Risk assessment of phthalates in pharmaceuticals.

Phthalates are used for industrial plasticizers to impart flexibility and durability to polyvinyl chloride. Despite widespread use of phthalates, reported endocrine-disrupting properties raise safety concerns for consumers. Since phthalates are permitted as excipients in controlled-release capsules and enteric coatings, patients taking drugs containing these chemicals may potentially be at some health risk. In this study, 102 distinct pharmaceutical products were analyzed by gas chromatography/mass spectrometry to determine phthalate content and maximal phthalate exposure rate was calculated. In 102 drug samples, di(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), and diethyl phthalate (DEP) were detected in 9.8, 27.45, and 5.88% of cases, respectively. The highest level of DEP was found in extended-release (ER) capsules with concentrations ranging from 935.5 to 1535.37 ppb. The highest levels of DBP (1.32-7.07 ppb) were detected in tablets, whereas highest level (7.07 ppb) of DEHP was found in suspension preparations. The phthalate hazard index (HI) (human exposure tolerable daily intake) was calculated for each sample, but no sample exhibited an HI value exceeding 1; the minimum value taken to indicate a serious health risk. Thus, no apparent serious health risk from phthalate exposure arises from taking these medications. The low HI values suggest that phthalate contamination in pharmaceuticals may not pose an apparent significant risk to humans. However, the sources of phthalate present in pharmaceutical products still needs to be investigated and verified through on-site inspections in manufacturing processes in order to minimize human exposure. It is recommended that measures be taken to prevent phthalate contamination in pharmaceuticals.

Risk assessment of benzalkonium chloride in cosmetic products.

A risk assessment of benzalkonium chloride (BAC) was conducted based upon its toxicological profile and exposure evaluation. Since 1935, BAC has been used in a wide variety of products such as disinfectants, preservatives, and sanitizers. It is well-established that BAC is not genotoxic nor does it display tumorigenic potential, but safety concerns have been raised in local usage such as for ocular and intranasal applications. The Foundation of Korea Cosmetic Industry Institute (KCII) reported that in a hair conditioner manufactured as a cosmetic or personal product in South Korea, BAC was present at concentrations of 0.5-2%. The systemic exposure dosage (SED) was determined using the above in-use concentrations and a risk assessment analysis was conducted. The Margin of Safety (MOS) values for hair conditioners were calculated to be between 621 and 2,483. The risk of certain personal and cosmetic products was also assessed based upon assumptions that BAC was present at the maximal level of regulation in South Korea and that the maximal amount was used. The MOS values for the body lotion were all above 100, regardless of the application site. Collectively, data indicate that there are no safety concerns regarding use of products that contain BAC under the current concentration restrictions, even when utilized at maximal permitted levels. However, a chronic dermal toxicity study on BAC and comprehensive dermal absorption evaluation needs to be conducted to provide a more accurate prediction of the potential health risks to humans.

Inhibition of di(2-ethylhexyl) phthalate (DEHP)-induced endocrine disruption by co-treatment of vitamins C and E and their mechanism of action.

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 malondialdehyde (MDA) or 8-hydroxydeoxyguanosine (8-OHdG) induced by DEHP treatment. These results support the concept that the adverse actions of DEHP may be related to increased free radical generation while co-treatment with vitamins C and E significantly blocked the actions of DEHP on male testicular functions.

Formation and inhibition of N-nitrosodiethanolamine in cosmetics under pH, temperature, and fluorescent, ultraviolet, and visual light.

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/m2) > VIS (4000 lux) > fluorescent light > 25°C > 10°C. In a mixture of DEA and SN under the same acidic pH 2 conditions, NDELA formation was significantly elevated in the following order: UV (2 W/m2) > VIS (4000 lux) > 50°C > 40°C > fluorescent light > 25°C > 10°C. Inhibition of NDELA formation by d-mannitol, vitamin C (Vit C), or vitamin E (Vit E) was determined under varying conditions of pH, temperature, and fluorescent, UV, and VIS. At high concentrations of 100 or 1000 µg/ml, Vit E significantly decreased residual NDELA compared with control levels under acidic pH 2, but not under basic pH 6. Among various antioxidants, Vit E reacted more effectively with many nitrosating agents such as nitrate and nitrite found in cosmetic products. Therefore, to reduce NDELA, it is recommended that cosmetics be stored under cool/amber conditions and that Vit E or Vit C inhibitors of nitrosation be optimally added to cosmetic formulations at concentrations between 100 and 1000 µg/ml.

Risk assessment of N-nitrosodiethylamine (NDEA) and N-nitrosodiethanolamine (NDELA) in cosmetics.

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 LCR <1 × 10-5, respectively. In addition, TEA and DEA concentrations in cosmetic samples resulted in MOS values >100. Therefore, no apparent safety concerns were associated with cosmetic products containing NDELA, NDEA, TEA, and DEA in this study. However, since amines and nitrosating agents produce carcinogenic nitrosamines, their use in cosmetics needs to be minimized to levels as low as technically feasible.

Non-cancer, cancer, and dermal sensitization risk assessment of heavy metals in cosmetics.

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, Cr3+, Mn, Fe, Co, Ni, Cu, Zn, Cd, Sb, and Ti in cosmetic samples resulted in a margin of safety (MOS) greater than 100 or a hazard index (HI) of less than 1. However, the probability of lifetime cancer risk (LCR) resulting from dermal exposure to heavy metals from cosmetics exceeded the acceptable risk levels (LCR > 10-5). An exposure-based sensitization quantitative risk assessment determined that the ratios of acceptable exposure level to consumers for Ni, Co, Cu, or Hg were above 1, suggesting an absence of skin-sensitizing potential. For an average daily user of lip cosmetics, the estimated intakes of heavy metals were within the acceptable daily intake (ADI). The percentage of heavy users for which metal intakes exceeded ADIs were 20.37% for Pb, 9.26% for Mn, 1.85% for Cr3+, and 1.85% for Cr6+, respectively. Data suggested that the heavy metals present in cosmetics do not appear to pose a serious risk to health. However, for heavy users of lip cosmetics, contamination with some heavy metals, such as Pb, Mn, and Cr needs to be minimized.

Risk assessment of zinc oxide, a cosmetic ingredient used as a UV filter of sunscreens.

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 (MOS > 1). Risk assessment of ZnO indicates that this compound may be used safely in cosmetic products within the current regulatory limits of 25% in Korea.

Toxicological evaluation of isopropylparaben and isobutylparaben mixture in Sprague-Dawley rats following 28 days of dermal exposure.

The alkyl esters of p-hydroxybenzoic acid (Parabens) have been of concern due to their probable endocrine disrupting property especially in baby consumer products. The safety of parabens for use as a preservative in cosmetics has come into controversy, and thus consumer demand for paraben-free products is ever increasing. Thus, more comprehensive studies are needed to conclusively determine the safety of the multiple prolonged exposure to parabens with cosmetic ingredients. This study was conducted to investigate the potential repeated 28 days dermal toxicity (50, 100, 300, or 600 mg/kg bw/day) of isopropylparaben (IPP), isobutylparaben (IBP), or the mixture of IPP and IBP in rats. There were no significant changes in body and organ weights in any group. However, histopathological examinations showed that weak or moderate skin damages were observed in female rats by macroscopic and microscopic evaluations. In female rats, no observed adverse effect levels (NOAELs) of IPP with no skin lesion and IBP for skin hyperkeratosis, were estimated to be 600 mg/kg bw/day, and 50 mg/kg bw/day, respectively. With regard skin hyperkeratosis, the lowest observed adverse effect level (LOAEL) of the mixture of IPP and IBP was estimated to be 50 mg/kg bw/day. Analysis of six serum hormones (estrogen, testosterone, insulin, T3, TSH, or FSH) in animals showed that only FSH was dose-dependently decreased in the mixture groups of 100 mg/kg bw/day or higher. These data suggest that the mixture of IPP and IBP showed a synergistic dermal toxicity in rats and should be considered for future use in consumer products.

Potential application of benzo(a)pyrene-associated adducts (globin or lipid) as blood biomarkers for target organ exposure and human risk assessment.

In order to investigate the potential application of blood biomarkers as surrogate indicators of carcinogen-adduct formation in target-specific tissues, temporal formation of benzo[a]pyrene (BaP)-associated DNA adducts, protein adducts, or lipid damage in target tissues such as lung, liver, and kidney was compared with globin adduct formation or plasma lipid damage in blood after continuous intraperitoneal (ip) injection of [(3)H]BaP into female ICR mice for 7 d. Following treatment with [(3)H]BaP, formation of [(3)H]BaP-DNA or -protein adducts in lung, liver, and kidney increased linearly, and persisted thereafter. This finding was similar to the observed effects on globin adduct formation and plasma lipid damage in blood. The lungs contained a higher level of DNA adducts than liver or kidneys during the treatment period. Further, the rate of cumulative adduct formation in lung was markedly greater than that in liver. Treatment with a single dose of [(3)H]BaP indicated that BaP-globin adduct formation and BaP-lipid damage in blood reached a peak 48 h after treatment. Overall, globin adduct formation and lipid damage in blood were significantly correlated with DNA adduct formation in the target tissues. These data suggest that peripheral blood biomarkers, such as BaP-globin adduct formation or BaP-lipid damage, may be useful for prediction of target tissue-specific DNA adduct formation, and for risk assessment after exposure.

Risk assessment of volatile organic compounds benzene, toluene, ethylbenzene, and xylene (BTEX) in consumer products.

Exposure and risk assessment was performed by evaluating levels of volatile organic compounds (VOC) benzene, toluene, ethylbenzene, and xylene (BTEX) in 207 consumer products. The products were categorized into 30 different items, consisting of products of different brands. Samples were analyzed for BTEX by headspace-gas chromatography/mass spectrometry (headspace-GC/MS) with limit of detection (LOD) of 1 ppm. BTEX were detected in 59 consumer products from 18 item types. Benzene was detected in whiteout (ranging from not detected [ND] to 3170 ppm), glue (1486 ppm), oil-based ballpoint pens (47 ppm), and permanent (marking) pens (2 ppm). Toluene was detected in a leather cleaning product (6071 ppm), glue (5078 ppm), whiteout (1130 ppm), self-adhesive wallpaper (15-1012 ppm), shoe polish (806 ppm), permanent pen (609 ppm), wig adhesive (372 ppm), tapes (2-360 ppm), oil-based ballpoint pen (201 ppm), duplex wallpaper (12-52 ppm), shoes (27 ppm), and air freshener (13 ppm). High levels of ethylbenzene were detected in permanent pen (ND-345,065 ppm), shoe polish (ND-277,928 ppm), leather cleaner (42,223 ppm), whiteout (ND-2,770 ppm), and glue (ND-792 ppm). Xylene was detected in permanent pen (ND-285,132 ppm), shoe polish (ND-87,298 ppm), leather cleaner (12,266 ppm), glue (ND-3,124 ppm), and whiteout (ND-1,400 ppm). Exposure assessment showed that the exposure to ethylbenzene from permanent pens ranged from 0 to 3.11 mg/kg/d (men) and 0 to 3.75 mg/kg/d (women), while for xylene, the exposure ranges were 0-2.57 mg/kg/d and 0-3.1 mg/kg/d in men and women, respectively. The exposure of women to benzene from whiteout ranged from 0 to 0.00059 mg/kg/d. Hazard index (HI), defined as a ratio of exposure to reference dose (RfD), for ethylbenzene was 31.1 (3.11 mg/kg/d/0.1 mg/kg/d) and for xylene (2.57 mg/kg/d/0.2 mg/kg/d) was 12.85, exceeding 1 for both compounds. Cancer risk for benzene was calculated to be 3.2 × 10(-5) based on (0.00059 mg/kg/d × 0.055 mg/kg-d(-1), cancer potency factor), assuming that 100% of detected levels in some products such as permanent pens and whiteouts were exposed in a worst-case scenario. These data suggest that exposure to VOC via some consumer products exceeded the safe limits and needs to be reduced.

Safety evaluation and risk assessment of d-Limonene.

d-Limonene, a major constituent of citrus oils, is a monoterpene widely used as a flavor/fragrance additive in cosmetics, foods, and industrial solvents as it possesses a pleasant lemon-like odor. d-Limonene has been designated as a chemical with low toxicity based upon lethal dose (LD50) and repeated-dose toxicity studies when administered orally to animals. However, skin irritation or sensitizing potential was reported following widespread use of this agent in various consumer products. In experimental animals and humans, oxidation products or metabolites of d-limonene were shown to act as skin irritants. Carcinogenic effects have also been observed in male rats, but the mode of action (MOA) is considered irrelevant for humans as the protein α(2u)-globulin responsible for this effect in rodents is absent in humans. Thus, the liver was identified as a critical target organ following oral administration of d-limonene. Other than the adverse dermal effects noted in humans, other notable toxic effects of d-limonene have not been reported. The reference dose (RfD), the no-observed-adverse-effect level (NOAEL), and the systemic exposure dose (SED) were determined and found to be 2.5 mg/kg/d, 250 mg/kg//d, and 1.48 mg/kg/d, respectively. Consequently, the margin of exposure (MOE = NOAEL/SED) of 169 was derived based upon the data, and the hazard index (HI = SED/RfD) for d-limonene is 0.592. Taking into consideration conservative estimation, d-limonene appears to exert no serious risk for human exposure. Based on adverse effects and risk assessments, d-limonene may be regarded as a safe ingredient. However, the potential occurrence of skin irritation necessitates regulation of this chemical as an ingredient in cosmetics. In conclusion, the use of d-limonene in cosmetics is safe under the current regulatory guidelines for cosmetics.

Uterotrophic and Hershberger assays for endocrine disruption properties of plastic food contact materials polypropylene (PP) and polyethylene terephthalate (PET).

Plasticizers or plastic materials such as phthalates, bisphenol-A (BPA), and styrene are widely used in the plastic industry and are suspected endocrine-disrupting chemicals (EDC). Although plastic materials such as polypropylene (PP) and polyethylene terephthalate (PET) are not EDC and are considered to be safe, their potential properties as EDC have not been fully investigated. In this study, plastic samples eluted from plastic food containers (PP or PET) were investigated in Sprague-Dawley rats using Hershberger and uterotrophic assays. In the Hershberger assay, 6-wk-old castrated male rats were orally treated for 10 consecutive days with plastic effluent at 3 different doses (5 ml/kg) or vehicle control (corn oil, 1 ml/100 g) to determine the presence of both anti-androgenic and androgenic effects. Testosterone (0.4 mg/ml/kg) was subcutaneously administered for androgenic evaluation as a positive control, whereas testosterone (0.4 mg/ml/kg) and flutamide (3 mg/kg/day) were administered to a positive control group for anti-androgenic evaluation. The presence of any anti-androgenic or androgenic activities of plastic effluent was not detected. Sex accessory tissues such as ventral prostate or seminal vesicle showed no significant differences in weight between treated and control groups. For the uterotrophic assay, immature female rats were treated with plastic effluent at three different doses (5 ml/kg), with vehicle control (corn oil, 1 ml/100 g), or with ethinyl estradiol (3 µg/kg/d) for 3 d. There were no significant differences between test and control groups in vagina or uterine weight. Data suggest that effluents from plastic food containers do not appear to produce significant adverse effects according to Hershberger and uterotrophic assays.

Potential metabolomic biomarkers for evaluation of adriamycin efficacy using a urinary 1H-NMR spectroscopy.

A metabolomics approach using proton nuclear magnetic resonance (NMR) was applied to investigate metabolic alterations following adriamycin (ADR) treatment for gastric adenocarcinoma. After BALB/c-nu/nu mice were implanted with human gastric adenocarcinoma, ADR (1 or 3 mg kg(-1) per day) was intraperitoneally administered for 5 days. Urine was collected on days 2 and 5 and analyzed by NMR. The levels of trimethylamine oxide (TMAO, ×0.3), hippurate (×0.3) and taurine (×0.6) decreased significantly (P < 0.05), whereas the levels of 3-indoxylsulfate (×12.6), trigonelline (×1.5), citrate (×2.5), trimethylamine (TMA, ×2.0) and 2-oxoglutarate (×2.3) increased significantly (P < 0.05) in the tumor model. After ADR treatment, TMAO, hippuarte and taurine were increased significantly on day 5 compared with those of the tumor model. The levels of 2-oxoglutarate, 3-indoxylsulfate, trigonelline, TMA and citrate, which increased in the tumor model, significantly decreased to those of normal control by ADR treatment. Furthermore, the ratio between TMA and TMAO was dramatically altered in both tumor and ADR-treated groups. Overall, metabolites such as TMAO, TMA, 3-indoxylsulfate, hippurate, trigonelline, citrate and 2-oxoglutarate related to the tricarboxylic acid (TCA) cycle might be considered as therapeutic targets to potentiate the efficacy of ADR. Thus, these results suggest that the metabolomics analysis of tumor response to ADR treatment may be applicable for demonstrating the efficacy of anticancer agent, ADR and treatment adaptation.

DA6034 promotes gastric epithelial cell migration and wound-healing through the mTOR pathway.

BACKGROUND AND AIM: 7-Carboxymethyloxy-3',4',5-trimethoxy flavone (DA6034), a synthetic derivative of eupatilin, has a protective effect on gastric mucosa against various ulcerogens, and is currently in the phase III clinical trial in the treatment of peptic ulcer disease. Cell migration and/or growth plays a role in the repair process of gastric ulcer, so this study investigated the effect of DA6034 on the movement and proliferation of gastric epithelial cells and its associated signaling pathway. METHODS: The migration of AGS or SNU484 human gastric epithelial cells was shown by scratch-induced wound healing and transwell assays, and the proliferation of the cells was assessed by FACS and proliferation assays. RESULTS: Treatment of DA6034 promoted the migration of gastric epithelial cells in a concentration-dependent manner. DA6034 treatment facilitated the phosphorylation of mTOR that led to an increase in the activity of S6K1, indicating its ability to activate mTOR and S6K1. Rapamycin aborted the wound-healing effect of DA6034, which supported the role of mTOR activation in the wound-healing process. In addition, DA6034 treatment increased PI3K-dependent Akt phosphorylation, which was necessary for the enhancement of cell migration. DA6034, however, did not stimulate the proliferation of gastric epithelial cells, being consistent with no activation of ERK1/2 by the agent. CONCLUSIONS: DA6034 has the ability to heal scratch wounds, which may result from an increase in gastric epithelial cell migration as mediated by PI3K-Akt-dependent activation of mTOR and S6K1. Our finding may be of help in understanding the molecular basis of the anti-ulcer effect of DA6034.

Beneficial effects of the combination of amlodipine and losartan for lowering blood pressure in spontaneously hypertensive rats.

A combination of antihypertensive agents can better control blood pressure and reduce the number and severity of side effects than a monotherapy. Since both CCBs (calcium channel blockers) and ARBs (angiotensin II receptor type-1 blockers) are current and effective antihypertensive drugs, this study assessed the synergistic antihypertensive effects as well as the optimal combination ratio of these two drugs. Amlodipine (3 mg/kg) or losartan (30 mg/kg) alone or a combination of each drug at a ratio 1:10 and 1:20 was administered orally to spontaneously hypertensive rats (SHR). A four-week treatment of either 3 mg/kg amlodipine or 30 mg/kg losartan alone decreased the systolic blood pressure (SBP). However, their combination significantly lowered the SBP from the 3(rd) week, and there was a positive correlation between this reduction in blood pressure and the improvement in arterial endothelium-dependent relaxation. In addition, the combination therapy (1:20) decreased both the cardiac mass and left ventricular weight to a greater extent than with either amlodipine or losartan alone. The collagen content in the cardiac tissue was also significantly lower after the 4-week combination therapy (1:10). These results suggest that the combined use of amlodipine and losartan might be more effective in treating hypertension than a monotherapy.

Detoxifying effect of pyridoxine on acetaminophen-induced hepatotoxicity via suppressing oxidative stress injury.

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.

Chronic treatment of DA-8159, a new phosphodiesterase type V inhibitor, attenuates endothelial dysfunction in stroke-prone spontaneously hypertensive rat.

This study examined the effects of chronic treatment of a new phosphodiesterase type 5 inhibitor, DA-8159, on endothelial dysfunction in stroke-prone spontaneously hypertensive rats (SHR-SP). Six-week-old male SHR-SP were divided into 4 groups; vehicle control, DA-8159 1, 3, and 10 mg/kg/day. During a 32-week experimental period, the animals were administered DA-8159 orally and fed a 4% NaCl-loaded diet. The systolic blood pressure was measured every two weeks throughout the experimental period using the tail-cuff method. At the end of experiments, the vascular function (acetylcholine-induced vasodilation) in the endothelium-intact aortic rings was investigated. In addition, the mortality, the left ventricular hypertrophy index, the plasma parameters and the incidence of a cerebral infarction were assessed. In the DA-8159 treated-rats, the vascular reactivity improved significantly in a dose-dependent manner. Although DA-8159 did not alter the elevation of the systolic blood pressure directly, the 3 and 10 mg/kg/day DA-8159 treatment delayed the early death caused by stroke. DA-8159 significantly reduced the left ventricular heart weight/body weight ratio compared with the vehicle control group. Furthermore, the DA-8159 treatment significantly increased the plasma nitric oxide, cGMP, and the total antioxidative status. The DA-8159 treatment also reduced the occurrence of stroke-associated cerebral damage. These results indicate that DA-8159 can ameliorate an endothelial dysfunction-related vascular injury. Therefore, pharmacological intervention aimed at attenuating an endothelial dysfunction is important and might be useful in both preventing and treating endothelial dysfunction-related complications.

Increased susceptibility of ethanol-treated gastric mucosa to naproxen and its inhibition by DA-9601, an Artemisia asiatica extract.

AIM: To examine the effect of DA-9601, a new gastroprotective agent, on the vulnerability of ethanol-treated rat's stomach to naproxen (NAP). METHODS: Male Sprague-Dawley rats were pretreated with 1 mL of 50% ethanol twice a day for 5 d and then NAP (50 mg/kg) was administered. DA-9601 was administered 1 h before NAP. Four hours after NAP, the rats were killed to examine gross injury index (mm2), histologic change and to determine mucosal levels of malondialdehyde (MDA), prostaglandin E2 (PGE2), glutathione (GSH) and myeloperoxidase (MPO). RESULTS: Pretreatment of ethanol significantly increased NAP-induced gastric lesions, as well as an increase in MDA and MPO. On the contrary, mucosal PGE2 and GSH contents were decreased dramatically by ethanol pretreatment, which were aggravated by NAP. DA-9601 significantly reduced NAP-induced gastric injury grossly and microscopically, regardless of pretreatment with ethanol. DA-9601 preserved, or rather, increased mucosal PGE2 and GSH in NAP-treated rats (P<0.05), with reduction in mucosal MDA and MPO levels. CONCLUSION: These results suggest that repeated alcohol consumption renders gastric mucosa more susceptible to NSAIDs though, at least in part, reduction of endogenous cytoprotectants including PGE2 and GSH, and increase in MPO activation, and that DA-9601, a new gastroprotectant, can reduce the increased vulnerability of ethanol consumers to NSAIDs-induced gastric damage via the mechanism in which PGE2 and GSH are involved.

DA-9201 shows anti-asthmatic effects by suppressing NF-kappaB expression in an ovalbumin-induced mouse model of asthma.

Nuclear factor kappa B (NF-kappaB) regulates the expression of multiple cytokines, chemokines, and cell adhesion molecules that are involved in the pathogenesis of asthma. We investigated the anti-asthmatic effects and the mechanism of action of DA-9201, an extract of the black rice, in a mouse model of asthma. Mice immunized with ovalbumin (OVA) were administered with DA-9201 (30, 100 or 300 mg/kg) or dexamethasone (DEXA, 3 mg/kg) for 2 weeks and challenged with aerosolized OVA during the last 3 days. Anti-asthmatic effects were assessed by means of enhanced pauses, level of total IgE and Th2 cytokines in plasma or bronchoalveolar lavage fluid (BALF), the percentage of eosinophils in BALF, and histopathological examination. The expression of NF-kappaB in nuclear and cytoplasmic fraction and its DNA-binding activity in lung tissues were analyzed by means of Western blotting and electrophoretic gel mobility shift assay (EMSA), respectively. DA-9201 significantly reduced airway hyperresponsiveness (AHR), total IgE level in plasma and BALF, IL-4, IL-5, and IL-13 levels in BALF, and the percentage of eosinophils in BALF. Tissue inflammation was significantly improved by DA-9201 treatment. In addition, DA-9201 dramatically suppressed the expression of NF-kappaB and its DNA-binding activity. These results suggest that DA-9201 may be useful for the treatment of asthma and its efficacy is related to suppression of NF-kappaB pathway.

Comparative safety evaluation of selective androgen receptor modulators and anabolic androgenic steroids.

INTRODUCTION: Anabolic androgenic steroids (AASs) have been in use for decades for the treatment of short stature, severe burns, HIV wasting syndrome, osteoporosis, and anemia. However, their lack of selective effects on certain symptoms and unfavorable pharmacokinetic properties has limited their long-term usage in clinics. AREAS COVERED: Selective androgen receptor modulators (SARMs) have some advantages over AASs; they are highly specific for androgen receptors, are orally available, and, most importantly, act as strong receptor agonists in skeletal muscle and bone, and as weak agonists or antagonists in androgen-responsive tissues such as the prostate and sebaceous glands. The exact molecular mechanism, however, has not been fully elucidated. This article includes a toxicological review of major AASs, and a comparative safety analysis of major AASs and SARMs in clinical trials to evaluate the therapeutic potential of SARMs. EXPERT OPINION: Based on the robust tissue selectivity of SARMs over AASs, they are worth considering as a promising therapeutic option for the treatment of various muscle-wasting diseases.