Latest ArticlesStudies have shown that acetylcholinesterase inhibitors donepezil and galantamine have effects of reducing neuronal damage caused by glucose deprivation and reducing the cerebral infarction volume of cerebral ischemic animals, but their effects may not be entirely dependent on its inhibition of cholinesterase activity. In order to study the effects of donepezil and galantamine on neuronal injury of cerebral ischemia, the rat neuron-astrocyte co-culture model was successfully established in this study. In this model, we studied the effects of donepezil and galantamine on neuron apoptosis induced by oxygen-glucose deprivation/reoxygenation (OGD/R) and investigated the mechanism. The results showed that donepezil and galantamine significantly reduced the neuron apoptosis, and promoted the synthesis and secretion of BDNF and NGF in astrocytes in the co-culture system. Donepezil and galantamine activated the PI3K/Akt pathway and ERK pathway, and promoted the phosphorylation of the nuclear transcription factor CREB. These results suggest that donepezil and galantamine exhibit protective effects on neuronal damage induced by OGD/R. The mechanism may be related to activation of PI3K/Akt pathway and ERK pathway in astrocytes and promote phosphorylation of CREB, which lead to the synthesis and secretion of BDNF and NGF from astrocytes.
Although multiple studies have shown that matrine can inhibit the proliferation of hepatoma cells, its mechanism of action has not been systematically investigated. In this study, the effects of matrine on the proliferation and migration of human hepatoma SMMC-7721 cells were investigated. Based on this result, anti-hepatoma target-functionally related protein interaction network of matrine was constructed, and topological analysis and clustering analysis were performed to predict the crucial targets of matrine for the anti-hepatoma effects. Pathway enrichment analysis was performed on the validated targets to predict the crucial pathways of matrine. Parts of the crucial proteins were examined by Western blot. Cellular experiments showed that matrine at concentrations of 1, 2 and 4 mg·mL-1 significantly inhibited the proliferation of SMMC-7721 cells, and matrine at concentrations of 0.5, 1 and 2 mg·mL-1 significantly inhibited the migration of SMMC-7721 cells. The results of network pharmacology suggest that matrine exerts its anti-hepatoma effects through acting on the key validated targets of heparanase (HPSE), caspase 3 (CASP3), Myc proto-oncogene protein (MYC), matrix metalloproteinases 2 (MMP2) and predicted targets of carbonic anhydrase 1 (CA1), lithostathine 1 alpha precursor (REG1A), carboxylesterases 1 (CES1) and acetaldehyde dehydrogenase 2 (ALDH2), and invasion and migration associated pathways. Western blot results suggest that matrine can down-regulate the expression of MMP2 and up-regulate the expression of CASP3. In this paper, we applied network pharmacology to explain the targets and pathways of matrine against hepatoma. The results provide a scientific basis for elucidation of the mechanisms of matrine against hepatoma.
This study was designed to investigate the chemical constituents of the anti-osteoporotic part of Lepidium meyenii Walp. (maca) produced in Heqing, Yunnan. Seven compounds were isolated from the n-BuOH extract of maca using combination of column chromatographies on MCI resin, silica gel, C18 bonded silica gel, and Sephadex LH-20, followed by semi-preparative HPLC and recrystallization. The purified compounds were identified on the basis of their physicochemical properties and spectral data as macaolidine (1), tryptophan (2), daucosterol (3), (3S)-1, 2, 3, 4-tetrahydro-β-carboline-3-carboxylicacid (4), chlorogenic acid (5), luteolin (6), and hyperoside (7). Compound 1 is a new phenylacetamide alkaloid, and compounds 4-7 were isolated from Lepidium meyenii for the first time.
IG-105, N-(2, 6-dimethoxypyridine-3-yl)-9-methylcarbazole-3-sulfonamide, a novel antimicrotubule agent, showed potent anticancer activity in a variety of human tumor cells in vitro and in vivo. In order to characterize the metabolism and the possible drug-drug interaction of IG-105, we carried out a series of experiments. Drug metabolizing enzymes involved in IG-105 metabolism were investigated by using pooled human liver microsomes (HLMs) and recombinant cytochrome P450 isoforms (rP450s) respectively. The possible metabolites were analyzed by liquid chromatography-orbitrap-mass spectrometry (LC-Orbitrap-MS). The inhibitory effect of IG-105 on main P450 enzymes was also evaluated. The results showed that IG-105 can be metabolized by a series of rP450s, including CYP1A2, CYP2B6, CYP2C9, CYP2C19, CYP2D6, CYP3A4 and CYP3A5, with the major contribution enzymes being CYP1A2, CYP2B6, CYP2C19, and CYP3A. Three metabolites (M1-M3) were identified and demethylation was the major phase I metabolic reaction for IG-105. IG-105 moderately inhibited CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A enzyme activities with IC50 values of 6.42, 23.64, 0.39, 1.4, and 3.14 μmol·L-1, respectively. Since the biotransformation of IG-105 involves multiple enzymatic pathways, the compound is less likely to be a victim of a concomitantly used medicine which inhibits activity of one of the CYPs. However, as IG-105 showed medium to strong inhibition on CYP1A2, CYP2D6, CYP3A, and CYP2C19, caution is particularly needed when IG-105 is co-administrated with other anticancer drugs which are mainly metabolized by the above enzymes.
Cathepsin K (CTSK) is considered a critical pharmaceutical target in the treatment of osteoporosis. CTSK exerts proteolytic activities against regulatory proteins besides its collagenase function, which may account for some of the adverse reactions when blocked by active site-directed inhibitors. Exosite inhibitors that can discriminate between the therapeutic collagenase and other biological activities of CTSK specifically inhibit the collagenase activity of CTSK without interfering with the other proteolytic activities of the protease. Active recombinant CTSK was expressed in Pichia pastoris, and purified by n-butyl sepharose and SP sepharose column chromatography. Herba Ecliptae is a common traditional Chinese medicine in the treatment of bone diseases. Collagenase assay and benzyloxycarbonyl-Phe-Arg-7-amido-4-methylcoumarin (Z-FR-MCA) substrate assay based on CTSK are applied to verify the exosite inhibitors. n-Butanol extract of Herba Ecliptae are the most active fraction and eclalbasaponin Ⅸ isolated from n-butanol fraction is the potential exosite inhibitor of CTSK.
The radiation is regarded as the fourth biggest pollution following the water, air and noise pollution, which generates a broad impact on human physiology and healthy. The radiation mainly comes from medical rays, industrial rays, nuclear wastes and atmospheric ultraviolet rays. The universality makes people pay more and more attention to the damage effect and mechanism of radiation. The radiation is divided into ionizing and non-ionizing radiation. It is a good idea to study the effect of ionizing and non-ionizing radiation on drug's metabolism, which may give a guidance to clinical medication to avoid adverse reactions and to support personalized medicine. This article reviews the effect of ionizing radiation (γ-rays, X-rays, uranium and cesium) and non-ionizing radiation (ultraviolet rays) on drug metabolism, their impact on metabolic characteristics of some drugs and the impact on expression of enzymes and transporters in drug metabolism, which is conducted with a focus on clinical significance.
Mitochondrion is an important organelle in cells and plays a crucial role in tumor development. Therefore, improvement of the targeting ability of anticancer drugs to mitochondria will increase the treatment efficacy for tumor and reduce the side effect on normal tissues. Here, research progresses in mitochondrial targeting have been reviewed in three aspects for tumors treatment: the potential, permeability and translocase of mitochondrial membrane. The review provides a reference for the development of mitochondria targeted therapeutic systems.
Scorpion toxin BmK AngM1 has been reported to have a strong analgesic effect. However, its anti-inflammatory activity was unknown. In this study, the recombinant BmK AngM1 (rBmK AngM1) was expressed in Escherichia coli BL21 trxB (DE3). The purified rBmK AngM1 was obtained efficiently through the IMPACTTM-TWIN system. The anti-inflammatory activity of the recombinant protein was investigated. In order to improve the anti-inflammatory activity of rBmK AngM1, the potential active sites (Y5, Y42, R58) were substituted with different amino acids. The results showed that rBmK AngM1 and its mutants all have significant anti-inflammatory activity. The activities were significantly increased in the single mutant R58N and mutants Y5F/R58N, Y42F/R58N over the wild type protein. The data suggest that position 58 in BmK AngM1 plays a functional role in the anti-inflammatory activity. This study lays a foundation for the protein engineering design of BmK AngM1 to improve its pharmacological activity.
A method of ultra flow liquid chromatography-tandem mass spectrometry (UFLC-MS/MS) was developed to elucidate the impurity of linezolid tablets. Linezolid was subjected to forced degradation under hydrolytic (acid, base and neutral), oxidative, photolytic and thermal. The structure identification of the degradation products and the fragmentation patterns for the related impurities were analyzed. A total of four degradation impurities were characterized, impurity 1 is (S)-1-amino-3-((3-fluoro-4-morpholinophenyl)amino)propan-2-ol, impurity 2 is (S)-4-(4-(5-(acetamidomethyl)-2-oxo-oxazolidin-3-yl)-2-fluorophenyl)morpholine 4-oxide, impurity 3 is (S)-5-(aminomethyl)-3-(3-fluoro-4-morpholinophenyl)oxazolidin-2-one, impurity 4 is (R)-N-(3-((3-fluoro-4-morpholinophenyl)amino)-2-hydroxypropyl)acetamide. Acid degradation induced impurity 3 and impurity 4, base degradation induced impurity 1 and impurity 4, oxidation degradation induced impurity 2, hydrolysis degradation induced impurity 4. The study also determined calibration factor using impurity references, and the calibration factors were found to be 1.3, 1.4, 0.9 and 1.1, respectively. The toxicity of the degradation impurities was predicted by web-based prediction system. The results from this study provide an important reference in quality control and evaluation of linezolid.
This study was designed to establish a multiplex allele-specific polymerase chain reaction method for simultaneous identification of Dendrobium huoshanense, D. officinale and D. devonianum, which may resolve identification problems of caulis dendrobii. Internal transcribed spacer sequences and trnL-trnF sequences of the Dendrobium species were aligned by BioEdit software, then specific SNPs of the three species were analyzed for designing allele-specific primers and the multiplex allele-specific PCR reaction system was established. The different origin of Dendrobium huoshanense, D. officinale and D. devonianum was amplified and identified by the sizes of respective band. The results showed that 584 bp, 397 bp and 211 bp bands could be amplified by D. devonianum, Dendrobium officinale and Dendrobium huoshanense respectively, when the annealing temperature was 61 ℃ and the number of cycles was 35. The limit of detection (LOD) of D. devonianum and D. huoshanense were both 1.2 ng, while D. officinale was low than 0.24 ng. The detection limit of adulterates in D. devonianum, D. devonianum and D. huoshanense mixture sample was 1%, 1% and 5% respectively. This result suggests that the method of multiplex allele-specific PCR is useful to identify D. huoshanense, D. officinale and D. devonianum is accurate and specific.