Latest ArticlesThe study was designed to establish a 2D UPLC-QTOF method to extrapolate the structure of an unknown substance in carboplatin injection and its relationship with the excipient. By using phenyl-hexyl column (250 mm×4.6 mm, 5 μm) with mobile phase consisting of tetrabutylammonium sulfate buffer (pH 7.5) and acetonitrile in gradient elution mode, an unknown impurity in carboplatin injection was found and quantitatively determined. Then a 2D UPLC-QTOF, HSS T3 column (100 mm×2.1 mm, 1.7 μm) was employed to confirm the molecular weight and the structure of the unknown impurity (electrospray ionization source, positive ion mode, MSE mode) with mobile phase consisting of 0.1% formic acid and acetonitrile. The relationship among impurities, API and excipient was investigated by accelerated stability test with ICP-MS/MS, ICP-AES. Results showed that disodium edetate in the formulation interacted with carboplatin producing an unknown impurity containing platin, and induced the increase of 1, 1-cyclobutanedicarboxylic acid. The research should be done on the rationality of the addition of disodium edetate in such injections containing heavy metals.
Study on the integrated pharmacokinetics/pharmacodynamics (PK/PD) model of rhubarb in rats with yang-deficiency constipation based on the principle of traditional Chinese medicine system. The rat model of yang-deficiency constipation was established using vinegar and ice water containing activated carbon. The blood samples with 0.5 mL were collected from orbital venous plexus at 0, 5, 10, 15, 30, 60, 120, 240, 480, 720, 1 440 min time points after oral administration of rhubarb decoction, and the dosage is equivalent to crude drug 2.5 g·kg-1. The concentration of aloe-emodin, rhein, emodin and chrysophanol in rat plasma were determined by HPLC, and ELISA method was used to detect the activities of motilin (MTL), gastrin (GT), endothelin (ET) and vasoactive intestinal peptide (VIP) at different time points in serum. SPSS 21.0 software was used for analysis of component correlation and principal component, and WinNonlin 6.30 software was used to fit PK/PD model. Compared with the pharmacokinetic parameters of normal rats, in addition to emodin in the model rats showed characteristics of good absorption and slow to elimination; the content of MTL in model rats was significantly lower than that in normal rats. The composite values of the concentration and effect obtained by principal component analysis were connected by Sigmoid-Emax model. We established the integrated PK/PD model of rhubarb in treating yang-deficiency constipation to provide a new research direction for the material basis and mechanism of rhubarb treatment of yang deficiency constipation.
In this study, we used a mathematic-based modeling system to screen the cytokines that are sensitive to Zhuangguguanjie wan (ZGW)-induced idiosyncratic liver injury. The values of 27 cytokines were used as the data source in rat liver of lipopolysaccharide (LPS) + ZGW group. The alanine aminotransferase (ALT) activity value of liver function indexes was used as the outcome evaluation index of liver injury. Cytokines of ZGW-induced idiosyncratic liver injury were screened using Logistic regression, random forest method, LASSO Logistics regression and method of combining rule discovery algorithm with LASSO, and cytokines filtered out were revalued in THP1 macrophage. Susceptible cytokine combinations:interleukin-1β (IL-1β), epidermal growth factor (EGF) and interleukin-18 (IL-18) closely related to ZGW-induced idiosyncratic liver injury were obtained after preliminary screening analysis. The result of revalued in THP1 showed that the ethanolic extract of ZGW (EtZ) combined with IL-1β or IL-18 synergistically enhanced tumor necrosis factor-α (TNF-α) secretion in THP1 macrophage, and EtZ combined with IL-1β significantly enhanced interleukin-6 (IL-6) secretion in THP1 macrophage, but EtZ combined with EGF markedly inhibited IL-6 secretion in THP1 macrophage. The results suggest that the sensitive cytokines that can be characterized in the ZGW-induced idiosyncratic liver injury are IL-1β and IL-18, which provides a basis for screening the ZGW-induced idiosyncratic liver injury patients, and a new experimental evidence for clinical safety medication and risk prevention of ZGW.
Muscimol, cycloserin and ibotenic acid which are extracted from mushroom contain isoxazole pharmacophore structure. By using muscarinic structure as a model compound and molecular recombination method, we synthesized muscarinic analogues compounds 3-(1', 2'-di-O-isopropylidenedioxyethyl)-5-aryl-3a, 6a-dihydro-4, 6-dioxopyrrolino[3', 4'-d]isoxazoline derivatives through 1, 3-dipolar cycloaddition reaction. The structures of the target compounds were confirmed by UV-Vis, 1H NMR, IR and elemental analysis. The drug activities of obtained compounds were screened in vitro. The pharmacophore in the structure is a potential non-covalent DNA binding, the compounds have anticancer activity and the leukocyte common antigen activity in a different extent. The preliminary results of in vitro anticancer test suggest that the inhibitory rates of compounds 3a-3o to Cdc25A phosphatase in cell division cycle ranged from 56.99%-99.94%; at the test concentration of 20 μg·mL-1, 3f, 3h, 3i, 3m, 3o were no inhibition activity, and the rest of the compounds shows moderate to good excellent inhibition rate from 66.85% to 99.84%, even at the concentration as low as 5 μg·mL-1. At the test concentration of 20 μg·mL-1, except compound 3i, the rest compounds' inhibition activity of against leukocyte common antigen (LCA) CD45 protein tyrosine phosphatase A, are 63.08%-92.09%. These active compounds are potential inhibitors against Cdc25A and CD45 protein tyrosine phosphatase A, which have great application prospects in the treatment of cancers and Inflammatory and immune diseases.
Flavonoids, especially chalcones such as hydroxysafflor yellow A and carthamin are the main active ingredients of safflower. To study the biosynthesis pathway of safflower flavonoids is of great significance for the quality control of safflower. Chalcone synthase (CHS) is an enzyme that plays an important role in regulation of the synthesis of flavonoids. However, for the time being, the role of CHS is not yet clear in the biosynthesis of safflower flavonoids. As a plant signaling regulator, JA/MeJA can activate CHS gene expression in plants. CtCHS1, one of the CHS genes in safflower, was elucidated in our previous work. In our continuous search for CtCHSs functions from this plant, other CHS genes CtCHS2 and CtCHS4 in safflower were examined. The floret was stimulated with methyl jasmonate (MeJA) and the transcriptome expression of CtCHS2 and CtCHS4 was analyzed by qRT-PCR at different time points of 0, 3, 6, and 12 h after stimulation. Further metabolites under stimulation by MeJA were analyzed by UHPLC/Q-TOF-MS. The results showed that the expression of CtCHS4 in response to MeJA significantly increased at 3 and 6 h, while the expression of CtCHS2 showed a trend of decrease after induction. Meanwhile, the accumulation of rutin, hydroxysafflor yellow A, D-phenylalanine, kaempferol-3-O-β-rutinoside and carthamin increased obviously. Especially, accumulation of hydroxysafflor yellow A was increased significantly at 3, 6 and 12 h after induction (P ≥ 0.05 or 0.01), but the change in kaempferol, kaempferol-3-O-β-D-glucoside, luteolin, quercetin-3-β-D-glucoside was not significant. The accumulation of hydroxysafflor yellow A and carthamin was positively correlated with the expression abundance of CtCHS4 with Pearson correlation analysis method (r ≥ 0.8). The data suggest that CtCHS4 may be a key gene for forming hydroxysafflor yellow A and carthamin and plays an important role in the accumulation of safflower chalcones. The CtCHS4-pMAL-C5X recombinant vector was successfully expressed in BL21 (DE3) Plys to express the product naringenin in vitro under the catalytic substrates p-coumaryol-COA and malonyl-CoA. The results of this study provide a new insight into synthetic genes involved in flavonoids biosynthetic pathway to elucidate the biosynthesis pathway of safflower chalcones.
Chinese pharmacopoeia stipulates that the content of liquiritin in licorice slices should be no less than 0.5%. However, there are lots of unqualified licorice slices in the herbal medicine markets. Due to the important role of functional gene polymorphism in secondary metabolism, this study attempts to analyze the influence of chalcone synthase (CHS) gene polymorphism on liquiritin biosynthesis and find out the unique haplotypes in licorice samples with high or low content of liquiritin, and to provide a basis for further analysis of molecular mechanism in flavonoid biosynthetic pathway. The contents of the 4 main flavonoids (liquiritin, isoliquiritin, liquiritigenin, isoliquiritigenin) in 60 licorice samples were assayed by HPLC and the results were analyzed by Spearman and χ2 tests. The contents of the 4 main flavonoids were related to each other and obviously different in different original plants. They were highest in Glycyrrhiza uralensis samples and lowest in Glycyrriza inflate samples. Five G. uralensis samples with the highest liquiritin contents and five G. inflate samples with the lowest liquiritin contents were selected to clone the CHS cDNA sequences. 336 CHS cDNA sequences with a full length of 1 175 bp were obtained, 249 variable sites (141 missense mutation sites) were found, and 137 haplotypes were determined. 130 variable sites were found in the 336 CHS amino acid sequences and 102 types were determined. AA-3 is the major type of CHS in licorice, AA-35 is the special major type of CHS in the group with high flavonoids contents and AA-36 is the special major type of CHS in the group with low flavonoids contents. The mutation sites between AA-35 and AA-36 are I/V at 193 and V/T at 229. Discovery Studio 2.5 analysis of the three-dimensional structure of the CHS protein shows that the valine at site 229 of AA-35 is combined with malonyl-CoA. Homology analysis indicates that the homology of CHS among different species is low. This study is significant for identification of the unique haplotypes in licorices with high or low content of liquiritin and guiding the further molecular breeding of high-quantity licorice.
A change in vascular smooth muscle cell (VSMC) phenotype, known as converting from a contractile state into a synthetic phenotype, is a crucial event in vascular remodeling, which determines the occurrence, development and prognosis of cardiovascular diseases such as pulmonary hypertension and atherosclerosis. Research shows that the expression level of key signaling molecules, which controls the phenotype change of VSMC, is regulated by microRNA (miRNA), a type of non-encoding RNA. In this article, we provide a review of miRNA in the regulation of VSMC phenotype changes with a focus on the key molecules in MAPK, TGFβ/Smad and PI3K/Akt signaling pathways.
Apoptosis is an important self-stabilizing mechanism of multicellular organisms, which plays a vital role in the development of normal living organisms and the maintenance of tissue homeostasis. The abnormalities in apoptosis often lead to body lesions including tumors. Studies have shown that Bcl-2 protein with anti-apoptosis activity is an important target in the treatment of cancer. After nearly two decades of efforts, many small molecule Bcl-2 inhibitors have been discovered to induce cell apoptosis. The small-molecule Bcl-2 inhibitor, venetoclax, was developed based on fragment-based drug design strategy and approved by the FDA in 2016 for clinical application. This agent is the first approved small-molecule drug inhibiting Bcl-2 through protein-protein interaction to induce cell apoptosis. The achievement of venetoclax benefits from a combination of drug discovery technologies and represents a milestone in the history of drug discovery. In this review we will introduce the current progress in Bcl-2 inhibitors.
Gene therapy has obvious advantages in the treatment of ocular diseases due to the unique structure of the eye. In recent years, there are more and more therapeutic gene-based drugs for ophthalmic application in clinical trials. Most of the delivery vectors are adeno-associated virus and administered via intraocular injection, which has potential risks. Traditional remedies, such as topical instillationor systemic administration, have limited therapeutic effects on the diseases in the posterior segment of the eye, where the chemical drugs are hard to reach. This makes the research of new strategies for gene drug delivery extremely urgent. For better understanding of the latest hot topics of ocular gene therapy, this article is prepared to introduce application of gene therapy to the typical ocular diseases and the corresponding gene-based medicines. The absorption routes for gene delivery into eyes and existing barriers are summarized. Finally, the gene delivery strategies are highlighted. The clinical application of ocular gene therapy will be boosted by overcoming the absorbing barriers and reducing the potential pitfalls.
Sab (SH3 domain-binding protein that preferentially associates with Btk) that is also called SH3BP5 (SH3 domain-binding protein 5), is a scaffold protein on mitochondrial outer membrane in the modulation of mitochondrial function. Sab not only combines with the tyrosine kinase Btk (Bruton's tyrosine kinase), but also binds to the serine threonine kinase JNKs (c-Jun amino-terminal kinases) and p38γ. Thus Sab can regulate B cell antigen receptor, mitochondrial JNK and p38γ signaling pathway, which is associated with the critical physiological function, such as B-cell development and differentiation and regulation of mitochondrial signaling transcription. Inhibition or induction on the expression of Sab can ameliorate the diseases arising from the abnormal level of Btk, JNKs and p38γ, such as nervous system diseases and liver injury. Therefore, Sab could be expected as a new target for drug development. In this article, we provide an overview of the structure and functions of Sab and its relationship to diseases of diffuse large B-cell lymphoma, nervous system diseases and liver injury, aiming to provide new ideas and theoretical basis for the development of new drugs.