Six-well plate-based colony-forming efficacy assay and Co-Culture application to assess toxicity of metal oxide nanoparticles.

The development of a universal, label-free, and reliable in vitro toxicity testing method for nanoparticles is urgent because most nanoparticles can interfere with toxicity assays. In this regard, the colony-forming efficacy (CFE) assay has been suggested as a suitable in vitro toxicity assay for testing nanoparticles without such interference. Recently, the Organisation for Economic Co-operation and Development (OECD) developed a 60 × 15 mm Petri dish-based CFE assay for testing nanoparticles in MDCK-1 cells. However, further investigations are needed, including testing with other cell types, at a smaller scale for greater efficiency, and the application of the co-culture technique. In this study, we selected TiO2, CuO, CeO2, and SiO2 as test nanoparticles and successfully developed a 6-well plate-based CFE assay using HepG2 and A549 cells and a co-culture assay for combinations of HepG2 cells and THP-1 macrophages or A549 cells and THP-1 monocytes. The results suggest that the 6-wellplate-based CFE assay for HepG2 and A549 cells can be applied to nanoparticles, but the co-culture CFE assay has limitations in that it is not different from the single culture study, and it inhibits colony-formation by A549 cells in the presence of macrophages; this warrant further study.

Prediction of Postoperative Mortality in Patients with Organ Failure After Gastric Cancer Surgery.

BACKGROUND: Scarce data are available on the characteristics of postoperative organ failure (POF) and mortality after gastrectomy. We aimed to describe the causes of organ failure and mortality related to gastrectomy for gastric cancer and to identify patients with POF who are at a risk of failure to rescue (FTR). METHODS: The study examined patients with POF or in-hospital mortality in Seoul National University Hospital between 2005 and 2014. We identified patients at a high risk of FTR by analyzing laboratory findings, complication data, intensive care unit records, and risk scoring including Acute Physiology and Chronic Health Evaluation (APACHE) IV, Sequential Organ Failure Assessment (SOFA) score, and Simplified Acute Physiology Score (SAPS) 3 at ICU admission. RESULTS: Among the 7304 patients who underwent gastrectomy, 80 (1.1%) were identified with Clavien-Dindo classification (CDC) grade ≥ IVa. The numbers of patients with CDC grade IVa, IVb, and V were 48 (0.66%), 11 (0.15%), and 21 (0.29%), respectively. Pulmonary failure (43.8%), surgical site complication (27.5%), and cardiac failure (13.8%) were the most common causes of POF and mortality. Cancer progression (100%) and cardiac events (45.5%) showed high FTR rates. In univariate analysis, acidosis, hypoalbuminemia, SOFA, APACHE IV, and SAPS 3 were identified as risk factors for FTR (P < 0.05). Finally, SAPS 3 was identified as an independent predictive factor for FTR. CONCLUSIONS: Cancer progression and acute cardiac failure were the most lethal causes of FTR. SAPS 3 is an independent predictor of FTR among POF patients after gastrectomy.

Risk Factors for Recurrence of Right Colonic Diverticulitis.

BACKGROUND: Right colonic diverticulitis (RCD) is more common in Asian countries than in Western countries, and the risk factors for recurrence of RCD are not fully understood. The objective of this study was to assess the risk factors for recurrence of RCD. METHODS: We analyzed 296 patients admitted for treatment of RCD in the Gachon University Gil Medical Center from December 2001 to October 2014. Gender, age, BMI, obesity, hypertension, diabetes mellitus, alcohol consumption, smoking, Hinchey classification, and hospital stay were investigated as risk factors for recurrence. RESULTS: Of the 296 patients with RCD, 31 patients recurred after conservative treatment. The median time interval between the initial episode and recurrence of diverticulitis was 10.4 months. In the univariate analysis, a high recurrence rate was observed in patients with a history of alcohol consumption, smoking, and long hospital stay. In the multivariate analysis, the recurrence rate was much higher (p < 0.001) in patients who stayed in the hospital for more than 10 days after the first attack. Smoking also elevated the recurrence rate (p = 0.011). CONCLUSION: Factors associated with recurrence of RCD may include smoking and the long hospital stay due to complexity when first diverticulitis occurs. Further prospective large-scale studies are needed to draw a definite conclusion.

The comprehensive complication index (CCI) is a more sensitive complication index than the conventional Clavien-Dindo classification in radical gastric cancer surgery.

BACKGROUND: The comprehensive complication index (CCI) integrates all complications of the Clavien-Dindo classification (CDC) and offers a metric approach to measure morbidity. The aim of this study was to evaluate the CCI at a high-volume center for gastric cancer surgery and to compare the CCI to the conventional CDC. METHODS: Clinical factors were collected from the prospective complication data of gastric cancer patients who underwent radical gastrectomy at Seoul National University Hospital from 2013 to 2014. CDC and CCI were calculated, and risk factors were investigated. Correlations and generalized linear models of hospital stay were compared between the CCI and CDC. The complication monitoring model with cumulative sum control-CCI (CUSUM-CCI) was displayed for individual surgeons, for comparisons between surgeons, and for the institution. RESULTS: From 1660 patients, 583 complications in 424 patients (25.5%) were identified. The rate of CDC grade IIIa or greater was 9.7%, and the overall CCI was 5.8 ± 11.7. Age, gender, Charlson score, combined resection, open method, and total gastrectomy were associated with increased CCI (p < 0.05). The CCI demonstrated a stronger relationship with hospital stay (ρ = 0.721, p < 0.001) than did the CDC (ρ = 0.634, p < 0.001). For prolonged hospital stays (≥30 days), only the CCI showed a moderate correlation (ρ = 0.544, p = 0.024), although the CDC did not. The CUSUM-CCI model displayed dynamic time-event differences in individual and comparison monitoring models. In the institution monitoring model, a gradual decrease in the CCI was observed. CONCLUSIONS: The CCI is more strongly correlated with postoperative hospital stay than is the conventional CDC. The CUSUM-CCI model can be used for the continuous monitoring of surgical quality.

WNT5A Correlates with Clinicopathological Characteristics in Gastric Cancer: a Meta-Analysis.

BACKGROUND/AIMS: Gastric cancer (GC), the third-leading cause of cancer death in the world, is typically diagnosed only in its advanced stages. WNT signaling has been associated with clinicopathological characteristics in diverse cancer types. But the systematic analysis of WNT5A, a member in the signaling, has not been inspected. Thus, our study used a meta-analysis to statistically associate WNT5A expression with GC clinicopathological characteristics. METHODS: For a systematic literature review of GC in combination with the WNT signaling molecule WNT5A, we searched for PubMed, Cochrane Library, and Web of Science. It led to the five cohorts, in four eligible studies, consisting of 1,034 patients (617 WNT5A-positive and 417 WNT5A-negative patients). These patients were inspected by the library "meta" in R software for our meta-analysis. RESULTS: Our meta-analysis, revealed a statistically significant associations of WNT5A-positivity with lymph node metastasis (p=0.0047), some types of Lauren diffuse subtype GCs (p<0.0001), advanced tumor depth (p<0.0001), and advanced UICC stages (p=0.0461) with no observation of bias or confounding factors. CONCLUSIONS: These results support the feasibility of targeting this embryonic signaling pathway, both for therapy, and as a biomarker to "guide" various individual interventions (i.e., "personalized medicine").

Short- and Long-Term Outcomes After Gastrectomy in Elderly Gastric Cancer Patients.

BACKGROUND: The number of elderly patients undergoing gastric cancer surgery has recently increased. We therefore evaluated the short- and long-term outcomes of elderly patients after curative gastrectomy. METHODS: Overall, 824 patients were included in this retrospective study, which comprised of a non-elderly group (60-64 years; n = 558), an early-elderly group (75-79 years; n = 198), and a late-elderly group (≥80 years; n = 68) who underwent curative gastrectomy for gastric cancer between 2005 and 2009. Postoperative complications, according to the Clavien-Dindo classification, and survival of both elderly groups were compared with the non-elderly group. Postoperative life expectancy of the late-elderly group was compared with the corresponding aged general population. RESULTS: Overall and severe (grade III or higher) complications in the early-elderly group were comparable with the non-elderly group; however, those in the late-elderly group were significantly more common than in the non-elderly group (p = 0.013 and p = 0.043, respectively). Multivariable analysis revealed that age ≥80 years was an independent risk factor for severe complications (hazard ratio 3.02, 95 % confidence interval 1.12-8.17; p = 0.029), and the disease-specific survivals of both elderly groups were comparable with the non-elderly group in all TNM stages. Postoperative life expectancy of late-elderly patients eliminating death from recurrence was comparable with the corresponding aged general population eliminating death from gastric cancer. CONCLUSIONS: Gastric cancer surgery in elderly patients aged ≥80 years achieves reasonable long-term survival despite the increased risk of severe complications.

Identification of Candidates for Early Discharge After Gastrectomy.

OBJECTIVE: The aim of this study was to analyze clinical and laboratory variables associated with complications after gastrectomy for gastric cancer to predict candidates for successful early discharge. METHODS: Consecutive patients undergoing gastrectomy at Seoul National University Hospital from January through December 2013 were identified from a prospective complications database. Clinicopathologic and postoperative laboratory parameters were analyzed to determine variables associated with complications. An additional validation study was performed from March through May 2014. RESULTS: Overall, complications occurred in 180/855 patients (21.1 %). Age >68 years (odds ratio [OR] 1.64), use of an open approach (OR 1.9), and use of combined resection (OR 1.67) were significant independent risk factors for complications (p < 0.05). The postoperative day (POD) 5 to preoperative white blood cell count (WBC) ratio (risk ratio [RR] 2.01), C-reactive protein (CRP) level on POD 5 (RR 1.1), and maximum body temperature on POD 4 (RR 2.36) independently predicted complications in a multivariate analysis (p < 0.05). After establishing an early discharge profile (EDP) based on these six variables, 152/855 patients (17.8 %) were predicted to have an uncomplicated course. Of these, 8/152 (5.3 %) experienced complications. In a validation study of 217 patients, 43/217 (19.8 %) were candidates for early discharge on POD 5, and 3 (7.0 %) had a false-positive EDP. CONCLUSIONS: Patients younger than 68 years of age who underwent laparoscopic gastrectomy without combined resection might be candidates for early discharge on POD 5 if the POD 5 to preoperative WBC ratio is ≤1.2, POD 5 CRP level is ≤5.38 g/mL, and POD 4 body temperature is ≤37.4 °C.

The role of surface functionalization on the pulmonary inflammogenicity and translocation into mediastinal lymph nodes of graphene nanoplatelets in rats.

Graphene, a two-dimensional monocrystalline layer of carbon atoms, has potential in many applications not only in material sciences, but also in the biomedical fields, but there is little information about the role of surface modification on the toxicity of graphene-based nanomaterials. Here, we evaluated the role of surface functionalization of the graphene nanoplatelets (GNPs) on the pulmonary inflammogenicity and translocation into mediastinal lymph nodes using a rat intratracheal instillation model. Six types of GNPs were used: All types of GNPs were based on the pristine GNPs (GNPdot), and different functional groups were conjugated onto them including a COOH (GNPCOOH), COH [Formula: see text], N-H [Formula: see text], F x (GNPF), and N=H [Formula: see text]. All types of GNPs showed very high potential for the generation of reactive oxygen species (ROS) in a dose-dependent manner when measured by a 2'7'-dichlorofluorescin diacetate assay. GNPs were instilled into the lungs of rats at 0.3 and 1 mg/rat for the evaluation of acute (24 h) inflammation and at 3 mg/rat for chronic (1 and 4 weeks) inflammation. At 24 h after instillation, all types of GNPs showed good dose-dependent increases in polymorphonuclear leukocytes with a clear dose-dependency although significant increases compared to vehicle control were found only in positively charged GNPs [Formula: see text]. While the acute inflammation in all treatment groups was returned to control levels at 1 and 4 weeks after instillation, GNPs showed similar patterns of translocation into the mediastinal lymph nodes with a higher degree over time. This study implies that the main factors of GNPs for producing lung inflammation are the potential for ROS generation and surface charge. In addition, functional groups on the GNPs might not play an important role in the extrapulmonary translocation into the mediastinal lymph nodes.

Is There Any Role of Adjuvant Chemotherapy for T3N0M0 or T1N2M0 Gastric Cancer Patients in Stage II in the 7th TNM but Stage I in the 6th TNM System?

BACKGROUND: Controversy surrounds adjuvant chemotherapy (CTx) for T3N0M0 and T1N2M0 in the American Joint Committee on Cancer (AJCC) 7th edition stage IIA gastric cancer patients. The purpose of this study was to evaluate the benefit of adjuvant CTx for stage IIA cancer, including T3N0M0 and T1N2M0. METHODS: A total of 630 patients with stage IIA cancer who underwent a radical gastrectomy between January 1999 and December 2009 at Seoul National University Hospital were retrospectively analyzed. We compared the outcomes of 434 patients who did not receive CTx (the non-CTx group) with those of 196 patients who received CTx comprising of 5-fluorouracil-based regimens (the CTx group). RESULTS: The 5-year overall survival (OS) rates of the non-CTx and CTx groups were 86.4 and 89.3 %, respectively (p = 0.047). In the subgroup analysis of T2N1M0 (6th II/7th IIA), there was a significant difference in OS between the non-CTx and CTx groups (p = 0.003), but no differences were observed in T3N0M0 and T1N2M0 (6th IB/7th IIA) (p = 0.574 and p = 0.934). The multivariate analysis showed that a tumor size greater than 5 cm in T3N0M0 [odds ratio (OR) 1.929; p = 0.030], no adjuvant CTx in T2N1M0 (OR 4.853; p = 0.025), and no factors in T1N2M0 were found to be risk factors for recurrence-free survival. CONCLUSIONS: Adjuvant CTx may be associated with an improved outcome of patients with T2N1M0 (6th II/7th IIA), but not T3N0M0 or T1N2M0 (6th IB/7th IIA), gastric cancer. To confirm these results, further studies are needed.

Is preoperative staging enough to guide lymph node dissection in clinically early gastric cancer?

BACKGROUND: Limited by the accuracy of preoperative staging, some cases of gastric cancer invading the muscularis propria (pT2) are underestimated as early gastric cancer (EGC) in the preoperative assessment. The aim of this present study was to determine prognostic factors and to propose indications for limited lymph node dissection in patients with clinically EGC (cEGC). METHODS: Patients of cEGC (n = 2072) who were postoperatively diagnosed as pT1 (cT1pT1, n = 1858) and pT2 (cT1pT2, n = 214) from 2005 to 2009 at Seoul National University Hospital were retrospectively analyzed. RESULTS: There was no difference in 5-year survival rate between the cT1pT1 and cT1pT2 group (95.5 % vs. 92.5 %, P = 0.059), and both groups had better overall survival than pT2 patients who were preoperatively diagnosed as locally advanced gastric cancer (cT2-4pT2), whose 5-year survival rate was 78.0 % (P < 0.001). Multivariate analysis indicated lymph node metastasis (LNM) was the independent prognostic factor for cEGC (P < 0.001). In cEGC patients, three preoperative factors, including N stage by multidetector-row computed tomography (MDCT) (P < 0.001), preoperative histological type (P < 0.001), and tumor size (P < 0.001), were associated with LNM by multivariate analysis. Regarding the possibility of LNM, low-risk (4.4 %) and high-risk (17.3 %) groups were developed based on weighted scores of the aforementioned independent three variables. Among 52 patients in the low-risk group, the extension of LNM was limited to the perigastric area. CONCLUSIONS: Comprehensive evaluation based on MDCT, preoperative histological type, and tumor size is an effective method to predict LNM and guide tailored LN dissection for cEGC.

Portomesenteric vein thrombosis after gastric surgery.

BACKGROUND: Postoperative portomesenteric venous thrombosis (PMVT) is a rare but potentially serious complication of gastric surgery. This study analyzed the incidence, characteristics, risk factors, and outcomes of PMVT following gastric surgery. METHODS: Medical records of patients who underwent gastric surgery between January 2007 and December 2012 were reviewed retrospectively. The risk factors of PMVT were analyzed by a logistic regression analysis with control group matched 1:4 by age, sex, and cancer stage and by a Poisson regression analysis with unmatched control group. The resolution rate of PMVT in 12 months was compared between the treatment group and the nontreatment group. RESULTS: The total incidence of PMVT after gastric surgery was 0.67 % (31/4611). Most (54.84 %) PMVT cases were detected within 1 month postoperatively. No accompanying deep vein thrombosis (DVT) was noted. Multivariate comparison with 1:4 matched control showed that combined splenectomy, synchronous malignancy, and intra-abdominal complication were independent risk factors. Advanced stage, combined splenectomy, and synchronous malignancy were independent risk factors in Poisson regression analysis using unmatched controls. The resolution rate of PMVT was not different from patients treated with anticoagulation (n = 6) or antiplatelet therapy (n = 1) and were not significantly different with those of the untreated group [85.7 % (6/7) vs. 82.3 % (14/17), p = 0.935] during 1-year follow up. CONCLUSIONS: PMVT after gastric surgery was associated with advanced cancer stage, combined splenectomy, and synchronous malignancy, but it was not related to laparoscopy or DVT. Significant differences in the natural course of PMVT were not found between the treatment group and observation group.

Prognostic factors for reoperation of recurrent retroperitoneal sarcoma: The role of clinicopathological factors other than histologic grade.

BACKGROUND AND OBJECTIVES: Reoperation is recommended for resectable retroperitoneal sarcoma (RS) recurrence; however, the long-term overall survival (OS) benefit varies. Although histologic grade is an important OS predictor after primary tumor resection, its prognostic value tends to diminish with subsequent reoperations. The objective of this study was to identify prognostic factors of OS after reoperation for recurrent RS. METHODS: The medical records of 95 patients who underwent resection for RS at Seoul National University Hospital between January 1999 and July 2011 were retrospectively reviewed. Of the 95 patients, 50 patients underwent second resection for recurrence, and 26 of these patients underwent third resection. Prognostic factors were analyzed at each reoperation. RESULTS: Higher histologic grade and gross residual disease were poor prognostic factors of OS after first resection. After second resection, higher histologic grade and time since previous operation of within 1 year were poor prognostic factors. After third resection, only contiguous organ resection was a significant independent prognostic factor. CONCLUSIONS: The significance of prognostic factors changes with repetitive reoperations for RS recurrence. The prognostic value of histologic grade diminishes after the third resection, whereas other clinical factors such as time since previous operation and contiguous organ resection achieve significance.

Simple high-throughput analytical method using ultra-performance liquid chromatography coupled with tandem mass spectrometry to quantify total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol in urine.

BACKGROUND: Since the urinary concentration of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) is a reliable biomarker of exposure to tobacco smoke, we developed a relatively simple high-throughput chromatographic method to quantify total urinary NNAL concentrations in the general population. METHODS: The high-throughput analytical method was developed using ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) to identify and quantify total urinary NNAL concentrations in 10 non-smokers and 15 otherwise healthy smokers. RESULTS: Loss of nitric oxide at m/z 30 was found to be the predominant mass transitioned, and therefore was used as the SIM transition to quantify both NNAL and NNAL-methyl-d3 in urine. The analytical method did not require sample derivatization. Standard curves for total NNAL concentrations were linear between 20 and 1500 pg/mL, with coefficients of determination >0.95. Precision and accuracy ranged from 2.2% to 8.6% (CV) and from -5.6% to 10.9% (percent error), respectively. The lowest limit of quantification was 6.7 pg/mL, and 2.0 pg/mL the lowest limit of detection (LLOD). Total urinary NNAL concentrations in non-smoker subjects were

Evaluation of developmental toxicity using undifferentiated human embryonic stem cells.

An embryonic stem cell test (EST) has been developed to evaluate the embryotoxic potential of chemicals with an in vitro system. In the present study, novel methods to screen toxic chemicals during the developmental process were evaluated using undifferentiated human embryonic stem (hES) cells. By using surface marker antigens (SSEA-4, TRA-1-60 and TRA-1-81), we confirmed undifferentiated conditions of the used hES cells by immunocytochemistry. We assessed the developmental toxicity of embryotoxic chemicals, 5-fluorouracil, indomethacin and non-embryotoxic penicillin G in different concentrations for up to 7 days. While expressions of the surface markers were not significantly affected, the embryotoxic chemicals influenced their response to pluripotent ES cell markers, such as OCT-4, NANOG, endothelin receptor type B (EDNRB), secreted frizzled related protein 2 (SFRP2), teratocarcinoma-derived growth factor 1 (TDGF1), and phosphatase and tensin homolog (PTEN). Most of the pluripotent ES cell markers were down-regulated in a dose-dependent manner after treatment with embryotoxic chemicals. After treatment with 5-fluorouracil, indomethacin and penicillin G, we observed a remarkable convergence in the degree of up-regulation of development, cell cycle and apoptosis-related genes by gene expression profiles using an Affymetrix GeneChips. Taken together, these results suggest that embryotoxic chemicals have cytotoxic effects, and modulate the expression of ES cell markers as well as development-, cell cycle- and apoptosis-related genes that have pivotal roles in undifferentiated hES cells. Therefore, we suggest that hES cells may be useful for testing the toxic effects of chemicals that could impact the embryonic developmental stage.

Role of Recurrence Pattern Multiplicity in Predicting Post-recurrence Survival in Patients Who Underwent Curative Gastrectomy for Gastric Cancer.

PURPOSE: This study aimed to investigate the recurrence patterns in patients who underwent curative surgery for gastric cancer (GC) and analyze their prognostic value for post-recurrence survival (PRS). MATERIALS AND METHODS: We retrospectively reviewed the medical records of 204 patients who experienced GC recurrence following curative gastrectomy for GC at a single institution between January 2012 and December 2017. Specific recurrence patterns (lymph node, peritoneal, and hematogenous) and their multiplicity were analyzed as prognostic factors of PRS. RESULTS: The median PRS of the 204 patients was 8.3 months (interquartile range [IQR]: 3.2-17.4). For patients with a single recurrence pattern (n=164), the difference in each recurrence pattern did not show a significant prognostic value for PRS (lymph node vs. peritoneal, P=0.343; peritoneal vs. hematogenous, P=0.660; lymph node vs. hematogenous, P=0.822). However, the patients with a single recurrence pattern had significantly longer PRS than those with multiple recurrence patterns (median PRS: 10.2 months [IQR: 3.7-18.7] vs. 3.9 months [IQR: 1.8-10.4]; P=0.037). In the multivariate analysis, multiple recurrence patterns emerged as independent prognostic factors for poor PRS (hazard ratio, 1.553; 95% confidence interval, 1.092-2.208; P=0.014) along with serosal invasion, recurrence within 1 year after gastrectomy, and the absence of post-recurrence chemotherapy. CONCLUSIONS: Regardless of the specific recurrence pattern, multiple recurrence patterns emerged as independent prognostic factors for poor PRS compared with a single recurrence pattern.

Trust your gut: Establishing confidence in gastrointestinal models - An overview of the state of the science and contexts of use.

The webinar series and workshop titled "Trust Your Gut: Establishing Confidence in Gastrointestinal Models ­ An Overview of the State of the Science and Contexts of Use" was co-organized by NICEATM, NIEHS, FDA, EPA, CPSC, DoD, and the Johns Hopkins Center for Alternatives to Animal Testing (CAAT) and hosted at the National Institutes of Health in Bethesda, MD, USA on October 11-12, 2023. New approach methods (NAMs) for assessing issues of gastrointestinal tract (GIT)- related toxicity offer promise in addressing some of the limitations associated with animal-based assessments. GIT NAMs vary in complexity, from two-dimensional monolayer cell line-based systems to sophisticated 3-dimensional organoid systems derived from human primary cells. Despite advances in GIT NAMs, challenges remain in fully replicating the complex interactions and pro­cesses occurring within the human GIT. Presentations and discussions addressed regulatory needs, challenges, and innovations in incorporating NAMs into risk assessment frameworks; explored the state of the science in using NAMs for evaluating systemic toxicity, understanding absorption and pharmacokinetics, evaluating GIT toxicity, and assessing potential allergenicity; and discussed strengths, limitations, and data gaps of GIT NAMs as well as steps needed to establish confidence in these models for use in the regulatory setting.

Non-animal methods to assess whether chemicals may be toxic to the human digestive tract promise to complement or improve on animal-based methods. These approaches, which are based on human or animal cells and/or computer models, are faced with their own technical challenges and need to be shown to predict adverse effects in humans. Regulators are tasked with evaluating submitted data to best protect human health and the environment. A webinar series and workshop brought together scientists from academia, industry, military, and regulatory authorities from dif­ferent countries to discuss how non-animal methods can be integrated into the risk assessment of drugs, food additives, dietary supplements, pesticides, and industrial chemicals for gastrointestinal toxicity.

Genotoxicity assessment of root extracts of Paeonia lactiflora Pall.

The roots of Paeonia lactiflora Pall., (Paeoniae Radix, PL) are a well-known herbal remedy used to treat fever, rheumatoid arthritis, systemic lupus erythematosus, hepatitis, and gynecological disorders in East Asia. Here we evaluated the genetic toxicity of PL extracts (as a powder [PL-P] and hot-water extract [PL-W]) in accordance with the Organization for Economic Co-operation and Development guidelines. The Ames test revealed that PL-W was not toxic to S. typhimurium strains and E. coli in absence and presence of the S9 metabolic activation system at concentrations up to 5000 µg/plate, but PL-P produced a mutagenic response to TA100 in the absence of S9 mix. PL-P was cytotoxic in in vitro chromosomal aberrations (more than a 50 % decrease in cell population doubling time), and it increased the frequency of structural and numerical aberrations in absence and presence of S9 mix in a concentration-dependent manner. PL-W was cytotoxic in the in vitro chromosomal aberration tests (more than a 50 % decrease in cell population doubling time) only in the absence of S9 mix, and it induced structural aberrations only in the presence of S9 mix. PL-P and PL-W did not produce toxic response during the in vivo micronucleus test after oral administration to ICR mice and did not induce positive results in the in vivo Pig-a gene mutation and comet assays after oral administration to SD rats. Although PL-P showed genotoxic in two in vitro tests, the results from physiologically relevant in vivo Pig-a gene mutation and comet assays illustrated that PL-P and PL-W does not cause genotoxic effects in rodents.

In Vivo Evaluation of the Oral Toxicity of the Chlorobutanol.

Chlorobutanol (CB) is used as a preservative in cosmetics and has antibacterial activity. This study investigated the single- and repeated-dose 28-day oral toxicity of a CB solvent in Sprague Dawley (SD) rats. For the single-dose oral toxicity study, a dose of 62.5, 125, or 250 mg per kg of body weight (mg/kg b.w.) of CB was given once orally via gavage. For the repeated-dose 28-day toxicity study, the high dose was set as 100 mg/kg b.w./day, and the middle, middle-low, and low doses were set to 50, 25, and 12.5 mg/kg b.w./day, respectively. Body weight was not significantly changed in the repeated-dose toxicity study. Relative liver and kidney weights were significantly increased in both sexes of the 100 mg/kg b.w./day treatment group. However, there were histopathological changes in liver and kidney for females and males, respectively. These data suggested that the approximate lethal dose (ALD) of CB was over 250 mg/kg b.w./day in the single-dose study, and the no adverse effect level (NOAEL) for CB was over 50 and 12.5 mg/kg b.w./day for female and male rats in the repeated-dose toxicity study.

Colony-Forming Efficiency Assay to Assess Nanotoxicity of Graphene Nanomaterials.

The nano-market has grown rapidly over the past decades and a wide variety of products are now being manufactured, including those for biomedical applications. Despite the widespread use of nanomaterials in various industries, safety and health effects on humans are still controversial, and testing methods for nanotoxicity have not yet been clearly established. Nanomaterials have been reported to interfere with conventional cytotoxicity tests due to their unique properties, such as light absorption or light scattering. In this regard, the colony-forming efficacy (CFE) assay has been suggested as a suitable test method for testing some nanomaterials without these color-interferences. In this study, we selected two types of GNPs (Graphene nanoplatelets) as test nanomaterials and evaluated CFE assay to assess the cytotoxicity of GNPs. Moreover, for further investigation, including expansion into other cell types, GNPs were evaluated by the conventional cytotoxicity tests including the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS), Cell Counting Kit-8 (CCK-8), and Neutral red uptake (NRU) assay using MDCK, A549 and HepG2 cells. The results of CFE assay suggest that this test method for three cell lines can be applied for GNPs. In addition, the CFE assay was able to evaluate cytotoxicity regardless more accurately of color interference caused by residual nanomaterials.

Comparative sub-chronic toxicity studies in rats of two indistinguishable herbal plants, Cynanchum wilfordii (Maxim.) Hemsley and Cynanchum auriculatum Royle ex Wight.

Sub-chronic toxicity studies using rats have been conducted for Cynanchum wilfordii (Maxim.) Hemsley (CW) and Cynanchum auriculatum Royle ex Wight (CA). CW water extract didn't show any adverse effects whereas administering CW powder decreased body weights in complication with decreased food consumptions. In the case of CA water extract, triglyceride and absolute/relative liver weights were elevated and vacuolation was observed in liver. Treated CA powder in male rats increased alanine aminotransferase and aspartate aminotransferase and induced single cell necrosis and multinucleated hepatocyte in liver. As for female rats, increased absolute/relative weights and hypertrophy/vacuolation in adrenal glands and vacuolation in ovaries were observed when administered CA powder. In conclusion, no observed adverse effect level (NOAEL) of CW water extract was over 5000 mg/kg/day, while NOAEL of CW powder was 700 mg/kg/day for female and 150 mg/kg/day for male. In case of CA, NOAEL of water extract was 1500 mg/kg/day for male and 2000 mg/kg/day for female, while NOAEL of powder was 150 mg/kg/day for both gender. To the best of our knowledge, this is the first sub-chronic toxicity study on the adverse effects, target organs and its dose levels of C. wilfordii (Maxim.) Hemsley and C. auriculatum Royle ex Wight following GLP protocols.