Tumor, especially malignant tumor has become one of the major diseases, a serious threat to the health of people around the world. Modern clinical practice shows that the natural active products extracted from traditional Chinese medicine, marine medicine and other natural drugs, such as terpenes, alkaloids, polysaccharides, volatile oils and peptides, can effectively inhibit the growth of tumor cells. In this paper, the active components of natural antitumor products in recent years were summarized and their related mechanism was elucidated, so as to provide theoretical basis for the further development of natural antitumor drugs.

Chiral amino acid analysis is a sensitive, efficient and economical method for controlling racemic peptide impurities, especially for synthetic polypeptide drugs with complex composition of amino acids. Unexpected amino acid enantiomers in racemic peptides can be measured by chiral amino acid analysis coupled with mass spectrometry. The position of amino acid isomerization in the peptide segment can be accurately mapped by mass spectrometry, which lays a solid foundation for screening of racemic peptide impurities and rapid identification or quantification of trace racemic peptide impurities. Combination of the two techniques is vital for quality control of the synthetic polypeptide drugs and for research of polypeptide drugs based on chemical synthesis. The strategies of peptide hydrolysis have been summarized in this review. The latest chiral amino acid analysis based on mass spectrometry is briefly reviewed. Based on our knowledge, we have pointed to the direction of research and control of racemic peptide impurities in synthetic polypeptide drugs.

The Lewis lung carcinoma (LLC) metastatic mouse model was used to investigate the effects of gefitinib and Sijunzi Tang (SJZ) on pre-metastatic niche. The experimental protocol was approved by the Ethics Committee which belongs to Cancer Hospital, Chinese Academy of Medical Sciences. To generate spontaneous lung metastatic models, 1×10⁶ luciferase-labeled LLC cells were injected subcutaneously in the shaved right flank of mice. One day after LLC inoculation, the mice were randomly divided into model (saline), gefitinib (50 mg·kg^-1) treatment, SJZ treatment (25.74 g·kg^-1), and co-treatment gefitinib with SJZ groups, with intragastrical administration. After 14 days of continuous administration, tumor size was detected by IVIS^® Spectrum system. The number of monocytes and neutrophils and the expression levels of chemokine receptors (CXCR1, CCR2) and carcinogenic gene (c-Kit), in peripheral blood, spleen and lung tissues of mice were determined by flow cytometry. The contents of interleukin-IL-1α (IL-1α) and interleukin-6 (IL-6) were detected by the enzyme linked immunosorbent assay (ELISA). After 21 days of treatment, tumors were surgically removed, weighed and the tumor volume was measured with vernier caliper and the antitumor effect of co-administration was evaluated. After 45 days of administration, the survival of mice was recorded. The results of flow cytometry showed that the percentage of neutrophils in gefitinib group, SJZ group, and co-treatment group was significantly decreased in the lung tissue compared to the model group (P < 0.05 or P < 0.01), but there was no significant difference between three treatment groups (P > 0.05). In the mouse peripheral blood and lung tissue, compared with the model group, the expression levels of CXCR1, CCR2 and c-Kit on the surface of neutrophils and monocytes in SJZ group and co-treatment group decreased or decreased significantly (P < 0.01 or P < 0.05). However, there was a significant increase in the expression level of c-Kit on the surface of monocytes (P < 0.05). In the mouse spleen tissue, the expression levels of CXCR1, CCR2 and c-Kit in the gefitinib group increased significantly (P < 0.05), while decreased significantly in SJZ or co-treatment group (P < 0.05). The results of ELISA showed that the content of IL-1α in SJZ group decreased significantly in the plasma of the mice compared with the model group (P < 0.01) and the content of IL-6 in co-treatment group decreased significantly (P < 0.05). Compared with the gefitinib group, the content of IL-1 in the co-treatment group decreased significantly (P < 0.05). In the tumor tissues of mice, compared with the model group, the content of IL-1α in the co-treatment group decreased significantly (P < 0.05). Furthermore, the content of IL-1α in co-administrated group and IL-6 in SJZ or co-treatment group decreased significantly compared with the gefitinib group (P < 0.05). After 21 days of continuous administration, the tumor inhibition rates of gefitinib group, SJZ group and co-administrated group were 45.7%, 38.4%, and 84.8%, respectively. After 45 days of administration, the survival rate of the model group was 0%, whereas the gefitinib, SJZ or co-treatment group has a survival rate of 40%, 60%, or 60%, respectively. In summary, our study illustrated that Sijunzi Tang could improve the anti-tumor effect of gefitinib by regulating pre-metastatic niche.

We evaluated the effects of Danggui-Chuanxiong (GX) herb pair with different proportions (1:0, 3:2, 1:1, 2:3, 0:1) and preparation methods (water extract W, alcohol extract A, and water-alcohol extracts WA) on vasoactive substances and endothelial cell adhesion molecules in the serum of acute blood stasis in rats. An acute blood stasis model was co-replicated by ice water bath and subcutaneous injection of epinephrine hydrochloride in rats. The expressions of vasoactive substances (arachidonic acid metabolites, coagulation-fibrin system index) and adhesion molecules in the serum were detected by enzyme linked immunosorbent assay method; the Spearman method was used to analyze the correlation of those detection indicators; the partial least squares-discriminant analysis and multi-attribute comprehensive index method were used to comprehensively evaluate the total effect of GX herb pair samples with different proportions and preparation methods on vasoactive substances and adhesion molecules. The experimental scheme was approved by the Animal Experimental Ethics Committee of the First Affiliated Hospital of Henan University of Chinese Medicine. The results showed that GX 1:1_WA had the strongest effect on the improvement of vasoactive substances and adhesion molecules in the serum of acute blood stasis in rats (the total effect value was 6.96). When extraction method was same, the overall effect of GX 1:1 had better effect than that of other proportions; when the proportion of GX was same, the total effects of GX_WA and GX_A were better than GX_W. The combination of Danggui and Chuanxiong can significantly improve the expressions of vasoactive substances and adhesion molecules in the serum of blood stasis in rats. But the action strength of GX herb pairs was different when the proportions and preparations of GX herb pair were different. These findings provide a basis for clinical rational application of GX herb pair, and lay the foundation for in-depth research on GX herb pair for treatment of blood stasis related diseases.

The chemical constituents from Brassica rapa were identified by various chromatographic techniques including silica gel, reversed-phase silica gel, macroporous resin and Sephadex LH-20 column chromatography. Eight compounds were isolated from this plant. The isolated compounds were elucidated by physicochemical properties and spectroscopic methods, including extensive 1D, 2D-NMR, and HR-ESI-MS techniques. Compounds 1, 2 are new triterpenoids and 3-7 were isolated for the first time from Brassica rapa. The cytotoxic effect of compounds 1 and 2 were tested by MTT assay against five cancer cell lines. The result showed that all compounds exhibit growth inhibition for the cancer lines. Compound 1 has an IC₅₀ value of 5.87 μmol·L^-1 for growth inhibition of leukemia cell line HL-60, and IC₅₀ value for compound 2 was 10.32 μmol·L^-1.

The methods for determination of freezing point include cooling curve cryoscopy and air humidity cryoscopy. These methods are usually influenced by many factors, such as instrumentation, environment and operators. Despite the numerous experimental methods, precise freezing point values are challenging to obtain due to time-consuming procedures, limited sample size and extensive manual work. In this study, a semi-empirical hydration model (SEHM) was developed to calculate freezing point of NaH₂PO₄-K₂HPO₄ mixed electrolyte solution. According to SEHM, the water activity of mixed electrolyte solution was calculated by molality of solutes. Then the freezing point of solution was calculated. The calculated results were compared with those obtained by cooling curve cryoscopy and air humidity cryoscopy. The results indicate that the SEHM calculations are comparable to the measurements of cooling curve cryoscopy and air humidity cryoscopy.

Polymyxin B and polymyxin E (colistin) are increasingly used as last-resort drugs for treatment of infections caused by multidrug-resistant gram-negative pathogens. Unfortunately, the application was limited due to the serious side effects, especially nephrotoxicity. Very recently, the need for developing more tolerated and more effective polymyxin analogues has grown. This study details the design, synthesis, and evaluation of two classes of polymyxin B analogues with varying hydrophobicity and bulkiness at the N-terminal fatty acyl chain or position 6 amino acid. 20 polymyxin B analogues were synthesized and the chemical structures of the analogues were confirmed by HR-MS and ¹H NMR spectra. Compounds 7e (MIC:0.5-4 μg·mL^-1) and 7l (MIC:0.25-2 μg·mL^-1) showed similar or better antimicrobial activity against both susceptible and resistant strains of Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa compared to polymyxin B (MIC:0.5-2 μg·mL^-1). Besides, compound 7l (CC₅₀:217.1±13.2 μg·mL^-1) displayed noticeably decreased renal cytotoxicity compared to polymyxin B (CC₅₀:120.3±6.0 μg·mL^-1). This work establishes the base of further study on the structure-activity relationship of polymyxin B.

Seven main components in eleutheroside were used as research objects, and the mechanism of action of total eleutheroside for treatment of diabetes mellitus type 2 was investigated by network pharmacology. The SwissTargetPrediction, GeneCard, and String platforms were used to predict the 35 potential targets of these 7 components that are related to diabetes mellitus type 2. Then we used cytoscape 3.6.1 to build a " component-target" network map and used the Networkanalyzer tool for topology analysis. Gene ontology (GO) enrichment analysis and KEGG pathway enrichment analysis were performed on the DAVID6.8 platform, and the " component-target-path" network map was constructed based on the enrichment results. Those components mainly used in diabetes mellitus type 2 were screened as core components, and the core components were docked with key disease target proteins to verify the potential mechanism of the total eleutheroside. After screening, 8 important pathways associated with diabetes mellitus type 2 were identified. This study showed that eleutheroside A, eleutheroside D, eleutheroside E and sesamin played key roles in insulin resistance, apoptosis and inflammation pathways. The total eleutheroside may ameliorate type 2 diabetes mainly through regulating signal transducer and activator of transcription factors (STATs), non-receptor protein tyrosine phosphatase (PTPN) 1, PTPN2, c-Jun N-terminal kinase (JNK), and p38 mitogen activate protein kinase. These components worked together through multiple signaling pathway. Based on our data, eleutheroside is proposed as a novel therapeutic strategy for treatment of type 2 diabetes.

Provirus Integration in Maloney murine leukemia virus (PIM) represents a novel class of unique Ser/Thr kinase, which has been identified to be over-expressed in multiple hematological malignancies and some solid tumors, and the expression quantity correlates with malignant grade and poor prognosis in patients with cancer. PIM kinase plays important roles in regulation of cell proliferation and differentiation through the phosphorylation of its protein substrates, and it has become the emerging target for cancer treatment. A large number of highly active PIM kinase inhibitors have been reported by domestic and foreign research institutions, and the research progress will be summarized according to affiliations in this review.

We explore and verify the optimized condition for HEK-Blue IL-17 screening model, and screen the compounds that inhibits IL-17-medited signaling pathway. HEK-Blue IL-17 cells (5×10⁴ cells per well) were seeded into the 96 plates followed by different concentrations of IL-17A or IL-17F alone, or in combination with tested compounds for 16 h. Then, the supernatant medium was incubated with QUANTI-Blue for 1 or 3 h to detect the OD value at λ_{655 nm}. The secreted alkaline phosphatase (SEAP) production was an index of IL-17-mediated signaling activation in HEK-Blue IL-17 cells. We found that both IL-17A and IL-17F can significantly activate the IL-17 signaling pathway in HEK-Blue IL-17 cells. The available dosage of IL-17A and IL-17F were 10 and 100 ng·mL^-1, respectively. The reaction time of SEAP and QUANTI-Blue was 1 h. In this model, arctigenin and epigallocatechin gallate (EGCG) could inhibit the IL-17A and IL-17F-mediated signaling pathway. This established and optimized screening model of HEK-Blue IL-17 cells was suitable for screening inhibitors of IL-17-mediated signaling pathway.