Derivative emission spectrofluorimetry: Application to the analysis of newly approved FDA combination of ibuprofen and famotidine in tablets

A new combination of ibuprofen (NSAID) and famotidine (H₂ receptor antagonist) was recently approved by the FDA. It was formulated to relief pain while decreasing the risk of ulceration, which is a common problem for patients receiving NSAID. A rapid and simple derivative emission spectrofluorimetric method is proposed for the simultaneous analysis of this combination in their pharmaceutical preparation. The method is based upon measurement of the native fluorescence intensity of the two drugs at λ_ex = 233 nm in acetonitrile. The emission data were differentiated using the first (D1) derivative technique. The plots of derivative fluorescence intensity versus concentration were rectilinear over a range of 2–35 and 0.4–8 µg/mL for both ibuprofen (IBU) and famotidine (FAM), respectively. The method was sensitive as the limits of detection were 0.51 and 0.12 µg/mL and limits of quantitation were 1.70 and 0.39 µg/mL, for IBU and FAM respectively. The proposed derivative emission spectrofluorimetric method was successfully applied for the determination of the two drugs in their synthetic mixtures and tablets with good accuracy and precision. The proposed method was validated as per ICH guidelines. Copyright © 2014 John Wiley & Sons, Ltd.     

Vitamin D receptor TaqI and ApaI polymorphisms: A comparative study in patients with Behçet’s disease and Rheumatoid arthritis in Tunisian population

Recent genetic surveys have identified vitamin D receptor (VDR) as a susceptibility gene for several autoimmune diseases. This study was designed to investigate the association of VDR gene polymorphisms with Behçet’s disease (BD) and Rheumatoid arthritis (RA). A case–control study including 151 BD, 106 RA patients and an appropriate number of healthy control subjects were performed using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) techniques. Association between TaqI polymorphism and BD was marginal under codominant and recessive models (P = 0.078 and P = 0.058, respectively). After stratification, we found evidence for a significant association between TaqI polymorphism and BD in the elderly subjects (P = 0.037). The minor ApaI a allele tended to confer an increased risk for BD susceptibility (P = 0.087). BD patients with VDR homozygous AA or aa genotypes were at increased risk for development of erythema nodosum (EN) skin manifestation (P = 0.038). No significant association was observed for VDR ApaI and TaqI polymorphisms with RA risk (P > 0.05). TaqI and ApaI polymorphisms might be modestly implicated in BD pathogenesis. They could be considered as potential biomarkers in BD rather than susceptibility genes. However, TaqI and ApaI seemed not to be implicated in RA pathogenesis.     

Nobiletin protects against diabetes-induced testicular injury via hypophysis–gonadal axis upregulation and amelioration of oxidative stress

Background

Testicular injury is one of the most serious problems associated with diabetes mellitus. The present study aimed to compare the effects of two different doses of nobiletin and analyze its mechanisms of action against diabetes-induced testicular impairment in rats.

Methods and results

Streptozotocin injection was used to induce diabetes. Diabetic rats received nobiletin orally at 10 or 25 mg/kg daily for 30 days. Diabetic rats displayed significant elevations in glucose, glycosylated hemoglobin (HbA1c), Homeostatic Model of Insulin Resistance (HOMA-IR), and pro-inflammatory cytokines, while the serum levels of insulin, testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) were significantly reduced. Histological changes to positivity for caspase-3 and decreased androgen receptors (AR) immunoexpression were observed in diabetic rats. Both doses of nobiletin improved hyperglycemia, reduced pro-inflammatory cytokines, and augmented insulin, testosterone, LH, and FSH levels. LH and FSH receptors and cytochrome P450 17 α-hydroxylase (CYP17A1) were markedly downregulated in terms of both gene and protein expression in testicular tissues of the diabetic group, effects that were markedly ameliorated with both doses of nobiletin. In addition, both doses significantly reduced lipid peroxidation and caspase-3 immunoexpression and improved the activity of the antioxidant enzymes and AR in testicular tissues of the diabetic group.

Conclusion

Both nobiletin doses showed protective effects against diabetes-induced testicular injury by reducing oxidative stress, hyperglycemia, inflammation, and caspase-3 and upregulating the hypophysis–gonadal axis and AR. The high dose of nobiletin was more effective than the lower one.

     

Fenugreek potent activity against nitrate-induced diabetes in young and adult male rats

Nitrate has described as an endocrine disruptor that promotes onset of diabetes. This study was undertaken to evaluate diabetic effect of high nitrate intake in young and adult male rats and its amelioration by fenugreek administration. The study revealed significant increase in serum glucose and blood glycosylated hemoglobin (HbA1c%), while serum insulin and liver glycogen were decreased among nitrate exposed animals, in particular the young group. A significant reduction in the body weight gain and serum thyroid hormones (T4 & T3) was also recorded. Further reduction in serum levels of urea and creatinine, as well as total protein in serum, liver and pancreas was demonstrated, with elevation in their levels in the urine of all nitrate exposed groups. Meanwhile, the activity of serum transaminases (ALT and AST) was increased, with decline in their activity in the liver tissue. In addition, an elevation in serum total bilirubin, tissues (liver and pancreas) nitric oxide and lipid profile, as well as liver activity of glucose-6-phosphatase was recorded. Fenugreek administration to nitrate exposed rats was found to be effective in alleviating hyperglycemia and other biochemical changes characterizing nitrate-induced diabetes. So, fenugreek can be considered to possess potent activity against onset of nitrate induced-diabetes.     

Proteomics analysis identifies PARK7 as an important player for renal cell resistance and survival under oxidative stress

Renal fibrosis is a process that is characterized by declining excretory renal function. The molecular mechanisms of fibrosis are not fully understood. Oxidative stress pathways were reported to be involved in renal tissue deterioration and fibrosis progression. In order to identify new molecular targets associated with oxidative stress and renal fibrosis, differential proteomics analysis was performed with established renal cell lines (TK173 and HK-2). The cells were treated with oxidative stress triggering factor H(2)O(2) and the proteome alterations were investigated. Two dimensional protein maps were generated and differentially expressed proteins were processed and identified using mass spectrometry analysis combined with data base search. Interestingly the increase of ROS in the renal cell lines upon H(2)O(2) treatment was accompanied by alteration of a large number of proteins, which could be classified in three categories: the first category grouped the proteins that have been described to be involved in fibrogenesis (e.g. ACTA2, VIN, VIM, DES, KRT, COL1A1, COL4A1), the second category, which was more interesting involved proteins of the oxidative stress pathway (PRDX1, PRDX2, PRDX6, SOD, PARK7, HYOU1), which were highly up-regulated under oxidative stress, and the third category represented proteins, which are involved in different other metabolic pathways. Among the oxidative stress proteins the up-regulation of PARK7 was accompanied by a shift in the pI as a result of oxidation. Knockdown of PARK7 using siRNA led to significant reduction in renal cell viability under oxidative stress. Under H(2)O(2) treatment the PARK7 knockdown cells showed up to 80% decrease in cell viability and an increase in apoptosis compared to the controls. These results highlight for the first time the important role of PARK7 in oxidative stress resistance in renal cells.     

EPR Oximetry Sensor—Developing a TAM Derivative for In Vivo Studies

Oxygenation is one of the most important physiological parameters of biological systems. Low oxygen concentration (hypoxia) is associated with various pathophysiological processes in different organs. Hypoxia is of special importance in tumor therapy, causing poor response to treatment. Triaryl methyl (TAM) derivative radicals are commonly used in electron paramagnetic resonance (EPR) as sensors for quantitative spatial tissue oxygen mapping. They are also known as magnetic resonance imaging (MRI) contrast agents and fluorescence imaging compounds. We report the properties of the TAM radical tris(2,3,5,6-tetrachloro-4-carboxy-phenyl)methyl, (PTMTC), a potential multimodal (EPR/fluorescence) marker. PTMTC was spectrally analyzed using EPR and characterized by estimation of its sensitivity to the oxygen in liquid environment suitable for intravenous injection (1?mM PBS, pH?=?7.4). Further, fluorescent emission of the radical was measured using the same solvent and its quantum yield was estimated. An in vitro cytotoxicity examination was conducted in two cancer cell lines, HT-29 (colorectal adenocarcinoma) and FaDu (squamous cell carcinoma) and followed by uptake studies. The stability of the radical in different solutions (PBS pH?=?7.4, cell media used for HT-29 and FaDu cells culturing and cytotoxicity procedure, full rat blood and blood plasma) was determined. Finally, a primary toxicity test of PTMTC was carried out in mice. Results of spectral studies confirmed the multimodal properties of PTMTC. PTMTC was demonstrated to be not absorbed by cancer cells and did not interfere with luciferin-luciferase based assays. Also in vitro and in vivo tests showed that it was non-toxic and can be freely administrated till doses of 250?mg/kg BW via both i.v. and i.p. injections. This work illustrated that PTMTC is a perfect candidate for multimodal (EPR/fluorescence) contrast agent in preclinical studies.