Resveratrol alleviates diabetic cardiomyopathy in rats by improving mitochondrial function through PGC-1α deacetylation.

Recent evidence shows that resveratrol (RSV) may ameliorate high-glucose-induced cardiac oxidative stress, mitochondrial dysfunction and myocardial fibrosis in diabetes. However, the mechanisms by which RSV regulates mitochondrial function in diabetic cardiomyopathy have not been fully elucidated. Mitochondrial dysfunction contributes to cardiac dysfunction in diabetic patients, which is associated with dysregulation of peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α). In this study we examined whether resveratrol alleviated cardiac dysfunction in diabetes by improving mitochondrial function via SIRT1-mediated PGC-1α deacetylation. T2DM was induced in rats by a high-fat diet combined with STZ injection. Diabetic rats were orally administered RSV (50 mg·kg-1·d-1) for 16 weeks. RSV administration significantly attenuated diabetes-induced cardiac dysfunction and hypertrophy evidenced by increasing ejection fraction (EF%), fraction shortening (FS%), ratio of early diastolic peak velocity (E velocity) and late diastolic peak velocity (A velocity) of the LV inflow (E/A ratio) and reducing expression levels of pro-hypertrophic markers ANP, BNP and ß-MHC. Furthermore, manganese superoxide dismutase (SOD) activity, ATP content, mitochondrial DNA copy number, mitochondrial membrane potential and the expression of nuclear respiration factor (NRF) were all significantly increased in diabetic hearts by RSV administration, whereas the levels of malondialdehvde (MDA) and uncoupling protein 2 (UCP2) were significantly decreased. Moreover, RSV administration significantly activated SIRT1 expression and increased PGC-1α deacetylation. H9c2 cells cultured in a high glucose (HG, 30 mmol/L) condition were used for further analyzing the role of SIRT1/PGC-1α pathway in RSV regulation of mitochondrial function. RSV (20 µmol/L) caused similar beneficial effects in HG-treated H9c2 cells in vitro as in diabetic rats, but these protective effects were abolished by addition of a SIRT1 inhibitor sirtinol (25 µmol/L) or by SIRT1 siRNA transfection. In H9c2 cells, RSV-induced PGC-1α deacetylation was dependent on SIRT1, which was also abolished by a SIRT1 inhibitor and SIRT1 siRNA transfection. Our results demonstrate that resveratrol attenuates cardiac injury in diabetic rats through regulation of mitochondrial function, which is mediated partly through SIRT1 activation and increased PGC-1α deacetylation.

Effects of gene polymorphisms in the endoplasmic reticulum stress pathway on clinical outcomes of chemoradiotherapy in Chinese patients with nasopharyngeal carcinoma.

There is considerable inter-individual variabil¬ity in chemoradiotherapy responses in nasopharyngeal carcinoma (NPC) patients receiv¬ing the same or similar treatment protocols. In this study we evaluated the association between the gene polymorphisms in endoplasmic reticulum (ER) stress pathway and chemoradiation responses in Chinese NPC patients. A total of 150 patients with histopathologically conformed NPC and treated with concurrent chemoradiotherapy were enrolled. Genotypes in ER stress pathway genes, including VCP (valosin-containing protein) rs2074549, HSP90B1 rs17034943, CANX (calnexin) rs7566, HSPA5 [heat shock protein family A (Hsp70) member 5] rs430397, CALCR (calcitonin receptor) rs2528521, and XBP1 (X-box binding protein 1) rs2269577 were analyzed by Sequenom MassARRAY system. The short-term effects of primary tumor and lymph node after radiotherapy were assessed based on the Response Evaluation Criteria in Solid Tumors (RECIST) of WHO. And acute radiation-induced toxic reactions were evaluated according to the Radiation Therapy Oncology Group or European Organization for Research and Treatment of Cancer (RTOG/EORTC). The effects of gene polymorphisms on clinical outcomes of chemoradiotherapy were assessed by chi-square test, univariate and multivariate logistic regression analyses. We found that CT and CT+CC genotypes of CANX rs7566 was significantly correlated with primary tumor treatment efficacy at 3 months after chemoradiotherapy and with occurrence of radiation-induced myelosuppression in Chinese NPC patients. CT and CT+CC genotypes of CALCR rs2528521 were significantly correlated with cervical lymph node efficacy at 3 months after chemoradiotherapy. And CC and CT+CC genotypes of VCP rs2074549 were significantly associated with occurrence of myelosuppression. In conclusion, SNPs of VCP rs2074549, CANX rs7566 and CALCR rs2528521 in ER stress pathway genes may serve as predictors for clinical outcomes of chemoradiotherapy in Chinese NPC patients.

Contrast Media-Induced Renal Inflammation Is Mediated Through HMGB1 and Its Receptors in Human Tubular Cells.

With the rapid development of imaging diagnosis and interventional therapy, contrast media (CM) are widely used in clinics. However, contrast-induced nephropathy (CIN) is the third leading cause of hospital-acquired acute renal failure accounting for 10-12% of all causes of hospital-acquired renal failure. Recent study found that inflammation may participate in the pathogenesis of CIN, but the role of it remains unclear. HK-2 cells were treated with Iohexol, Urografin, and mannitol. Two types of CM increased the release of HMGB1 in cell supernatant accompanied by increased expression of TLR2 and CXCR4. Iohexol and Urografin also caused a significant increase in NF-κB followed by the release of IL-6 and MCP-1. To clarify the role of HMGB1, TLR2, and CXCR4, glycyrrhizin, anti-TLR2-IgG, and AMD3100 were used to inhibit HMGB1, TLR2, and CXCR4, respectively. Significant decrease in the expression of TLR2, CXCR4, nuclear NF-κB, and the release of IL-6 and MCP-1 were observed. These results indicate that TLR2 and CXCR4 signaling are involved in CM-induced HK-2 cell injury model in an HMGB1-dependent pathway, which may provide a new target for the prevention and the treatment of CIN.

Assessment of a pharmacokinetic and pharmacodynamic interaction between simvastatin and Ginkgo biloba extracts in healthy subjects.

1. Ginkgo biloba extract (GBE) is one of the most commonly used herbal remedies worldwide. It is usually concomitantly administrated with statins to treat diseases in geriatric patients. We aim to determine the influence of GBE on the pharmacokinetics (PK) and pharmacodynamics of simvastatin, which is currently unknown. 2. An open-label, randomized, two-period, two-treatment, balanced, crossover study was performed in 14 healthy volunteers. Subjects received simvastatin 40 mg once daily, co-treated with placebo or GBE 120 mg twice daily. Each treatment was administered for 14 d, separated by a wash-out period of 1 month. Simvastatin, simvastatin acid and lipoprotein concentrations were assessed. 3. GBE administration reduced mean simvastatin area under the curve (AUC)0-24, AUC0-∞ and Cmax by 39% (p = 0.000), 36%(p = 0.001) and 32% (p = 0.002), respectively, but did not cause significant differences in simvastatin acid PK or its cholesterol-lowering efficacy. 4. GBE consumption decreased simvastatin system exposure, but did not affect simvastatin acid PK. However, we cannot rule out the possibility for a pharmacodynamic interaction between GBE and simvastatin in vivo.

Association of CYP3A polymorphisms with the pharmacokinetics of cyclosporine A in early post-renal transplant recipients in China.

AIM: To evaluate retrospectively the association of cytochrome P450 3A (CYP3A) and ATP-binding cassette sub-family B member 1 (ABCB1) gene polymorphisms with the pharmacokinetics of cyclosporine A (CsA) in Chinese renal transplant patients. METHODS: One hundred and twenty-six renal transplant patients were recruited. Blood samples were collected, and corresponding clinical indices were recorded on the seventh day after the procedure. The patients were genotyped for CYP3A4*1G, CYP3A5*3C, ABCB1 1236 C>T, ABCB1 2677 G>T/A, and ABCB1 3435 C>T polymorphisms. Whole blood trough concentrations of CsA at time zero (C(0)) were measured before the drug administration. A multiple regression model was developed to analyze the effects of genetic factors on the CsA dose-adjusted C(0) (C(0)/dose) based on several clinical indices. RESULTS: The CYP3A5*3C polymorphism influenced the C(0) and C(0)/dose of CsA, which were significantly higher in patients with the GG genotype than in patients with the AA or GA genotypes. No significant differences were detected for other SNPs (CYP3A4*1G, ABCB1 1236 C>T, ABCB1 2677 G>T/A, and ABCB1 3435 C>T). In a univariate analysis using Pearson's correlation test, age, hemoglobin, blood urea nitrogen and blood creatinine levels were significantly correlated with the log-transformed CsA C(0)/dose. In the multiple regression model, CYP3A5*3C, age, hemoglobin and blood creatinine level were associated with the log-transformed CsA C(0)/dose. CONCLUSION: CYP3A5*3C correlates with the C(0)/dose of CsA on the seventh day after renal transplantation. The allele is a putative indicator for the optimal CsA dosage in the early phase of renal transplantation in the Chinese population.

Effects of Ginkgo biloba extracts on pharmacokinetics and efficacy of atorvastatin based on plasma indices.

Ginkgo biloba extract (GBE) is one of the most widely used herbal medicines in the world. It is often administered in combination with statins to treat diseases, especially some nervous system disorders. We aimed to investigate the influences of GBE on pharmacokinetics and efficacy of atorvastatin, which are currently unclear. Sixteen volunteers received a single oral dose of 40 mg atorvastatin, followed by a wash-out period of at least 5 days. Then the volunteers took 360 mg GBE daily for 14 days, followed by a single dose of 40 mg atorvastatin. Serial blood samples obtained over a period of 48 h after atorvastatin ingestion were subjected to determination of atorvastatin plasma concentrations and markers of cholesterol synthesis (lathosterol) and cholesterol absorption (sitosterol). With GBE administration, AUC0₋48, AUC(0-∞) and C(max) of atorvastatin were reduced by 14.27% (p = 0.005), 10.00% (p = 0.03) and 28.93% (p = 0.002), respectively; Vd/F and CL/F of atorvastatin were increased by 31.95% (p = 0.017) and 6.48% (p = 0.044). After 14 days of treatment, GBE has no significant effects on cholesterol-lowering efficacy of atorvastatin. This study suggests that GBE slightly decreases the plasma atorvastatin concentrations, but has no meaningful effect on the cholesterol-lowering efficacy of atorvastatin.

Simultaneous analysis of amoxicillin and sulbactam in human plasma by HPLC-DAD for assessment of bioequivalence.

A simple and accurate high-performance liquid chromatography with diode array detection-based (HPLC-DAD) method has been developed and validated for simultaneous determination of amoxicillin and sulbactam in human plasma. Sample preparation was involved in protein precipitation with acetonitrile followed by one-step extraction procedure. Chromatographic separation was achieved on a C18 column with an isocratic mobile phase consisting of water (containing 30 mM potassium dihydrogen phosphate, pH 2.8) and acetonitrile. The detection wavelengths of a diode array detector were set at 210 nm for amoxicillin and sulbactam, and 263 nm for the internal standard (cefadroxil). The method was validated for linearity, accuracy, precision, and stability. The calibration curve was linear from 0.163 to 14.7 µg/mL with correlation coefficient squared of 0.9991 for amoxicillin and 0.250-15.0 µg/mL with correlation coefficient squared of 0.9988 for sulbactam using 500 µL plasma samples. The lower limit of quantification was 0.163 and 0.250 µg/mL for amoxicillin and sulbactam, respectively. The imprecisions of intra- and inter-day validations for amoxicillin and sulbactam were <11% and their accuracies (%) were within the range of 95.4-105.7%. Mean recoveries were 75.9, 72.8, and 70.0% for amoxicillin, sulbactam, and cefadroxil, respectively. The established method was successfully applied to a bioequivalence study of two combination formulations of amoxicillin and sulbactam pivoxil in healthy male volunteers.

Antiproliferative activity of the total saponin of Solanum lyratum Thunb in Hela cells by inducing apoptosis.

Total saponin of Solanum lyratum Thunb (TSSLT), a species of natural biologically active substances isolated from Solanum lyratum Thunb, possesses various bioactivities. It has been proposed that the induction of apoptosis may be the basis of its antitumor activity. However, the molecular mechanism underlying the total saponin-induced apoptotic process remains unknown. In the present study, we describe the anti-proliferative effect of TSSLT on human cervical cancer cells (Hela). The TSSLT induced apoptosis of Hela in a time-dependent manner with an IC50 for cell viability of 6 microg/ml. The TSSLT-induced cell death was characterized by changes in cell morphology, DNA fragmentation, activation of caspase-like activities, poly (ADP-ribose) polymerase (PARP) cleavage and release of cytochrome c (cyt c) into cytosol. TSSLT activated various caspases such as caspase-3, -8, and -9 (like) activities but not caspase-1 like activity. The cell death was completely prevented by the pan caspase inhibitor benzyloxy carbonyl-Val-Ala-Asp- fluoromethyl-ketone (Z-VAD-FMK). More than 80% cell survival was observed in the presence of a caspase-3 inhibitor. In addition, treatment with TSSLT induced the increase of Bax:Bcl-2 ratio in Hela cells. These results suggest that the induction of apoptosis by TSSLT involves multiple pathways antigen including death receptor and mitochondrial pathway and strongly suggest that the mitochondrial pathway was mediated by low expression of Bcl-2 and upregulation of Bax, release of cyt c and subsequent activation of caspase-3 followed by down stream events leading to apoptotic cell death.