ArchiveThis paper summarizes research progresses of Chinese scholars in the field of drug metabolism and pharmacokinetics (DMPK) in 2018. Chinese scholars focused on drug metabolizing enzymes and transporters, and carried out studies on the mechanisms of drug metabolism and transport of active molecules. Topics of research included regulatory mechanisms of drug metabolizing enzymes or transporters, and their implications in drug development and disease etiology or progression. Here, we summarized studies on drug toxicity based on drug metabolism or transport, rational drug use in the clinic, drug metabolism mediated by intestinal flora, metabolism of traditional Chinese medicines, and new technologies or models in DMPK. In recent years, the research focus of drug metabolism in China has transformed from serving for new drug discovery and rational use, to innovation driven and mechanism oriented research. The domestic research topics and technology utilization are gradually aligning with the international conventions.
Myeloproliferative neoplasms (MPNs) result from clonal expansion of haematopoietic stem cells and are characterized by abnormal proliferation of myeloid lineage cells in the bone marrow. Sustained activation of JAK-STAT signaling pathway due to JAK2 phosphorylation is an important cause of MPNs, and mutation of JAK2 kinase can keep it in a state of continuous phosphorylation. The most typical mutation in JAK2 is a site mutation of V617F in the pseudokinase domain. The JAK2V617F-activating mutation is highly prevalent in MPNs, with frequencies estimated at approximately 95% in polycythaemia vera (PV) and 50% in primary myelofibrosis (PMF) and essential thrombocytosis (ET) patients. It is now clear that JAK2 is an important target for treatment of MPNs. Inhibiting aberrant activation of the JAK2-STAT signaling pathway has become a popular trend in research for effective treatment of MPNs. This review summarizes the research progress in developing JAK2 inhibitors for treatment of MPNs in recent years, including the new discoveries of the biological functions of JAK2, the relationship between JAK2 and MPN, and the status of development of JAK2 small molecule inhibitors.
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.
Alzheimer'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.
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.
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.
Exosomes are membranous vesicles that are actively secreted by cells. They can be isolated from various cell culture media and animal body fluids. Exosomes are mainly composed of lipids, proteins and nucleic acids. They have small molecular structure and high biocompatibility with size of 40-100 nm. In addition, exosomes are natural endogenous nanocarriers that can transport lipids, proteins, DNA and RNA. Studies have shown that exosomes play an important role in long-distance communication between cells, in physiological and pathological processes. This article introduces the composition and physiological functions of exosomes, and summarizes the relevant content of exosomes as drug delivery vehicles. The applications of exosomes in central nervous system diseases, especially brain diseases and tumors are summarized.
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.
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.
The rat models of focal cerebral ischemic reperfusion and subarachnoid hemorrhage were used to evaluate the therapeutic effects of artificial musk to provide support for its clinical application. All animal experiments were performed following the regulations of the Animal Ethics Committee of Peking Union Medical College. The results showed that oral administration of artificial musk had significant protective effects on acute ischemic and hemorrhagic stroke. In the dose range of 10-200 mg·kg-1, the mortality, neurobehavioral and cerebral infarction volume of rats in model group indicated a clear dose dependent relationship. The effective dose of artificial musk is 10 mg·kg-1 in ischemic stroke and 200 mg·kg-1 in hemorrhagic stroke. These findings suggest that the treatments of artificial musk in ischemic stroke and in hemorrhagic stroke are different, and such differences should be noted for its clinical use.
To investigate the effects of small molecule compound bicyclol on type 2 diabetes mellitus (T2DM) and its mechanism of action, KKAy mice were treated with various doses of bicyclol (100, 200, and 400 mg·kg-1·d-1) with metformin (200 mg·kg-1·d-1) as a positive control, respectively. Age-matched C57BL/6J mice were used as the non-diabetic control (Con). The effect on hyperglycemia was evaluated by the levels of no-fasting blood glucose, fasting blood glucose (FPG), and glucose tolerance. Whole body insulin sensitivity was evaluated by fasting plasma insulin (FPI) and homeostasis model assessment-insulin resistance (HOMA-IR). The hepatic response to insulin was evaluated by insulin-induced activation of insulin signaling pathway. Western blot was performed to detect hepatic protein expressions. All animal experimental procedures were approved by the Animal Ethics Committee of Chinese Academy of Medical Sciences. KKAy mice showed T2DM characteristics such as hyperglycemia and insulin resistance, including attenuated response to insulin in the liver. A 28-day treatment of bicyclol suppressed both FPG and no-fasting blood glucose, in a dose-and time-dependent manner. Moreover, FPI and HOMA-IR values were both significantly decreased, and hepatic insulin-induced-phosphorylation of IRβ and Akt were up-regulated in KKAy mice after bicyclol treatment. Phosphorylation of FoxO1, the key transcription factor for regulating gluconeogenesis, was also significantly elevated by bicyclol treatment. These results suggested that bicyclol has some therapeutic effects on hyperglycemia in a time-and dose-dependent manner in KKAy mice. Its mechanism might be attributed to improving insulin resistance, enhancing hepatic insulin signaling pathway, and inhibiting gluconeogenesis. No significant interference on the hypoglycemic effect of metformin by bicyclol was observed in this study.
This study was designed to investigate the effect on tumor growth inhibition activity of lizards (Gekkoswinhonis Guenther) with different extent of broiling. Samples were prepared by a traditional drying method combined with broiling on clay tiles. Four groups of samples were all dried before broiling. Group A was without broiling; group B was mildly broiled; group C was moderately broiled; and group D was heavily broiled. Crispiness was detected by the sizes of the generated fragments of different groups and crispiness increased with broiling. Sensory evaluation of vision and olfaction was performed, and scores were generated by evaluators. Moderately broiled group had the highest total score in sensory evaluation. Water content and content of water-soluble extracts were detected according to Chinese Pharmacopoeia. With the increasing broiling extent, content of water-soluble extracts increased while water content decreased. Soluble protein concentration was detected by bicinchoninic acid (BCA) kit and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) with the same crude drug content. Soluble protein concentration decreased with the increasing broiling extent. With equal loading of proteins at the same concentration, soluble protein diversity was detected by SDS-PAGE. Band difference was marked by red boxes. Soluble protein molecule weights showed significant difference with the increasing broiling extent. H22 tumor-bearing mice model was established and used to detect tumor growth inhibition rate and immune organ index. Life quality of mice was evaluated. Mice treated with Gekkoswinhonis Guenther had better appetites and higher average weights compared with positive control group treated with fluorouracil (5-FU). Animal experiments were approved by the Ethics Committee of Beijing University of Chinese Medicine. Group A had the highest tumor growth inhibition rate (34.11%), followed by Group B (29.14%) and Group D (28.43%), Group C (21.98%) had the lowest tumor growth inhibition rate, but sensory evaluation was on the contrary. These results indicated that moderately broiling improved sensory evaluation but reduced the tumor growth inhibition activity of Gekkoswinhonis Guenther. The best tumor growth inhibition activity appeared when water content was 7.71%.
Wu-tou decoction (WTD) was originally recorded in the synopsis of the golden chamber and it had been widely used for the treatment of neuropathic pain (NP) with exact therapeutic efficacy. However, the underlying molecular mechanisms still remain unclarified. Thus, in this research, we aimed at clarifying the underlying molecular mechanisms of WTD against NP by combining network analysis and experimental validation based on the spinal nerve ligation (SNL) model. Firstly, the network analysis indicated that key targets of WTD were significantly involved in the MAPK signaling pathway (P=4.04E-12) and four important components of the above pathway, AKT kinase (AKT), MAP kinase kinase 4 (MKK4), c-Jun N-terminal kinase (JNK) and transcription factor AP-1 (JUN) had been reported to play a vital role in neuroinflammation during the disease process of NP. Then, experimental validation results proved that WTD markedly reduce the severity of mechanical allodynia (P < 0.01) and cold hypersensitivity (P < 0.05) of SNL rats. In addition, Western blot results provided evidence that the phosphorylated protein expression levels of AKT, MKK4, JNK and JUN in the superficial lamina of spinal cord of SNL rats were markedly increased (P < 0.001), and WTD could improve the phosphorylated protein expression level of AKT (P < 0.001) which was reported to be nerve protective and attenuate the phosphorylated protein expression levels of MKK4, JNK and JUN (P < 0.01) which were closely involved into neuroinflammation. In conclusion, this study indicated that WTD might exert anti-hyperalgesia action through the inhibition of neuroinflammation mediated by AKT-MKK4-JNK-JUN which belong to the MAPK signaling pathway. These findings also provided scientific evidences that WTD might be a promising candidate for NP. Animal experiments in this study were approved by the Ethics Committee of Experimental Animals of the China Academy of Chinese Medical Sciences.
Cyclophosphamide (CPA) is one of the most commonly used alkylating agents in the treatment of malignant cancer. CPA is metabolized by cytochrome P450 enzymes into 4-hydroxycyclophosphamide in vivo which can exhibit anti-tumor activity. Metabolic activation of CPA can cause adverse reactions such as myelosuppression, cystitis, and liver injury. The aim of this study was to evaluate the dynamic changes of hepatic injury induced by CPA in mice. Male BALB/c mice were injected CPA (200 mg·kg-1) intraperitoneally. Both serum and liver samples were collected at 0, 2, 6, 12 and 24 hours after dosing. The animal experiment protocol was approved by the Institutional Animal Care and Use Committee at Sun Yat-sen University. The results showed that hepatotoxicity was observed at 2 hours after CPA dosing, and the most serious liver injury was measured at 12 hours. The level of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and malondialdehyde (MDA) was significantly increased, glutathione (GSH) level was significantly decreased, hepatocyte edema and vacuolar degeneration were widely observed in liver tissue, and began to recover 24 hours after dosing. In addition, due to oxidative stress damage caused by CPA, nuclear factor-erythroid 2-related factor 2 (NRF2) signaling pathway was activated and the mRNA and protein expression of its downstream targets such as quinine oxidoreductase 1 (NQO1), heme oxygenase-1 (HO-1), glutamate-cysteine ligase catalytic subunit (GCLC) and glutamate cysteine modifier subunit (GCLM) were up-regulated, which alleviated oxidative stress injury. In a summary, this study demonstrate the dynamic change of CPA-induced liver injury and the NRF2-mediated protective mechanisms, providing new insights into the CPA-induced liver injury.
Urate transporter 1 (URAT1) is a validated target for the treatment of hyperuricemia. Based on the structure of URC-102, which is currently under a phase Ⅱ clinical trial, fourteen novel analogs were designed and synthesized. Among them, four compounds (9b, 9c, 10e and 10g) exhibited substantial inhibitory effect against URAT1. The most active compound 9b showed an IC50 value of 0.061 μmol·L-1, which is significantly more potent than Lesinurad and Benzbromarone. Preliminary SAR was drawn, providing clues for further structural optimization.
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.
The grading and quality analysis methods for different commercial Glycyrrhiza Polygalae Radix slices were established. The qualities of different grade samples were analyzed and compared, in order to provide useful information for the formulation of the grading standards of Glycyrrhiza Polygalae Radix slices. A total of 34 batches of Glycyrrhiza Polygalae Radix slice samples collected from 12 companies were divided into two grades:first-grade (diameter ≥ 3.0 mm) and second-grade (diameter < 3.0 mm). Thin-layer chromatography (TLC), multi-component content determination and fingerprint analysis were used to analyze the qualities of different grades of Glycyrrhiza Polygalae Radix slices, and the fingerprints were statistically analyzed using partial least squares-discriminant analysis (PLS-DA) and orthogonal partial least squares-discriminant analysis (OPLS-DA). The results showed that the established TLC method can simultaneously identify three major types of components, including sugar esters, xanthones, and saponins in Glycyrrhiza Polygalae Radix slices, and has obvious advantage compared to the existing methods for its rich information, low cost, and easy or safe operation. The multi-component determination showed that the contents of three index components (polygalaxanthone Ⅲ, 3, 6'-disinapoyl sucrose and tenuifolin) in the first-grade products of Glycyrrhiza Polygalae Radix slices were lower than those in the second-grade products. The results of PLS-DA and OPLS-DA indicated significant differences were observed between the first-grade and second-grade products, with sibiricose A5, sibiricose A6, polygalaxanthone Ⅲ, 3, 6'-disinapoyl sucrose and tenuifoliside A being identifies as the major differentiate markers.
A method for determining dipropofol in the plasma of Beagle dogs was established by HPLC-MS/MS. We also studied the pharmacokinetic characteristics of two different forms of crystal tablets of dipropofol in Beagle dogs. All animal experiments were approved by the Animal Experimental Management, Welfare and Ethics Committee of Pharmacology Evaluation Research Center, Shanghai Institute of Pharmaceutical Industry. The results indicate that the maximum plasma concentration (Cmax) of dipropofol was 69.02 ±20.16 μg·L-1 after 20 mg·kg-1 crystal form Ⅰ tablet taken orally, and the AUC0-t was 160.49 ±55.26 μg·L-1·h. After 20 mg·kg-1 crystal form Ⅱ tablet taken, the Cmax of dipropofol was 92.58 ±60.26 μg·L-1, and the AUC0-t was 243.59 ±148.36 μg·L-1·h. The AUC0-t and Cmax of crystal form Ⅱ were significantly different from that of crystal form Ⅰ (P < 0.05). Crystal form Ⅱ was the dominant crystal form. The results suggest that we should control crystal form during the development of dipropofol oral tablets.
To provide a basis for the establishment of the commodity grade of Astragali Radix (AR), we compared the chemical components and the anti-fatigue effect of different grades of AR. The components of primary metabolites were analyzed by 1H NMR and the contents of five flavonoids were determined by HPLC-UV with different grades of AR. Fatigue efficacy of different grades of AR was compared. All the procedures were approved by the Laboratory Animal Ethics Committee of the Shanxi University. The results showed that the content of water soluble extracts (WSE) of the Grade Ⅱ AR was the lowest, and 21 compounds were identified through 1H NMR spectrum. There are 3 components showing a higher content in the Grade-top AR, and 7 components were higher in the Grade-Ⅳ, and 7 other components were higher in the Grade-Ⅱ AR. Total flavonoid content was the highest in Grade-Ⅱ but it was the lowest in the Grade-Ⅳ. Pharmacodynamic results showed that AR could significantly enhance the exhaustion time of rats and improve the biochemical indexes of serum and gastrocnemius muscle, and the best anti-fatigue effect was observed with Grade -Ⅱ AR. Therefore, chemical composition and efficacy index were used to evaluate the quality of different grades of AR, and the quality evaluation approach was established based on chemical and pharmacological effects to provide a scientific basis for the development of AR. The study may provide useful information for construction of the quality grade standard of AR.
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.
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.
In this paper, a new type of preparation for treatment of initial dry eye disease, thermosensitive in situ gel, was prepared using levocarnitine as a model drug. Poloxamer 407 and poloxamer 188 were used as the gel matrix, and sodium hyaluronate and sodium carboxymethylcellulose were used as bioadhesive materials. Gelation temperature was determined by a rotor method and the prescription was optimized by central composite design-response surface methodology. The pH value, viscosity value and gelation temperature of the optimal prescription were measured. The release of the drug in vitro was examined by dialysis membrane permeation, and retention time of the thermosensitive in situ gel preparation on the rabbit's ocular surface was observed by a slit lamp microscope. The results showed that the dosage of the poloxamer 407 and poloxamer 188 were 20.81% and 3.46%, respectively, and sodium hyaluronate was 0.02%, sodium carboxymethyl cellulose was 0.10% of the optimal formulation of levocarnitine thermosensitive in situ gel. The pH value was 6.90 ±0.06 at room temperature and the viscosity value started to rise sharply at 27℃ of the optimal formulation. The gelation temperature of the optimal preparation before and after dilution by simulated tear fluid were (26.37 ±0.06)℃ and (33.57 ±0.21)℃, respectively. In the first 240 min, in vitro release rate per unit area of levocarnitine thermosensitive in situ gel was lower than that of solution (P < 0.05), and after 600 min, the cumulative release rate of levocarnitine thermosensitive in situ gel could reach more than 80%. The retention time of the thermosensitive in situ gel preparation on rabbit's ocular surface reached about 25 min, at least 5 times as much as that of the solution. The animal experiment was conducted following the National Institutes of Health Guidelines for the use of experimental animals, and approved by the Ethics Committee of the Experimental Animal Center of Beijing University of Chinese Medicine. The levocarnitine thermosensitive in situ gel showed good characteristics and sustained release property and significantly improved the retention time of the drug on the rabbit's ocular surface.
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.
In this study, 13 xyloglucan endotransglycosylases/hydrolases (XTHs) and 8 expansin (EXPs) were screened from safflower floret transcriptome database. Through correlation analysis between the safflower gene expression profile chip and the corolla development, only 4 XTHs (CtXTH1-4) and 1 EXP (CtEXP1) have positive relevance with corolla elongation (r ≥ 0.60) and were therefore validated by qRT-PCR. The full length of these genes were cloned by RACE. According to the bioinformatic analysis, CtXTH1 correlated with the development of the floret, and the expression pattern analysis indicated that CtXTH1 had accumulated in the floret. The recombinant vector (pMT39-CtXTH1) was constructed for gene transformation. Overexpression of CtXTH1 significantly increased the corolla length (about 5.34% to 10.25%) and corolla weight (about 30.00% to 36.02%) in transgenic safflower. The overexpression lines also showed an increasing tendency in the weight of seeds, average number of corollas per cone and average number of seeds in each cone. Meanwhile, overexpression of CtXTH1 had no significant effect on flavonoids. According to the corolla microstructure, the OVX-line tubular part of floret exhibited a looser and irregular character. These data suggested that CtXTH1 can potentially increase relaxation of the tissues and boost corolla elongation. Our study provides a valuable clue for plant breeding in the future.