Enantioselective adsorption of ibuprofen enantiomers using chiral-active carbon nanoparticles induced S-α-methylbenzylamine.

The chiral media is crucial to the chiral recognition and separation of enantiomers. In this study, we report the preparation of novel chiral carbon nanoparticles (CCNPs) via surface passivation using glucose as the carbon source and S-(-)-α-methylbenzylamine as the chiral ligand. The structures of the obtained CCNPs are characterized via FT-IR, Raman spectroscopy, DLS, XPS, XRD, TEM, and zeta potential analysis. These CCNPs could be employed as the chiral adsorbent and used for the enantioselective adsorption of the ibuprofen enantiomers. The results demonstrated that the CCNPs could selectively adsorb R-enantiomer from ibuprofen racemate solution and give an enantiomeric excess (e.e.) of about 50% under an optimal adsorption condition. Moreover, the regeneration efficiency of the CCNPs remained above e.e. of 43% after the fifth cycle. The present work confirmed that the prepared CCNPs show great potential in the enantioselective separation of ibuprofen racemate.

Ursane-Type Triterpenes with a Phenylpropanoid Unit from Camellia ptilosperma and Evaluation of Their Cytotoxic Activities.

Six new ursane-type triterpenes with a phenylpropanoid unit and five known oleanane-type triterpenes were isolated from the leaves of Camellia ptilosperma. The undescribed compounds were identified by analysis of 1D and 2D NMR and HRESIMS spectroscopic data as ptilospermanols A-F. The cytotoxicity of new compounds against six human cancer cell lines and three mouse tumor cell lines was evaluated by MTT assay.

Triterpenes and Pheophorbides from Camellia ptilosperma and Their Cytotoxicity, Photocytotoxicity, and Photodynamic Antibacterial Activity.

Phytochemical investigation of the leaves of Camellia ptilosperma S. Y. Liang et Q. D. Chen led to the isolation of ten undescribed compounds, including six new triterpenes (1-6) and four new pheophorbide-related compounds (7-10). Meanwhile, the cytotoxic activity of the six triterpenes against six cancer cell lines was evaluated by MTT assay. Compound 2 showed potent cytotoxicity toward HepG2 cells with an IC50 value of 2.57 µM. Compounds 4 and 5 exhibited cytotoxicity against MDA-MB231 cells, with IC50 values of 11.31 and 5.52 µM, respectively. Additionally, the cytotoxicity of four new pheophorbides against these cancer cells was evaluated both in the presence and absence of light treatment. Compound 7 exhibited exceptional photocytotoxicity against Hela, MCF-7, and A549 cells, with IC50 values of 0.43 µM, 0.28 µM, and 0.92 µM, respectively. Compound 10 demonstrated significant photodynamic cytotoxic activity against BEL-7402 and HepG2 cells with IC50 values of 0.77 µM and 0.33 µM, respectively. The photodynamic antibacterial activity of 7-10 was also tested for S. aureus, E. coli, K. pneumoniae, and P. aeruginosa under direct illumination. Compounds 8 and 10 exhibited sensitivity to E. coli and demonstrated a photodynamic antibacterial effect, with a MIC value of 0.625 µM.

A novel surgical planning system using an AI model to optimize planning of pedicle screw trajectories with highest bone mineral density and strongest pull-out force.

OBJECTIVE: The purpose of this study was to evaluate the ability of a novel artificial intelligence (AI) model in identifying optimized transpedicular screw trajectories with higher bone mineral density (BMD) as well as higher pull-out force (POF) in osteoporotic patients. METHODS: An innovative pedicle screw trajectory planning system called Bone's Trajectory was developed using a 3D graphic search and an AI-based finite element analysis model. The preoperative CT scans of 21 elderly osteoporotic patients were analyzed retrospectively. The AI model automatically calculated the number of alternative transpedicular trajectories, the trajectory BMD, and the estimated POF of L3-5. The highest BMD and highest POF of optimized trajectories were recorded and compared with AO standard trajectories. RESULTS: The average patient age and average BMD of the vertebral bodies were 69.6 ± 7.8 years and 55.9 ± 17.1 mg/ml, respectively. On both sides of L3-5, the optimized trajectories showed significantly higher BMD and POF than the AO standard trajectories (p < 0.05). On average, the POF of optimized trajectory screws showed at least a 2.0-fold increase compared with AO trajectory screws. CONCLUSIONS: The novel AI model performs well in enabling the selection of optimized transpedicular trajectories with higher BMD and POF than the AO standard trajectories.

Structural Characterization and Assessment of Anti-Inflammatory and Anti-Tyrosinase Activities of Polyphenols from Melastoma normale.

Polyphenols, widely distributed in the genus Melastoma plants, possess extensive cellular protective effects such as anti-inflammatory, anti-tyrosinase, and anti-obesity, which makes it a potential anti-inflammatory drug or enzyme inhibitor. Therefore, the aim of this study is to screen for the anti-inflammatory and enzyme inhibitory activities of compounds from title plant. Using silica gel, MCI, ODS C18, and Sephadex LH-20 column chromatography, as well as semipreparative HPLC, the extract of Melastoma normale roots was separated. Four new ellagitannins, Whiskey tannin C (1), 1-O-(4-methoxygalloyl)-6-O-galloyl-2,3-O-(S)-hexahydroxydiphenoyl-ß-d-glucose (2), 1-O-galloyl-6-O-(3-methoxygalloyl)-2,3-O-(S)-hexahydroxydiphenoyl-ß-d-glucose (3), and 1-O-galloyl-6-O-vanilloyl-2,3-O-(S)-hexahydroxydiphenoyl-ß-d-glucose (4), along with eight known polyphenols were firstly obtained from this plant. The structures of all isolates were elucidated by HRMS, NMR, and CD analyses. Using lipopolysaccharide (LPS)-stimulated RAW2 64.7 cells, we investigated the anti-inflammatory activities of compounds 1-4, unfortunately, none of them exhibit inhibit nitric oxide (NO) production, their IC50 values are all > 50 µM. Anti-tyrosinase activity assays was done by tyrosinase inhibition activity screening model. Compound 1 showed weak tyrosinase inhibitory activity with IC50 values of 426.02 ± 11.31 µM. Compounds 2-4 displayed moderate tyrosinase inhibitory activities with IC50 values in the range of 124.74 ± 3.12-241.41 ± 6.23 µM. The structure-activity relationships indicate that hydroxylation at C-3', C-4', and C-3 in the flavones were key to their anti-tyrosinase activities. The successful isolation and structure identification of ellagitannin provide materials for the screening of anti-inflammatory drugs and enzyme inhibitors, and also contribute to the development and utilization of M. normale.

Effects of long-term fluoride exposure on cognitive ability and the underlying mechanisms: Role of autophagy and its association with apoptosis.

Autophagy and apoptosis are two important cellular processes that are crucial for neurodevelopment. Evidence shows that apoptosis is implicated in fluoride neurotoxicity. However, the biological roles of autophagy, especially its interplay with apoptosis in the neurotoxicity induced by long-term fluoride exposure remain unclear. Here we present in vivo and in vitro evidence that fluoride-induced defective autophagy elicits excessive apoptosis, thus inducing neurotoxicity. Using Sprague-Dawley rats exposed to sodium fluoride from 60 days before pregnancy until 6 months post-delivery as in vivo model, we showed that fluoride impaired the learning and memory abilities of offspring rats, with decreased neuronal number, suppressed autophagy and enhanced apoptosis in hippocampus. These results were validated in human neuroblastoma SH-SY5Y cells in vitro. Mechanistically, mTOR signaling, responsible for autophagy induction, was activated in vivo and in vitro, and targeting inhibition of mTOR with rapamycin protected SH-SY5Y cells from defective autophagy and excessive apoptosis, thereby enhancing neuronal survival. Furthermore, circulating levels of autophagy markers were low in children with higher fluoride body burden and lower intelligence quotient scores. Collectively, our results suggest that defective autophagy plays a pivotal role in fluoride neurotoxicity, and mTOR might be a promising target for the prevention and treatment of fluoride neurotoxicity.

Essential oils and ethanol extract from Camellia nitidissima and evaluation of their biological activity.

Camellia nitidissima, a well-known species of yellow Camellia, has undergone commercial cultivation as a new tea resource recently. Herein, the composition, antioxidant and antimicrobial activities of the essential oil and ethanol extract of C. nitidissima were investigated. The essential oils from the leaves and flowers of C. nitidissima were obtained by hydro-distillation. A total of 56 and 34 constituents accounting for 77.5 and 96.8% of the oils were identified by GC-MS. Linalool (35.8%), phytol (7.9%), cis-geranyl acetone (7.3%) and methyl salicylate (6.8%) were found to be the primary components in the leaf oil, while the flower oil was rich in α-eudesmol (34.3%), γ-eudesmol (31.5%) and linalool (11.1%). The ethanol extract of C. nitidissima leaves contained 281.04 mg gallic acid equivalent/g of total phenols. The antioxidant activities of the two oils and extract were evaluated by DPPH and ABTS radical-scavenging assays. The IC50 values varied from 17.4 (extract) to 720.3 µg/mL (flower oil) for DPPH and from 28.8(extract) to 889.6 µg/mL (flower oil) for ABTS. Both essential oils exhibited moderate antioxidant activities, and the extract possessed strong effects close to ascorbic acid. Additionally, the antimicrobial activities of the oils and extract against Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa were evaluated by agar dilution assay. No considerable bactericidal activities were observed for either essential oil or extract compared with ampicillin and tobramycin standards. The results indicated the extract was more efficient than the two essential oils against S. aureus (MIC = 0.625 mg/mL) and B. subtilis (MIC = 1.25 mg/mL).

Prenatal bisphenol a exposure leads to reproductive hazards on male offspring via the Akt/mTOR and mitochondrial apoptosis pathways.

BACKGROUND: Bisphenol A (BPA) exposure is ubiquitous, and in laboratory animals and humans, exposure has been associated with male spermatogenesis dysfunction. However, it is largely unknown if this association has a fetal origin. OBJECTIVE: The aim of this research is to explore the mechanism whereby prenatal BPA exposure exerts its reproductive toxicities on spermatogenesis in male offspring. METHODS: We fed pregnant SD rats BPA at doses ranging from 1 to 100 mg/kg body weight during gestation days 14-21. The male offspring were euthanized at postnatal day 21, and the levels of sex hormones and reactive oxygen species (ROS), expressions of proteins and genes in the Akt/mTOR, and mitochondrial apoptosis pathways were detected. Several closely linked autophagy indexes were also measured incidentally. Additionally, semen quality of adult offspring was tested at the end of the study. RESULTS: The results revealed that prenatal BPA exposure can cause endocrine disruption and oxidative stress in male offspring, leading to inhibition of spermatogenesis by suppressing the Akt/mTOR pathway and activating the mitochondrial apoptosis pathway. CONCLUSIONS: These preliminary results indicate noteworthy and far-reaching effects of BPA on the reproductive system of male offspring. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1007-1023, 2017.

Bisphenol a induces autophagy and apoptosis concurrently involving the Akt/mTOR pathway in testes of pubertal SD rats.

Bisphenol A (BPA), a typical endocrine disrupting chemical (EDC), has been proven to cause male reproductive toxicity. However, the precise mechanisms of this effect are still unclear. Puberty is a crucial period of reproductive development, and adolescents are more susceptible to xenobiotics. This research was designed to explore the mechanism of BPA toxicity on pubertal male reproduction. Rats were exposed to 0, 2, 10, 50 mg kg-1 bw BPA, then the levels of sex hormones, oxidative stress, and semen quality were detected. HE staining, TUNEL assay and transmission electron microscopy were used to investigate the morphological changes, apoptosis, and autophagy in testes, respectively. Expressions of relevant genes and proteins were measured by RT-PCR, western blotting, and immunohistochemical staining. The results indicated that BPA exposure led to oxidative stress and endocrine disorders in pubertal male SD rats, caused apoptosis and autophagy in testes, and then damaged spermatogenesis ultimately. The Akt pathway was activated and the mTOR pathway was inhibited in the process. Taken together, BPA induced apoptosis and autophagy concurrently in pubertal testes, and this added a new layer to our understanding on male reproductive toxicity of BPA. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1977-1989, 2017.

Mitochondrial Dysfunction and Ca2+ Overload in Injured Sertoli Cells Exposed to Bisphenol A.

Bisphenol-A (BPA) is well known as one of endocrine-disrupting chemicals and testicular toxicant. In this present study, we determined whether BPA caused cell injury through mitochondria impairment and ROS overproduction. The cellular ROS production, mitochondrial ATP synthetase activity and Ca2+ concentration were examined. We have found BPA caused the cellular mitochondria dysfunction and followed by cell death in Sertoli cells. Moreover cytoplasm Ca2+ overload was also involved. Furthermore, pretreatment with N-acetyl-L-cysteine (NAC) could alleviate the damage by causing a remarkable decrease in ROS production and mitochondrial dysfunction. Collectively, our results showed that BPA exposure induced Sertoli cell apoptosis because of excessive ROS generation and mitochondrial dysfunction. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 823-831, 2017.

4-Nonylphenol induces disruption of spermatogenesis associated with oxidative stress-related apoptosis by targeting p53-Bcl-2/Bax-Fas/FasL signaling.

4-Nonylphenol (NP) is a ubiquitous environmental chemical with estrogenic activity. Our aim was to test the hypothesis that pubertal exposure to NP leads to testicular dysfunction. Herein, 24 7-week-old rats were randomly divided into four groups and treated with NP (0, 25, 50, or 100 mg/kg body weight every 2 days for 20 consecutive days) by intraperitoneal injection. Compared to untreated controls, the parameters of sperm activation rate, curvilinear velocity, average path velocity, and swimming velocity were significantly lower at doses of 100 mg/kg, while sperm morphological abnormalities were higher, indicating functional disruption and reduced fertilization potential. High exposure to NP (100 mg/kg) resulted in disordered arrangement of spermatoblasts and reduction of spermatocytes in seminiferous tubules, while tissues exhibited a marked decline in testicular fructose content and serum FSH, LH, and testosterone levels. Oxidative stress was induced by NP (50 or 100 mg/kg) as evidenced by elevated MDA, decreased SOD and GSH-Px, and inhibited antioxidant gene expression (CAT, GPx, SOD1, and CYP1B1). In addition, NP treatment decreased proportions of Ki-67-positive cells and increased apoptosis in a dose-dependent manner. Rats treated with 100 mg/kg NP exhibited significantly increased mRNA expression of caspase-1, -2, -9, and -11, decreased caspase-8 and PCNA1 mRNA expression, downregulation of Bcl-2/Bax ratios and upregulation of Fas, FasL, and p53 at the protein and mRNA levels. Taken together, NP-induced apoptosis, hormonal deficiencies, and depletion of fructose potentially impairs spermatogenesis and sperm function. p53-independent Fas/FasL-Bax/Bcl-2 pathways may be involved in NP-induced oxidative stress-related apoptosis. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 739-753, 2017.

[Effects of fluoride on autophagy level in human neuroblastoma SH-SY5Y cells].

OBJECTIVE: To explore the effects of fluoride on autophagy level in human neuroblastoma SH-SY5Y cells. METHODS: SH-SY5Y cells were treated with different concentrations( 20, 40, 60 mg/L) of fluoride for 24 h. Transmission electron microscope( TEM) was used to detect the ultrastructure of autophagosomes in SH-SY5Y cells. Acridine orange staining was used to examine the form of autophagic vesicles and Western blotting was used to check the expression levels of autophagy relevant proteins of Atg5, LC3 and P62 in SH-SY5 Y cells. RESULTS: The TEM results showed the presence of autophagic ultrastructure in SH-SY5Y cells and fluoride could decrease the amount of autophagosomes. Acridine orange staining results showed that the amount of autophagic vesicles were obviously decreased in 40 and 60 mg/L Na F-treated groups compared with control, and 60 mg/L Na F-treated group was decreased the most. The expression level of Atg5 and LC3-II protein was dose-dependently decrease and P62 protein was dosedependently increased compared with control( P < 0. 05). CONCLUSION: Fluoride maysuppress the level of autophagy in SH-SY5Y cells.

p,p'-DDE damages spermatogenesis via phospholipid hydroperoxide glutathione peroxidase depletion and mitochondria apoptosis pathway.

One, 1-dichloro-2,2-bis(p-chlorophenyl) ethylene (p,p'-DDE), the major metabolite of 2,2-bis(4-chlorophenyl)-1,1,1-trichloroethane (DDT), is a known persistent organic pollutant (POPs) and male reproductive toxicant. However, the mechanism by which p,p'-DDE exposure causes male reproductive toxicity remains unknown. The objective of this study was to elucidate some mechanisms involved in this process, including the mitochondria apoptosis pathway and the role of phospholipid hydroperoxide glutathione peroxidase (PHGPx). Puberty male SD rats were given different doses of p,p'-DDE (0, 20, 60, 100 mg/kg body weight), after the treatment, the semen quality was evaluated. Western blotting was used to detect the PHGPx protein expression. Furthermore, real-time PCR was used to analyze the genetic expression of PHGPx, Bax, Cytochrom C (Cyt C), Apaf-1, and caspase-3 in the testis. Results indicated that after the exposure, sperm malformation rate showed a significant rise compared with the control group, and meanwhile, the sperm density and sperm motility parameters were reduced to some extent in different treated groups. The mitochondria apoptosis pathway was activated. And remarkably, the expression of PHGPx protein was greatly reduced by the exposure. We conclude that p,p'-DDE can damage spermatogenesis via PHGPx depletion and mitochondria apoptosis pathway.

[PI3K-Akt/LKB1-AMPK-mTOR-p70S6K/4EBP1 signaling pathways participate in the regulation of testis development and spermatogenesis: An update].

Male infertility is closely associated with spermatogenesis disorders triggered by aberrant gene expression or abnormal signaling pathways in the testis. The mammalian target of rapamycin (mTOR) is a central regulator of cell metabolism, playing an important role in regulating cell proliferation, differentiation, translation, actin polymerization, cycle progression, energy metabolism, autophagy, and other cellular activities. PI3K-Akt and LKB1-AMPK, the two well-defined classic signal transduction pathways, regulate the expressions of mTOR and its downstream p70S6K/4EBP1 through different molecular pathways. Recent studies show that mTOR-p70S6K/4EBP1 signaling participates in the regulation of the proliferation and differentiation of testicular cells and spermatogenesis. This review focuses on the role of PI3K-Akt/LKB1- AMPK-mTOR signaling cascades in testis development and spermatogenesis, providing some new perspectives for the studies of the molecular mechanism underlying male sterility.

Optical resolution and optimization of (R,S)-propranolol using dehydroabietic acid via diastereomeric crystallization.

The optical resolution of (R,S)-propranolol by the diastereomeric crystallization method was successfully performed using dehydroabietic acid (DHAA) as the resolving agent in methanol. The three important parameters: DHAA amount, solvent (methanol) amount, and crystallization temperature of diastereomeric salts were optimized employing the response surface methodology (RSM). When maintaining a lower limit of 95% for the purity of (S)-propranolol, the optimal resolution conditions were a DHAA/(R,S)-propranolol molar ratio of 1.1, solvent/(R,S)-propranolol ratio of 16.2 mL.g(-1) , and crystallization temperature of -5 °C. The desired (S)-propranolol was prepared with 94.8% optical purity and 72.2% yield under the optimal conditions.

The role of Pten/Akt signaling pathway involved in BPA-induced apoptosis of rat Sertoli cells.

Bisphenol-A (BPA), one of endocrine-disrupting chemicals, is a male reproductive toxicant. Previous studies have revealed the direct cytotoxicity of BPA in many cultured cells, such as mitotic aneuploidy in embryonic cells and somatic cells, and apoptosis in neurons and testicular Sertoli cells. To understand the action of BPA and assess its risk, the Pten/Akt pathway was investigated in cultured Sertoli cells to elucidate the mechanism of the reproductive effects of BPA. The results showed that over 50 µM BPA treatment could decrease the viability of Sertoli cells and cause more apoptosis. In addition, BPA could induce the increase in mRNA levels of Pten and Akt. The protein level of Pten was increased; however, the protein levels of phospho-Akt and procaspase-3 were decreased after BPA exposure. Taken together, observed results suggested that the Pten/Akt pathway might be involved in the apoptotic effects of BPA on Sertoli cells.

DEVELOPMENT AND IMPLEMENTATION OF A PRACTICAL PUBLIC HEALTH TRAINING SYSTEM IN CHINA.

Public health education is becoming an increasing priority among educators of medicine. In China, little attention has been paid to public health education reform. A new public health training system was introduced in China in 2007. We conducted this study during 2006-2012 to evaluate the graduate core competencies under the new system. Data were collected from 231 graduates and 49 public health agencies. The 144 graduates who enrolled in 2006 and were trained under the old system constituted the control group; the 87 graduates who enrolled in 2007 and were trained under the new system constituted the experimental group. Surveys of graduate core competencies found analyzing and solving problems in the laboratory, conducting on-site practice and learning new technologies were the top three abilities most expected by public health agencies. After 5-year practical ability training, the graduates in the experimental group had better performance; on-site practical ability and laboratory practical ability increased significantly by 24.5% and 20.0%, respectively. Three other important competencies also improved: designing epidemiologic surveys, collecting information from the literature and doing statistical analyses. However, preventing and controlling common diseases and dealing with emergencies remained weak. These results show the new training system should be continued, but revisions are needed to improve this training system, especially in the areas of preventing and controlling common diseases and dealing with emergencies.

Coactivation of the PI3K/Akt and ERK signaling pathways in PCB153-induced NF-κB activation and caspase inhibition.

Polychlorinated biphenyls (PCBs) are a group of persistent and widely distributed environmental pollutants that have various deleterious effects, e.g., neurotoxicity, endocrine disruption and reproductive abnormalities. In order to verify the hypothesis that the PI3K/Akt and MAPK pathways play important roles in hepatotoxicity induced by PCBs, Sprague-Dawley (SD) rats were dosed with PCB153 intraperitoneally at 0, 4, 16 and 32mg/kg for five consecutive days; BRL cells (rat liver cell line) were treated with PCB153 (0, 1, 5, and 10µM) for 24h. Results indicated that the PI3K/Akt and ERK pathways were activated in vivo and in vitro after exposure to PCB153, and protein levels of phospho-Akt and phospho-ERK were significantly increased. Nuclear factor-κB (NF-κB) activation and caspase-3, -8 and -9 inhibition caused by PCB153 were also observed. Inhibiting the ERK pathway significantly attenuated PCB153-induced NF-κB activation, whereas inhibiting the PI3K/Akt pathway hardly influenced phospho-NF-κB level. However, inhibiting the PI3K/Akt pathway significantly elevated caspase-3, -8 and -9 activities, while the ERK pathway only synergistically regulated caspase-9. Proliferating cell nuclear antigen (PCNA), a reliable indicator of cell proliferation, was also induced. Moreover, PCB153 led to hepatocellular hypertrophy and elevated liver weight. Taken together, PCB153 leads to aberrant proliferation and apoptosis of hepatocytes through NF-κB activation and caspase inhibition, and coactivated PI3K/Akt and ERK pathways play critical roles in PCB153-induced hepatotoxicity.

Two undescribed compounds from Aspergillus Niger, an endophytic fungus isolated from Camellia flavida.

A new naphtho-γ-pyrone dimer, asperosperma A, and a new methyl nicotinate derivative, asperosperma B, with 12 known compounds were isolated from the endophytic fungus Aspergillus niger from the stem of Camellia flavida. Their structure was elucidated by NMR, ECD spectrum, and HR-ESI-MS data. Asperosperma A exhibited a highly cytotoxicity against H460 and 4T1 cancer cells with the IC50 values were 0.37 ± 0.06 and 2.04 ± 0.79 µM, respectively. Moreover, it showed a highly sensitive against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and methicillin-resistant S. aureus.

Comparison of extracts and toxicities of organic compounds in drinking water concentrated by single and composite XAD resins.

We compared extracts and toxicities of organic compounds (OCs) in drinking water concentrated by composite XAD-2/8 resin (mixed with an equal volume of XAD-2 and XAD-8 resins) with those extracted by single XAD-2 (non-polar) and XAD-8 (polar) resins. Drinking water was processed from raw water of the Han River and the Yangtze River in Wuhan section, China. The extraction efficiency of all resins was controlled at 30%. The types of extracted OCs were detected by gas chromatography-mass spectrometry, and the cytotoxicity and genotoxicity were assessed by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and comet assays, respectively, in human hepatoma HepG2 cells. Our results showed that XAD-2/8 extracted a larger variety of OCs, compared with XAD-8 and XAD-2. The cytotoxicity and genotoxicity of extracted OCs were in the order of XAD-8> XAD-2/8> XAD-2 at almost all tested concentrations after 24 h treatment (P < 0.05). Our findings suggest that single XAD resin selectively extracts either polar or non-polar OCs, which would lead to over- or under-estimation of the toxicity of drinking water. Nevertheless, composite resin extracts both polar and non-polar OCs, and could be utilized as a useful extraction technique to evaluate the level and toxicity of OCs in drinking water.