Latest ArticlesThe chemical constituents of Cydonia oblonga (Quince) seeds were investigated using chromatographic methods, including silica gel, Sephadex LH-20 and semi-preparative-HPLC. Eleven compounds were isolated and their structures were elucidated on 1D or 2D NMR, and HR-ESI-MS. These analyses have lead to identification of 5, 7-dihydroxy-2-n-pentacosanyl chromen-4-one (1), ursolic acid (2), tormentic acid (3), oleanolic acid (4), β-daucosterol (5), β-sitosterol (6), amygdalin (7), rutin (8), kaempferol (9), quercetin (10) and isoquercitrin (11). Among these, compound 1 is a new compound, and compounds 3, 5 were isolated from this plant for the first time. Compounds 1-4 and 8 showed significant PTP1B inhibitory activities with IC50 value of 0.465, 16.14, 28.96, 23.78 and 11.70 μmol·L-1, respectively.
Ferroptosis is a novel type of regulated cell death with morphology, biochemistry and mechanisms differing from traditional cell death types such as apoptosis, necrosis and pyroptosis. The regulatory mechanisms of ferroptosis mainly involve iron metabolism, amino acid metabolism and lipid metabolism. It has been found that ferroptosis plays a key role in the pathogenesis of diseases including neurodegenerative diseases, malignant tumors and ischemic reperfusion injury. Parkinson's disease (PD) is one of the most common neurodegenerative diseases and its etiology and pathogenesis remains unclear. Recent studies revealed that ferroptosis might be involved in the pathogenesis of PD, as evidenced by high iron content, depletion of reduced form of glutathione and elevated levels of lipid peroxides detectable in the midbrain of PD patients. Both in vitro and in vivo models of PD have shown that some ferroptosis inhibitors have the ability of attenuating the symptoms and one iron chelator is undergoing a clinic trial. We here summarize the mechanisms of ferroptosis and its association with PD, in an effort to suggest potential novel targets for therapies of PD.
Carbon monoxide (CO) is an important chemical gas messenger molecule in the body with anti-inflammatory activity. As an active substance in gaseous state, the method for its safe and effective delivery towards the lesion sites remains to be established. Based on the natural affinity of carbon monoxide to hemoglobin, a main component of red blood cells (RBCs), this study proposes a carbon monoxide-red blood cell (CO-RBC) composite system, and tested its therapeutic effect against lung injury in an animal model. The mouse model of septic lung injury was adopted, and the carbon monoxide release molecule (CORM-2) was used as a positive control. CO-RBC system was characterized by CO release, stability, toxicity and in vivo lung targeting. The expression of intercellular adhesion molecule (ICAM-1) and pulmonary surfactant protein-A (SP-A) were evaluated in the animal model and the therapeutic effect of CO-RBC system for sepsis was measured by inflammatory factors tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), as well as survival time of mice and pathological changes of the lung. Our results show that CO-RBC system exhibited satisfactory stability with negligible CO release during 48 h storage under nitrogen protection, while the CO release was about 70% within 12 h under physiological condition, in contrast to CO burst release from CORM-2. The CO-RBC system showed no significant toxicity in the animal model, and in vivo fluorescence imaging results showed effective accumulation in the lungs, supporting its lung targeting effects. The secretion of TNF-α and IL-6 in the CO-RBC group was significantly lower than that in other groups, the degree of pulmonary interstitial edema was relieved, the white blood cell infiltration was decreased, and the survival rate was significantly improved. Therefore, the CO-RBC system has a significant inhibitory effect on the pulmonary inflammatory response in septic mice compared with CORM-2. This system provides a new hope for therapeutic treatment of sepsis.
This study aimed to evaluate the predictive performance of a vancomycin population pharmacokinetic model in 0-10 year Chinese pediatric patients. This study was approved by the Ethics Research Committee of the First Affiliated Hospital of Guangxi Medical University, data from hospitalized children ≤ 10 years of age who receiving vancomycin were collected retrospectively. Individual predictive values (IPRED) were estimated by Bayesian Analysis based on a previous published population pharmacokinetic model, and compared with the observed steady state trough concentration. As results, a total of 371 vancomycin serum concentrations from 191 patients were taken for the external validation. The mean error (ME), the mean relative prediction error (ME%), the mean absolute error (MAE) and the root mean square error (RMSE) in individual prediction method for the total patients were -0.50 mg·L-1, 6.03%, 1.84 mg·L-1, 2.86 mg·L-1 respectively. The correlation coefficient between individual predictions and detection values was 0.95. The stability and the predictive performance of model were accepted by goodness-of-fit, visual predictive check (VPC) and Bland-Altman. The percentage of individual prediction error within ±30% was 82.75%. The above results suggest that, this Chinese pediatric population pharmacokinetic model in 0-10 years old has a good prediction performance. It can be applied to the design of initial treatment plan and predicting the extent of drug exposure.
Alterations of mitochondrial structure and function in tumor cells allow cell survival and proliferation under hypoxic and acidic microenvironment. The effect of normal mitochondria on tumor initiation and development remains unknown. In this study, mice were euthanized by rapid cervical dislocation for isolation of hepatic mitochondria, which were injected intravenously to melanoma-bearing mice. This animal experiment had been approved by Southwest University Experiment Animal Ethics Review Committee. The results showed that exogenous mitochondria can significantly inhibit the growth of melanoma. Mitochondria isolated from the liver of young mice had more potent anti-melanoma effect than those isolated from aging mice. The average volume of tumors decreased significantly from 1.35 cm3 to 0.34 cm3, and the average mass of tumors decreased significantly from 0.63 g to 0.22 g. This anti-tumor mechanism might be associated with induction of mitophagy and cell necrosis after the exogenous mitochondria entering the melanoma cells. As mitotherapy can clinically improve somatic cell survival for treatment of pediatric patients with myocardial ischemia, the observed anti-tumor effect of exogenous mitochondria provides a hope for selective tumor treatment.
Recently, hepatic sinusoidal obstruction syndrome (HSOS) caused by Gynura Rhizoma (Tusanqi) has gained global attention. The purpose of this research is to investigate the effects and mechanisms of Danning tablet, a traditional Chinese formula, on protecting against HSOS induced by Gynura Rhizoma. All experiments were approved by the Animal Research Committee of Shanghai University of Traditional Chinese Medicine. Animal welfare and the animal experimental protocols were strictly consistent with related ethics regulations of Shanghai University of Traditional Chinese Medicine. HSOS was induced by intragastrical administration of Gynura Rhizoma extract (1 g·kg-1·d-1) for 40 consencutive days. On the other hand, mice in the protection group were intragastrical administration of Danning tablet powder (3 g·kg-1·d-1) 4 hours before treatment of Gynura Rhizoma extract. The results showed that Danning tablet could significantly attenuate the liver injury in HSOS mice. Mice in the protection group showed decreased serum activity of spartate amino transferase, and levels of total bile acids and total bilirubin. In addition, the endothelial damage to the central venules, subendothelial hemorrhage, sinusoidal hemorrhage, and subendothelial fibrosis in HSOS mice were clearly attenuated in the protection group. Measurements of the key factors involved in liver fibrosis revealed that protection group showed significantly reduction in hepatic hydroxyproline concentration, mRNA expression of α-smooth muscle actin and fibrosis-related genes such as Collagen-1, Collagen-3, Mmp2 and Mmp9, as well as Smad3 phosphorylation (p-Smad) and serum transforming growth factor-β (TGF-β). Moreover, pro-inflammatory cytokines, including tumor necrosis factor-α and interleukin-1β, were also reversed in the protection group. All these results demonstrate the key roles of the TGF-β/p-Smad3 and inflammatory signaling pathways in the protection effect of Danning tablet on Gynura Rhizoma-induced HSOS, and pointing to the possibility of utilizing Danning tablet for protection against Gynura Rhizoma induced HSOS clinically.
The purpose of this study was to select the active compounds targeting Hsp90 protein in pancreatic cancer cells through a new dual "target + activity" rapid discovery technique. We combined an in vitro anti-cancer activity screening method with a dual-luciferase reporter gene and multi-chromatography separation technology, for rapid discovery of potential Hsp90 inhibitors from the Chinese herbal medicine Physalis angulata L. The anti-proliferation activity of those compounds was assessed in pancreatic cancer cell line BxPC-3 by MTT assays. The molecular mechanisms of Hsp90 inhibition were explored by Western blot and shRNA knockdown assays. As a result, two withanolides, withanolide E (WE) and 4β-hydroxywithanolide E (HWE), were identified from Physalis angulata L. The half maximal inhibitory concentration (IC50) of WE and HWE were 0.71±0.03 and 1.23±0.10 μmol·L-1 for the growth of BxPC-3 cells in 48 h. Luciferase reporter assay demonstrated that WE and HWE significantly induced heat shock element (HSE) activity in a dose-and time-dependent manner. The molecular mechanism study showed that after exposing to 5 μmol·L-1 WE or HWE for 48 h, the aggregation of Hsp90 dimer was upregulated to 6.5±1.3 and 11.8±2.0 fold, while the expression of Hsp90 client protein Akt was downregulated to 21.7%±2.8% and 9.8%±1.4% of the control group. Moreover, the Hsp90 inhibitory activity of WE or HWE was canceled by shRNA mediated Hsp90 knockdown. Overall, based on the dual "target + active" rapid discovery technique, two new Hsp90 inhibitors WE and HWE were found from Physalis angulata L. The Hsp90 inhibitory mechanism of WE and HWE may be mediated by induction of Hsp90 aggregate dimer and inhibition of Hsp90 client protein Akt expression.
Melatonin (MLT) is an endogenous chemical that has antitumor effects at high doses. However, it shows low oral bioavailability and short in vivo half-life, leading to drug resistance. Here, liposomal melatonin dry powder inhalers (LMD) were prepared, and were used for treatment of primary rat lung cancer by pulmonary delivery. Liposomal melatonin (LM) was prepared by the ethanol injection method to achieve an entrapment efficiency of 98.89%. LMD was obtained by freeze-drying after LM was mixed with mannitol. LMD appeared as spherical particles under a scanning electron microscope. The rehydrated liposomes had a small size of 65.15 nm and the zeta potential of -14.2 mV without change inentrapment efficiency. LMD had an aerodynamic particle size of 6.73 ±0.012 μm and a fine particle fraction (FPF < 8.06 μm) of 22.2%, suitable for pulmonary delivery. When administered with the same dose, LMD showed much higher inhibition on A549 lung cancer cells than MLT and gemcitabine. LMD of a large dose had no effect on the growth of normal lung epithelial cells (BEAS-2B). Rat lung cancer models were established after 45 days by instilling 3-methylcholanthrene (MCA) and N, N-dimethylnitrosamine (DEN) into the rat lungs once (the experiments had been approved by the ethics committee and carried out in accordance with relevant guidelines and regulations). Decreases of tumor nodules and inflammatory cells in the tumor-bearing rat lungs were observed after treatment of MLT, gemcitabine and LMD by pulmonary delivery compared with the models, wherein LMD was most effective. The efficiencies of inhibition of NF-κB p65, increase of Tunel detection (indicating enhancement of apoptosis), and decrease of malondialdehyde corresponded to LMD being most effective. Therefore, given the fact that LMD can deliver the drug into the tumor tissues of lungs, and it presents as a promising pulmonary inhalable regiment for treatment of lung cancer.
A sensitive and efficient liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for quantitative determination of diflucortolone in rabbit plasma after dermal administration of diflucortolone valerate cream to rabbits. After extraction with ethyl acetate, the chromatographic separation was performed on Zorbax Eclipse XDB-C18 (50 mm×4.6 mm, 5 μm) with a gradient mobile phase consisting of 50% acetonitrile-50% methanol and 0.1% formic acid-5% methanol-5 mmol·L-1 ammonium formate at a flow rate of 0.35 mL·min-1. The quantitative analysis was carried out using multiple reaction monitoring (MRM) at specific ion transitions of m/z[M+H]+ 395.2→m/z 355.2 for diflucortolone and m/z[M+H]+ 258.1→m/z 120.9 for ethoxyphenylethylamine (internal standard) in positive ion mode with electrospray ionization (ESI) source. This validated LC-MS/MS method had a linearity over the concentration range of 0.01-10 ng·mL-1 with the lower limit of quantification (LLOQ) at 0.01 ng·mL-1. At level of LLOQ, the inter and intra-assay precision (RSD) were no greater than 9.82% and 11.0%, respectively. The main pharmacokinetic parameters of the diflucortolone including tmax, Cmax, AUC0-72 h, and t1/2 were as follows:(6.33±1.21) h, (0.168±0.080 0) ng·mL-1, (3.15±0.834) h·ng·mL-1, (32.0±17.4) h. The method was validated in the pharmacokinetic study of diflucortolone in rabbit following dermal administration of diflucortolone valerate cream at dose of 0.01 g·cm-2. In this study, the program of animal testing had been approved by Committee on the management and usage of experimental animal in the Evaluation Company of Innovative Drug, Tianjin Institute of Pharmaceutical Research.
Tropinone reductase Ⅰ (TRI) is a key branch point enzyme in the midstream of tropane alkaloids (TAs) biosynthesis pathway and represents an important target for TAs metabolic engineering, which can lead to metabolic flux of substrate tropinone to TAs. A novel TRI gene was isolated from Datura arborea, a woody resource plant, and designated as DaTRI2 (GenBank accession number is MH705164). The full-length cDNA of DaTRI2 with 1 135 bp exhibits a high sequence homology (96.8%) with DaTRI, and is predicted to encode a protein of 347 amino acids. Deduced DaTRI2 protein contain a conserved TGXXXGXG motif involved in NADPH binding, the catalytic N-S-Y-K tetrad motif and eleven amino acid residues important for binding to its substrate tropinone. The phylogenetic analysis revealed that DaTRI2 and other TRIs from Solanaceous plants belong to the same cluster and DaTRI2 exhibited closest phylogenetic proximity to TRIs from Datura. DaTRI2 was expressed in E. coli and the purified recombinant protein can catalyze both tropinone reduction and tropine oxidation with an optimum pH value of 8.0 and 9.6, respectively. When tropinone was used as the substrate, the Km and Vmax values of DaTRI2 at pH 6.4 were 210.05 μmol·L-1 and 69.6 nkat·mg-1 protein respectively, while the Km and Vmax values for tropine as the substrate were 188.03 μmol·L-1 and 114 nkat·mg-1 protein respectively, at pH 9.6. DaTRI2 transcript was most abundant in the young leaf, followed by the root. Cloning of DaTRI2 gene and biochemical analysis of recombinant DaTRI2 facilitate further research on the molecular mechanism on TAs biosynthesis in woody plants and provide a more potent candidate for TAs metabolic engineering.