Digital PCR and its applications in noninvasive prenatal testing.

In the past decade, digital PCR (dPCR), as a new nucleic acid absolute quantification technology, has been widely used in clinical research. dPCR does not rely on the standard curve and has a higher tolerance to inhibitors. Therefore, it is more accurate than quantitative real-time PCR (qPCR) for the absolute quantification of target sequences. In this article, we aim to review the application of dPCR in noninvasive prenatal testing (NIPT). We focused on the progress of dPCR in screening and identifying fetal chromosome aneuploidies and monogenic mutations. We introduced some common strategies for dPCR in NIPT and analyzed the advantages and disadvantages of different methods. In addition, we compared dPCR with qPCR and next-generation sequencing, respectively, and described their superiority and shortcomings in clinical applications. Finally, we envisaged what the future of dPCR might be in NIPT. Although dPCR can provide reproducible results with improved accuracy due to the digital detection system, it is essential to combine the merits of dPCR and other molecular techniques to achieve more effective and accurate prenatal diagnostic strategies.

Bioaccessibility and bioavailability adjusted dietary exposure of cadmium for local residents from a high-level environmental cadmium region.

The critical health risks caused by cadmium (Cd) via dietary exposure are commonly assessed by detecting Cd concentrations in foods. Differently, in this study, the bioaccessibility and bioavailability of Cd in major local harvests were introduced to assess the dietary exposure of local residents from a high-level environmental Cd region. The results indicated that certain Cd was released into the digestive juice after in vitro digestion with a bioaccessibility of 20-63% for rice and 3-32% for leafy vegetables, and the released portion was partially absorbed by Caco-2 cells with a bioavailability of 2-21% for rice and 0.2-13% for leafy vegetables. The results obtained from the toxicokinetic model revealed that the predicted urinary Cd values from the estimated daily intake (EDI) of Cd, which accounted for bioaccessibility and bioavailability, were consistent with the actual measured values, and the EDIs were considerably lower than the acceptable daily intake. This suggests that the bioaccessibility and bioavailability adjusted dietary Cd exposure should be more precise. The key issues addressed in our study implores that a potential health risk cannot be neglected in people with high consumption of rice from high-level zone.

TcpC inhibits toll-like receptor signaling pathway by serving as an E3 ubiquitin ligase that promotes degradation of myeloid differentiation factor 88.

TcpC is a virulence factor of uropathogenic E. coli (UPEC). It was found that TIR domain of TcpC impedes TLR signaling by direct association with MyD88. It has been a long-standing question whether bacterial pathogens have evolved a mechanism to manipulate MyD88 degradation by ubiquitin-proteasome pathway. Here, we show that TcpC is a MyD88-targeted E3 ubiquitin ligase. Kidney macrophages from mice with pyelonephritis induced by TcpC-secreting UPEC showed significantly decreased MyD88 protein levels. Recombinant TcpC (rTcpC) dose-dependently inhibited protein but not mRNA levels of MyD88 in macrophages. Moreover, rTcpC significantly promoted MyD88 ubiquitination and accumulation in proteasomes in macrophages. Cys12 and Trp106 in TcpC are crucial amino acids in maintaining its E3 activity. Therefore, TcpC blocks TLR signaling pathway by degradation of MyD88 through ubiquitin-proteasome system. Our findings provide not only a novel biochemical mechanism underlying TcpC-medicated immune evasion, but also the first example that bacterial pathogens inhibit MyD88-mediated signaling pathway by virulence factors that function as E3 ubiquitin ligase.

Jujuboside B promotes the death of acute leukemia cell in a RIPK1/RIPK3/MLKL pathway-dependent manner.

Initiation of necroptosis has been considered as a promising strategy for anticancer therapies, especially for eradicating apoptosis-resistant malignant cells. Jujubisode B is a natural saponins extracted from the seeds of Zizyphi Spinosi Semen, and possesses multiple pharmacological activities, including antianxiety, anti-inflammation, antiplatelet aggregation and induction of apoptosis. This study aims to explore the effect of jujuboside B on acute leukemic cells and the underlying mechanisms. Our results showed that jujuboside B inhibited leukemia cell growth in a dose-dependent manner and attenuated the clonogenic ability of U937 cells, concomitant with activation of RIPK1/RIPK3/MLKL pathway; these phenomena were evidently blocked by necroptosis inhibitor (Nec-1). With the help of Molecular Operating Environment (MOE) program, we identified that RIPK1, RIPK3 and MLKL are potential targets of jujuboside B. To the best of our knowledge, this is the first study to provide evidence that jujuboside B possesses antileukemic activity via a mechanism involving activation of RIPK1/RIPK3/MLKL pathway.

Comparison of the gastric acid inhibition function among lansoprazole, pantoprazole, and their respective stereoisomers in healthy Chinese subjects
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OBJECTIVE: This study was conducted to evaluate the difference in acid inhibition function among lansoprazole (LPZ), pantoprazole (PPZ), and their respective stereoisomers following single and multiple intravenous doses in healthy Chinese subjects. MATERIALS AND METHODS: The dosage groups were set as follows: 30 mg single and multiple intravenous administrations of LPZ or R-LPZ, 40 mg single and multiple intravenous administrations of PPZ or S-PPZ. Subjects received an intravenous infusion of LPZ, R-LPZ, PPZ, or S-PPZ injection in sterile saline solution (100 mL/h, 60 minutes), respectively. The intragastric pH was sampled every second for 24 hours at baseline and for 24 hours after drug administration. The baseline-adjusted pharmacodynamic (PD) parameters include ΔMean (pH), ΔMedian (pH), ΔTpH≥3 (%), ΔTpH≥4 (%), ΔTpH≥6 (%), and ΔAUECph-tτ1-τ2. The PD parameters were evaluated in different time intervals (0 - 24 hours, 0 - 4 hours and 14 - 24 hours). RESULTS: After a single dose, the ΔTpH≥4 (%) of R-LPZ, LPZ, S-PPZ and PPZ was 56.6 ± 19.6, 53.1 ± 23.3, 35.6 ± 24.9 and 26.8 ± 30.2, respectively. The ΔTpH≥6 (%) was 50.7 ± 26.1, 41.4 ± 26.2, 25.4 ± 24.9 and 22.1 ± 27.6, respectively. The ΔAUECph-τ1-τ was 45,564 ± 16,107, 41,798 ± 16,153, 31,914 ± 17,304 and 20,744 ± 21,500, respectively. Statistically significant differences were found with R-LPZ vs. S-PPZ, R-LPZ vs. PPZ, LPZ vs. S-PPZ and LPZ vs. PPZ. The average TpH≥4 of R-LPZ, LPZ, S-PPZ, and PPZ was (47.2 ± 26.1) minutes, (49.6 ± 19.3) minutes, (56.1 ± 23.7) minutes, and (72.1 ± 27.3) minutes, respectively. Statistically significant differences were found with R-LPZ vs. PPZ (p = 0.009) and LPZ vs. PPZ (p = 0.019). After multiple doses, the ΔTpH≥4 (%) of R-LPZ, LPZ, S-PPZ, and PPZ was 71.7 ± 20.2, 63.5 ± 19.4, 59.5 ± 17.8 and 64.0 ± 22.4, respectively. The ΔTpH≥6 (%) was 64.0 ± 22.2, 52.0 ± 19.2, 49.6 ± 20.4 and 50.9 ± 23.8, respectively. The ΔAUECph-τ1-τ was 326,149 ± 94,839, 288,565 ± 93,279, 296,189 ± 83,412 and 300,960 ± 108,057, respectively. No statistically significant differences were found in baseline-adjusted PD parameters during all time periods after multiple doses. CONCLUSION: After a single dose, the mean gastric pH inhibition value of R-LPZ was the highest, followed by LPZ, then S-PPZ and PPZ. R-LPZ and LPZ provided significantly better pH control compared with PPZ and S-PPZ in healthy subjects. The onset time of R-LPZ was the fastest and R-LPZ can provide better acid inhibition during sleeping time. After multiple doses, the mean values in all PD parameters of R-LPZ were the highest, the values of LPZ, S-PPZ, and PPZ were similar. However, no significant difference was found in acid inhibition among these four drugs after multiple doses.

The deafness gene GSDME: its involvement in cell apoptosis, secondary necrosis, and cancers.

Gasdermin E (GSDME), also called DFNA5, is a member of the gasdermin family. GSDME is involved in the regulation of apoptosis and necrosis. The N-terminal domain of GSDME displays an apoptosis-inducing activity while the C-terminal domain may serve as an apoptosis-inhibiting regulator by shielding the N-terminal domain. Besides its function in the regulation of apoptosis, GSDME was recently reported to be a substrate of caspase-3 and cleavage of GSDME by caspase-3 into necrotic N-terminal fragment leads to the induction of secondary necrosis. GSDME was first identified as a deafness gene because its mutation was associated with a specific form of autosomal dominant progressive sensorineural hearing loss. Furthermore, GSDME has been considered a tumor suppressor implicated in several types of cancer. This mini-review summarized recent reports relevant to the functions of GSDME in the regulation of apoptosis and necrosis as well as its clinical relevance.

Ligustroflavone reduces necroptosis in rat brain after ischemic stroke through targeting RIPK1/RIPK3/MLKL pathway.

Receptor-interacting protein kinase 1/3 (RIPK1/3) and mixed lineage kinase domain-like (MLKL)-mediated necroptosis contributes to brain injury after ischemic stroke. Ligustroflavone is an ingredient of common privet with activities of anti-inflammation and complement inhibition. This study aims to explore the effect of ligustroflavone on ischemic brain injury in stroke rat and the underlying mechanisms. A rat model of ischemic stroke was established by middle cerebral artery occlusion (MCAO), which showed ischemic injury (increase in neurological deficit score and infarct volume) and upregulation of necroptosis-associated proteins (RIPK1, RIPK3 and MLKL/p-MLKL). Administration of ligustroflavone (30 mg/kg, i.g.) 15 min before ischemia evidently improved neurological function, reduced infarct volume, and decreased the levels of necroptosis-associated proteins except the RIPK1. Consistently, hypoxia-cultured PC12 cells (O2/N2/CO2, 1:94:5, 8 h) caused cellular injury (LDH release and necroposis) concomitant with up-regulation of necroptosis-associated proteins, and these phenomena were blocked in the presence of ligustroflavone (25 µM) except the elevated RIPK1 levels. Using the Molecular Operating Environment (MOE) program, we identified RIPK1, RIPK3, and MLKL as potential targets of ligustroflavone. Further studies showed that the interaction between RIPK3 and RIPK1 or MLKL was significantly enhanced, which was blocked in the presence of ligustroflavone. Based on these observations, we conclude that ligustroflavone protects rat brain from ischemic injury, and its beneficial effect is related to the prevention of necroptosis through a mechanism involving targeting RIPK1, RIPK3, and/or MLKL.

Natural compound methyl protodioscin protects rat brain from ischemia/reperfusion injury through regulation of Mul1/SOD2 pathway.

Methyl protodioscin (MPD) is reported to relieve angina pectoris and myocardial ischemia, and mitochondrial E3 ubiquitin ligase 1 (Mul1) plays a key role in maintaining mitochondrial functions. Bioinformatic analysis shows potential interactions between MPD and Mul1. This study aims to explore whether MPD could protect rat brain against ischemia/reperfusion (I/R) injury through regulation of Mul1/ superoxide dismutase 2 (SOD2) pathway. The SD rat brains were subjected to 2 h of ischemia following by 24 h of reperfusion, which showed I/R injury (increase in neurological deficit score and infarct volume), up-regulation of Mul1 and down regulation of SOD2, these phenomena were attenuated by MPD treatment (3 or 10 mg/kg, i.g.). Consistently, in cultured HT22 cells, hypoxia-reoxygenation (H/R) treatment induced cellular injury (apoptosis and LDH release) concomitant with up-regulation of Mul1 and down regulation of SOD2, these phenomena were blocked in the presence of MPD (5 µM). Knockdown of Mul1 could also decrease SOD2 protein levels in HT22 cells accompanied by alleviation of H/R injury (reduction of apoptosis and LDH release). In agreement with the change of SOD2, reactive oxygen species generation was increased in H/R-treated HT22 cells while decreased in the presence of MPD. Based on these observations, we conclude that upregulation of Mul1 in rat brain contributes to cerebral I/R injury via suppression of SOD2 and that MPD protects rat brain from I/R injury through a mechanism involving regulation of Mul1/SOD2 pathway.

Characterization of potential plasma biomarkers related to cognitive impairment by untargeted profiling of phospholipids using the HILIC-ESI-IT-TOF-MS system.

Early diagnosis of neural changes causing cognitive impairment is critical for development of preventive therapies for dementia. Biomarkers currently characterized cannot be extensively applied due to the invasive sampling of cerebrospinal fluid. The other imaging approaches are either expensive or require a high technique. Phospholipids (PLs), which are basic constituents of neurons, might be a key variable in the pathogenesis of cognitive impairment. Changes in plasma PL provide the possibility for development of novel biomarkers with minimal invasion and high patient acceptance. In this work, a HILIC-ESI-IT-TOF-MS system was introduced for untargeted profiling of plasma PLs to investigate the relationship between changes of plasma PL profiles and cognitive impairment. A total of 272 types of PL molecular structures were characterized in human plasma and quantified through the internal standard method. Univariate analysis shows 29 PLs were significantly different between the control (n = 41) and the cognitive impairment (CI) group (n = 41). Multivariate analysis (PCA and OPLS-DA) was conducted based on these 29 potential PL biomarkers. Both univariate and multivariate analyses show abnormality of PL metabolism in the CI group, and the downregulation of ethanolamine plasmalogen (pPE) supply, especially those with PUFAs, in the circulation system should be strongly associated with neurodegeneration. A discriminative model was established with satisfied fit (R2) and prediction (Q2) abilities, and the classification test showed better recognition of the CI group than the control group indicating that this model of PL biomarkers could be used as indicators for screening of CI. Graphical abstract Characterization of potential plasma biomarkers related to cognitive impairment by untargeted profiling of phospholipids.

Characterization of phospholipid profiles in six kinds of nut using HILIC-ESI-IT-TOF-MS system.

Nuts, a class of fatty natural food, are associated with a series of health benefit. Lipid, which is the most abundant nutrient in nuts, could be one of the major contributors to many beneficial effects. In previous studies, only the composition of fatty acids was investigated. To better understand the nutritional value of nuts, phospholipids (PLs), with widely confirmed bioactivities, should be profiled as well. In this work, a HILIC-ESI-IT-TOF-MS system is applied to characterize PL profiles in six kinds of nut, including almonds, cashews, pecans, pistachios, walnuts and peanuts. A total of 165 PL molecular species were characterized and quantified. The obtained results showed that pistachios, cashews and walnuts are favorable nuts with diverse and high content of PLs; peanuts consist of abundant PL species but lower concentration of PLs; almonds and pecans might not be the first choice for PLs with relatively low species abundance and content.

Safety, pharmacokinetics, and pharmacodynamics of S-(-)-pantoprazole sodium injections after single and multiple intravenous doses in healthy Chinese subjects.

PURPOSE: The objective of this study was to evaluate the safety, pharmacokinetics, and pharmacodynamics of S-(-)-pantoprazole (PPZ) sodium injections following single and multiple intravenous doses in healthy Chinese subjects. METHODS: The dosage groups were set as followed: 20 mg of single and multiple intravenous administration of S-(-)-PPZ, 40 mg of single and multiple intravenous administration of S-(-)-PPZ or pantoprazole, and 80 mg of single dosage group of S-(-)-PPZ. Subjects were sampled for pharmacokinetic analysis and were monitored for 24-h intragastric pH prior to and 48-h intragastric pH after administration for the pharmacodynamic study. The pharmacokinetic and pharmacodynamic parameters were compared between S-(-)-PPZ and PPZ. Safety was evaluated on the basis of adverse events, vital signs, laboratory tests, and physical examination. RESULTS: All adverse events were mild and of limited duration. Maximum plasma concentration and area under the concentration-time curve for S-(-)-PPZ were dose proportional over the range of 20-80 mg following a single intravenous administration. Elimination rate constant and half-life observed statistical difference from a single dose to multiple doses in 40 mg of S-(-)-PPZ groups. After administration of a single dose, the mean 24-h intragastric pH value was observed higher in 80-mg group than in 40- and 20-mg groups. Slightly increase of intragastric pH was found after a single dose of 40 mg S-(-)-PPZ than 40 mg PPZ; however, the differences were not statistically significant. CONCLUSIONS: Twice daily of 40 mg S-(-)-PPZ sodium injections is effective in achieving satisfying acid inhibition. Compared with plasma R-(+)-PPZ levels, most subjects presented more potent and prolonged suppression of gastric acid of S-(-)-PPZ, while a few subjects showed faster metabolic rate of S-(-)-PPZ in vivo.

Impact of Gastric H+/K+-ATPase rs2733743 on the Intragastric pH-Values of Dexlansoprazole Injection in Chinese Subjects.

Background: Not all patients with acid-related disorders receiving proton pump inhibitor (PP) treatment get adequate gastric pH control. The genetic variation of receptors, metabolic enzymes, and transporters are known to cause failures of therapies. We have conducted a study to evaluate the influence of gastric H+/K+-ATPase, CYP2C19, and ABCB1 polymorphisms on the pharmacokinetic and pharmacodynamic profiles of dexlansoprazole injection in healthy Chinese subjects. Methods: A total of 51 subjects were enrolled for pharmacokinetic and pharmacodynamic study after a single intravenous administration of 20 or 30 mg dexlansoprazole. Plasma concentrations were determined using a chiral liquid chromatography-mass spectrometry method. The intragastric pH and baseline-adjusted intragastric pH parameters were introduced to evaluate the pharmacodynamic characters. Genotyping was performed by polymerase chain reaction. Results: The pharmacokinetic parameters were significantly influenced by CYP2C19 phenotypes, and gastric acid secretion inhibition were affected by both gastric H+/K+-ATPase and CYP2C19 polymorphisms. Gastric H+/K+-ATPase genotypes had greater effects than CYP2C19 genotypes on the suppression of gastric acid secretion. Conclusion: Gastric H+/K+-ATPase polymorphism may be one of the main reasons that cause insufficient gastric acid inhibition.

A Review of the Novel Application and Potential Adverse Effects of Proton Pump Inhibitors.

Proton pump inhibitors (PPIs) are known as a class of pharmaceutical agents that target H+/K+-ATPase, which is located in gastric parietal cells. PPIs are widely used in the treatment of gastric acid-related diseases including peptic ulcer disease, erosive esophagitis and gastroesophageal reflux disease, and so on. These drugs present an excellent safety profile and have become one of the most commonly prescribed drugs in primary and specialty care. Except for gastric acid-related diseases, PPIs can also be used in the treatment of Helicobacter pylori infection, viral infections, respiratory system diseases, cancer and so on. Although PPIs are mainly used short term in patients with peptic ulcer disease, nowadays these drugs are increasingly used long term, and frequently for a lifetime, for instance in patients with typical or atypical symptoms of gastroesophageal reflux disease and in NSAID or aspirin users at risk of gastrotoxicity and related complications including hemorrhage, perforation and gastric outlet obstruction. Long-term use of PPIs may lead to potential adverse effects, such as osteoporotic fracture, renal damage, infection (pneumonia and clostridium difficile infection), rhabdomyolysis, nutritional deficiencies (vitamin B12, magnesium and iron), anemia and thrombocytopenia. In this article, we will review some novel uses of PPIs in other fields and summarize the underlying adverse reactions.

Safety, tolerability, pharmacokinetics and pharmacodynamics of dexlansoprazole injection in healthy Chinese subjects.

PURPOSE: This study was conducted to evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of dexlansoprazole injection in healthy subjects. METHODS: Dexlansoprazole (20-90 mg) or lansoprazole (30 mg) was administrated intravenously to healthy male and female volunteers. All the subjects were sampled for pharmacokinetic (PK) analysis and 64 of them were monitored for 24-h intragastric pH prior to and after administration in the pharmacodynamic (PD) study. RESULTS: Maximum plasma concentration (Cmax) and area under the concentration-time curve (AUC0-τ) for dexlansoprazole injection was dose-proportional over the range of 20-90 mg following a single intravenous administration. Total clearance and half-life (t1/2) was independent of dose, and ranged from 4.69 L/h to 5.85 L/h and from 1.24 h to 2.17 h, respectively. A single dose of dexlansoprazole (30 mg) resulted in higher gastric pH compared to that of lansoprazole, evidenced by a mean 24-h gastric pH of 6.1 ± 1.2 (lansoprazole: 5.4 ± 1.1) and 24-h gastric pH > 6 post drug dose holding time of 64.2 ± 21.0% (lansoprazole: 49.5 ± 21.5%). CONCLUSION: Dexlansoprazole injection was safe and well tolerated for up to 5-day repeated intravenous administration dose of 30 mg. The recommended dosage for dexlansoprazole injection is 30 mg for an adequate gastric acid control.

Phase IIb trial of in vivo electroporation mediated dual-plasmid hepatitis B virus DNA vaccine in chronic hepatitis B patients under lamivudine therapy.

AIM: To assess the efficacy and safety of in vivo electroporation (EP)-mediated dual-plasmid hepatitis B virus (HBV) DNA vaccine vs placebo for sequential combination therapy with lamivudine (LAM) in patients with chronic hepatitis B. METHODS: Two hundred and twenty-five patients were randomized to receive either LAM + vaccine (vaccine group, n = 109) or LAM + placebo (control group, n = 116). LAM treatment lasted 72 wk. Patients received the DNA vaccine or placebo by intramuscular injection mediated by EP at weeks 12 (start of treatment with vaccine or placebo, SOT), 16, 24, and 36 (end of treatment with vaccine or placebo, EOT). RESULTS: In the modified intent-to-treat population, more patients had a decrease in HBV DNA > 2 log10 IU/mL in the vaccine group at week 12 after EOT compared with the control group. A trend toward a difference in the number of patients with undetectable HBV DNA at week 28 after EOT was obtained. Adverse events were similar. In the dynamic per-protocol set, which excluded adefovir (ADV) add-on cases at each time point instantly after ADV administration due to LAM antiviral failure, more patients had a decrease in HBV DNA > 2 log10 IU/mL in the vaccine group at week 12 and 28 after EOT compared with the control group. More patients with undetectable HBV DNA at week 28 after EOT in the vaccine group were also observed. Among patients with a viral load < 1000 copies/mL at week 12, more patients achieved HBeAg seroconversion in the vaccine group than among controls at week 36 after EOT, as well as less virological breakthrough and YMDD mutations. CONCLUSION: The primary endpoint was not achieved using the HBV DNA vaccine. The HBV DNA vaccine could only be beneficial in subjects that have achieved initial virological response under LAM chemotherapy.

[Comparative analysis of the efficacies of entecavir capsules and lamivudine in chronic hepatitis B patients].

OBJECTIVE: To investigate the efficacy profile of entecavir capsule (ETV) as a chronic hepatitis B therapy, as compared to lamivudine (LAM). METHODS: In this multicenter, randomized, double-blind, parallel group evaluation of ETV, 232 subjects were administered a 96-week course of 0.5 mg/day ETV or 100 mg/day LAM. PCR measurement of hepatitis B virus (HBV) was conducted throughout the treatment course to determine achievement of complete virologic response (CVR; defined as less than 500 copies/ml of HBV DNA) or experience of virology rebound ( more than 500 copies/ml of HBV DNA after achievement of CVR). RESULTS: After week-48 of treatment, the ETV group showed a higher CVR rate (90.3% vs. LAM: 59.4%) and lower virology rebound rate (1.9% vs. LAM: 13.9%). After week-96 of treatment, the ETV group continued to have a higher CVR rate (86.0% vs. LAM: 71.4%), and virology rebound was experienced by significantly less subjects in the ETV group (1.2% vs. LAM: 11.9%, P = 0.005). CONCLUSION: ETV therapy can quickly and continuously suppress HBV replication in chronic hepatitis B patients, and has a lower resistance rate than LAM. Compared to LAM, ETV may be a superior long-term treatment choice for chronic hepatitis B.

Chemical analysis of Eriocaulon buergerianum and adulterating species by high-performance liquid chromatography with diode array detection and electrospray ionization tandem mass spectrometry.

Eriocaulon buergerianum Koern. is the botanical source for the Chinese herbal medicine Gu-Jing-Cao. Other Eriocaulon species are also used as the same herb in local areas and are difficult to be differentiated. In order to improve the quality control of Gu-Jing-Cao, chemical constituents of E. buergerianum and adulterating species were analyzed by high-performance liquid chromatography with diode array detection and electrospray ionization tandem mass spectrometry (HPLC-DAD-ESI-MS(n)). The 70% methanol extracts were separated on a Zorbax SB-C(18) column and eluted with acetonitrile-water (each containing 0.1% formic acid). The compounds were identified by ion-trap mass spectrometry in both positive and negative ion modes. From E. buergerianum, E. faberi, E. sexangulare and E. cinereum, a total of 72 compounds were characterized, including 37 flavonols, 6 flavones, 4 isoflavones, 6 xanthones, 14 naphthopyranones, 3 phenolic acids, and 2 other flavonoids. Chemical variation of these four species were studied at three tiers, HPLC fingerprinting, quantitation of six major flavonoids, and semi-quantitative analysis of all characterized compounds, in combination with principal component analysis. E. buergerianum contained abundant flavonols and naphthopyranones, with minor flavones and xanthones; E. cinereum contained abundant isoflavones and flavones, together with few naphthopyranones; E. sexangulare was rich in flavones; and E. faberi contained abundant xanthones. Based on the above chemical analysis, E. buergerianum could be explicitly differentiated from the adulterating species, and the botanical species of 13 commercial batches of Gu-Jing-Cao were identified correctly. This is the first report on comprehensive chemical analysis of Eriocaulon species.

On-line enrichment and determination of polycyclic aromatic hydrocarbons in atmospheric particulates using high performance liquid chromatography with fluorescence as detector.

Seven polycyclic aromatic hydrocarbons (PAHs) in atmospheric particulates were determinated by high performance liquid chromatography (HPLC) with fluorescence detector using direction injection and an on-line enrichment trap column. The method simplified the sample pretreatment, saved time and increased the efficiency. With the on-line trap column, PAHs were separated availably even underground injecting 1.0 ml sample with relatively high column efficiency. The recoveries of the seven PAHs were from 85% to 120% for spiked atmospheric particulate sample. The limit of detection was 15.3-39.6 ng/L (S/N=3.3). There were good linear correlations between the peak areas and concentrations of the seven kinds of PAHs in the range of 1-50 ng/ml with the correlation coefficients over 0.9970. Furthermore, it also indicated that the method is available to determine PAHs in atmospheric particulates well.

Protective effects of echinacoside on carbon tetrachloride-induced hepatotoxicity in rats.

The aim of this study was to investigate the possible protective effects of echinacoside, one of the phenylethanoids isolated from the stems of Cistanches salsa, a Chinese herbal medicine, on the free radical damage of liver caused by carbon tetrachloride in rats. Treatment of rats with carbon tetrachloride produced severe liver injury, as demonstrated by dramatic elevation of serum ALT, AST levels and typical histopathological changes including hepatocyte necrosis or apoptosis, haemorrhage, fatty degeneration, etc. In addition, carbon tetrachloride administration caused oxidative stress in rats, as evidenced by increased reactive oxygen species (ROS) production and MDA concentrations in the liver of rats, along with a remarkable reduction in hepatic SOD activity and GSH content. However, simultaneous treatment with echinacoside (50mg/kg, intraperitoneally) significantly attenuated carbon tetrachloride-induced hepatotoxicity. The results showed that serum ALT, AST levels and hepatic MDA content as well as ROS production were reduced dramatically, and hepatic SOD activity and GSH content were restored remarkably by echinacoside administration, as compared to the carbon tetrachloride-treated rats. Moreover, the histopathological damage of liver and the number of apoptotic hepatocytes were also significantly ameliorated by echinacoside treatment. It is therefore suggested that echinacoside can provide a definite protective effect against acute hepatic injury caused by CCl(4) in rats, which may mainly be associated with its antioxidative effect.