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.

An in vitro analysis of an innovative standardized phospholipid carrier-based Melissa officinalis L. extract as a potential neuromodulator for emotional distress and related conditions.

Background: Melissa officinalis L. (MO), commonly known as lemon balm, a member of the mint family, is considered a calming herb. In various traditional medicines, it has been utilized to reduce stress and anxiety and promote sleep. A growing body of clinical evidence suggests that MO leaf extract supplementation possesses considerable neuropharmacological properties. However, its possible mechanism of action largely remains unknown. Objective: In the present in vitro studies, we comparatively investigated the central nervous system (CNS)-calming and antioxidative stress properties of an innovative standardized phospholipid carrier-based (Phytosome™) MO extract (Relissa™) vs. an unformulated dry MO extract. Methods: The neuropharmacological effect of the extract was studied in the anti-depressant enzymes γ-aminobutyrate transaminase (GABA-T) and monoamine oxidase A (MAO-A) assays and SH-SY5Y cells brain-derived neurotrophic factor (BDNF) expression assay. The neuroprotective effect of the extract against oxidative stress was assessed in SH-SY5Y cell-based (H2O2-exposed) Total Antioxidant Status (TAS) and Total Reactive Oxygen Species (ROS) assays. The cytotoxic effect of the extract was evaluated using MTT and LDH assays. The extract antioxidant effect was also evaluated in cell-free chemical tests, including TEAC-ABTS, DPPH, Ferric Reducing Antioxidant Power (FRAP), Oxygen Radical Antioxidant Capacity (ORAC), and Hydroxyl Radical Antioxidant Capacity (HORAC) assays. Results: Relissa™ exhibited high GABA-T inhibitory activity, IC50 (mg/mL) = 0.064 vs. unformulated dry MO extract, IC50 (mg/mL) = 0.27. Similar inhibitory effects were also observed for MAO-A. Relissa™ demonstrated an improved neuroprotective antioxidant effect on SH-SY5Y cells against H2O2-induced oxidative stress. Compared to unformulated dry MO extract, Relissa™ exerted high protective effect on H2O2-exposed SH-SY5Y cells, leading to higher cells BDNF expression levels. Moreover, cell-free chemical tests, including TEAC-ABTS, DPPH radical scavenging, FRAP, ORAC, and HORAC assays, validated the improved antioxidant effect of Relissa™ vs. unformulated dry MO extract. Conclusion: The results of the present study support the neuromodulating and neuroprotective properties of Relissa™, and its supplementation may help in the amelioration of emotional distress and related conditions.

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, NFKß 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.

The sesquiterpenoid valerenic acid protects neuronal cells from the detrimental effects of the fungicide benomyl on apoptosis and DNA oxidation.

BACKGROUND: Valerenic acid (VA), a sesquiterpenoid of the plant Valeriana officinalis, has attracted attention of the research community due to its potential positive role against neurodegenerative diseases induced by chemicals. However, the relevant evidence in the literature is scarce. Therefore, this study aimed to examine the putative protective role of VA on the toxic effects of the fungicide benomyl on SH-SY5Y neural cells. METHODS: Cell viability was determined via the MTT and NRU assays, DNA damage was assessed via comet assay and apoptosis was evaluated through the expression of relevant genes. RESULTS: According to the results, exposure of the cells to benomyl enhanced viability inhibition and promoted DNA damage and apoptosis since the expression levels of the genes coding for MAPK8, NF-kB, Bax, Caspase-9 and Caspase-3 were increased. Treatment of the cells with VA ameliorated these effects in a concentration dependent manner. CONCLUSION: It is concluded that the molecular mechanism through which benomyl exerts its toxic action appears to depend on DNA oxidation and apoptosis induction. Furthermore, VA, a plant-derived compound is a protective antioxidant against pesticide-induced toxicity. Therefore, herbs, extracts and compounds of plant origin could be used as nutritional supplements that back up the beneficial role of medicine in neurodegenerative diseases.

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.

In Vitro Cytotoxicity and Oxidative Stress Evaluation of Valerian (Valeriana officinalis) Methanolic Extract in Hepg2 and Caco2 Cells

Objectives: Traditional treatment methods are becoming popular and commonly used in many societies and have become the first treatment option for most people. While some of these methods are helpful, they can interact with medications the patient is taking for another disease and cause a variety of life-threatening risks. Valerian (catweed) plant is used in traditional medicine as a sleep aid due to its sedative effects. Valerian may also exert anticancer effect in vitro. Materials and Methods: In this study, the cytotoxicty and oxidative stress effects of valerian root extract were evaluated in human liver hepatocellular carcinoma (Hepg2) and human colorectal adenocarcinoma (Caco2) cell lines. The cytotoxicity was evaluated via the 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide test. Total reactive oxygen species analysis was performed via a 2',7'-dichlorodihydrofluorescein diacetate assay in flow cytometry. Results: Inhibition concentration 50 values were calculated as 936.6 and 1097.5 µg/mL in the Hepg2 and Caco2 cell lines, respectively. It was observed that valerian root extract did not induce oxidative stress in HepG2 and Caco2 cell lines. Conclusion: These results indicate that the use of valerian root extract as an alternative method in cancer treatment may not be effective and may cause a risk for public health. On the other hand, it may be safe at recommended tolerated concentrations since it does not cause oxidative stress.

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

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.

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.

Ameliorative Effects of the Sesquiterpenoid Valerenic Acid on Oxidative Stress Induced in HepG2 Cells after Exposure to the Fungicide Benomyl.

Valerenic acid (VA) is a sesquiterpenoid and a phytoconstituent of the plant valerian used for sleeping disorders and anxiety. The frequency of using herbal components as therapeutic nutritional agents has increased lately. Their ability to improve redox homeostasis makes them a valuable approach against harmful xenobiotics. The purpose of this study was to evaluate the putative beneficial role of VA against the redox-perturbating role of the fungicide benomyl in HepG2 human liver cells in terms of oxidative stress in the cellular environment and in endoplasmic reticulum (ER). Benomyl increased cell total oxidant status and reactive oxygen species production and decreased total antioxidant status. The expression of genes coding for antioxidant molecules, namely, heme oxygenase-1, alpha glutathione s-transferase, NF-ĸB, and liver fatty acid binding protein, were decreased due to benomyl. VA ameliorated these effects. Benomyl also increased ER-stress-related molecules such as endoplasmic reticulum to nucleus signaling 1 protein, glucose-regulated protein 78, and caspase-12 levels, and VA acted also as a preventive agent. These results indicate that VA exerts ameliorative effects after benomyl-induced oxidative stress. VA, a widely used nutritional supplement, is a compound with potent antioxidant properties, which are valuable for the protection of cells against xenobiotic-induced oxidative damage.

Assessment of perfluorooctanoic acid toxicity in pancreatic cells.

Perfluorooctanoic acid (PFOA) was classified as a possible carcinogen for humans (Group 2B). The in vivo studies have reported that PFOA might lead to hepatic, testicular and pancreatic toxicities and cancers. However, its mechanisms in pancreatic tissue are still unclear and insufficiently discussed. Since inflammation is the most important mechanism leading to pancreatitis and ultimately cancer, we aimed to investigate the role of inflammation in PFOA-induced pancreatic toxicity. To this end, the effect of PFOA on cell viability, apoptosis, oxidative stress and inflammatory pathways, as well as levels of trypsin and chymotrypsin were assessed in the human pancreatic cell line (PANC-1). PFOA caused cell death in concentration dependent manner (IC50 195.6 µM), apoptosis appears to be the major cell death pathway. A significant increase in trypsin and chymotrypsin levels was detected in PANC-1 cells. Oxidative stress parameters and gene expression level-related inflammation were significantly altered with PFOA exposure. These results indicate oxidative stress plays a role in PFOA-induced pancreatic toxicity and highlight the incidence of inflammation with PFOA exposure. However, this data is preliminary. Advanced in vivo and in vitro mechanistic studies should be conducted in order to better understand the inflammation-induced oxidative stress role in the toxicity of PFOA.

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.

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.

Benomyl, a benzimidazole fungicide, induces oxidative stress and apoptosis in neural cells.

Fungicides are used in the agricultural sector against the harmful action of fungi, however they are potential toxic agents for the environment and the living organisms. Benomyl is a widely encountered benzimidazole fungicide that exerts its toxicity via inhibiting microtubule formation in the nervous system and the male reproductive and endocrine systems, whilst it is a known teratogen. Since toxic effects of benomyl and its molecular mechanisms are not fully understood, we aimed to detect its neurotoxic potential via evaluating cytotoxicity, oxidative stress and apoptosis in SH-SY5Y cell line. The cells were incubated with benomyl in a concentration range between 1 and 6 µM for 24 h. Our results indicated a concentration-dependent enhancement of reactive oxygen species measured through flow cytometry and DNA damage evaluated via the comet assay. Additionally, it induced apoptosis in all tested concentrations. According to the findings of the present study, benomyl is a xenobiotic, which it appears to exert its toxic action via a redox-related mechanism that, finally, induces cell apoptosis and death. We believe that this study will offer further insight in the toxicity mechanism of benomyl, although further studies are recommended in order to elucidate these mechanisms in the molecular level.

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

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.

Inflammation and oxidative stress are key mediators in AKB48-induced neurotoxicity in vitro.

Synthetic cannabinoids were introduced into market in early 2000s; since these "legal highs" are dramatically popular among youth, it becomes a deadly problem. Synthetic cannabinoids have high affinity to cannabinoid receptors; leading to various clinical symptoms. AKB48 (Apinaca) has been classified as a third-generation synthetic cannabinoid for the first time in 2014. The toxicity profile of AKB48 is unclear due to little information that mainly obtained from clinical and forensic cases; however, it is believed to be similar with other psychoactive substances. Thus, we aimed to investigate the possible toxicity mechanisms of AKB48 in SH-SY5Y (human bone marrow neuroblastoma) cell line. IC50 value of AKB48 was calculated as 160.91 µM by MTT assay. AKB48 treatment enhanced (≥1.2-fold) the fluorescence intensity indicating increased reactive oxygen species production; however, glutathione levels did not changed in the range of 25-200 µM exposure concentrations. Cannabinoid type-1 receptor (CB1) expression was increased ≥15-fold in the range of 25-50 µM of AKB48, while cannabinoid type-2 receptor (CB2) did not expressed in SH-SY5Y cells. Interleukin-6 (IL-6) and tumor necrosis factor-α (TNF- α) were up-regulated with a dose-dependent manner, and the profiles were almost identical; however, mitogen-activated protein kinase 8 (MAPK 8) was only upregulated with 25 µM of AKB48 and nuclear factor kappa B (NF-ĸB) did not change. Our results should raise the concerns about the safety associated with synthetic cannabinoids uses.

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.

Association between genetic polymorphism and levothyroxine bioavailability in hypothyroid patients.

Thyroid hormones play a vital role in the human body for growth and differentiation, regulation of energy metabolism, and physiological function. Hypothyroidism is a common endocrine disorder, which generally results from diminished normal circulating concentrations of serum thyroxine (fT4) and triiodothyronine (fT3). The primary choice in hypothyroidism treatment is oral administration of levothyroxine (L-T4), a synthetic T4 hormone, as approximately 100-125 µg/day. Generally, dose adjustment is made by trial and error approach. However, there are several factors which might influence bioavailability of L-T4 treatment. Genetic background could be an important factor in hypothyroid patients as well as age, gender, concurrent medications and patient compliance. The concentration of thyroid hormones in tissue is regulated by both deiodinases enzyme and thyroid hormone transporters. In the present study, it was aimed to evaluate the effects of genetic differences in the proteins and enzymes (DIO1, DIO2, TSHR, THR and UGT) which are efficient in thyroid hormone metabolism and bioavailability of L-T4 in Turkish population. According to our findings, rs225014 and rs225015 variants in DIO2, which catalyses the conversion of thyroxine (pro-hormone) to the active thyroid hormone, were associated with TSH levels. It should be given lower dose to the patients with rs225014 TT and rs225015 GG genotypes in order to provide proper treatment with higher effectivity and lower toxicity.

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.

The Effect of the CYP1A1*2A Allele on Colorectal Cancer Susceptibility in a British Population.

AIM: Colorectal cancer (CRC) is a major health problem despite recent improvements in overall survival rates. Genetic polymorphisms affecting carcinogen biotransformation or DNA repair play pivotal roles in the carcinogenesis process. CYP1A1*2A (6235 T/C, rs4646903, MspI) is thought to be associated with an increased risk of CRC because of its role in metabolic activation of polycyclic aromatic hydrocarbons; however, the results of previous studies are conflicting. In this study, a possible association between the CYP1A1*2A allele and CRC and the effect of cigarette smoking on this risk were examined in a British population. MATERIAL AND METHODS: A prospective case-control study including 200 cases and 254 age-and-sex-matched controls was conducted with British participants from the north-east of England. Genotyping of the CYP1A1*2A allele was performed using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. RESULTS: CYP1A1*2A was not associated with CRC development (OR = 1.566; 95% confidence interval [CI] = 0.90-2.73; p = 0.12). However, it was observed that C allele-carrying individuals who had smoked within the past 5 years had a significant risk of CRC (OR = 2.28; 95% CI = 1.07-4.86; p = 0.043). CONCLUSION: These data are of interest in understanding CRC etiology and identifying an individual's risk of developing CRC. However, a full evaluation of an association between CYP1A1*2A and cancer susceptibility in Europeans is difficult and will require a larger number of participants.