Population pharmacokinetics and exposure-response analysis of tigecycline in patients with hospital-acquired pneumonia.

BACKGROUND: Tigecycline has been widely used to treat hospital-acquired pneumonia (HAP) off-label since it is effective against a wide range of multidrug-resistant bacteria. However, no recommended dosage for this indication has been evaluated, resulting in possible inadequate treatment. AIMS: The aims of this study are to establish the population pharmacokinetic (PPK) model of tigecycline in Chinese patients with HAP, as well as to evaluate the exposure-response relationship for the treatment of HAP with multidrug-resistant gram-negative bacteria. METHODS: A PPK analysis of tigecycline was conducted on pooled data from 328 blood samples obtained from 89 patients with HAP. Tigecycline plasma concentrations were measured by a two-dimensional liquid chromatographic system and the data were analysed using Phoenix NLMETM software. Exposure-response analyses for efficacy were performed based on the data from 79 HAP patients with multidrug-resistant gram-negative infections. Classification and regression tree and logistic regression analyses were employed to identify which pharmacokinetic-pharmacodynamic (PK-PD) indices and magnitudes were the significant predictors of tigecycline efficacy. RESULTS: A two-compartment model with zero-order absorption and first-order elimination adequately described the data. A larger body weight was associated with increased central volume of distribution and clearance (P < .005), and increased age, baseline creatinine concentration and aspertate aminotransferase were associated with decreased clearance (P < .005). The AUC0-12h  × V/MIC ratio, APACHEII score and combined Pseudomonas aeruginosa infection are the strong predictors for tigecycline clinical response. Classification and regression tree analyses indicated that the combination of APACHEII score < 24 and AUC0-12h  × V/MIC ratio ≥ 100 was associated with clinical success. CONCLUSIONS: The proposed PPK model may serve as the basis for estimating tigecycline exposure for PK-PD analyses, and the PK-PD index and magnitude found in this study could be used for designing proper dosage regimens of tigecycline.

Evidence-based Guideline for Therapeutic Drug Monitoring of Vancomycin: 2020 Update by the Division of Therapeutic Drug Monitoring, Chinese Pharmacological Society.

BACKGROUND: Clinical practice guidelines or recommendations often require timely and regular updating as new evidence emerges, because this can alter the risk-benefit trade-off. The scientific process of developing and updating guidelines accompanied by adequate implementation can improve outcomes. To promote better management of patients receiving vancomycin therapy, we updated the guideline for the therapeutic drug monitoring (TDM) of vancomycin published in 2015. METHODS: Our updated recommendations complied with standards for developing trustworthy guidelines, including timeliness and rigor of the updating process, as well as the use of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. We also followed the methodology handbook published by the National Institute for Health and Clinical Excellence and the Spanish National Health System. RESULTS: We partially updated the 2015 guideline. Apart from adults, the updated guideline also focuses on pediatric patients and neonates requiring intravenous vancomycin therapy. The guideline recommendations involve a broadened range of patients requiring TDM, modified index of TDM (both 24-hour area under the curve and trough concentration), addition regarding the necessity and timing of repeated TDM, and initial dose for specific subpopulations. Overall, 1 recommendation was deleted and 3 recommendations were modified. Eleven new recommendations were added, and no recommendation was made for 2 clinical questions. CONCLUSIONS: We updated an evidence-based guideline regarding the TDM of vancomycin using a rigorous and multidisciplinary approach. The updated guideline provides more comprehensive recommendations to inform rational and optimized vancomycin use and is thus of greater applicability.

Dihydromyricetin affect the pharmacokinetics of triptolide in rats.

1. Dihydromyricetin (DMY) has anti-tumor and hepatoprotective activities and inhibits the activity of CYP enzymes and P-gp. In this research, we explored the effect of DMY on the pharmacokinetics of triptolide (TP), an anti-tumor Chinese medicine that is mainly metabolized by CYP enzymes and is the substrate of P-gp.2. Rats were administrated TP (1.2 mg/kg) with and without DMY in different dosage regimens, then a sensitive and reliable LC-MS/MS method was developed and applied to assess the pharmacokinetics of TP. The blood samples for TP were collected from each rat up to 120 min after administration of TP.3. When co-administrated with single dose of DMY (100 mg/kg), the AUC, Cmax and T1/2 of TP were significantly enhanced by 98, 83 and 66%, respectively. The T1/2 of TP was significantly prolonged from 23.6 ± 6.4 to 70.5 ± 12.5 min with 14-doses pretreatment of DMY (500 mg/kg), conversely, the Cmax was decreased by 30% and the AUC was enhanced by 24%.4. These results hinted that administration of DMY with TP did alter the pharmacokinetics of TP, and provided the theoretical pharmacokinetic basis to study on the protective effects of DMY against acute liver injury caused by TP.

Dexamethasone changes the pharmacokinetics of amitriptyline and reduces its accumulation in rat brain: The roles of P-gp and cyp3a2.

The wide spread use of central nervous system (CNS) drugs has caused thousands of deaths in clinical practice while there are few antidotes or effective treatments to decrease their accumulation in CNS. In this study, we used amitriptyline (AMI) and dexamethasone (DEX) as the corresponding poisoning and pre-protecting drugs, respectively, to study whether DEX has the potential to reduce AMI accumulation in brain. By measuring the pharmacokinetic data of AMI and its main metabolite nortriptyline (NOR), we found that DEX possibly accelerated the metabolism and elimination of AMI with minimal effects on the concentrations of NOR in blood. Nevertheless, the results indicated that DEX reduced the brain/plasma concentration ratio of AMI and NOR, even if the plasma concentration of NOR had an upward trend. Western blot results showed the overexpression of cyp3a2 and P-gp in rat liver and brain capillaries tissues. We propose that cyp3a2 and P-gp could be upregulated in the liver and blood-brain barrier (BBB) when using DEX. Further experiments suggest that DEX may serve as the ligand of PXR to induce P-gp expression.

Salvianolic acid B protects against lipopolysaccharide-induced behavioral deficits and neuroinflammatory response: involvement of autophagy and NLRP3 inflammasome.

BACKGROUND: The NLRP3 inflammasome activation and neuroinflammation are known to be involved in the pathology of depression, whereas autophagy has multiple effects on immunity, which is partly mediated by the regulation of inflammasome and clearance of proinflammatory cytokines. Given the emerging evidence that autophagy dysfunction plays an essential role in depression, it is very likely that autophagy may interact with the inflammatory process in the development and treatment of depression. Salvianolic acid B (SalB), a naturally occurring compound extracted from Salvia miltiorrhiza, contains anti-inflammatory and antidepression properties and has recently been proven to modulate autophagy. In this study, we sought to investigate whether autophagy is involved in the inflammation-induced depression and the antidepressant effects of SalB. METHODS: The effects of prolonged lipopolysaccharide (LPS) treatment and SalB administration on behavioral changes, neuroinflammation, autophagic markers and NLRP3 activation in rat hippocampus were determined by using behavioral tests, real-time PCR analysis, western blot, and immunostaining. RESULTS: Our data showed that periphery immune challenge by LPS for 2 weeks successfully induced the rats to a depression-like state, accompanied with enhanced expression of pro-inflammatory cytokines and NLRP3 inflammasome activation. Interestingly, autophagic markers, including Beclin-1, and the ratio of LC3II to LC3I were suppressed following prolonged LPS exposure. Meanwhile, co-treatment with SalB showed robust antidepressant effects and ameliorated the LPS-induced neuroinflammation. Additionally, SalB restored the compromised autophagy and overactivated NLRP3 inflammasome in LPS-treated rats. CONCLUSIONS: Collectively, these data suggest that autophagy may interact with NLRP3 activation to contribute to the development of depression, whereas SalB can promote autophagy and induce the clearance of NLRP3, thereby resulting in neuroprotective and antidepressant actions.

Bioequivalence and food effect study of enteric-coated mesalazine tablets in healthy Chinese volunteers by HPLC-ESI-MS/MS.

OBJECTIVE: To establish a developed HPLC-ESI-MS/MS method for simultaneous determination of mesalazine (5-ASA) and its major metabolite N-Ac-5-ASA in human plasma and to investigate bioequivalence of two enteric-coated mesalazine tablets as well as the effect of high-fat food on the pharmacokinetics of 5-ASA and N-Ac-5-ASA. METHODS: In this open-label, randomized, crossover, two-states, four-period study, 20 healthy Chinese volunteers were randomized to receive a single oral dose of trial or reference preparation (2 × 250 mg) under fasting and fed state. Plasma samples were obtained at 0, 1, 2, 3, 4, 4.5, 5, 5.5, 6, 6.5, 7, 8, 10, 12, 24, and 36 hours postdose and were measured by a developed HPLC-ESI-MS/MS method. Safety and tolerability were assessed throughout the study. RESULTS: The HPLC-ESI-MS/MS method required only 7.0 minutes run time and was successfully applied in analyzing ~ 2,000 samples. High-fat-food administration prolonged tmax of 5-ASA and N-Ac-5-ASA (p < 0.05), while AUC was not significantly affected by the meal (p > 0.05). The 90% confidence intervals (CIs) of the fed/fasting and trial/reference ratios of log-transformed Cmax and AUC were within 80-125%. The two one-sided t-tests showed that the trial and reference preparation were bioequivalent (p > 0.05). CONCLUSIONS: This developed HPLC-ESI-MS/MS method is suitable for massive biomedical analysis. Trial and reference preparations are bioequivalent under fasting and fed state. High-fat-food administration delays the absorption of mesalazine while total exposure is not affected. Dietary habits should always be taken into consideration when enteric-coated mesalazine tablets were prescribed to patients.

Maternal diet of polyunsaturated fatty acid altered the cell proliferation in the dentate gyrus of hippocampus and influenced glutamatergic and serotoninergic systems of neonatal female rats.

BACKGROUND: Long-chain polyunsaturated fatty acids (PUFAs) are major components of the phospholipids that forming the cell membrane. Insufficient availability of PUFAs during prenatal period decreases accretion of docosahexaenoic acid (DHA) in the developing brain. DHA deficiency is associated with impaired attention and cognition, and would precipitate psychiatric symptoms. However, clinical studies on the potential benefits of dietary DHA supplementation to neural development have yielded conflicting results. METHODS: To further investigate the neurochemical influence of maternal PUFAs levels, we assessed the functioning of various neurotransmitter systems including glutamatergic, dopaminergic, norepinephrinergic and serotoninergic systems in the brain of neonatal female rats by HPLC-MS/MS. Meanwhile, the cell proliferation of neonatal rats was investigated using immunefluorescence. RESULTS: Different maternal n-3 PUFAs dietary influenced the FA composition, cell proliferation in the dentate gyrus of hippocampus and the contents of γ-aminobutyric acid (GABA), glutamine (GLN), dopamine (DA) and its metabolites [3,4- dihydroxyphenyl acetic acid (DOPAC) and homovanillic acid (HVA)], norepinephrine (NE), vanilmandelic acid (VMA) and 5-HT turnover in the brain of neonatal rats. However, the mRNA expression of key synthase of neurotransmitters remains stable. CONCLUSIONS: Our study showed that maternal deficiency of n-3 PUFAs might play an important role in central nervous system of neonatal female rats mainly through impairing the normal neurogenesis and influencing glutamatergic system and 5-HT turnover.

Effect of Antiepileptic Therapy on Serum 25(OH)D3 and 24,25(OH)2D3 Levels in Epileptic Children.

BACKGROUND: Vitamin D deficiency is not only associated with the adverse effects of chronic treatment with antiepileptic drugs (AEDs), but also with epilepsy. Although emerging evidence suggests that AEDs can accelerate the vitamin D catabolism, resulting in suboptimal vitamin D status, there are a limited number of studies examining the vitamin D status in epileptic patients, especially in first-episode or AEDs-naïve children. METHODS: Determined with high-performance liquid chromatography-tandem mass spectrometry, circulating 25(OH)D3 and 24,25(OH)2D3 levels, and 24,25(OH)2D3:25(OH)D3 ratio were compared between AEDs-treated epileptic (n = 363) and control (n = 159) children. To further figure out whether the patients were in a vitamin D deficient prone state even before treatment, epileptic children before their initiation of treatment (n = 51) were enrolled into a follow-up study. RESULTS: A significant decrease of 25(OH)D3 and 24,25(OH)2D3 levels, but a significant increase of 24,25(OH)2D3:25(OH)D3 ratio was observed in epileptic children, compared with controls. Baseline 25(OH)D3, 24,25(OH)2D3 and 24,25(OH)2D3:25(OH)D3 ratio in the follow-up group were similar to those in controls, but significantly changed with 2 months of AED therapy. CONCLUSIONS: Disturbed vitamin D levels were possibly the consequence of AED therapy, rather than the contributing factor of epilepsy. Collectively, circulating vitamin D levels should be monitored and corrected in AEDs-treated epileptic children.

Isoliquiritigenin protects against triptolide-induced hepatotoxicity in mice through Nrf2 activation.

Isoliquiritigenin, a flavonoid found in licorice, has been considered as an antioxidive and hepato-protective agent. Recent studies have shown that a possible mechanism for triptolide-induced hepatotoxicity is related to oxidative damage induced by reactive oxygen species. This study was done to investigate the protection effect of isoliquiritigenin against triptolide-induced hepatotoxicity and the mechanism involved. An acute liver injury model was established by intraperitoneal injection of triptolide (1.0 mg · kg-1) in mice. Different doses of isoliquiritigenin (12.5, 25 and 50 mg · kg-1) were employed as protection. The activities of AST, ALT, ALP and LDH in serum and levels of GSH, GPx, SOD, CAT and MDA in liver tissue were detected. The histopathological changes of liver tissues were observed after HE staining. The protein expression of Nrf2 was detected by western blot. Pretreatment with isoliquiritigenin significantly prevented the triptolide-induced hepatotoxicity indicated by reduced activities of AST, ALT, ALP and LDH. Moreover, isoliquiritigenin pretreatment also prevented from triptolide-induced hepatotoxicity by inhibiting MDA and restoring the levels of GSH, GPx, SOD and CAT. In addition, isoliquiritigenin could attenuate histopathological changes induced by triptolide. Furthermore, the results indicated that isoliquiritigenin pretreatment caused an increase in the protein expression of Nrf2. These results indicated that isoliquiritigenin could protect against triptolide-induced hepatotoxicity via activation of the Nrf2 pathway.

Pharmacokinetics and penetration into synovial fluid of systemical and electroporation administered sinomenine to rabbits.

Sinomenine is an anti-rheumatoid arthritis (RA) drug derived from the Sinomenium acutum. The major site of RA treatment is within the synovial compartment. However, the pharmacokinetic and penetration into synovial fluid (SF) of sinomenine have not been reported. In our study, the pharmacokinetics and penetration into SF of systemic and electroporation administered sinomenine were investigated by microdialysis incorporated with HPLC-MS/MS. Sinomenine went into plasma and SF more rapidly with higher peak concentration (Cmax ) by intramuscular injection compared with oral administration. The area under the concentration-time graph (AUC0-∞ ) of intramuscularly injected sinomenine was 1,403,294.75 ± 125,534.567 ng min/mL in plasma and 456,116.37 ± 62,648.36 ng min/mL in SF, which were equivalent with those for an oral dose. These results indicated that equal amounts of sinomenine could penetrate into SF by the two administration routes, and the permeation ratios were approximately 1:3. The AUC0-∞ and Cmax were lower with electroporation compared with systemic administration, but the CSF /CPlasma (concentration of sinomenine in SF vs that of plasma) at 90, 120, 150, 180, 240 and 480 min by electroporation was 3- to 10-fold higher relative to systemic administration. This illustrated that sinomenine can be targeted into joints by electroporation, and electroporation is a potential technique for sinomenine's transdermal delivery.

Fish oil supplementation alleviates depressant-like behaviors and modulates lipid profiles in rats exposed to chronic unpredictable mild stress.

BACKGROUND: Patients with major depressive disorder have a higher prevalence and incidence of dyslipidemia. However, clinical studies concerning the association between lipid levels and depression are inconsistent. Adipokines (like leptin and adiponectin) and ghrelin are strongly associated with lipid metabolism. Fish oil, which is reported to possess antidepressant effect, also have beneficial effects on lipid metabolism and the cardiovascular system. In the present study, we investigated lipid metabolism in rats exposed to chronic unpredictable mild stress (CUMS) and the effect of fish oil on lipid profiles, aforementioned adipokines and ghrelin. METHODS: Sucrose preference test (SPT), open field test (OFT) and forced swimming test (FST) were used to evaluate the antidepressant-like effects of fish oil. After the behavior tests, peripheral blood were collected. Serum parameters, including fasting triglyceride (TG), total cholesterol (TCH), high density lipoprotein-cholesterol (HDL-c), low density lipoprotein-cholesterol (LDL-c), free fatty acid (FFA), glucose (GLU), adipokines (leptin, adiponectin) and ghrelin were assayed. RESULTS: After 5 weeks of CUMS procedures, rats were induced to depressive-like state, and exhibited increased serum levels of TCH, HDL-c, FFA and decreased serum levels of leptin and ghrelin, whereas the serum status of adiponectin, GLU, TG and LDL-c remained stable. Fish oil treatment showed robust antidepressant effect and reversed the stress-induced lipid disturbance and decrease in serum concentration of ghrelin. CONCLUSIONS: Our results suggested that CUMS altered the serum levels of lipid profiles, leptin and ghrelin in rats. Fish oil supplementation not only provided antidepressant-like effects, but also reversed the altered lipid profiles and ghrelin level in serum. Our data indicated that fish oil treatment exerts anti-depressant effect and regulates lipid disturbance simultaneously.

Progress on mechanism of Tripterygium wilfordii-induced liver injury and detoxification mechanism of licorice.

Tripterygium wilfordii has exihibited multiple pharmacological activities, such as anti-inflammatory, immune modulation, anti-tumor and anti-fertility. T. wilfordii have been used for the therapy of inflammation and autoimmune diseases including rheumatoid arthritis, immune complex nephritis and systemic lupus erythematosus clinically. However, it is well known that T. wilfordii has small margin between the therapeutic and toxic doses and could cause serious injury on digestive, reproductive and urogenital systems. Among all the organs, liver is one of the most remarkable targets of T. wilfordii-induced toxicities, and the damage is more serious than others. It is generally accepted that T. wilfordii-induced liver injury is a result of the combined effects of toxic elements of T. wilfordii. It is reported in several studies that the mechanism of T. wilfordii-induced liver injury may be related to lipid peroxidation, cell apoptosis and immune damage, and so on. Licorice is one of the most commonly used Chinese herbal medicine, with effects of heat- clearing and detoxicating, anti-inflammatory and hepatoprotective, reconciling various drugs, and so on. Licorice often accompany T. wilfordii in clinical application which can significantly reduce the liver injury induced by T. wilfordii. The attenuated effect is exact, but the mechanism is still a lack of in-depth study. This paper reviews the studies on T. wilfordii-induced liver injury and the related mechanism as well as licorice and other traditional Chinese medicine accompany T. wilfordii to reduce the injury in recent years, so as to provide reference for related research in the future.

Effect of licorice on the induction of phase II metabolizing enzymes and phase III transporters and its possible mechanism.

Licorice has a marked detoxifying effect that can treat drug poisoning and/or relieve adverse effects. However, the exact mechanism of this action is not entirely elucidated, but is believed to be related to the modulation of drug disposition when interacting with other drugs. Additionally, Nuclear factor erythroid 2-related factor 2 (Nrf2) plays a significant role in mediating phase II xenobiotic metabolizing enzymes (XMEs) and phase III transporters. In the present study, we showed that licorice induced the mRNA expression of phase II XMEs UDP-glucuronosyltransferases 1A1 (UGT1A1), glutamate cysteine ligase (GCL), glutathione-s-transferase (GST) and phase III transporters multidrug resistance protein 2 (MRP2), as well as a rapid increase in Nrf2 nuclear accumulation. These findings suggests that licorice may intervene in the Nrf2 signal pathway to induce UGT1A1, GCLC, GST and MRP2, which provide a novel mechanism for the use of licorice to treat drug poisoning and/or relieve adverse effects.

Predictive value of plasma ephrinB2 levels for amputation risk following endovascular revascularization in peripheral artery disease.

Background: The aim of this study is to investigate the expression levels of ephrinB2 in patients with lower extremity peripheral arterial disease (PAD) and explore its association with the severity of the disease and the risk of amputation after endovascular revascularization. Methods: During the period from March 2021 to March 2023, this study collected blood samples and clinical data from 133 patients diagnosed with lower extremity PAD and 51 healthy volunteer donors. The severity of lower extremity PAD patients was classified using the Rutherford categories. The expression of ephrin-B2 in plasma samples was detected using the Western Blotting. Results: Compared to the control group, the levels of serum ephrinB2 in patients were significantly elevated (p < 0.001). Moreover, the plasma EphrinB2 levels were positively correlated with white blood cell counts (r = 0.204, p = 0.018), neutrophil counts (r = 0.174, p = 0.045), and neutrophil-to-lymphocyte ratio (NLR) (r = 0.223, p = 0.009). Furthermore, the AUCs of plasma ephrinB2 level, NLR, and their combination as predictors for amputation events within 30 months after lower extremity PAD endovascular revascularization were 0.659, 0.730 and 0.811. In the high-ephrinB2 group, the incidence of amputation events within 30 months after endovascular revascularization was higher. Conclusions: Plasma EphrinB2 levels may be linked to lower extremity PAD development, inflammation, and postoperative amputation. Combining EphrinB2 and NLR can improve amputation prediction accuracy after endovascular revascularization in lower extremity PAD patients.

Repeated haloperidol administration has no effect on vitamin D signaling but increase retinoid X receptors and Nur77 expression in rat prefrontal cortex.

Both vitamin D (VD) signaling and Nur77 are implicated in dopaminergic neurotransmission and dopamine-related neuropsychiatric disorders, such as schizophrenia and Parkinson's disease. Developmental vitamin D (DVD) deficiency rats exhibit schizophrenia-like behaviors and disturbance of dopamine system, which could be partly normalized by haloperidol treatment. By blocking dopamine D2 receptor, haloperidol induces Nur77 expression, suggesting a modulatory role of Nur77 in brain dopamine system. Rxr is the heterodimeric partner of both Nur77 and vitamin D receptor and also participates in homeostatic regulation of central dopamine neurotransmission. Although D2 antagonist-induced Nur77 expression has been reported by several studies, the change of its active partner Rxr remains elusive. Here, we studied the impact of 2 weeks administration of haloperidol on VD signaling and Nur77/Rxr expression in rat prefrontal cortex. It was found that haloperidol has no effect on local VD signaling, but could significantly increase Nur77, Rxrß, and Rxrγ expression, which indicated that Nur77/Rxr, but not vdr/Rxr, was implicated in dopamine-related neuroadaptation. Given that VD deficiency is commonly observed in schizophrenia patients, the renal metabolism of VD was also examined.

Lack of effect of continuous glycyrrhizin administration on the pharmacokinetics of the P-glycoprotein substrate talinolol in healthy volunteers.

PURPOSE: To investigate the effects of repeated glycyrrhizin ingestion on the oral pharmacokinetics of talinolol, a probe drug for P-glycoprotein (P-gp) activity in humans. METHODS: Fourteen healthy adult male subjects were enrolled in a two-phase randomized crossover-design study. In each phase the volunteers received placebo or compound glycyrrhizin tablets (75 mg glycyrrhizin three times daily) for 6 days. On the seventh day, a single oral dose of 100 mg talinolol was administered, and blood samples were obtained to determine plasma talinolol concentrations, measured in plasma by high-performance liquid chromatography with an ultraviolet detector. Non-compartmental analysis was used to characterize talinolol plasma concentration-time profiles. All pharmacokinetics parameters were calculated using DAS ver. 2.1 software, and statistical analyses were performed with SPSS ver. 13.0 software. Analysis of variance was used to check the difference of the means of the pharmacokinetic parameters between the two treatments at a significance level of 0.05. RESULTS: All treatments were well tolerated during the study period. The geometric mean ± standard deviation of the AUC(0-∞) for talinolol treated by glycyrrhizin and talinolol treated by placebo was 2,218.3 ± 724.3 and 1,988.2 ± 649.2 ng·h/mL, respectively. The 90 % confidence intervals for the ratio of adjusted geometric means (glycyrrhizin:placebo) for AUC(0-∞) and C (max) fell wholly within the interval [80, 125]. Six days of glycyrrhizin treatment resulted in no significant alterations in the pharmacokinetic parameters (AUC(0-∞), AUC(0-24), C (max), t (max), t (½)) for talinolol. CONCLUSIONS: Continuous glycyrrhizin administration had no induction effect on the expression of P-gp in our trial. Further research is needed to study the direct inhibition effect of glycyrrhizin on the function of P-gp with the simultaneous administration of both glycyrrhizin and P-gp substrate.

HPLC-DAD method for comprehensive quality control of Semen Strychni.

CONTEXT: Semen Strychni is the seed of Strychnos nux-vomica L. (Loganiaceae). Its quality control procedure remains an issue since previous reports only focused on Strychnos alkaloids. To the best of our knowledge, chlorogenic acid (a phenolic acid) and loganin (an iridoid glycoside) are selected for the first time as marker constituents of quality control for Semen Strychni because of their bioactive activity correlating with therapeutic effects. OBJECTIVE: This study aimed to develop a simple and comprehensive quantity control method for Semen Strychni. MATERIALS AND METHODS: The optimal ultrasonic extraction procedure was carried out for 45 min using 50% aqueous methanol with 1% formic acid. The satisfactory chromatographic separation was achieved on an Ultimate LP-C18 column with gradient elution using acetonitrile and water containing 30 mmol/L ammonium acetate and 1% formic acid. The high performance liquid chromatography method with diode array detector was validated for linearity, limit of detection and quantification (LOQ), precision, repeatability, accuracy and stability. RESULTS: All the calibration curves showed good linearity (r(2) ≥ 0.999). The LOQ values for chlorogenic acid, loganin, strychnine, brucine, strychnine N-oxide and brucine N-oxide were 0.54, 0.83, 0.48, 0.50, 0.52 and 0.54 µg/mL, respectively. The method was reproducible with good accuracy in the range 95.6-104.4% and relative standard deviation (RSD) values less than 4.55%. The method was then applied to determine the components of the seed coat, seed leaf, endosperm and whole seed of Semen Strychni. CONCLUSION: This newly established method is validated as a simple and practical tool for authentication and quality control of Semen Strychni.

[Endothelial progenitor cells: the new target of anti-atherosclerosis drugs].

Endothelial progenitor cells (EPCs) are a kind of progenitor cells with high potential of proliferation, which exist in the bone marrow, umbilical cord blood, and peripheral blood. Under certain conditions, EPCs can differentiate into mature vascular endothelial cells. Many studies have shown that EPCs could delay the onset and development of atherosclerosis by promoting the repair of the endothelium and neovascularization. EPCs have also been considered to be a biological marker for cardiovascular diseases. Recent investigations demonstrate that EPCs can mediate the effect of some anti-atherosclerosis drugs. This paper reviews the role of EPCs in atherosclerosis and the influence of drugs on EPC function. The feasibility and the problem of using EPCs as a treatment strategy are also discussed.

Metabolomic analysis of biochemical changes in the plasma and urine of first-episode neuroleptic-naïve schizophrenia patients after treatment with risperidone.

Early findings propose that impaired neurotransmission in the brain plays a key role in the pathophysiology of schizophrenia. Recent advances in understanding its multiple etiologies and pathogenetic mechanisms provide more speculative hypotheses focused on even broader somatic systems. Using a targeted tandem mass spectrometry (MS/MS)-based metabolomic platform, we compared metabolic signatures consisting of monoamine and amino acid neurotransmitter (NT) metabolites in plasma/urine simultaneously between first-episode neuroleptic-naïve schizophrenia patients (FENNS) and healthy controls before and after a 6-week risperidone monotherapy, which suggest that the patient NT profiles are restoring during treatment. To detect and identify potential biomarkers associated with schizophrenia and risperidone treatment, we also performed a combined ultraperformance liquid chromatography-mass spectrometry (UPLC-MS) and 1H nuclear magnetic resonance (NMR)-based metabolomic profiling of the same samples, indicating a further deviation of the patients' global metabolic profile from that of controls. The NTs and their metabolites together with the 32 identified biomarkers underpin that metabolic pathways including NT metabolism, amino acid metabolism, glucose metabolism, lipid metabolism, energy metabolism, antioxidant defense system, bowel microflora and endocrine system are disturbed in FENNS. Among them, pregnanediol, citrate and α-ketoglutarate (α-KG) were significantly associated with symptomatology of schizophrenia after Bonferroni correction and may be useful biomarkers for monitoring therapeutic efficacy. These findings promise to yield valuable insights into the pathophysiology of schizophrenia and may advance the approach to treatment, diagnosis and disease prevention of schizophrenia and related syndromes.

[Effect of 18alpha-glycyrrhizic acid and 18beta-glycyrrhizic acid on P-gp function and expression in Caco-2 cells].

OBJECTIVE: The aim of the present study was to evaluate the modulating effect of glycyrrhizic acid C-18 epimers, 18alpha-glycyrrhizic acid (alpha-GL) and 18beta-glycyrrhizic acid (beta-GL) on both P-glycoprotein (P-gp) activity and expression in Caco-2 cell. METHOD: The effects of P-gp activity were analyzed by rhodamine (Rhd 123) accumulation test, and those of P-gp expression were analyzed by flow cytometry and real-time PCR. RESULT: At middle and high concentrations (10, 60 micromol x L(-1)), alpha-GL inhibited the function of P-gp and with on dose dependent while beta-GL induced the function of P-gp at three test concentrations with no dose dependent too. At middle and high concentrations (10, 60 micromol x L(-1)), alpha-GL down-regulated the expression of MDR1 mRNA. At high concentrations (60 micromol x L(-1)), beta-GL up-regulated the expression of MDR1 mRNA; At high concentrations (60 micromol x L(-1)), beta-GL induced the expression of P-gp protein while alpha-GL has no effect on the expression of P-gp protein at three test concentrations. CONCLUSION: The effects of alpha-GL and beta-GL on the expression of MDR1 mRNA and CYP3A mRNA showed the same trend. The character that epimers of GL act on CYP3A and P-gp show similar stereo selectivity whether relate to PXR need further study.