Schisandrin ameliorates cognitive impairment and attenuates Aß deposition in APP/PS1 transgenic mice: involvement of adjusting neurotransmitters and their metabolite changes in the brain.

Neurotransmitters (NTs) in the brain are involved in neurodegenerative diseases, such as Alzheimer's disease (AD). Schisandrin is a major ingredient of Schisandra chinensis (Turcz.) Baill and has been used for the treatment of AD. In this study we examined the therapeutic effects of schisandrin in APP/PS1 transgenic mice, and correlated the beneficial effects on cognitive impairment with the adjustments in NTs and their metabolites in the mouse brains. APP/PS1 mice were treated with schisandrin (2 mg·kg-1·d-1, ip) for 2 weeks. In Morris Water Maze test; untreated APP/PS1 mice displayed significant cognitive impairment compared with normal mice; schisandrin administration ameliorated the cognitive impairment and significantly decreased Aß deposition in the hippocampus. In order to assess the effects of schisandrin on NTs and their metabolites, we developed a rapid and sensitive UPLC-MS/MS method for simultaneous determination of serotonin, 5-hydroxyindole acetic acid, dopamine, norepinephrine, γ-aminobutyric acid, glutamic acid, homovanillic acid, 3,4-dihydroxyphenylacetic acid and acetylcholine in mouse brains. This method conformed to methodology validation requirements. We found that there were statistically significant differences in these NTs and their metabolites between untreated APP/PS1 mice and normal mice, whereas schisandrin administration restored the abnormal NTs and their metabolites levels. These results suggest that schisandrin could alter the levels of these NTs and their metabolites in the brain, thus ameliorating learning and memory impairments in APP/PS1 mice.

Development of a UPLC-MS/MS Method for Simultaneous Determination of Six Flavonoids in Rat Plasma after Administration of Maydis stigma Extract and Its Application to a Comparative Pharmacokinetic Study in Normal and Diabetic Rats.

Maydis stigma is an important medicine herb used in many parts of the world for treatment of diabetes mellitus, which main bioactive ingredients are flavonoids. This paper describes for the first time a study on the comparative pharmacokinetics of six active flavonoid ingredients of Maydis stigma in normal and diabetic rats orally administrated with the decoction. Therefore, an efficient and sensitive ultra high performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) method for the simultaneous determination of six anti-diabetic ingredients (cynaroside, quercetin, luteolin, isorhamnetin, rutin and formononetin) of Maydis stigma in rat plasma has been developed and validated in plasma samples, which showed good linearity over a wide concentration range (r² > 0.99), and gave a lower limit of quantification of 1.0 ng·mL-1 for the analytes. The intra- and interday assay variability was less than 15% for all analytes. The mean extraction recoveries and matrix effect of analytes and IS from rats plasma were all more than 85.0%. The stability results showed the measured concentration for six analytes at three QC levels deviated within 15.0%. The results indicated that significant differences in the pharmacokinetic parameters of the analytes were observed between the two groups of animals, whereby the absorptions of these analytes in the diabetic group were all significantly higher than those in the normal group, which provides an experimental basis for the role of Maydis stigma in anti-diabetic treatment.

A metabonomic analysis of serum from rats treated with ricinine using ultra performance liquid chromatography coupled with mass spectrometry.

A metabonomic approach based on ultra performance liquid chromatography coupled with mass spectrometry (UPLC/MS) was used to study the hepatotoxicity of ricinine in rats. Potential biomarkers of ricinine toxicity and toxicological mechanism were analyzed by serum metabonomic method. The significant differences in the metabolic profiling of the control and treated rats were clear by using the principal components analysis (PCA) of the chromatographic data. Significant changes of metabolite biomarkers like phenylalanine, tryptophan, cholic acid, LPC and PC were detected in the serum. These biochemical changes were related to the metabolic disorders in amino acids and phospholipids. This research indicates that UPLC/MS-based metabonomic analysis of serum samples can be used to predict the hepatotoxicity and further understand the toxicological mechanism induced by ricinine. This work shows that metabonomics method is a valuable tool in drug mechanism study.

δ ENaC: a novel divergent amiloride-inhibitable sodium channel.

The fourth subunit of the epithelial sodium channel, termed delta subunit (δ ENaC), was cloned in human and monkey. Increasing evidence shows that this unique subunit and its splice variants exhibit biophysical and pharmacological properties that are divergent from those of α ENaC channels. The widespread distribution of epithelial sodium channels in both epithelial and nonepithelial tissues implies a range of physiological functions. The altered expression of SCNN1D is associated with numerous pathological conditions. Genetic studies link SCNN1D deficiency with rare genetic diseases with developmental and functional disorders in the brain, heart, and respiratory systems. Here, we review the progress of research on δ ENaC in genomics, biophysics, proteomics, physiology, pharmacology, and clinical medicine.

Changes of the tubular markers in type 2 diabetes mellitus with glomerular hyperfiltration.

AIM: To assess whether glomerular hyperfiltration (GHF) could result in renal tubular damage in type 2 diabetes mellitus (T2DM) patients. METHODS: Reference value of estimated glomerular filtration rate (eGFR) was determined in 248 healthy individuals based on serum CysC levels. GHF was defined as an eGFR exceeding the sex-specific 97.5th percentile in non-diabetic individuals. In the present study, 30 with GHF, 58 with norm-GFR T2DM, and 24 healthy controls were recruited. Tubular markers, such as urinary N-acetyl-ß-D-glucosaminidase (NAG) and kidney injury molecule 1 (KIM-1), as well as serum and urinary neutrophil gelatinase-associated lipocalin (NGAL), were measured and compared. The correlation of these markers with eGFR was analyzed in the GHF group. RESULTS: The GHF group had higher urinary NGAL and KIM-1 levels but lower serum NGAL level than the norm-GFR and control groups. Slightly decreased serum NGAL and increased urinary NGAL levels were also noted in the norm-GFR group compared with those of the controls. There was no statistical difference in the urinary NAG values among the three groups. Correlation analysis showed that eGFR was positively related to fasting blood glucose (FBG), HbA1c, urinary NGAL, and KIM-1, but negatively with serum NGAL in the GHF group. CONCLUSION: Higher urinary tubular damage markers were found in T2DM patients with GHF than the norm-GFR and control groups, probably a direct proof that GHF is a deleterious factor for diabetic nephropathy.