Latest ArticlesAlzheimer's disease (AD) is characterized clinically as irreversible cognitive dysfunction. Although a significant progress has been made in the study of AD pathogenesis, the effective measures to block AD progress have not been satisfactory. Abnormal autophagy is thought to be involved in the pathogenesis of AD, and regulation of autophagy may become a new strategy for AD treatment. Some medicines, which regulate autophagy by mTOR-dependent and independent (Bcl-2/Beclin-1, GSK-3β, and p-AKT) pathways, have shown excellent effects in alleviating AD symptoms. In addition, certain compounds extracted from plants have also been reported to regulate autophagy and prevent AD progression through multiple pathways and multiple targets. This article reviews the recent advances in the regulation of autophagy and AD treatment. It provides a new theoretical basis for clinical treatment of AD.
Plant-derived triterpenoids constitute a large and structurally diverse class of natural products with various implications in industrial and pharmaceutical uses. The oleanane type triterpenoids are widely known for their pharmacological and/or biological activities. The biosynthesis pathway of oleanane triterpenoids is divided into three stages:precursor supply, skeleton synthesis, and terpenoids synthesis. Plant cytochrome P450 monooxygenases enzymes (P450s) are involved in the synthesis and diversification of natural products, and are responsible for other modifications of terpenoids, such as formation of triterpenoids. P450s-catalyzed structural modification prior to glycosylation is crucial for diversification and functionalization of triterpenoid scaffolds. In this paper, the catalyses of P450s on β-amyrin and oleanolic acid in oleanane type triterpenoid saponins biosynthesis were reviewed. Presenegenin is a major aglycon of Polygala saponins. The CYP716A249 in Polygala tenuifolia was used as an example to other P450s participating in the possible biosynthetic pathways of presenegenin. These results provide references for elucidation of the biosynthesis pathways of plant-derived oleanane type triterpenoids.
This study aimed to construct an intelligent fluorescent nanocarrier for tumor cell tracing. Doxorubicin (DOX) was used as a model drug, and the gene targeting siBcl-2 was loaded to achieve synergistic inhibition of tumor cells. Mesoporous silicon nanoparticles (MSN) were prepared by a sol-gel method, and acetaldehyde cystine (AC) and polyethyleneimine (PEI) were covalently modified. The prepared nanocarrier MSN-AC-PEI was uniformly dispersed, with a particle size of 235.53 nm and a potential of 14.63 mV. The carrier material MSN-AC-PEI could load siRNA with the mass ratio of 60:1 (Wvectors:WsiRNA) and protect siRNA from RNase I degradation. To simulate the microenvironment of tumor, DOX release in phosphate buffer (pH 5) including 10 mmol·L-1 glutathione (GSH) was investigated. The cumulative release rate of DOX at 120 h is 35 times that of the normal physiological environment, which lays the foundation for the intelligent release of DOX in tumor cells. The results of cell experiments showed that the carrier material MSN-AC-PEI had significant green fluorescence, and the traceability can be maintained for 24 h after taken up by MCF-7 cells. After 24 hours of administration of the nano drug delivery system MSN-AC-PEI@DOX/siBcl-2, the inhibition rate of tumor cell proliferation reached 40.91%, and the late apoptosis rate was 60.84%. The Western blot results showed that compared with free DOX and siBcl-2, the nano-delivery system MSN-AC-PEI@DOX/siBcl-2 can significantly reduce the expression of anti-apoptotic protein Bcl-2, thereby enhancing its anti-tumor ability.
The incidence of thrombotic diseases has increased in the past decade, a factor endangering human health. Currently, antithrombotic drugs used in the clinic have side effects such as inducing bleeding. Data from clinical observation indicate that congenital deficiency of factor XI (FXI) gene decreases the incidence of stroke and deep venous thrombosis, without causing spontaneous bleeding. This unique property of FXI makes it a potential new target for antithrombotic drugs development. Many studies have focused on the discovery of novel inhibitors targeting FXI. This review summarizes the research progress in searching for the inhibitors against FXI.
This study aimed to evaluate the effects of Jiawei Foshou San capsule (JWFSSC) on CYP1A2, CYP2C6, CYP2D2, CYP2E1 and CYP3A1/2 enzyme activities in rat liver microsomes in vitro and in vivo, and to provide pharmacokinetic data for its combined use with other medicines. After incubating liver microsomes with a cocktail of probe drugs, the metabolites were quantitated with LC-MS/MS to assess the CYP enzyme activity. The hepatic pathological changes were evaluated by histology after hematoxylin and eosin (HE) staining. With the dose range up to 3 200 mg·L-1, the IC50 of JWFSSC for CYP2D2, CYP2E1 and CYP3A1/2 in vitro was 229.3 mg·L-1, 361.9 mg·L-1 and 274.6 mg·L-1 respectively. Compared with the vehicle control group, the enzyme activities of CYP1A2, CYP2C6 and CYP3A1/2 showed a significant increase in animals given JWFSSC 180 mg·kg-1·d-1 (P < 0.01). Based on histology, several pathological changes were observed in JWFSSC groups:there was less inflammatory infiltration compared to the tetrahydropalmatine (THP) group. These results of inhibition in vitro and induction in vivo suggest a strengthened efficacy and a prolonged effective time of drugs metabolized by CYP2D2 and CYP2E1 enzymes when combined with JWFSSC in use. The dosage of parent drugs should be appropriately reduced when used in combination with JWFSSC. However, if a drug is metabolized by CYP1A2 and CYP2C6 when used in combination with JWFSSC, the effect of the drug is likely reduced and the dosage should be increased appropriately. In addition, the combination of ferulic acid (FA), ligustrazine (LZ) and THP can significantly reduce the toxicity of THP in rat livers. In this study, the program of animal testing had been approved by Committee on the management and usage of experimental animal in the College of Pharmaceutical Sciences, Southwest University.
The drug delivery system with "gatekeeper" is designed to achieve a stable entrapment state of the payload under normal physiological conditions through the gatekeepers. With tumor microenvironment or stimulation of exogenous factors, the gatekeeper is detached or altered to promote the responsive release of the drug. In this paper, we focus on applications of stimuli-responsive linkages and stimuli-responsive groups, and review research progresses of drug delivery system with "gatekeeper" developed over the past 10 years.
Phosphoglycerate kinase 1 (PGK1) is a key metabolic enzyme in the glycolysis pathway, which catalyzes the transfer of 1, 3-bisphosphoglycerate (1, 3-BPG) to 3-phosphoglycerate (3-PG) with ATP production. Over-expression of PGK1 has been observed in many types of malignance. Besides as a metabolic enzyme, PGK1 can also act as a protein kinase, which promotes the development and progression of tumors and correlates with chemoradiotherapy resistance and poor survival of cancer patients by regulating tumor cell metabolism. Functions of PGK1 were summarized in this article to provide theoretical basis for PGK1-targeting drug development.
Mutation and amplification of epidermal growth factor receptor (EGFR), one of the most important driver gene, are both reported to participate in the regulation of lung cancer development and progression. Here we investigated the effect and molecular mechanism of tripartite motif 25 (TRIM25) in the regulation of development of lung cancer. CCK-8 and Transwell assays were used to explore the tumor-promoting effect of TRIM25. Results showed that knockdown of TRIM25 significantly inhibited cell proliferation (34% inhibition rate) and invasion (42% inhibition rate). Gene set enrichment analysis (GSEA), Western blot and immunohistochemistry were adopted to detect the effect of TRIM25 on EGFR expression and its downstream signal activity. The results explained that TRIM25 not only up-regulated the expression level of EGFR, but also promoted EGFR signal activation. Co-immunoprecipitation, real-time PCR and cycloheximide (CHX) inhibit protein degradation assays were employed to explore the molecular mechanism of TRIM25 in regulating EGFR stability. Preliminary exploration results indicate that TRIM25 increases the expression level of EGFR and activates its downstream signaling activity through promoting K63-linked ubiquitination of EGFR. Restoration of EGFR expression rescues the phenotype of TRIM25 depletion. In A549 cells, overexpression of EGFR increased cell proliferation rate 1.5-fold and invasion rate 1.6-fold compared with knockdown of TRIM25 cells. Similarly, in H1975 cells, cell proliferation rate was enhanced 2-fold and invasion rate was improved 1.7-fold. These data suggest that TRIM25 promotes lung cancer development via maintaining EGFR stability and continuous EGFR signaling activation. The human lung cancer tissues were obtained from lung cancer patients at Cancer Hospital Chinese Academy of Medical Sciences. Informed consent was obtained from all participants in accordance with the Declaration of Helsinki. The study was approved by the Ethics Committee of the Cancer Hospital Chinese Academy of Medical Sciences.
CAT3 is a promising anti-brain tumor agent that has significant anti-tumor activity on Daoy or U87MG orthotopic xenograft in nude mice. This study was carried out to investigate the metabolic profiles of CAT3 in mouse/dog/human blood and microsome as well as in humanized recombinant enzymes. All animal care and experimental procedures were reviewed and approved by the Animal Ethics Committee of Chinese Academy of Medical Sciences. Our findings showed that CAT3 could be hydrolyzed to active metabolite PF403 by carboxylesterase, butyrylcholinesterase and serine hydrolase in mouse/dog/human blood. PF403 could be further metabolized to M1 oxidative dehydration product, M2 double oxidation dehydration product, M3 methylation oxidative dehydration product, M4 oxidation product and M5 demethylation product, which were mainly catalyzed by CYP1A2, 1A1, 2C9 and 3A4, and slightly by CYP2B6, 2C8, 2C19 and 2D6. Besides oxidative metabolism, PF403 also was transformed into glucuronylation metabolites GLU-PF403 by Phase Ⅱ enzymes UGT1A1, 1A3 and 1A9. Taken together, the metabolism of CAT3 was a multiple enzyme catalytic reaction. These results could provide valuable information for potential enzyme-mediated DDI in clinic studies.
Five alkaloids were isolated from a decoction of Uncaria rhynchophylla by a combination of various chromatographic techniques, including macroporous adsorbent resin, MCI resin, silica gel, Sephadex LH-20, and reversed phase HPLC. Their structures were characterized by comprehensive analyses of spectroscopic data as monoterpene indole alkaloids (+)-(7R)-3-oxo-7-hydroxy-3, 7-seco-dihydrorhynchohylline (1), (+)-(7S)-3-oxo-7-hydroxy-3, 7-seco-dihydrorhyncho-hylline (2), (+)-(7R)-3-oxo-7-hydroxy-3, 7-seco-rhynchohylline (3) and (+)-(7S)-3-oxo-7-hydroxy-3, 7-seco-rhynchohylline (4), and a β-carboline alkaloid 1, 2, 3, 4-tetrahydro-1-oxo-β-carboline (5). Among them, 1 and 2 are new compounds, 3 and 4 are new natural products that were semi-synthesized from isorhynchohylline with incorrect specific rotations, and 5 is isolated for the first time from the genus Uncaria.