Latest ArticlesWith the development of small-molecule immunotherapy drugs, its combination with the programmed cell death ligand 1/programmed cell death protein 1 (PD-L1/PD-1) antibodies would provide a new opportunity for cancer treatment. Therefore, targeting PD-L1/PD-1 axis by small-molecule drug is an attractive approach to enhance antitumor immunity and considered as the next generation of tumor immunotherapy. In the present study, we investigated the anti-tumor role of salvianolic acid B (SAB) by regulating the PD-L1 level in tumors. Changes of total PD-L1 and membrane PD-L1 levels were determined by Western blot, flow cytometry and PD-1/PD-L1 interaction assays. The expression of mRNA level of PD-L1 was detected by real-time PCR. The cytotoxicity of activated peripheral blood mononuclear cell (PBMC) cells toward co-cultured tumor cells was measured by cell impedance assay and crystal violet experiment. Surface plasma resonance technique was used to analyze the direct interaction between SAB and ubiquitin carboxyl-terminal hydrolase 2 (USP2). The antitumor effect of SAB in vivo was examined by C57BL/6 mice bearing MC38 xenograft tumor (all animal experiments were conducted in accordance with the Animal Ethics Committee of the Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences). Western blot and flow cytometry assay showed that SAB can significantly downregulate the abundance of PD-L1 in RKO and PC3 cells in dose- and time-dependent manner. PD-1/PD-L1 binding assay revealed that SAB reduces the binding of tumor cells to recombinant PD-1 protein. Mechanism studies revealed that SAB can bind directly to USP2 protein and inhibit its activity, thus promote the ubiquitin-proteasome pathway degradation of PD-L1 proteins. In addition, Cell impedance and crystal violet staining indicated that SAB enhances the killing activity of co-cultured PBMC cells toward tumor cells. MC38 tumor transplanted mouse experiments revealed that SAB treatment displayed significant suppression in the growth of MC38 tumor xenografts in C57BL/6 mice with an inhibition rate of 63.2% at 20 mg·kg-1. Our results demonstrate that SAB exerts its anti-tumor activity by direct binding and inhibiting the activity of USP2 and reducing the PD-L1 level. Our study provides an important material basis and scientific basis for the potential application of SAB in tumor immunotherapy drug targeting USP2-PD-L1 axis.
Nine compounds were isolated from the crude extract of the solid culture of endophyte Trichoderma atroviride B7 of Colquhounia coccinea var. mollis by silica gel column chromatography, Sephadex LH-20 gel column chromatography, and HPLC. They were identified as atroviridanol (1), 3-oxo-3-[(2-phenylethyl) amino]-propanoic acid (2), N-(2′-phenylethyl)-acetamide (3), neoechinulin A (4), echinulin (5), gancidin W (6), N-isobutyl-3-methylbutanamide (7), 5-acetamido-1-pentanol (8), and N-2-methylpropyl-2-methylbutenamide (9) by NMR, HR-MS, and so on. Among them, compound 1 is a new compound, and compounds 2-9 are firstly isolated from Trichoderma spp.
A new siderophore chelate (1) and 8 known compounds were identified from the liquid co-cultures of the marine-derived Streptomyces sp. IMB18-531 and Cladosporium sp. IMB19-099 by a combination of chromatography methods, including C18 reversed-phase medium pressure chromatography, gel column chromatography and HPLC. Their structures were determined by spectroscopic analysis and chemical methods as aluminioxamine E (1), desferrioxamine E (2), ferrioxamine E (3), terragine E (4), capsimicin (5), cyclo(L-prolinyl-L-tyrosine) (6), anthranilic acid (7), (Z)-14-methylpentadec-9-enoic acid (8), and (Z)-hexadec-8-enoic acid (9). Compound 2 showed inhibitory activities against the expression of liver fibrosis related genes COL1A1, MMP2, and TIMP2. Compounds 5, 8, and 9 displayed antibacterial activities against methicillin-resistant Staphylococcus aureus, S. epidermidis and Bacillus subtilis, with MICs of 16-64 μg·mL-1. Compound 5 showed cytotoxicities against human pancreatic cancer MIA Paca-2 and human colon cancer HT-29 cell lines with IC50 of 2.9 and 6.3 μmol·L-1, respectively.
Ten dimeric phthalide racemates (1-10) were isolated from an aqueous extract of the Angelica sinensis root head (Guitou) by separation techniques of column chromatography over macroporous adsorbent resin, MCI resin, silica gel, and Sephadex LH-20, together with preparative thin-layer chromatography and reversed phase HPLC. The racemates were further separated into (+)-/(-)-1-(+)-/(-)-10 with chiral HPLC. Their structures including absolute configurations were elucidated by comprehensive analysis of spectroscopic data, combined with electronic circular dichroism (ECD) and NMR calculations as well as single crystal X-ray diffractions. Compounds (+)-/(-)-1-(+)-/(-)-10 are either new structure or new natural product, named (+)-/(-)-angelidipthalidic acids A-H [(+)-/(-)-1-(+)-/(-)-8] and (+)-/(-)-angelidipthalidols A and B [(+)-/(-)-9 and (+)-/(-)-10], respectively. Meanwhile, dimeric phthalide mono- and bis-lactone derivatives with 3.3′a, 8.6′- and 3.6′, 8.3′a-coupling patterns as well as determination of their relative configurations are discussed.
Seventeen minor triterpenoid acids (1-17) were isolated from an aqueous decoction of Uncaria rhynchophylla by a combinatory application of column chromatography using multiple stationary phases, including macroporous adsorbent resin, MCI resin, Sephadex LH-20, Toyopearl HW-40C, silica gel, and C18 reversed phase silica gel, combined with separation techniques of flash chromatography (FC) and high performance liquid chromatography (HPLC). Their structures were determined by analysis of HR-ESI-MS, UV, CD, and IR as well as 1D and 2D NMR spectroscopic data, of which eight new compounds (1-8) are named successively uncarinic acids Q-X, while the structures of 2 and 7 were confirmed by single crystal X-ray diffraction. In the in vitro assays, 27-hydroxyolean-12-en-28-oic acid (17) inhibited TGF-β-induced HSC-T6 cell activation at the concentration of 5 μmol·L-1.
The whole herb of Solanum nigrum L. can be used as the herbal drug. In this study, UHPLC-Q Exactive high resolution mass combined with GNPS molecular network was used for the rapid characterization of the components in the leaves of S. nigrum L. A total of 157 compounds were identified, including 30 steroid alkaloids, 61 steroid saponins, 35 flavonoids, and 31 other compounds (amino acids and organic acids), by comparison with the data reported in the literature, and mass fragmentation characteristics analysis, as well as the correlation of known and unknown nodes in the GNPS molecular network. Compared with the fruits and stems, the leaves of S. nigrum L was rich in a variety of steroidal saponins, steroidal alkaloids, and flavonoids, and the results lay the foundation for the precise resources utilization of S. nigrum L.
According to the theory of 'Xingben Dazao' of Psoralea corylifolia Linn. (BL), the susceptible syndromes and biomarkers of liver injury caused by BL were searched. Rat models of kidney-yin deficiency syndrome (M_yin) and kidney-yang deficiency syndrome (M_yang) were established, and all animal experimental operations and welfare following the provisions of the First Affiliated Experimental Animal Ethics and Animal Welfare Committee of Henan University of Traditional Chinese Medicine (No. YFYDW2020017). The results showed that BL significantly decreased the body weight, water intake, and urine weight of M_yin rats and increase the organ indexes of the liver, testis, adrenal gland, and spleen and the expression of alanine aminotransferase (ALT). Meantime, BL significantly increased the urine weight of M_yang rats and decreased the expression of ALT and aspartate aminotransferase (AST). Hematoxylin and eosin (HE) staining showed that BL could aggravate inflammatory infiltration of hepatocytes in rats with M_yin and alleviate liver injury in rats with M_yang. Metabolomics identified 17 BL co-regulated significant differential metabolic markers in M_yin and M_yang rats. Among them, 8 metabolites such as glutamine, quinolinate, biliverdin, and lactosylceramide showed opposite trends, mainly involving cysteine and methionine metabolism, tyrosine metabolism, tryptophan metabolism, purine metabolism, sphingolipid metabolism, glycerol phospholipid metabolism, glutamine metabolism, and other pathways. M_yin/M_yang may be the susceptible constitution of BL for liver damage or protection, which may be related to the regulation of amino acid metabolism and sphingolipid metabolism. The study can provide some experimental data support for the safe and accurate use of BL in the clinical practice of traditional Chinese medicine.
The aim of this paper is to explore the key anti-fatigue active components in the saponin-like composition of American ginseng. The anti-fatigue activity of western ginseng samples was evaluated using a zebrafish model; metabolomics techniques were used to identify the main saponins in western ginseng from different origins; the active substances and relevant targets of the anti-fatigue effect of western ginseng were initially screened by constructing a PPI protein interaction network between western ginseng saponins and disease targets, and the key active ingredients were screened using a molecular docking method; finally, the anti-fatigue activity of the key active ingredients was evaluated using a zebrafish, animal experiment was approved by the Ethics Committee of Shandong Academy of Medical Sciences (SYXK20220005). The anti-fatigue activity of the key active ingredients was evaluated using a zebrafish model. The results of the zebrafish activity evaluation showed that there were significant differences in the activities of the western ginseng samples from the two origins, and a total of 10 different saponins were identified as possibly related to the anti-fatigue activity after further metabolomic testing and pattern discrimination. The core anti-fatigue targets were screened with the help of component-disease target PPI, combined with pharmacophore-like parameters and molecular docking techniques, and pseudoginsenoside F11 was found to have good binding activity to five of the targets. Finally, the zebrafish model revealed that pseudoginsenoside F11 exhibited significant anti-fatigue activity. This study used metabolomics and zebrafish model to screen the key active substances of pseudoginsenoside F11 for its anti-fatigue activity, which will provide a reference for further research on the anti-fatigue of pseudoginsenosides.
In this study, alkali-soluble polysaccharide was extracted from Poria residue, and the structure of alkali-soluble polysaccharide was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), and differential scanning calorimetry (DSC). The physical morphology of alkali-soluble polysaccharide and ethyl cellulose (EC) was investigated by scanning electron microscopy (SEM), and the focus on angle of repose, bulk density, tapped density, Carr index, interparticle porosity, cohesion index, Hausner ratio, etc. The physical fingerprints were drawn, and the powder properties were evaluated by multivariate analysis. Diclofenac sodium extended-release tablets were prepared by direct compression method using alkali-soluble polysaccharide and EC as insoluble backbone materials to evaluate the basic properties of the extended-release tablets, investigate the in vitro drug release behavior and study the release mechanism. The results showed that alkali-soluble polysaccharide is a semi-crystalline polymer with smooth lamellar structure, and its stacking and compressibility are stronger than EC. The in vitro release experiments showed that the slow release performance of alkali-soluble polysaccharide is stronger than EC, and the release behavior of the prepared slow release tablets is in accordance with the Higuchi model. The pore structure is formed inside the tablets during the release process, and the release mode is pore diffusion release. The results of this study are of great significance for the development of new slow-release materials and the rational use of resources.
Mannitol-calcium chloride metal organic framework (MOF) cocrystal significantly improved the tabletability of β-mannitol and could be developed as a new tablet filler. However, mannitol monomer was found in the product during the scale-up production of the excipient, which significantly affected the functional properties of the excipient. In this study, we intend to quantify the multi-component eutectic system of mannitol-calcium chloride. In this experiment, the MOF cocrystal excipient mannitol-calcium chloride cocrystal was used as the model compound, and infrared spectrum was collected. Based on partial least squares regression (PLSR) method, the abnormal bands were removed and the spectrum was preprocessed by normalization. The quantitative correction model of mannitol-calcium chloride MOF cocrystal content in cocrystal excipients was established and compared by two different variable screening methods, genetic algorithm (GA) and competitive adaptive reweighting algorithm (CARS). Two different variable screening methods, GA method and CARS method, were used to screen out 160 and 14 variables, respectively. The mannitol-calcium chloride cocrystal model established by CARS-PLSR method had the best performance, and the average relative error (MRE) and corrected root mean square error (RMSEC) of the model were 0.008 8 and 0.892 5, respectively, the determination coefficient (R2) of the model was increased from 0.978 3 to 0.994 4. The quantitative method of eutectic system established in this study has high prediction accuracy, fast detection speed and good stability, which is of great significance for optimizing the preparation process conditions and quality control methods of such eutectic excipients.