Latest ArticlesThe antioxidant activities of Vleriana jatamansi Jones were investigated and the relationship between the antioxidant effect and the chemical structure was explored. The free radical scavenging test, 2, 2-diphenyl-1-picrylhydrazyl (DPPH•), was used to evaluate the antioxidant activities of the extracts of Vleriana jatamansi Jones with 0−100% menthol as extraction solvents. The polar and nonpolar HPLC conditions were conducted to isolate the main chemical compositions. The DPPH• tests were used in analysis of the free radical scavenging activities. Under polar HPLC separation conditions, 5 kinds of compounds were detected:chlorogenic acid, 3, 5-dicaffeoylquinic acid, 4, 5-dicaffeoylquinic acid, hesperidin, and coffeic acid; under nonpolar HPLC separation conditions, acevaltrate, 1β-acevaltrate and valtrate were founded. Chlorogenic acid, 3, 5-dicaffeoylquinic acid, and 4, 5-dicaffeoylquinic acid presented high DPPH• free radical scavenging activities. The results of antioxidant activity suggested that the coffee acyl from chlorogenic acid-like compounds had a high DPPH• free radical scavenging ability. Our investigation indicated that structure of the ortho hydroxyl phenol of chlorogenic acid-like compounds play a significant role in antioxidant activities. In addition, this work can also provide method and theory reference for improving the antioxidant activities of Vleriana jatamansi Jones.
The flower bud of Tussilago farfara L. has been commonly used in the treatment of cough, bronchitis and asthmatic disorders in the Traditional Chinese Medicine. In Europe, the leaves were also used as herbal drugs with similar pharmacological activities. In order to utilize the leaves, it is important to conduct the chemical comparison between the flower buds and the leaves. In this study, ultra high liquid chromatography (UHPLC) coupled with Q Exactive high resolution mass spectrometry (HR-MS) was used to compare the chemical composition of the flower buds and leaves of T. farfara L. forty three metabolites were identified by the combination of targeted and untargeted approach. The results suggest that the sesquiterpenes, such as tussilagone and 7β-(3'-ethyl-cis-crotonoyloxy)-1α-(2'-methylbutyryloxy)-3(14)-dehydro-Z-notonipetranone were higher in the flower buds. While the phenylpropanoids, such as cholorgenic acid and isochlorogenic acid were higher in the leaves. The flavonoids, such as hyperin and quercetin exhibited no difference between the flower buds and leaves, while the rutin and kaempferol were higher in the flower buds. The leaves and flower buds had similar chemical components, and the phenylpropanoids, which were closely related with the antitussive and expectorant activities, were found at higher concentrations in the leaves. The results presented here laid the basis for the rational utilization of the leaves of T. farfara L.
Gambogic acid (GA), the main active ingredient in gamboge, has been reported to have good anti-tumor activity with excellent selectivity.However, its clinical application is limited by the poor water solubility.GA nanosuspensions were designed in this study in order to solve this problem.GA nanosuspensions were prepared by microprecipitation method based on pH adjustment.Suitable stabilizer was screened according to the size and polydispersity index (PDI) of the resultant nanosuspensions.Dynamic light scattering method was used to measure the particle size and transmission electron microscopy was used to observe the morphology.The stability was studied in different medium.The drug release was evaluated using a dialysis method.MTT assay was used to assess their cytotoxicity in vitro against cancer cell line.Anti-tumor effect in vivo was investigated on H22-bearing mice.In result, Poloxamer (P188) was found to be a good stabilizer.The resultant GA nanosuspensions (GA-NSps) were 135.9 ±5.1 nm in diameter, with PDI value being 0.26 ±0.01 and the zeta potential being -35.1 ±1.36) mV.GA-NSps were nearly spherical.They were quite stable in various physiological media.GA-NSps exhibited a sustained drug release pattern, with the cumulative release reaching 90.26% within 312 h.In MTT assay, GA-NSps had a stronger cytotoxicity against HepG2 cells than the free drug (IC50, 0.851 8 μg·mL-1 vs 2.104 μg·mL-1, P < 0.05).The pharmacodynamics study suggest that the antitumor effect of GA-NSps was dose-dependent.The anti-tumor effect at the high dose is better than that of paclitaxel (72.35% vs 66.80%, P < 0.01).In summary, we prepared GA-NSps with high drug loading capacity, small particle size and good stability, and provided a solid basis for the effective dosage form of gambogic acid.
The purpose of this study was to prepare T7 peptide modified vincristine loaded low density lipoprotein (T7-LDL-VCR) nanoparticles to penetrate through blood brain barrier for targeting the brain tumor cells.Firstly, the low density lipoprotein (LDL) nanoparticles were extracted and separated from human serum by density gradient centrifugation method, and then was loaded into the nanoparticle's lipid core by the dry film method, T7 peptide was covalent modified on the surface of the nanoparticles.T7-LDL-VCR was characterized by particle size, entrapment efficiency and peptide attachment efficiency.The fluorescent probe DiR was used to track the brain biodistribution of T7-LDL-VCR in mice bearing intracranial C6 glioma by means of in vivo imaging.The therapeutic effect of nanoparticles was observed with magnetic resonance imaging (MRI).Finally, relative tumor volume and survival curve were determined in mice.The results showed that the mean size of the prepared T7-LDL-VCR nanoparticle was about 30 nm, encapsulation efficiency was 30.1%, and peptide attachment efficiency was 63.88%.As expected, the prepared preparation has good brain targeting and good effect on the treatment of glioma in mice:the relative tumor volumes of T7-VCR-LDL, LDL-VCR and VCR were 30%, 51.50% and 79.25%, respectively; the median survival time (36 days), which was 2, 1.85 and 1.38 fold higher than that of physiological saline, free VCR and LDL-VCR, respectively.This study suggests that dual modified hposomes possessed a better ability penetrating the blood brain barrier to target the brain tumor with significant antitumor activities.
Allene oxide cyclase (AOC), a key enzyme in biosynthesis of jasmonic acid, plays an essential role in the plant defense system.In present study, a full length cDNA of AsAOC gene was cloned by the reverse transcription PCR from Aquilaria sinensis calli.Meanwhile, the bioinformatics, prokaryotic expression, purification, tissue-specific expression analysis, and expression analysis under different abiotic stresses and hormone treatments were performed.The open reading frame (ORF) of AsAOC1 gene was 753 bp, encoding a protein of 251 amino acids with a calculated molecular mass (MW) of 27.46 kD.Bioinformatic analysis showed that AsAOC1 protein contains a conserved allene_ox_cyc domain in C-terminus.The phylogenetic analysis indicated that AsAOC1 protein had the highest level of homology with the AOC protein from Morus notabilis.The recombinant AsAOC1 protein was successfully expressed in Escherichia coli BL21(DE3) cells using the prokaryotic expression vector pET28a-AsAOC1 and was purified by Ni2+ affinity chromatography.Expression analysis in different tissues indicated that AsAOC1 was primarily observed in stems, and then stem tips and roots, following by leaves.The transcript level of AsAOC1 was induced by various abiotic stresses including salt, drought, cold, and heavy metal stress.Furthermore, AsAOC1 expression level was enhanced upon methyl jasmonate (MeJA), salicylic acid (SA), gibberellin (GA3), and abscisic acid (ABA) treatments.These results provide valuable insights into the role of JA in the mechanism of agarwood formation and plant defense system.
Berberine is an original antibacterial drug in China, and is widely used for its diverse biological functions. It is first used in clinic to treat intestinal bacterial infections. Berberine has different inhibitory effects on various microorganisms, but the effect is very weak with the minimum inhibitory concentration over 64 μg·mL-1 in most of the study bacteria. The effect is better for Bacillus dysteriae, which is one aspect of its selectivity. At the same time, because of the poor absorption of berberine in oral administration, it is retained in the intestine to reach a high concentration, which provides a basis for tissue selectivity in the treatment of intestinal bacterial infections. In this paper, we reviewed the antibacterial action, mechanism, clinical application of berberine, in order to provide a clue for the future direction of berberine research.
Ubiquitination and deubiquitination play important roles in the regulation of protein stability and function. Deubiquitinating enzymes (DUBs) are involved in the regulation of survival, migration and proliferation of cancer cells, by participating in a variety of signaling pathways. Most of the DUBs promote the malignant transformation and progression, while the others may function as tumor-suppressors. Given the central roles of DUBs in tumorigenesis and malignant progression, some of these enzymes have been regarded as promising anti-cancer targets. This paper reviews the recent advances in tumor-related DUBs and inhibitors.
Human carboxylesterase (CES) and arylacetamide deacetylase (AADAC) are important numbers of the serine esterase superfamily. They are involved in hydrolytic procedure of human endogenous cholesteryl esters, as well as drug metabolism, activation and detoxication. They are closely related to the personalized medication of drugs, especially for prodrugs. This review summarizes their structure and distribution, metabolic characteristics and research progress in recent years, which will provide a reference for new drug development and rational drug design.
Carboxylesterases (CESs) belong to the esterase family, which are mainly responsible for catalyzing metabolism of a variety of drug as well as endogenous and exogenous compounds. CESs are widely distributed in the body, mainly expressed in lung, liver, intestine, kidney, skin epithelial cells, etc. There are significant species differences in the expression of CESs, which results in the difference on the drug metabolism with genetic polymorphism. In this paper, an overview of the classification and distribution, physiological function and mechanism, species differences and gene polymorphism of CESs are provided for the research of CESs and drug design.
Plasma stability plays an important role in the druggability of lead compound. Improving the plasma stability of compounds by structural modification can lead to good pharmacokinetic and pharmacodynamics properties. This review provides a summary of varieties of structure modification strategies for improving plasma stability including bioisosterism, increasing steric hindrance, ring closure, scaffold hopping and etc.
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