL exposure concentrations. Nano-ZnO showed cytotoxic activity by acting on different targets in renal cells, with IC50 ≥ 73.05 μg/mL. Comet assay was used to evaluate the genotoxicity of nano-ZnO (12.5-50.0 μg/mL). Nano-ZnO caused statistically significant DNA damage. Our results highlight the important risk of cyto- and genotoxic effects of nano-ZnO over the kidney.

Indole-based hydrazide-hydrazones and 4-thiazolidinones: synthesis and evaluation as antitubercular and anticancer agents

A new series of indolylhydrazones (6) and indole-based 4-thiazolidinones (7, 8) have been designed, synthesized and screened for in vitro antitubercular activity against Mycobacterium tuberculosis H37Rv. 4-Thiazolidinone derivatives 7g-7j, 8g, 8h and 8j displayed notable antituberculosis (anti-TB) activity showing 99% inhibition at MIC values ranging from 6.25 to 25.0 µg/ml. Compounds 7g, 7h, 7i, 8h and 8j demonstrated anti-TB activity at concentrations 10-fold lower than those cytotoxic for the mammalian cell lines. The indolylhydrazone derivative 6b has also been evaluated for antiproliferative activity against human cancer cell lines at the National Cancer Institute (USA). Compound 6b showed an interesting anticancer profile against different human tumor-derived cell lines at sub-micromolar concentrations with obvious selectivity toward colon cancer cell line COLO 205.

Investigation on the toxic potential of Tribulus terrestris in vitro

CONTEXT

Tribulus terrestris L. (Zygophyllaceae) has been commonly used to energize, vitalize, and improve sexual function and physical performance in men.

OBJECTIVE

This study investigates the potential cytotoxic and genotoxic, and endocrine disrupting activities of T. terrestris in vitro.

MATERIALS AND METHODS

The whole T. terrestris plant was extracted with water, methanol, and chloroform. The genotoxic potential of T. terrestris extracts at 3-2400 µg/mL was assessed by Comet assay in a rat kidney cell line (NRK-52E) and by Ames assay in Salmonella typhimurium TA98 and TA100 strains. Endocrine disrupting effects of the extracts at concentrations of 0.22-25 000 µg/mL were assessed by YES/YAS assay in Saccharomyces cerevisiae. Cytotoxic activity of the extracts was determined by the MTT test in NRK-52E cells. The different exposure times were used for four tests (3-48 h).

RESULTS

The methanol extract of T. terrestris IC50 value was 160 µg/mL. The other extracts did not show cytotoxic effects. In the Comet and Ames genotoxicity assays, none of the extracts possessed genotoxic activities at concentrations of 0-2400 µg/mL. Only the water extract of T. terrestris induced frame shift mutations after metabolic activation. The water extract also showed estrogenic activity by YES/YAS assay in S. cerevisiae at concentrations ≥27 µg/mL (≥2.6-fold), while the other T. terrestris extracts had anti-estrogenic properties.

CONCLUSION

Tribulus terrestris had estrogenic and genotoxic activities. The study was useful in determining its toxicological effects and the precautions regarding consumption.

Toxic potentials of ten herbs commonly used for aphrodisiac effect in Turkey

BACKGROUND/AIM

Sexual dysfunction is a serious problem worldwide. In Turkey, herbal products are used by some people suffering from sexual dysfunction. Despite their therapeutic advantages, some constituents of herbs are potentially toxic and pose health risks because they can be bought from the market without a prescription. Therefore, we aimed to determine the safety of herbs possessing aphrodisiac effects, chosen on the basis of their frequency of medicinal use and commercial importance in Turkey.

MATERIALS AND METHODS

Ten herbs (Anethum graveolens, Carthamus tinctorius, Citrus aurantium, Cocos nucifera, Glycyrrhiza glabra, Melissa officinalis, Nigella arvensis, Pinus pinea, Prunus mahaleb, and Zingiber officinale) were extracted with water, methanol, and chloroform. The cyto- and genotoxic potentials of the extracts were assessed using an MTT test on a rat kidney cell line and an Ames assay in Salmonella typhimurium strains, respectively.

RESULTS

In the cytotoxic evaluation, IC50 values were 1.51-31.4 mg/mL for the methanol and chloroform extracts, while the water extracts were not cytotoxic. In the genotoxic evaluation, it was revealed that the water extracts had more mutagenic activity than the chloroform and methanol extracts. Water extract of M. officinalis was shown to have the most genotoxic activities to TA100 (±S9) and TA98 (-S9).

CONCLUSION

These results might be useful in determining the toxic effects of herbs and lead to precautions being taken in regards to their consumption.

Genetic variations in the xenobiotic-metabolizing enzymes CYP1A1, CYP1A2, CYP2C9, CYP2C19 and susceptibility to colorectal cancer among Turkish people

Cytochrome P450 (CYP) enzymes are genetically polymorphic and play key roles in the metabolism of xenobiotics. Colorectal cancer (CRC) is one of the most common malignant tumors in Turkey as well as in the world. In this study, it was aimed both to evaluate the effects of CYP variants on the susceptibility to CRC and to predict the individual response of the Turkish people to xenobiotics metabolized by CYP enzymes. For that, we assessed the association of CYP1A1, CYP1A2, CYP2C9, and CYP2C19 polymorphisms in patients with CRC in the Turkish population through a case-control study. Distributions of the variants were determined in 104 patients with CRC and 183 healthy volunteers. As results, CYP1A1 6235T/C was significantly associated with CRC risk (odds ratio [OR]=2.53; 95% confidence interval [CI]=0.99-6.45; p=0.046). In a haplotype-based analysis, CYP1A1 haplotype C6235-A2455 might be associated with the development of CRC (OR=2.70; 95% CI=0.58-5.90; p=0.046). We believe that the findings are the first results of CYP allele distributions in the Turkish population and provide an understanding of the epidemiological studies that correlate therapeutic approaches and etiology of CRC especially in Turkish patients.

Associations between the functional polymorphisms in the ABCB1 transporter gene and colorectal cancer risk: a case-control study in Turkish population

Colorectal cancer is among the most common cancer types in the world and its etiology involves the interaction of genetic and environmental factors. ABCB1 is highly expressed in the apical surface of colonic epithelial cells and acts as an efflux pump by transporting toxic endogenous substances, drugs and xenobiotics out of cells. ABCB1 polymorphisms may either change its protein expression or alter its function. Several studies have reported a possible association between ABCB1 variants and colorectal cancer, but no consistent conclusion has been arrived at. Therefore, we aimed to investigate the relationship between colorectal cancer and the functional common variants of ABCB1 (1236C > T; 2677G > T/A; 3435C > T). The distributions of the variants were determined in 103 patients with colorectal cancer and 150 healthy volunteers using polymerase chain reaction-restriction fragment length polymorphism methods. ABCB1 1236C > T was statistically significantly associated with colorectal cancer risk (OR, odd ratio = 1.91; 95% CI, confidence interval = 1.09-3.35; p = 0.034). In haplotype-based analysis, the proportion of individuals with the ABCB1 haplotype C1236-G2677-T3435 was significantly more common in patients than in controls (OR = 11.96; 95% CI = 2.59-55.32; p = 0.0004). We believe that the findings may be beneficial to the development of efficacious preventive strategies and therapies for colorectal cancer.

Acute pancreatitis is associated with Ser608Leu iNOS polymorphism

Acute pancreatitis is an initially localized inflammation of the pancreatic gland. The precise mechanisms by which aetiological factors induce acute pancreatitis are not yet known, but when initiated, common inflammatory pathways seem to be involved, with cytokines being their components of major importance. The inducible nitric oxide synthase gene (iNOS) encodes an enzyme involved in the pathway of reactive oxygen species and induced in response to infection, cytokines. iNOS is capable of generating large quantities of nitric oxide produced during inflammation. The objective of this study was to investigate the association between acute pancreatitis risk and iNOS polymorphisms. The studied single-nucleotide polymorphisms (SNPs) were Ser608Leu, resulting in an amino acid substitution, and 1173C/T and 954G/C, both in the gene promoter region that is linked to increased enzyme expression, leading to higher NO production. The genotypes for the three SNPs were determined in 93 patients with acute pancreatitis and 60 controls without pancreatitis or cancer that were matched for age and gender. Data analysis was done by conditional logistic regression. It was found that the Ser608Leu polymorphism was more frequent among cases with acute pancreatitis compared to controls (OR = 2.88; 95% CI: 1.49-5.57; P = 0.002), although no individually statistically significant associations for the other SNPs studied were detected. We suggest that iNOS Ser608Leu can be used as a marker to define the risk of acute pancreatitis.

Acrylamide-induced oxidative stress in human erythrocytes

Acrylamide (AA), a widely used industrial chemical, is shown to be neurotoxic, mutagenic and carcinogenic. This study was carried out to investigate the effects of different doses of AA on lipid peroxidation (LPO), haemolysis, methaemoglobin (MetHb) and antioxidant system in human erythrocytes in vitro. Erythrocyte solutions were incubated with 0.10, 0.25, 0.50 and 1.00 mM of AA at 37°C for 1 hour. At the end of the incubation, malondialdehyde (MDA), an end product of LPO, was determined by liquid chromatography (LC) while total glutathione, reduced glutathione (GSH) levels, activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) enzymes and the rates of haemolysis and MetHb were determined by spectrophotometric methods. All of the studied concentrations of AA increased MetHb formation and SOD activity, and induced MDA formation and haemolysis due to the destruction of erythrocyte cell membrane. AA caused a decrease in the activities of GSH-Px, CAT and GSH levels. However, these effects of AA were seen only at higher concentrations than AA intake estimated for populations in many countries. We suggest that LPO process may not be involved in the toxic effects of AA in low concentrations, although the present results showed that the studied concentrations of AA exert deteriorating effects on antioxidant enzyme activities, LPO process and haemolysis.