Phytochemicals Perturb Membranes and Promiscuously Alter Protein Function

A wide variety of phytochemicals are consumed for their perceived health benefits. Many of these phytochemicals have been found to alter numerous cell functions, but the mechanisms underlying their biological activity tend to be poorly understood. Phenolic phytochemicals are particularly promiscuous modifiers of membrane protein function, suggesting that some of their actions may be due to a common, membrane bilayer-mediated mechanism. To test whether bilayer perturbation may underlie this diversity of actions, we examined five bioactive phenols reported to have medicinal value: capsaicin from chili peppers, curcumin from turmeric, EGCG from green tea, genistein from soybeans, and resveratrol from grapes. We find that each of these widely consumed phytochemicals alters lipid bilayer properties and the function of diverse membrane proteins. Molecular dynamics simulations show that these phytochemicals modify bilayer properties by localizing to the bilayer/solution interface. Bilayer-modifying propensity was verified using a gramicidin-based assay, and indiscriminate modulation of membrane protein function was demonstrated using four proteins: membrane-anchored metalloproteases, mechanosensitive ion channels, and voltage-dependent potassium and sodium channels. Each protein exhibited similar responses to multiple phytochemicals, consistent with a common, bilayer-mediated mechanism. Our results suggest that many effects of amphiphilic phytochemicals are due to cell membrane perturbations, rather than specific protein binding

Development of a selective LC method for the determination of pravastatin sodium

A novel, simple and rapid stability-indicating high-performance liquid chromatographic (HPLC) method for pravastatin sodium (PRA) was successfully developed and validated for the assay of in tablets. Chromatographic separation was achieved isocratically on a C-18 column (150 mm x 4.6 mm) utilizing a mobile phase of methanol-phosphate buffer (pH 7; 0.02 M) (57:43, v/v) at a flow rate of 1.0 mL min(-1) with UV detection at 238 nm. A linear response (r = 0.9999) was observed in the range of 1-5 mu g mL(-1). The method showed good recoveries (100.50%) and the relative standard deviation of intra and inter-day were 1.40%. The method can be used for both quality control assay of pravastatin in tablets and for stability studies as the method separates provastatin from its degradation products and tablet excipients

The Effect of Continous or Intermittent Calcitonin in the Treatment of Postmenopausal Osteoporosis

The aim of this study was to compare the efficacy of continuous and intermittent salmon calcitonin in the treatment of postmenopausal osteoporosis. Sixty-eight women with postmenopausal osteoporosis were randomized to 2 treatment groups. The first group consisting of 33 patients received nasal salmon calcitonin 200 IU/day. Thirty-five patients in the second group were treated with 200 IU of nasal SCT daily for 5 days with a subsequent pause of 2 days. All received a daily supplement of 1000 mg calcium. Both treatment regimen were applied for 12 months. The effect of nasal calcitonin on bone mineral density (BMD)was investigated by DEXA. Serum ALP, Ca and P levels and urinary Ca excretion were assessed before the treatment and at the end of 12 months. Serum ALP levels decreased mildly, but in a statistically significant manner in both groups ( p 0.05). There was a significant increase above baseline in the BMD of the lumbar spine, trochanteric region and Ward’s triangle in both groups (p 0.05). This study indicates that both continuous and intermittent SCT at a dosage of 200 IU/day are effective in the treatment of postmenopausal osteoporosis

Selective LC determination of cabergoline in the bulk drug and in tablets: In vitro dissolution studies

Cabergoline (CAB) is an ergot alkaloid derivative with dopamine agonist activity. A novel, simple, and rapid stability-indicating high-performance liquid chromatographic (HPLC) method for assay of CAB in tablets has been developed and validated. Chromatography was performed on a 4.6 mm i.d. x 250 mm, 5 mu m particle, cyano column with acetonitrile-10 mM phosphoric acid, 35:65 (v/v), containing 0.04% triethylamine, as mobile phase, at a flow rate of 1.0 mL min(-1), and UV detection at 280 nm. Response was a linear function of concentration in the range 0.1-4 mu g mL(-1) (r(2) = 0.9999). The recovery of the method was good (99.45%) and RSD values for intra-day and inter-day precision were 0.24-0.88% and 0.66-1.19%, respectively. The method can be used for quality-control assay of CAB in tablets, for stability studies, and for in vitro dissolution studies

The Effect of Alendronate and Calcitonin Treatments on Bone Mineral Density and Quality of Life in Women With Postmenopausal Osteoporosis

The aim of this study was to compare the effect of alendronate and calcitonin treatments on bone mineral density (BMD) and quality of life of women with postmenopausal osteoporosis. One hundred ninety-three patients were randomly assigned to two groups: 93 patients received daily doses of 10 mg alendronate and calcium 1000 mg, and 98 patients used intranasal salmon calcitonin (sCt) at a dosage of 200 IU/day and they also received daily doses of 1000 mg calcium supplements. DXA was used for the measurement of BMD of the lumbar spine and proximal femur before and after the study period. SF-36 was used as a measure of health-related quality of life. At the end of the treatment, ALN produced significant increases in BMD at the lumbar spine (p< 0.001), femur neck (p<0.05), trochanteric region (p<0.001) and at the Ward triangle (p<0.05). In contrast, intranasal sCt treatment resulted in a significant bone loss in the femur neck (p<0.01) and Ward triangle (p<0.05), and only a significant increase in BMD of the lumbar spine was observed with calcitonin treatment(p< 0.05). Quality of life as assessed by SF-36 improved significantly in both groups(p<0.05). In conclusion, alendronate seemed to be more effective than calcitonin, increasing both spinal and femoral BMD, for the treatment of postmenopausal osteoporosis. Both treatments were found to be effective for the improvement of quality of life

Badanie właściwości fizycznych i geometrycznych dzianin pojedynczych lewo-prawych z udziałem przędz rdzeniowych elastomerowych

In this study, the adhesion strength properties of laminated polypropylene nonwoven fabrics treated with low-temperature, low-pressure, radio frequency argon plasma were investigated. The change in wettability was determined by water contact angle measurements. In order to observe the effect of plasma treatment on the washing resistance of the laminated samples, washing treatment by means of 10 wash cycles was also carried out. After the peel-off test, the remaining adhesives on the peeled surfaces were examined by SEM images in order to see the effect of plasma treatment. Contact angles of highly hydrophobic polypropylene nonwoven samples decreased by increasing the plasma exposure time and discharge power. The peel bond strength of the plasma treated laminated fabrics improved by up to 150% compared to the untreated fabrics. SEM and AFM analyses also showed that the surface roughness increased due to the etching effect of the plasma treatment, leading to the improvement of the mechanical adhesion of the polypropylene nonwoven fabrics.Głównym celem badań była ocena możliwości zastosowania przy produkcji dzianin na maszynach cylindrycznych bawełnianych przędz rdzeniowych elastomerowych jako alternatywę dla stosowania gołych przędz elastomerowych. Badano również wpływ długości splotu na geometrie i jakość dzianin, w tym na gęstość rządków i kolumienek, gęstość splotów i gęstość powierzchniową przy rożnych stanach relaksacji. Uzyskane wyniki wyraźnie wskazują, że proponowana przędza nadaje się jak najbardziej do projektowanego zastosowania. Stwierdzono również, że zmiany długości splotu nie mają wyraźnego wpływu na gęstość kolumienkową. Jednocześnie stwierdzono, że geometryczne właściwości próbek są odwrotnie proporcjonalne do długości splotu. Badano również zdolność próbek do osiągnięcia geometrycznej równowagi po kolejnych powtarzanych cyklach prania i suszenia. Stwierdzono, że wszystkie wyprodukowane próbki uzyskiwały stabilność wymiarową przed piątym cyklem prania i suszenia, w tym również te, które miały najmniejszą długość splotu

Investigation the usability of garnet as filler material in hot mix asphalt

In this study, the usability of garnet in hot mix asphalt (HMA) as the filler material is investigated. Therefore, the garnet material is sieved through 75 µm. Obtained garnet dust is substituted into hot mix asphalt (HMA) mixture as filler material in four different rates (25, 50, 75 and 100%). Optimum binder rates and the gradation are determined in accordance with the Superpave volumetric mix design procedure. After the determination of optimum binder rate for each different garnet rate, the mixtures have compacted using Superpave gyratory compactor. Indirect tensile strength values and the tensile strength ratios have been obtained in accordance with AASHTO T 283 test procedure. © Springer Nature Singapore Pte Ltd. 2020

Expanded Glass Usability in Hot-Mix Asphalt as Fine Aggregate

In this study, the usability of expanded glass (EG) in hot-mix asphalt (HMA) as the fine material is investigated. Firstly, standard tests on the EG have been done to determine the basic properties. Next, optimum binder content and aggregate gradation are determined in accordance with Superpave volumetric mix design. The EG is substituted into the HMA as a fine aggregate (in accordance with the original size) in four different rates (25, 50, 75 and 100%). Optimum binder content for each EG ratio is determined. The Superpave gyratory compactor is used for the compaction of the specimens. Prepared specimens have been tested for the indirect tensile strength and tensile strength ratio. © Springer Nature Singapore Pte Ltd. 2020