Gomisin J from Schisandra chinensis induces vascular relaxation via activation of endothelial nitric oxide synthase

Gomisin J (GJ) is a lignan contained in Schisandra chinensis (SC) which is a well-known medicinal herb for improvement of cardiovascular symptoms in Korean. Thus, the present study examined the vascular effects of GJ, and also determined the mechanisms involved. Exposure of rat thoracic aorta to GJ (1-30μg/ml) resulted in a concentration-dependent vasorelaxation, which was more prominent in the endothelium (ED)-intact aorta. ED-dependent relaxation induced by GJ was markedly attenuated by pretreatment with L-NAME, a nitric oxide synthase (NOS) inhibitor. In the intact endothelial cells of rat thoracic aorta, GJ also enhanced nitric oxide (NO) production. In studies using human coronary artery endothelial cells, GJ enhanced phosphorylation of endothelial NOS (eNOS) at Ser(1177) with increased cytosolic translocation of eNOS, and subsequently increased NO production. These effects of GJ were attenuated not only by calcium chelators including EGTA and BAPTA-AM, but also by LY294002, a PI3K/Akt inhibitor, indicating calcium- and PI3K/Akt-dependent activation of eNOS by GJ. Moreover, the levels of intracellular calcium were increased immediately after GJ administration, but Akt phosphorylation was started to increase at 20min of GJ treatment. Based on these results with the facts that ED-dependent relaxation occurred rapidly after GJ treatment, it was suggested that the ED-dependent vasorelaxant effects of GJ were mediated mainly by calcium-dependent activation of eNOS with subsequent production of endothelial NO.     

Bromophenol (5‐bromo‐3,4‐dihydroxybenzaldehyde) isolated from red alga Polysiphonia morrowii inhibits adipogenesis by regulating expression of adipogenic transcription factors and AMP‐activated protein kinase activation in 3T3‐L1 adipocytes

The aim of the present study was to investigate the effect of 5‐bromo‐3,4‐dihydroxybenzaldehyde (BD) isolated from Polysiphonia morrowii on adipogenesis and differentiation of 3T3‐L1 preadipocytes into mature adipocytes and its possible mechanism of action. Levels of lipid accumulation and triglyceride were significantly lower in BD treated cells than those in untreated cells. In addition, BD treatment reduced protein expression levels of peroxisome proliferator‐activated receptor‐γ, CCAAT/enhancer‐binding proteins α, and sterol regulatory element‐binding protein 1 compared with control (no treatment). It also reduced expression levels of adiponectin, leptin, fatty acid synthase, and fatty acid binding protein 4. AMP‐activated protein kinase activation was found to be one specific mechanism involved in the effect of BD. These results demonstrate that BD possesses inhibitory effect on adipogenesis through activating AMP‐activated protein kinase signal pathway.     

Effects of baicalin and wogonin on mucin release from cultured airway epithelial cells

Scutellaria baicalensis Georgi has been used for the treatment of diverse chronic inflammatory diseases including respiratory disease in oriental medicine and its major components - baicalin, baicalein and wogonin - were reported to have various biological effects. This study investigated whether baicalin, baicalein and wogonin affect basal and ATP-induced mucin release from cultured airway epithelial cells. Confluent primary hamster tracheal surface epithelial (HTSE) cells were metabolically radiolabeled using (3)H-glucosamine for 24 h and chased for 30 min in the presence of varying concentrations of each agent to assess the effects on (3)H-mucin release. The results were as follows: (1) Baicalein did not affect both basal and ATP-induced mucin release significantly. (2) Baicalin and wogonin increased basal mucin release at the highest concentrations (10(-3) m). (3) However, baicalin and wogonin significantly inhibited ATP-induced mucin release. It is concluded that baicalin and wogonin can slightly increase basal mucin release whereas they can inhibit ATP-induced mucin release, by directly acting on airway mucin-secreting cells. It is suggested that baicalin and wogonin be further investigated for the possible use as mucoregulators during the treatment of chronic airway diseases.     

Simultaneous determination of methamphetamine, 3,4-methylenedioxy-N-methylamphetamine, 3,4-methylenedioxy-N-ethylamphetamine, N,N-dimethylamphetamine, and their metabolites in urine by liquid chromatography-electrospray ionization-tandem mass spectrometry

A liquid chromatography-electrospray ionization-tandem mass spectrometric (LC-ESI-MS/MS) method was developed and validated for the simultaneous detection and quantification of seven amphetamine derivatives (amphetamine (AP), methamphetamine (MA), 3,4-methylenedioxy-N-amphetamine (MDA), 3,4-methylenedioxy-N-methamphetamine (MDMA), 3,4-methylenedioxy-N-ethylamphetamine (MDEA), N,N-dimethylamphetamine (DMA), and N,N-dimethylamphetamine-N-oxide (DMANO)) in human urine. Seven deuterium-labeled compounds were prepared for use as internal standards to quantify the analytes. One milliliter of urine was combined with 1 mL of 0.2 M sodium carbonate buffer solution (pH 9.0) before solid phase extraction (SPE). An Oasis HLB SPE column followed by chromatographic separation on a Capcell Pak C18 MG-II column (150 × 2.0 mm I.D., 5 μm) and electrospray mass spectrometry with multiple reaction monitoring were used for selective and sensitive detection. The use of ammonium formate (5 mM, pH adjusted to 4.0 with formic acid, Solvent A) and acetonitrile (Solvent B) as the mobile phase at a flow rate of 230 μL/min was found to be the most effective for the separation. The linear ranges were 5.0–1000 ng/mL for AP, MDA, MDMA, MDEA, DMA, and DMANO and 10.0–1000 ng/mL for MA, with good correlation coefficients (r² > 0.996). The intra-day, inter-day, and interperson precisions were within 14.6%, 12.1% and 15.5%, respectively. The intra-day, inter-day, and interperson accuracies were between ?11.6 and 9.0%, ?7.9 and 2.3%, and ?13.2 and 4.3%, respectively. The limits of detection (LODs) for each analytical compound were lower than 1.95 ng/mL. The recovery ranged from 72.3 to 103.3%. The applicability of the developed method was examined by analyzing several urine samples from confirmed drug abusers.     

Morphologic findings in "zero-hour" biopsies of renal transplants.

The extreme lack of renal grafts for transplantation stimulated us to analyze how strict the selection criteria of kidney donors must be. We investigated therefore if preexisting lesions in renal grafts influence initial and late renal function. 147 zero-hour biopsies of 101 donors (mean age 33, from 6-64 years) were examined. By ligh microscopy 38% of biopsies showed no, 44% showed nonspecific and 18% specific lesions. Nonspecific lesions comprised intimal fibrosis of small arteries in 44%, interstitial fibrosis in 8% and an arteriolar hyalinosis in 29%. Out of 102 immunohistologically examined biopsies 74.5% showed nonspecific IgM/C3 deposits in glomeruli and/or arterioles. An age dependent decrease of normal renal biopsies was found which was most evident in donors older than 40 years. Specific findings consisted of glomerulosclerosis (n = 4), glomerulonephritis (n = 11), intravascular coagulation (n = 10) and eclamptic kidney (n = 1). In case of nonspecific immunohistologic findings and in glomerulonephritis rebiopsies showed that antigen deposits usually disappeared within 4 months. Independent of morphologic findings 82% of transplant recipients had a good initial and late renal function. Since donor age, glomerulosclerosis, glomerulonephritis, intravascular coagulation or eclamptic changes seem not to compromise renal function after transplantation a more liberal choice of donors should be considered.     

Factors influencing vertebral bone density after renal transplantation

To improve our understanding of the mechanisms underlying osteoporosis following renal transplantation, we compared bone mineral density (BMD) in 158 transplant recipients and in 293 patients undergoing maintenance hemodialysis with age- and sex- matched normal controls. Observations in graft recipients were made up to several years following transplantation. Dual-energy X-ray absorptiometry was used to measure BMD. Correlations with clinical variables including serum concentration of parathyroid hormone (PTH) and steroid therapy were evaluated. Lumbar BMD was lower in transplant patients than in dialysis patients at all ages, and continued to decrease with increasing interval posttransplant until the second year after transplantation. Persistent hyperparathyroidism and daily prednisolone dosage were both associated with decreased BMD. Age and creatinine clearance were independent long-term predictors of BMD by multiple regression analysis. Treatment of renal graft recipients with calcium and vitamin D supplements or calcitonin may be indicated in the early months after transplantation.