Search

The mixture of 5-chloro-2-methylisothiazol-3(2H)-one (CMIT) and 2-methylisothiazol-3(2H)-one (MIT), CMIT/MIT, is a preservative in cosmetics. CMIT/MIT is a highly effective preservative; however, it is also a commonly known skin sensitizer. Therefore, in the present study, a risk assessment for safety management of CMIT/MIT was conducted on products containing 0.0015% of CMIT/MIT, which is the maximum MIT level allowed in current products. The no observed adverse effect level (NOAEL) for CMIT/MIT was 2.8 mg/kg bw/day obtained from a two-generation reproductive toxicity test, and the skin sensitization toxicity standard value for CMIT/MIT, or the no expected sensitization induction level (NESIL), was 1.25 μg/cm2/day in humans. According to a calculation of body exposure to cosmetics use, the systemic exposure dosage (SED) was calculated as 0.00423 mg/kg bw/day when leave-on and rinse-off products were considered. Additionally, the consumer exposure level (CEL) amounted to 0.77512 μg/cm2/day for all representative cosmetics and 0.00584 μg/cm2/day for rinse-off products only. As a result, the non-cancer margin of safety (MOS) was calculated as 633, and CMIT/MIT was determined to be safe when all representative cosmetics were evaluated. In addition, the skin sensitization acceptable exposure level (AEL)/CEL was calculated as 0.00538 for all representative cosmetics and 2.14225 for rinse-off products; thus, CMIT/MIT was considered a skin sensitizer when all representative cosmetics were evaluated. Current regulations indicate that CMIT/MIT can only be used at concentrations 0.0015% or less and is prohibited from use in other cosmetics products. According to the results of this risk assessment, the CMIT/MIT regulatory values currently used in cosmetics are evaluated as appropriate.

Triclosan (TCS) is an antimicrobial compound used in consumer products. The purpose of current study was to examine toxicology and risk assessment of TCS based on available data. Acute toxicities of oral, transdermal and inhalation routes were low, and phototoxicity and neurotoxicity were not observed. Topical treatment of TCS to animal caused mild irritation. TCS did not induce reproductive and developmental toxicity in rodents. In addition, genotoxicity was not considered based on in vitro and in vivo tests of TCS. It is not classified as a carcinogen in international authorities such as International Agency for Research on Cancer (IARC). No-observed-adverse-effect level (NOAEL) was determined 12 mg/kg bw/day for TCS, based on haematoxicity and reduction of absolute and relative spleen weights in a 104-week oral toxicity study in rats. Percutaneous absorption rate was set as 14%, which was human skin absorption study reported by National Industrial Chemicals Notification and Assessment Scheme (NICNAS) (2009). The systemic exposure dosage (SED) of TCS has been derived by two scenarios depending on the cosmetics usage of Koreans. The first scenario is the combined use of representative cosmetics and oral care products. The second scenario is the combined use of rinse-off products of cleansing, deodorants, coloring products, and oral care products. SEDs have been calculated as 0.14337 mg/kg bw/day for the first scenario and 0.04733 mg/kg bw/day for the second scenario. As a result, margin of safety (MOS) for the first and second scenarios was estimated to 84 and 253.5, respectively. Based on these results, exposure of TCS contained in rinse-off products, deodorants, and coloring products would not pose a significant health risk when it is used up to 0.3%.

Empirical studies based on spatial explorations have played a critical role in understanding dynamics of recreation resource impact and recovery at multiple scales. However, little research has been done to examine spatially varying relationships between resource conditions and associated geospatial variables, especially using a predictive modeling approach. The primary purpose of this study was to explore spatially varying relationships of recreation resource impacts by using a geographically weighted regression (GWR) model. Specifically, the study was designed to compare the GWR with an ordinary least squares (OLS) multiple linear regression model to better understand localized spatial variations with roadside campsite conditions in Adirondack Park, NY, USA. Geospatial variables contained in the OLS model explained approximately 22% of the variance in campsite conditions (adjusted R2 = 0.220, p < 0.001). Statistically significant predictors of the campsite condition at the global scale included site circumference, distance from water resource, distance from major road, distance from hosting forest road, and slope. Non-significant variables included site designation, distance from recreational trail, and elevation. The subsequent analysis using the GWR model resulted in adjusted R2 values ranging from 0.198 to 0.271 (mean = 0.221). Roadside campsites located in the northern region of the park exhibited relatively higher R2 values, and roadside campsites located in the southern region exhibited relatively lower R2 values. All of the statistically significant global variables showed spatially varying relationships with the campsite condition. Additionally, elevation and site designation factors in the GWR model, which were non-significant variables at the global scale, suggested localized spatial variations with the campsite condition. Overall, the GWR model provided a more robust examination of campsite condition by accounting for localized spatial variations and by improving the model performance. This paper provides a discussion of the methodological and resource management implications of these findings. Subscribe to JPRA

As an alternative to animal tests for skin sensitization potency and risk assessment, cell viability and biomarkers related to skin sensitization were analyzed in THP-1 human monocytic leukemia cells. Cell viabilities of 90% (CV90) and 75% (CV75) were determined for 24 selected test chemicals. Further biomarkers related to skin sensitization were also determined under equivalent comparative conditions. In cell viability analyses, potent skin sensitizers exhibited high cytotoxicity, but non-sensitizers did not display this tendency. In biomarker analyses, interleukin-I beta (IL-1β), inducible nitric oxide synthase (iNOS), IL-1β+iNOS, and THP-1 IL-1β+Raw 264.7 IL-1β were found to be suitable for prediction of skin sensitization potency following classification as either skin sensitizers or non-sensitizers (accuracies of 91.7%, 87.5%, 83.3%, and 82.6%, respectively). A significant positive correlation was found between biomarkers and skin sensitization potency, with a correlation coefficient (R) of 0.7 or more (correlation coefficients of 0.77, 0.72, 0.7, and 0.84, respectively). Finally, the skin sensitization potency effective threefold concentration (EC) 3% was predicted using a biomarker equation, with resulting prediction rates (match rate with actual data) of 58.3%, 54.2%, 62.5%, and 60.9%, respectively. The prediction accuracy for the EC3 value obtained from animal data was calculated as 83.3%, 79.2%, 79.2%, and 73.9%, respectively. Thus, these biomarkers, IL-1β and iNOS, may be alternatively used to predict skin sensitization potency and risk assessment.

Risk assessment and hormone evaluation were carried out for di(2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate (DBP), endocrine disrupting chemicals (EDCs), in 302 Korean children (n = 223) and adolescents (n = 79) ( age 19). Urinary and serum concentrations of DEHP, MEHP (mono(2-ethylhexyl) phthalate), DBP, MBP (monobutyl phthalate), and PA (phthalic acid, a common final metabolite of phthalates) were detected in children and adolescents. Daily exposure levels were estimated to be 16.45 ± 36.50 μg/kg b.w./day for DEHP, which is one-third of the tolerable daily intake (TDI) value (50 μg/kg b.w./day), but 14 out of 302 participants had a hazard index (HI = intake/TDI) value1. The mean daily exposure level of DBP was 1.23 ± 1.45 μg/kg b.w./day, which is one-eighth of the TDI value (10 μg/kg b.w./day), but 1 out of 302 participants had a HI value 1. Positive correlations were observed between serum DBP or MEHP, and serum estradiol (E2) and/or luteinizing hormone (LH) in prepubescent children. In addition, serum MBP levels were found to be negatively correlated with serum triiodothyronine (T3) or thyroxine (T4) in male participants, and serum DEHP levels with serum thyroid stimulating hormone (TSH) in female adolescents. Low-density lipoprotein (LDL) levels were positively correlated with serum PA levels in children and adolescents. DEHP, DBP or its metabolites may be associated with altered hormone levels in children and adolescents. Data suggest that exposure levels of DEHP and DBP in Korean children need to be reduced to levels below TDI to protect them from EDC-mediated toxicities. Abbreviations: DBP: dibutyl phthalate; DEHP: di(2-ethylhexyl) phthalate; E2: estradiol; EDC: endocrine disrupting chemical; EFSA: European Food Safety Authority; FSH: follicle stimulating hormone; HDL: high density lipoprotein; HI: hazard index; LDL: low density lipoprotein; LH: luteinizing hormone; MEHP: mono(2-ethylhexyl) phthalate; MBP: monobutyl phthalate; PA: phthalic acid; PPAR: peroxisome proliferator-activated receptor gamma; PVC: polyvinyl chloride; T3: triiodothyronine; T4: thyroxine; TDI: tolerable daily intake; TG: triglyceride; TSH: thyroid stimulating hormone; UPLC/MS/MS: Ultra Performance Liquid Chromatography/Tandem Mass Spectrometry; WWF: World Wildlife Fund.

The endocrine disrupting actions of di(2-ethylhexyl) phthalate (DEHP) on testicular functions are postulated to involve excess free radical generation. Thus the aim of this study was to examine the ability of antioxidant vitamins C and E to prevent DEHP-induced testicular disruption in male Sprague-Dawley (SD) rats. SD male rats were administered DEHP alone or DEHP with vitamin C and/or vitamin E for 30 days. DEHP alone increased the levels of testosterone (T) and reduced estradiol (E2) concentrations. Supplementation with antioxidant vitamins diminished or restored serum T levels noted in DEHP-treated rats to control values. In contrast vitamins C and E increased E2 levels to control in rats administered DEHP. Antioxidants significantly improved the decreased testicular levels of reduced glutathione and activity of superoxide dismutase compared to DEHP-treatment alone. Co-treatment of vitamins C and E also markedly improved the reduced epididymal sperm head counts and elevated levels of malondial...

The detoxifying effect of pyridoxine against acetaminophen (APAP)-induced hepatotoxicity was investigated. HepG2 cells were co-treated with APAP and pyridoxine to compare with betaine or methionine for 24 h. LDH, ALT and AST activities were measured to determine direct cells damage in vitro and in vivo. Lipid peroxidation, antioxidant enzymes activity, and glutathione level were measured. Cytochrome c releaseand procaspase-3, cleaved caspase-3, Bcl-2, or Bax protein levels were measured to determine APAP-induced apoptotic cell death. Pyridoxine treatment significantly increased cell viability and decreased leakage of LDH activity against APAP-induced hepatotoxicity in HepG2 cells. ALT and AST activities were dose-dependently reduced by pyridoxine treatment compared to APAP-treated group. Significant increases in activities of GST and GPx were observed after co-treatment with APAP and pyridoxine. Although APAP-induced Nrf2 and HO-1 expression levels were gradually reduced in HepG2 cells by pyridoxine treatment, induction of antioxidant enzymes activities were dose-dependently increased. These protected effects of pyridoxine against APAP-induced hepatoxicity were closely associated with suppression of APAP-induced oxidative stress and apoptotic cell death in HepG2 cells. These data indicated that the protective action of pyridoxine against hepatic cell injuries was involved in the direct antioxidant activity which provides a pivotal mechanism for its potential hepatoprotective action.

The heavy metal content of cosmetics may be a cause for concern in that exposure to these metals is associated with adverse consequences. Thus, the aim of this study was to assess consequences attributed to exposure to heavy metals in cosmetics as determined by non-cancer, cancer, and sensitization risks methodologies. The quantification and exposure assessments of aluminum (Al), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), lead (Pb), mercury (Hg), cadmium (Cd), antimony (Sb), and titanium (Ti) were performed by inductively coupled plasma-mass spectrometry. The non-cancer risk assessment of Al, Cr

Zinc oxide (ZnO), an inorganic compound that appears as a white powder, is used frequently as an ingredient in sunscreens. The aim of this review was to examine the toxicology and risk assessment of ZnO based upon available published data. Recent studies on acute, sub-acute, and chronic toxicities of ZnO indicated that this compound is virtually non-toxic in animal models. However, it was reported that ZnO nanoparticles (NP) (particle size, 40 nm) induced significant changes in anemia-related hematologic parameters and mild to moderate pancreatitis in male and female Sprague-Dawley rats at 536.8 mg/kg/day in a 13-week oral toxicity study. ZnO displayed no carcinogenic potential, and skin penetration is low. No-observed-adverse-effect level (NOAEL) ZnO was determined to be 268.4 mg/kg/day in a 13-week oral toxicity study, and a maximum systemic exposure dose (SED) of ZnO was estimated to be 0.6 mg/kg/day based on topical application of sunscreen containing ZnO. Subsequently, the lowest margin of safety (MOS) was estimated to be 448.2, which indicates that the use of ZnO in sunscreen is safe. A risk assessment was undertaken considering other routes of exposure (inhalation or oral) and major product types (cream, lotion, spray, and propellant). Human data revealed that MOS values (7.37 for skin exposure from cream and lotion type; 8.64 for skin exposure of spray type; 12.87 for inhalation exposure of propellant type; 3.32 for oral exposure of sunscreen) are all within the safe range (MOS1). Risk assessment of ZnO indicates that this compound may be used safely in cosmetic products within the current regulatory limits of 25% in Korea.

A risk assessment was performed for three types of phthalates, benzyl butyl phthalate (BBP), dibutyl phthalate (DBP), and di(2-ethylhexyl)phthalate (DEHP) unintentionally contaminated in cosmetics. A total of 100 products of 8 types of cosmetics were analyzed employing gas chromatography-mass spectrometry (GC-MS). By applying the maximum detected values of phthalates based on the worst exposure cases, their systemic exposure dosage (SED) was calculated. Accordingly, DEHP was identified as the main unintentional phthalates contaminants (0.10–600.00 ppm) in the cosmetics, with an SED of 3.37 × 10−9–3.75 × 10−4 mg/kg/day. In the non-cancer risk assessment, a margin of safety (MOS ≥ 100, safe) of 1.28 × 104–1.42 × 109 was estimated. In the cancer risk assessment, the lifetime cancer risk (LCR ≤ 10−5, safe) was determined to be 8.81 × 10−12–9.79 × 10−7. Based on the results of both risk assessments, the levels of unintentional phthalates contaminants in cosmetics were deemed safe. Some phthalates are widely used as plasticizers and are essential for daily life; however, various toxicities, including endocrine disruption, have been reported. Therefore, even under these “worst case” assumptions, an adequate margin of safety is shown such that this might be a low priority for further work although exposure to unintentional phthalates contaminants through cosmetics should be considered as part of cumulative exposure.

Use of lithium-ion batteries has raised safety issues owing to chemical leakages, overcharging, external heating, or explosions. A risk assessment was conducted for hydrofluoric acid (HF) and lithium hydroxide (LiOH) which potential might leak from lithium-ion batteries. The inhalation no-observed-adverse-effect-level (NOAEL) for HF was 0.75 mg/kg/d. When a lithium-ion battery explodes in a limited space, HF emissions amount to 10-100 ppm. Assuming the worst-case scenario, the conversion rate was calculated to be 81.8 mg/m3, and the average daily dose (ADD) was 19.5 mg/kg/d. Consequently, the margin of exposure (MOE = NOAEL/ADD) was 0.034, a value which constitutes an unsafe inhalation exposure for HF. Conversely, skin toxicity NOAEL for LiOH was 41.35 mg/kg/d-. This LiOH value reflects the amount of lithium in the lithium-ion battery, which is generated upon contact between water and the electrolyte. The quantity of lithium in a mobile phone is approximately 295 mg, and systemic exposure dose (SED) was 4.92 mg/kg/d. Accordingly, the MOE (NOAEL/SED) value was 8.41, and skin exposure of LiOH was deemed as safe for humans. However, it is important that Energy Storage System batteries still require safety measures and technologies for next-generation batteries, to prevent any potential explosions of lithium-ion batteries.

Dietary hydroxycinnamates are considered as attractive materials for radioprotection. This study explores whether hydroxycinnamates protect against γ-radiation-induced cellular damages and hematopoietic stem cell senescence. C57BL/6 mice were orally administered with each of caffeic acid, p-coumaric acid, and ferulic acid (20mg/kg body weight) once per three days for five times before exposure to total body radiation (5 Gy). Irradiation increased the activities of alanine amino transaminase and aspartate aminotransferase in blood serum but decreased the anti-oxidant defense enzyme activities in the liver and spleen tissues. Oral administration of the compounds almost completely prevented irradiation-mediated changes in these enzyme activities. The hydroxycinnamates also inhibited the irradiation-mediated increases in the mitochondrial superoxide anions of Lin−Sca-1+c-Kit+ (LSK) cells and CD150+CD48− LSK cells in the bone marrow. These results suggest that dietary hydroxycinnamates protect against irradiation-mediated oxidative damages of tissues and bone marrow progenitor cells.

Potential biomarkers of skin sensitization in RAW264.7 mouse macrophages were investigated as alternatives to animal experiments and risk assessment. The concentrations that resulted in a cell viability of 90% (CV90) and 75% (CV75) were calculated by using a water-soluble tetrazolium salt (WST)-1 assay and used to analyze the skin sensitization potency of 23 experimental materials under equivalent treatment conditions. In addition, the expression of interleukin (IL)-1α, IL-1β, IL-31, tumor necrosis factor (TNF)-α, inducible nitric oxide synthase (iNOS), prostaglandin E2 (PGE2), and cyclooxygenase-2 (COX-2) was analyzed utilizing Western blotting. In the cell viability analysis, skin sensitizers were generally more cytotoxic and exhibited increased skin sensitization potency. However, nonsensitizers did not show any marked cytotoxic tendency. Biomarker analysis demonstrated that IL-1α, IL-1β, and the combination of IL-1α and IL-1β (IL-1α + IL-1β) predicted reliably skin sensitization potential (1) sensitivities of 94.4%, 83.3%, and 83.3%, specificities of 100%, 100%, and 100%, and (2) accuracies of 95.7%, 87%, and 87%, respectively. These observations correlated most reliably as indicators for skin sensitization potency. Data suggest that IL-1α and IL-1β may serve as potential biomarkers for skin sensitization and provide an alternative method to animal experiments for prediction of skin sensitization potency and risk assessment.

N-nitrosamines and their precursors found in cosmetics may be carcinogenic in humans. Thus the aim of this study was to carry out risk assessment for N-nitrosamines (N-nitrosodiethanolamine [NDELA], N-nitrosodiethylamine [NDEA]) and amines (triethanolamine [TEA], diethanolamine [DEA]) levels in cosmetics determined using validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) procedures. NDELA and NDEA concentrations were present at levels of "not detected" (N.D.) to 596.5 μg/kg and N.D. to 40.9 μg/kg, respectively. TEA and DEA concentrations ranged from N.D. to 860 μg/kg and N.D. to 26.22 μg/kg, respectively. The nitrite concentration (3-2250 mg/l), number of nitrosating agents to a maximum 5, and pH (3.93-10.09) were also assessed. The impact of N-nitrosamine formation on the levels of TEA, DEA, nitrite, and other nitrosating agents was also examined. N-nitrosamine concentrations correlated with the number of nitrosating agents and nitrite concentrations. Data demonstrated that higher nitrite concentrations and a greater number of nitrosating agents increased NDELA and NDEA yields. Further, the presence of TEA and DEA exerted a significant influence on N-nitrosamine formation. Risk assessments, including the margin of exposure (MOE) and lifetime cancer risk (LCR) for N-nitrosamines and margin of safety (MOS) for amines, were calculated using product type, use pattern, and concentrations. Exposure to maximum amounts of NDELA and NDEA resulted in MOE 10,000 (based upon the benchmark dose lower confidence limit 10%) and LCR1 × 10

N-nitrosodiethanolamine (NDELA), a type of nitrosamine, is a possible human carcinogen that may form in cosmetic products. The aim of this study was to examine the formation and inhibition of NDELA through chemical reactions of secondary amines including mono-ethanolamine, di-ethanolamine (DEA), and tri-ethanolamine (TEA), and sodium nitrite (SN) under varying conditions such as pH, temperature, and fluorescent, ultraviolet (UV), and visual light (VIS) using liquid chromatography-mass spectroscopy. In a mixture of TEA and SN under acidic conditions pH 2, residual NDELA concentrations rose significantly under various storage conditions in the following order: 50°C 40°C UV (2 W/m

Ethnopharmacological relevance Water extract of Raphanus sativus L. (RSL) seeds was traditionally used to treat digestive inflammatory complaints in Korean culture. RSL seeds exerted antioxidant, anti-inflammatory, and anti-septic functions, suggesting their pharmacological potential for the treatment of inflammatory pathologies associated with oxidative stress such as inflammatory bowel disease. Aim of this study We evaluated the intestinal anti-inflammatory effects of RSL seed water extract (RWE) in experimental rat models of trinitrobenzenesulphonic acid (TNBS)- or dextran sodium sulfate (DSS)-induced colitis. Materials and methods RWE was characterized by determining the content of sinapic acid as a reference material and then assayed in the DSS and TNBS models of rat colitis. Male Sprague–Dawley rats were divided into 10 groups ( n =7/group): non-colitic control, DSS or TNBS control, DSS colitis groups treated with RWE (100 mg/kg) or mesalazine (25 mg/kg), and TNBS colitis groups treated with various doses (10, 40, 70, and 100 mg/kg) of RWE or mesalazine (25 mg/kg). RWE or mesalazine treatment started the same day of colitis induction and rats were sacrificed 24 h after the last treatment followed by histological and biochemical analyses. Results Oral administration with RWE suppressed intestinal inflammatory damages in both DSS- and TNBS-induced colitic rats. The treatment with 100 mg/kg RWE recovered intestinal damages caused by TNBS or DSS to levels similar to that of mesalazine, decreasing the activity of myeloperoxidase activity and the secretion of tumor necrosis factor (TNF)-α and interleukin (IL)-1β. RWE treatment inhibited malondialdehyde production and glutathione reduction in colon of colitis rats. The administration of RWE at dose of 100 mg/kg also suppressed the TNBS- or DSS-stimulated expression of TNF-α , IL-1β , monocyte chemotactic protein-1 , inducible nitric oxide , and intercellular adhesion molecule-1 . Furthermore, RWE inhibited p38 kinase and DNA–nuclear factor-κB binding activities, both of which were stimulated in the colitic rats. Conclusions The current findings show that RWE ameliorates intestinal oxidative and inflammatory damages in DSS and TNBS models of rat colitis, suggesting its beneficial use for the treatment of intestinal inflammatory disorders.