Latest ArticlesThe quality difference of pharmaceutical excipients from different sources affects the molding properties of the powder, resulting in changes in the properties of the final product. In this study, the critical quality attributes of hydroxypropyl methylcellulose (HPMC) with different specifications from two manufacturers (manufacturer A and manufacturer B) were characterized including particle size, physical morphology, viscosity and powder physical quality attributes. Aminophylline, diclofenac sodium, and metformin hydrochloride were utilized as model drugs with different solubility to prepare sustained-release tablets, and the effect of HPMC from different sources on drug release of sustained-release tablets in vitro was investigated. The results showed that HPMC with the same viscosity specification from different sources had outstanding differences in the physicochemical properties (including particle size, physical morphology, viscosity, dimension, compressibility and powder flow), which could change the hardness and friability of the sustained-release tablets. The differences in the physicochemical properties of HPMC had different effects on the dissolution of different sustained-release tablets in vitro. It had no significant effect on the release of easily soluble aminophylline and metformin hydrochloride, but had a greater impact on the release of poorly soluble diclofenac sodium. Compared with manufacturer A, the sustained-release effect of matrix tablets prepared by HPMC from manufacturer B was more excellent. The results of this study will provide a theoretical reference on selecting the appropriate excipients for formulation design.
In this study, nrDNA ITS sequences of Lycium cultivars were sequenced and used to test the existence of incomplete concerted evolution and pseudogenes. Together with 44 ITS sequences retrieved from GenBank, the pattern of base substitutions, GC content, 5.8S conserved motifs, the minimum free energy of secondary structures, nucleotide diversity and phylogenetic relationship of the samples were analyzed. While 83 of the 144 sequences were identified as pseudogenes, the results suggested a high degree of polymorphism and putative pseudogenes in Lycium, suggesting an incomplete concerted evolution of the ITS region. ITS polymorphism and pseudogene of Lycium were systematically tested for the first time. This research provides a references for ITS sequence to be used in the study of Lycium germplasm resources and DNA barcode identification.
Taking patient needs as the core and realizing clinical value as the guidance are the purpose and path of drug discovery. Whether the first-in-class drug or follow-on drugs are all to meet the demands of patients for drugs that are not treatable or more safe and effective. In order to realize clinical value, innovative drugs driven by basic biological research include three elements: understanding the molecular mechanism of pathogenesis; Grasping the microscopic features of the disease; clarifying the mechanism of action of drugs. The interrelation among the three is the translational medicine, and the medicinal chemistry plays an important role in the translations. That is, based on the results of basic research in biology/medicine, knowledge of the molecular mechanism of disease depends upon the establishment of various in vitro/in vivo models to find the key node and molecular regulation for the treatment of disease. Combined with the knowledge of gene deletion and variation, proteomics, epigenetics and other technologies, the molecular mechanism of disease provides multi-molecular information on the level of gene, proteins, enzymes, receptors, ion channels and signal transduction for molecular drug design. Insight into the microscopic characteristics of diseases would deepen the understanding of the molecular mechanism of the pathogenesis, as well as provide a feasible scientific path for the creation of new drugs. When the molecular mechanism of disease and the action mechanism of drugs are clarified, we have a deeper and wider understanding of the application of existing drugs (or active compounds), and may offer new ideas for drug design and application. In this translational process the medicinal chemistry plays a key role which requires medicinal chemists to break through the habitual thinking and working mode, backtracking (upstream) to basic research and its achievements and applying to the direction of creating new drugs in time, as well as paying attention to the clinical requirements (downstream) and implementing the specific content of the transformation process for the R&D of innovative drugs.
Cytochrome P450s (CYP450) is a superfamily of phase I metabolic enzymes, which participates in more than 90% of drug oxidation. The induction or inhibition of CYP450s is the main mechanism of drug-drug interaction. In recent years, in vitro metabolism studies conducted through isolated organs, cells, or enzyme systems have developed rapidly, due to their precision and simplicity. Therefore, profiles of the in vitro metabolism studies of traditional Chinese medicines can infer the possible metabolic pathways of drugs, predict the potential drug interactions, and may enhance the rational use of drugs in clinic. This article reviews the in vitro inhibitory effects of traditional Chinese medicine, ingredients, and extracts on the activities of CYP450 enzymes in the liver microsomes, which can provide a reference for further researches on the interaction between Chinese medicine and chemical medicine.
Hair roots induced by Agrobacterium rhizogene produce higher levels of secondary metabolites than non-induced plants, and the enhanced metabolic capacity is driven by the rol gene. We hypothesized that rol genes can be utilized to improve the biosynthesis of tropane alkaloids (TAs) in Atropa belladonna. In this study, the rolC gene from Agrobacterium rhizogene pRiA4 plasmid, driven by a CaMV35S promoter, was overexpressed in A. belladonna. The phenotypes, TAs content and transcriptional expression of key genes in TAs biosynthesis were analyzed in transgenic A. belladonna plants. Results show that transgenic A. belladonna exhibited a well-developed root system, male sterility, higher stamen column length than pistil, early flowering, internode shortening, smaller but more flowers, increased axillary buds and lateral buds, decreased apical dominance, and long and narrow leaves as compared to wild-type plants. Transgenic A. belladonna produced more TAs than wild-type plants, with the content of hyoscyamine, anisodamine and scopolamine reaching 2.58, 3.59 and 15.77-fold that of the control group, respectively. The gene expression of putrescine N-methyltransferase (PMT), tropinone reductase I (TRⅠ) and hyoscyamine 6-β-hydroxylase (H6H), key enzymes in TAs biosynthesis, were up-regulated compared with the control group. The above results indicate that the rolC gene enhances TAs biosynthesis in A. belladonna by up-regulating the expression of key enzymes in the TAs biosynthesis pathway, laying a foundation for genetic manipulation of A. belladonna to increase TAs content by increasing rolC gene expression.
Reactive oxygen species (ROS) is defined as the electron reduction product of oxygen with high reactivity which can maintain normal physiological functions and redox homeostasis. The tumor microenvironment is in a state of oxidative stress. ROS can affect multiple processes of tumor immune response by modulating the phenotype and functions of tumor cells and immune cells. With the rapid development of immunology, ROS-based tumor immunomodulation has been widely concerned and studied. In this review, the mechanism of ROS participating in tumor immune response is elaborated. Meanwhile, the research process and application of ROS in tumor immunomodulation in recent years are reviewed and analyzed.
Pulmonary hypertension (PH) is a kind of disease characterized by progressive increase of pulmonary vascular resistance and occlusive vascular remodeling. Hypoxic inductive factor-2α (HIF-2α) plays an important role in the abnormal proliferation of pulmonary vascular cells and pulmonary vascular remodeling. This review focuses on the role of HIF-2α in pulmonary hypertension at the cellular and the global level, and candidates targeting HIF-2α for the treatment of pulmonary hypertension, in order to better understand the pathogenesis of PH and find effective treatments.
KRAS is one of the most frequently mutated human oncogenes. In spite of mounting efforts on the development of direct or indirect inhibition targeting KRAS, little has been achieved because of insurmountable difficulties, titling KRAS "undruggable". Recently, subtype-specific inhibitors have shown great hope. Some KRASG12C inhibitors have entered clinical trials, including adagrasib and sotorasib, and have shown preliminary clinical effectiveness. Experiences from the inhibitors targeting the downstream factors of RAS pathways show that the anticancer activity of these drugs will be limited due to the development of drug resistance. Preclinical studies of KRASG12C inhibitors have revealed that the application of these agents might be hampered by the drug resistance issue. The current review aims to describe the current status of KRASG12C inhibitors, and discuss the mechanisms underlying KRASG12Cinhibitor resistance, so as to provide the clues for the combat of drug resistance.
Rhei Rhizoma is commonly used as a traditional Chinese medicine with multiple botanical origins. Different botanical sources may have different pharmacological activities. The germplasm resources of commercial Rhei Rhizoma were determined based on the chloroplast gene matK, and the anthraquinone and free anthraquinone content was determined by UPLC to analyze quality of commercial Rhei Rhizoma. Eighty-nine commercial Rhei Rhizoma samples were collected from 40 cities in 27 provinces. DNA was extracted and the matK gene was amplified by PCR. Results indicated that the collected samples were from the same botanical origin, Rheum palmatum, and 8 genotypes were identified, including Rp1, Rp2, Rp3, Rp4, Rp5, Rp6, Rp10 and Rp12. Rp4 and Rp6, cultivated in Gansu, Sichuan and Yunnan provinces were the main circulating genotypes, representing 40.45% and 37.08% of the total samples, respectively. Phylogenetic tree analysis showed that the eight genotypes were mainly divided into two branches, of which the main genotypes Rp4 and Rp6 were in one branch. Genetic distance analysis indicated that the genetic separation of the eight genotypes was between 0.001 and 0.010. UPLC analysis indicated that 93.26% of the samples met the Pharmacopoeia standards. There were significant differences in the content of total anthraquinone and free anthraquinone among the samples, in which the difference in free anthraquinone was 1.01% and the difference in total anthraquinone content was 3.79%, indicating that the quality of commercial Rhei Rhizoma samples varies considerably. There was no significant difference in the content of total anthraquinone and free anthraquinone in commercial Rhei Rhizoma among different collection provinces and genotypes. This study will help guide the circulation of Rhei Rhizoma in the market and provides valuable insights for molecular identification and quality analysis of other traditional Chinese medicines.
As one of the "Three Drugs Three Prescriptions" anti-COVID-19 traditional Chinese medicine, Jinhua Qinggan granules (JHQG) has been proved to have clear clinical effects. With complex medicinal flavors and ingredients, there is no systematic research report on chemical composition in vivo or in vitro. An ultrahigh pressure liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC-QTOF/MS) method was developed in this study to identify the components of the anti-COVID-19 traditional Chinese medicine JHQG granules. Analyze the collected rat plasma samples after administration and explore the exposed components in rats within 8 hours after intragastric administration. Preliminary pharmacokinetic analysis was then performed on this basis. Through UPLC-QTOF/MS analysis and verification by standard products, a total of 77 chemical components in JHQG formula have been identified, among which 22 compounds were highly exposed in vivo, mainly derived from three medicinal materials of honeysuckle, scutellaria and forsythia. Through the assessment of the blood drug concentration by the compartment model, 6 PK parameters of 4 high-exposure chemical components have been obtained, clarifying the metabolic characteristics of the main exposed components in JHQG briefly. The method is simple, efficient, sensitive and accurate and provides research basis to the clarification of the pharmacodynamics material basis and mechanism of JHQG, which has certain reference significance for the basics and applications research of the traditional Chinese medicine prescriptions in fighting the SARS-CoV-2.