Validated method to measure yakuchinone A in plasma by LC-MS/MS and its application to a pharmacokinetic study in rats

BACKGROUND: Yakuchinone A has a plethora of beneficial biological effects. However, the pharmacokinetic (PK) data of yakuchinone A still remain unknown so far. Furthermore, the quantification of yakuchinone A in biological samples has not been reported in the literature. Therefore, in the present study we aimed to develop a new method for the fast, efficient and accurate assessment of yakuchinone A concentration in plasma, as a means for facilitating the PK evaluation of yakuchinone A. RESULTS: A liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method was developed and validated for the determination of yakuchinone A in rat plasma. Mass spectrometric and chromatographic conditions were optimized. Plasma samples were pretreated by protein precipitation with methanol. LC separation was performed on a Phenomenex Luna C18 column with gradient elution using a mobile phase consisting of methanol–water containing 0.5 mM formic acid (HCOOH) at a flow rate of 0.28 mL/min. ESI-MS spectra were acquired in positive ion multiple reaction monitoring mode (MRM). The precursor-to-product ion pairs used for MRM of yakuchinone A and yakuchinone B were m/z 313.1 → 137.0 and 311.2 → 117.1, respectively. Low concentration of HCOOH reduced the ion suppression caused by matrix components and clearly improved the analytical sensitivity. Yakuchinone A showed good linearity over a wide concentration range (r > 0.99). The accuracy, precision, stability and linearity were found to be within the acceptable criteria. This new method was successfully applied to analyze the rat plasma concentration of parent yakuchinone A after a single oral administration of SuoQuan capsules. Low systemic exposure to parent yakuchinone A was observed. CONCLUSION: The proposed method is sensitive and reliable. It is hoped that this new method will prove useful for the future PK studies

Isoglycyrrhizin protects mouse lungs against acute respiratory distress syndrome via regulation of AMPK/Nrf2/ARE pathway

Purpose: To study the effect of isoglycyrrhizin on LPS-mediated acute respiratory distress syndrome (ARDS) in a mouse model, as well as the associated mechanism of action.Methods: Ninety (90) wild-type C57BL/6 male mice were randomly assigned to 3 groups, viz, control, ARDS and isoglycyrrhizin groups. Pathological lesions in mice lungs were determined using H&E staining. The mRNA and protein expressions of inducible nitric oxide synthase (iNOS), heme oxygenase (HO-1), cyclooxygenase-2 (COX-2), AMP- dependent protein kinase (AMPK), serine/threonine proteinkinase (Akt), glycogen synthase kinase 3 (GSK3), nucleotide-binding domain-like receptor protein 3 (NLRP3), and Nrf2 were assayed using quantitative reverse transcription polymerase chain reaction (RT-PCR) and immunoblotting, respectively.Results: The levels of mRNA and protein expressions of INO) and COX-2 were significantly upregulated in ARDS, when compared to control, but were markedly down-regulated by isoglycyrrhizin (p < 0.05). Similarly, exposure of ARDS mice to isoglycyrrhizin led to upregulations of mRNA and proteinlevels of Nrf2, NQO1, HO-1, GCLM, GCLC, p-GSK3, GSK3, p-AMPK, AMPK, p-Akt and AKT (p < 0.05). Moreover, isoglycyrrhizin significantly downregulated p-IκB and Nucl-p65 with respect to protein and mRNA levels, but upregulated IκBα expression. Histopathological examination revealed that pretreatment of ARDS mice with isoglycyrrhizin significantly reduced the number of infiltrating inflammatory cells, edema and ARDS score (p < 0.05).Conclusion: Isoglycyrrhizin protects mouse lungs against ARDS via regulation of AMPK/Nrf2/ARE pathway. Thus, this compound has potential for use in the treatment of ARDS

DIURETIC AND ANTI-DIURETIC BIOACTIVITY DIFFERENCES OF THE SEED AND SHELL EXTRACTS OF ALPINIA OXYPHYLLA FRUIT

Background: Alpinia oxyphylla fruit (AOF, Yizhi in Chinese) is a well-known traditional Chinese medicine as an anti-diuretic agent and composed of two parts i.e. seed and shell. These two parts have different components, but the bioactivity differences of the two parts are not clear. This study aims to evaluate the different anti-diuretic effects of the seed and shell of AOF. Materials and Methods: The potential bioactive components were analyzed by UPLC-Q-TOF-MS. The diuretic and anti-diuretic activity was determined with saline-loads rats. Results: The results showed that the 200 mg/kg and 400mg/kg of SREAO displayed a short-time anti-diuretic activity 1h after administration and then a significant diuretic activity was being observed at 5-6 h in 400mg/kg group of SREAO. And the 400mg/kg doses of SREAO also showed a remarkable increase for electrolyte excretion of K+. Three sesquiterpene compounds, namely oxyphyllol A (1), oxyphyllol B (2), and nootkatone (3) were identified from the active SREAO fraction by UHPLC-ESI-Q-TOF/MS. Conclusion: The seed part of Alpinia oxyphylla possessed pronounced diuretic and anti-diuretic effect. The sesquiterpene components are the major constituents and possibly contributed the diuretic and anti-diuretic activity

Large-scale physical modelling study of a flexible barrier under the impact of granular flows

Flexible barriers are being increasingly applied to mitigate the danger of debris flows. However, how barriers can be better designed to withstand the impact loads of debris flows is still an open question in natural hazard engineering. Here we report an improved large-scale physical modelling device and the results of two consecutive large-scale granular flow tests using this device to study how flexible barriers react under the impact of granular flows. In the study, the impact force directly on the flexible barrier and the impact force transferred to the supporting structures are measured, calculated, and compared. Based on the comparison, the impact loading attenuated by the flexible barrier is quantified. The hydro-dynamic approaches with different dynamic coefficients and the hydro-static approach are validated using the measured impact forces.</p

Enhancement of hydrogen physisorption on single-walled carbon nanotubes resulting from defects created by carbon bombardment

The defect effect on hydrogen adsorption on single-walled carbon nanotubes (SWNTs) has been studied by using extensive molecular dynamics simulations and density functional theory (DFT) calculations. It indicates that the defects created on the exterior wall of the SWNTs by bombarding the tube wall with carbon atoms and C-2 dimers at a collision energy of 20 eV can enhance the hydrogen adsorption potential of the SWNTs substantially. The average adsorption energy for a H-2 molecule adsorbed on the exterior wall of a defected (10,10) SWNT is similar to 150 meV, while that for a H-2 molecule adsorbed on the exterior wall of a perfect (10,10) SWNT is similar to 104 meV. The H-2 sticking coefficient is very sensitive to temperature, and has a maximum value around 70 to 90 K. The electron density contours, the local density of states, and the electron transfers obtained from the DFT calculations clearly indicate that the H-2 molecules are all physisorbed on the SWNTs. At temperatures above 200 K, most of the H-2 molecules adsorbed on the perfect SWNT are soon desorbed, but the H-2 molecules can still remain on the defected SWNTs at 300 K. The detailed processes of H-2 molecules adsorbing on and desorbing from the (10,10) SWNTs are demonstrated

Transformation of Co-containing birnessite to todorokite: Effects of Co on the transformation and implications for Co mobility

The mobility and fate of bioessential transition metals, such as Ni and Co, are strongly controlled by their association with phyllomanganate minerals such as birnessite. These minerals however, can transform to tectomanganates such as todorokite during soil and sediment diagenesis, yet the mobility and fate of most metals during the transformation process remain largely unknown. Here this research investigates the effect of Co on, and the mobility and fate of Co during the transformation of birnessite into tunnel structure minerals. A range of Co-containing birnessite precursors with up to 20% Co/(Co+Mn) molar ratios were synthesised, and subsequently transformed via a mild reflux procedure designed to mimic the diagenesis of these layered precursors into tunnel structures. The layered precursors and reflux products were characterized using a combination of mineralogical and geochemical techniques, including powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), high resolution transmission electron microscopy (HRTEM) and extended X-ray absorption fine structure (EXAFS) spectroscopy. The results show that Co(III) is structurally incorporated into the layered precursors and reflux products, through the isomorphic substitution of Mn(III). The structural incorporation of Co(III) into the layered precursors leads to an overall reduction of Jahn-Teller distorted Mn(III) octahedra in these minerals, a key factor for their transformation to tunnel structures. As a consequence, the presence of such structural Co(III) disrupts the transformation of birnessite into todorokite, leading to the coexistence of 9.6 Å asbolane-like phyllomanganate and non-ideal 3×n, or a-disordered, todorokite-like tectomanganates in the transformation products. Newly formed todorokite exhibits a wide range of 3×n tunnel dimensions (n up to 13) and a plate-like morphology. Overall the structural incorporation of non Jahn-Teller distorted cations like Co(III) into birnessite might help explain the often observed predominance of phyllomanganates over tectomanganates in soils and sediments, and the persistence of phyllomanganates in ferromanganese deposits that can be many millions of years old. The results also indicate that Co(III) initially associated with birnessite is retained in the solid phase during transformation, and thus the mobility of Co(III) is limited. EXAFS data suggest that Co is mainly located in the octahedral layers of asbolane-like phyllomanganate and at non-edge sites in non-ideal todorokite. Overall the transformation of Co-containing birnessite into non-ideal todorokite and asbolane-like layered structures maintains the strong sequestration of Co by Mn oxides

Invasive alien plants are phylogenetically distinct from other alien species across spatial and taxonomic scales in China

IntroductionPhylogenetic relatedness is one of the important factors in the community assembly process. Here, we aimed to understand the large-scale phylogenetic relationship between alien plant species at different stages of the invasion process and how these relationships change in response to the environmental filtering process at multiple spatial scales and different phylogenetic extents.MethodsWe identified the alien species in three invasion stages, namely invasive, naturalized, and introduced, in China. The occurrence records of the species were used to quantify two abundance-based phylogenetic metrics [the net relatedness index (NRI) and the nearest taxon index (NTI)] from a highly resolved phylogenetic tree. The metrics were compared between the three categories of alien species. Generalized linear models were used to test the effect of climate on the phylogenetic pattern. All analyses were conducted at four spatial scales and for three major angiosperm families.ResultsWe observed significantly higher NRI and NTI values at finer spatial scales, indicating the formation of more clustered assemblages of phylogenetically closely related species in response to the environmental filtering process. Positive NTI values for the invasive and naturalized aliens suggested that the presence of a close relative in the community may help the successful naturalization and invasion of the introduced alien species. In the two-dimensional phylogenetic space, the invasive species communities significantly differed from the naturalized and introduced species, indicating that established alien species need to be phylogenetically different to become invasive. Positive phylogenetic measures for the invasive aliens across the spatial scales suggested that the presence of invasive aliens could facilitate the establishment of other invasive species. Phylogenetic relatedness was more influenced by temperature than precipitation, especially at a finer spatial scale. With decreased temperature, the invasive species showed a more clustered assemblage, indicating conservatism of their phylogenetic niche. The phylogenetic pattern was different at the family level, although there was a consistent tendency across families to form more clustered assemblages.DiscussionOverall, our study showed that the community assemblage became more clustered with the progression of the invasion process. The phylogenetic measures varied at spatial and taxonomic scales, thereby highlighting the importance of assessing phylogenetic patterns at different gradients of the community assembly process

ORM 1 as a biomarker of increased vascular invasion and decreased sorafenib sensitivity in hepatocellular carcinoma

This study aimed to clarify the role of Orosomucoid 1 (ORM1) in the development and therapy resistance in hepatocellular carcinoma (HCC). The mRNA expression level of ORM1 was analyzed via integrative analysis of Gene Express Omnibus (GEO) and The Cancer Genome Atlas (TCGA) datasets. The protein expression level of ORM1 in our cohort was determined using immunohistochemistry. Correlation analysis was used to investigate the relationship between ORM1 expression and clinical parameters. The Cell Counting Kit-8 assay was used to clarify the role of ORM1 in HCC malignant behaviors, including cell growth and sorafenib sensitivity, in vitro. The results indicated that ORM1 was significantly downregulated in the hepatic cancer cells compared to that in the non-cancerous cells. However, it was upregulated in microvascular invasion samples, especially in the cancer embolus compared to that in the surrounding tumor cells. Though Kaplan-Meier analysis did not show an association of ORM1 expression with the overall survival rates of HCC patients, univariate analysis indicated that ORM1 expression was highly correlated with tumor grade and stage. An in vitro assay also revealed that downregulation of ORM1 led to the suppression of tumor growth and enhancement of sorafenib sensitivity without epithelial-to-mesenchymal transition (EMT) alteration, which was consistent with our bioinformatic analysis. Hence, ORM1 played a key role in HCC tumorigenesis and may serve as a potential target for the development of therapeutics against HCC in the future