Dihydromyricetin Improves Cognitive Impairments in d-Galactose-Induced Aging Mice through Regulating Oxidative Stress and Inhibition of Acetylcholinesterase.

SCOPE: Alzheimer's disease (AD) is a neurodegenerative disease with phenomena of cognitive impairments. Oxidative stress and cholinergic system dysfunction are two widely studied pathogenesis of AD. Dihydromyricetin (DMY) is a natural dihydroflavonol with many bioactivities. In this study, it is aimed to investigate the effects of DMY on cognitive impairment in d-galactose (d-gal) induced aging mice. METHODS AND RESULTS: Mice are intraperitoneally injected with d-gal for 16 weeks, and DMY is supplemented in drinking water. The results show that DMY significantly improves d-gal-induced cognitive impairments in novel object recognition and Y-maze studies. H&E and TUNEL staining show that DMY could improve histopathological changes and cell apoptosis in mice brain. DMY effectively induces the activities of catalase, superoxide dismutase and glutathione peroxidase, and reduces malondialdehyde level in mice brain and liver. Furthermore, DMY reduces cholinergic injury by inhibiting the activity of Acetylcholinesterase (AChE) in mice brain. In vitro studies show that DMY is a non-competitive inhibitor of AChE with IC50 value of 161.2 µg mL-1 . CONCLUSION: DMY alleviates the cognitive impairments in d-gal-induced aging mice partly through regulating oxidative stress and inhibition of acetylcholinesterase.

Physicochemical properties of dihydromyricetin and the effects of ascorbic acid on its stability and bioavailability.

BACKGROUND: Dihydromyricetin (DMY) is a natural dihydroflavonol with many bioactive effects. However, the physicochemical properties of DMY related to its bioavailability, especially its stability, are unclear. RESULTS: The effects of pH, temperature, metal ions and ascorbic acid (AA) on the stability of DMY were studied using high-performance liquid chromatography (HPLC). The bioavailability of DMY in the presence and absence of AA was compared. Dihydromyricetin was unstable in weak alkaline solutions, and the degradation was significantly accelerated in the presence of Cu2+ and Fe3+ . The degradation process followed the first-order kinetic model. The degradation rate constant (k) increased with increasing pH and temperature. The remaining DMY was only 49% of its initial concnentration after 4 h in simulated intestinal fluid (SIF) at 37 °C. However, by supplementing with AA, the degradation of DMY was rarely occured within 6 h. The solubility of DMY at pH 3-5 was about 750 µg mL-1 , slightly increasing to 853 µg mL-1 at pH 6. Pharmacokinetic studies showed that the bioavailability of DMY increased from 0.122% to 0.341% by supplementing with AA (10% of DMY). CONCLUSION: The degradation of DMY is one reason for its poor bioavailability. The presence of AA could significantly improve the stability of DMY, and further improve its bioavailability in rats. © 2020 Society of Chemical Industry.

A pan-cancer analysis of the expression of gasdermin genes in tumors and their relationship with the immune microenvironment.

BACKGROUND: Gasdermins (GSDMs) are a class of proteins related to pyrolysis and in humans, consist of GSDMA, GSDMB, GSDMC, GSDMD, DFNA5, and DFNB59. The inflammatory factors and cell contents released during pyrolysis can recruit immune cells and change the microenvironment. However, to date, there is a paucity of studies examining the relationship between GSDMs and the immune microenvironment in tumors. Therefore, this current report analyzed the expression of GSDM genes in tumors and their relationship with the immune microenvironment. METHODS: Apply GSCALite and GEPIA2 online analysis tools to analyze the gene expression levels and the Single nucleotide variant (SNV), copy number variation (CNV), and methylation characteristics of GSDM genes respectively. Use R software or TISIDB online analysis tool to carry out the correlation analysis required in the article. Furthermore, Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were conducted to examine the role of these GSDM genes in various cancers. RESULTS: The results demonstrated that CNV can cause an increase in GSDM gene expression, and methylation can inhibit GSDM gene expression. The elevated expression of GSDMA, GSDMB, GSDMC, GSDMD, and DFNA5 in some or most tumors was often accompanied by elevated immune scores, increased immune cell infiltration, and high expression of major histocompatibility complex (MHC) molecules, chemokines and their receptors, and immune checkpoint-related genes. However, DFNB59 was often negatively correlated with these indicators in tumors. GSDMD was the most highly expressed GSDM protein in various normal tissues and tumors, and showed the strongest correlation with immune microenvironment-related genes. Moreover, the methylation of GSDMD was accompanied by low immune cell infiltration, low expression of MHC molecule-related genes, low expression of chemokines and receptor-related genes, and low expression of immune checkpoint-related genes. CONCLUSIONS: Therefore, the expression of GSDM-related genes is associated with the tumor immune microenvironment. The GSDM genes, especially GSDMD, may be used as therapeutic targets to predict or change the tumor microenvironment and as biomarkers to predict the therapeutic efficacy of immune checkpoint inhibitors.

Fabrication and characterization of dihydromyricetin encapsulated zein-caseinate nanoparticles and its bioavailability in rat.

Dihydromyricetin (DMY) encapsulated zein-caseinate nanoparticles (DZP) were fabricated by antisolvent method. The encapsulation and loading efficiency of DMY in DZP were 90.2% and 22.6% as determined by HPLC. DZP is spherical with particle size and ζ potential of 206.4 nm and -29.6 mV, respectively. Physicochemical characterization showed that DMY existed in amorphous form in DZP and its interaction with proteins was found. The fabrication of DZP significantly improved the stability of DMY. Besides, the diffusion rate of DMY in DZP was faster than its suspensions in both simulated gastric and intestinal fluid. The adhesion of DMY in mice gastrointestinal tract was also improved. Besides DMY itself, its methylated metabolites with further sulfation and glucuronide were identified in rat plasma by UPLC-QTOF-MS. UPLC-QqQ-MS/MS quantitative analysis showed that the oral bioavailability of DMY was 1.95 times enhanced. Besides, the concentration of DMY metabolites in plasma were all increased.

Transcriptome analysis of differential gene expression in the longissimus dorsi muscle from Debao and landrace pigs based on RNA-sequencing.

RNA-seq analysis was used to identify differentially expressed genes (DEGs) at the genetic level in the longissimus dorsi muscle from two pigs to investigate the genetic mechanisms underlying the difference in meat quality between Debao pigs and Landrace pigs. Then, these DEGs underwent functional annotation, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, and protein-protein interaction (PPI) analyses. Finally, the expression levels of specific DEGs were assessed using qRT-PCR. The reference genome showed gene dosage detection of all samples which showed that the total reference genome comprised 22342 coding genes, including 14743 known and 190 unknown genes. For detection of the Debao pig genome, we obtained 14168 genes, including 13994 known and 174 unknown genes. For detection of the Landrace pig genome, we obtained 14404 genes, including 14223 known and 181 unknown genes. GO analysis and KEGG signaling pathway analysis show that DEGs are significantly related to metabolic regulation, amino acid metabolism, muscular tissue, muscle structure development etc. We identified key genes in these processes, such as FOS, EGR2, and IL6, by PPI network analysis. qRT-PCR confirmed the differential expression of six selected DEGs in both pig breeds. In conclusion, the present study revealed key genes and related signaling pathways that influence the difference in pork quality between these breeds and could provide a theoretical basis for improving pork quality in future genetic thremmatology.

Metabolism, Excretion, and Tissue Distribution of Astilbin-Zein Nanoparticles in Rats.

The excretion, tissue distribution, and metabolic profile of astilbin in rat were studied by HPLC and UPLC-QTOF-MS. Astilbin underwent isomerization in the small intestine, and its four isomers were found in feces. Besides, taxifolin, the aglycone of astilbin, and its further metabolites by gut microbes through hydrogenation, dehydration, and ring-fission were found. The total feces excretion of astilbin was about 14.4% of administration. The forming of zein-caseinate nanoparticles can significantly delay and reduce the feces excretion of astilbin. Astilbin and its isomers were absorbed in their intact form. The main metabolites found in plasma and tissues were the methylated products. Astilbin was rapidly distributed in various tissues including brain and maintained relatively high concentration in heart. Compared with other tissues, significantly higher concentration and longer duration of astilbin were found in the gastrointestinal tract. Astilbin and its isomers were excreted in their intact and methylated form in urine.

Arginine-Glycine-Aspartate-Binding Integrins as Therapeutic and Diagnostic Targets.

Arginine-glycine-aspartate (RGD)-binding integrins, including αvß1, αvß3, αvß5, αvß6, αvß8, α5ß1, αIIbß3, and α8ß1, recognize the tripeptide motif RGD in their ligands. RGD-binding integrins are involved in various cell functions, including cell proliferation, survival, differentiation, and motility that are critically important to both health and disease. The diagnostic and therapeutic value of some RGD-binding integrin inhibitors are either clinically proven or at different stages of development. In this review, we first summarized the structure and signaling characteristics of RGD-binding integrins. We then discussed the functions of RGD-binding integrins and their association with human disease. Finally, we recapitulated the research efforts and clinical trials of targeting RGD-binding integrins for the diagnosis and treatment of human disease. This comprehensive review of the current advances in RGD-binding integrins could assist scientists and clinicians in gaining a complete understanding of this group of molecules. It can also contribute to the design of new projects to further advance this field of research and to better apply the research results to benefit patients in clinical practice.

Endophytes in the plant Huperzia serrata: fungal diversity and discovery of a new pentapeptide.

Endophytic fungi are an underexploited resource of natural products and have a capacity to produce diverse classes of plant-derived secondary metabolites. Here, we investigated the diversity of endophytic fungi from Huperzia serrata and the potential for discovering novel fungal natural products. One hundred and fifty-five endophytic fungi isolates obtained from H. serrata, belonging to four classes Dothideomycetes (47.3 %), Sordariomycetes (36.8 %), Eurotiomycetes (10.6 %) and an undefined class (5.3 %, Mucoraceae), were grouped into nine genera based on morphological and molecular identification. Colletotrichum, Cladosporium, Sordariomycetes and Guignardia were the dominant genera, whereas the remaining genera were infrequent groups. To our knowledge, the fungal genera Mucor and Neurospora were first reported in Huperzia plant. Among these endophytic fungi isolates, strain B14, belonging to Penicillium oxalicum, gave a gray precipitate with Dragendorff's reagent. A new pentapeptide was isolated from the culture of strain B14, and its chemical structure was elucidated on the basis of spectroscopic data from (1)H NMR, (13)C NMR and ESI-MS/MS. Taken together, H. serrata has a significant diversity of endophytic fungi that could be a rich resource for the discovery of new natural products.

Integrins: players in cancer progression and targets in cancer therapy.

Integrins are a large family of cell surface receptors that bind extracellular matrix proteins. The interaction of integrins with extracellular matrix activates a number of intracellular signaling pathways involved in cell proliferation, differentiation, motility, and other essential cell functions. Integrins are critically important to both health and disease. In this review, we first describe the structure, functions, and signaling characteristics of integrins. We then discuss the roles of integrins in cancer progression. Finally, we recapitulate the laboratory and clinical efforts of targeting integrins as effective means of cancer therapy and diagnosis. This comprehensive review could help scientists and clinicians gain a complete understanding of integrins. It could also contribute toward the development of new drugs, new methods of diagnostics, and new treatment of cancers to benefit the patients in clinical practice.

Riccardin D, a macrocyclic bisbibenzy, inhibits human breast cancer growth through the suppression of telomerase activity.

Riccardin D, a liverwort-derived naturally occurring macrocyclic bisbibenzyl, has been found to exert anticancer effects in multiple cancer cell types. In this study, we investigated the effect and mechanism of Riccardin D on human breast cancer. Experiments were performed on human breast cancer MCF-7 and MDA-MB-231 cells. The antitumour effects of Riccardin D were assessed by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay and human breast cancer xenografts mice model. TRAPeze(®) XL Telomerase Detection assay was used for the detection of telomerase activity. γ-H2 AX foci formation was tested for the induction of DNA damage response. Cell cycle distribution was analysed by flow cytometry, and cell apoptosis was determined by annexin V-FITC/PI staining, terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) assay and Western blotting. Riccardin D effectively inhibited the growth of MCF-7 and MDA-MB-231 cells in vitro. And Riccardin D also effectively delayed the growth of MCF-7 and MDA-MB-231-luc-D3H2LN xenografts without significant loss of body-weight. Further analysis suggested that Riccardin D's effects may arise from its suppression of telomerase activity, which led to telomere dysfunction. Telomerase inhibition and telomere dysfunction could activate the canonical ataxia telangiectasia-mutated (ATM) kinase-mediated DNA damage response, as shown by elevated expression of γ-H2 AX, p-ATM and p-Chk2. This is finally followed by the induction of cell cycle arrest and apoptosis, as shown by the increase of TUNEL-stained cells, caspase activation, PARP cleavage and the increase of bax/bcl-2 ratio. Moreover, Riccardin D induced p53-proficient MCF-7 cells to arrest in G1 phase and p53-deficient MDA-MB-231 cells to arrest in G2/M phase. Overall, these results demonstrate that Riccardin D may inhibit human breast cancer growth through suppression of telomerase activity.

Inhibitory effect of riccardin D on growth of human non-small cell lung cancer: in vitro and in vivo studies.

Riccardin D is a macrocyclic bisbibenzyl compound extracted from liverwort plant Dumortiera hirsuta. Our previous study showed that riccardin D induced apoptosis of human leukemia cells by targeting DNA topoisomerase II (topo II). Riccardin D has been considered as a novel DNA topo II inhibitor and potential chemotherapeutic agent for treatment of cancers. In this study, we evaluated the inhibitory effects of riccardin D on growth of human non-small cell lung cancer (NSCLC) both in vitro and in vivo. Riccardin D effectively inhibited the proliferation of NSCLC cells as estimated by the MTT assay. Further examination showed that the ability of invasion and migration of NSCLC cells was suppressed on exposure to riccardin D as estimated by the assays of scratch and transwell chamber. The anticancer activity of riccardin D was verified in mice bearing human NSCLC H460 xenografts. Riccardin D injection produced a 44.5% inhibition of cancer growth without apparent signs of toxicity to animals. Further, riccardin D induced apoptosis of NSCLC cells as evidenced by the increases of cells with externalization of phosphatidylserine and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL)-positive in H460 xenografts. The analysis of apoptotic proteins showed that riccardin D activated the caspases cascade signaling pathway as demonstrated by the increases of cleaved caspase-3 and cleaved PARP in NSCLC cells in vitro and in H460 xenografts in mice. The pBR322 DNA relaxation assay indicated that riccardin D inhibited the activity of DNA topo II in H460 and A549 cells, suggesting the mechanism of riccardin D in induction of NSCLC apoptosis. In addition, we studied the activity and expression of matrix metalloproteinases (MMPs) in NSCLC cells. The activities of MMP-2 and MMP-9 in supernatants of NSCLC cells were suppressed on exposure to riccardin D as estimated by gelatin zymography assay. The inhibitory effects of riccardin D on expressions of MMP-2 and MMP-9 were verified in H460 xenografts in mice and the decreases of vascular endothelial growth factor (VEGF) and Erk1/2 might associate with the inhibition of MMPs and NSCLC growth. Together, our results suggest that riccardin D has a high inhibitory effect on human NSCLC growth through induction of apoptosis.

Riccardin D, a novel macrocyclic bisbibenzyl, induces apoptosis of human leukemia cells by targeting DNA topoisomerase II.

We studied the effect of riccardin D, a macrocyclic bisbibenzyl, which was isolated from the Chinese liverwort plant, on human leukemia cells and the underlying molecular mechanism. Riccardin D had a significant antiproliferative effect on human leukemia cell lines HL-60, K562 and its multidrug resistant (MDR) counterpart K562/A02 cells, but showed no effect on the topoisomerase-II-deficient HL-60/MX2 cells, as measured by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. The pBR322 DNA relaxation assay revealed that riccardin D selectively inhibited the activity of topoisomerase II (topo II). The suppression of topo II activity by riccardin D was stronger than that of etoposide, a known topo II inhibitor. After treatment with riccardin D, nuclear extracts of leukemia K562 and K562/A02 cells left the majority of pBR322 DNA in a supercoiled form. Further examination showed that riccardin D effectively induced HL-60, K562 and K562/A02 apoptosis as evidenced by externalization of phosphatidylserine and formation of DNA ladder fragments. The activation of cytochrome c, caspase-9, caspase-3 and cleaved poly ADP-ribose polymerase (PARP) was also enhanced, as estimated by Western blot analysis. By contrast, riccardin D was unable to induce apoptosis in the topoisomerase-II-deficient HL-60/MX2 cells, indicating that the induction of apoptosis by riccardin D was due to the inhibition of topo II activity. In addition, riccardin D was able to significantly decrease P-glycoprotein (P-gp) expression in K562/A02 cells. Taken together, our data demonstrate that riccardin D is a novel DNA topo II inhibitor which can induce apoptosis of human leukemia cells and that it has therapeutic potential for both regular and MDR strains of leukemia cells.

Inhibition of angiogenesis involves in anticancer activity of riccardin D, a macrocyclic bisbibenzyl, in human lung carcinoma.

Riccardin D is a novel macrocyclic bisbibenzyl compound extracted from Chinese liverwort plant Dumortiera hirsuta. Our previous studies showed that riccardin D is a DNA topo II inhibitor and has therapeutic potential for treatment of cancers. In this combined in vitro and in vivo study, we examined the inhibitory effects of riccardin D on tumor angiogenesis and the subsequent effect of anticancer activity was evaluated. Incubation with riccardin D weakly inhibited the proliferation of human umbilical vascular endothelial cells (HUVEC) as estimated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The scratch wound experiment showed that riccardin D effectively decreased the motility and migration of HUVEC cells. Riccardin D inhibited the formation of capillary tube as demonstrated by decrease of branch points formed by HUVEC cells on 3-D Matrigel. We examined the levels of angiogenic factors including vascular endothelial growth factor (VEGF), VEGF receptor 2, epidermal growth factor receptor (EGF receptor), and matrix metalloproteinase (MMPs) in HUVEC cells. The expressions of VEGF, phospho-VEGF receptor 2, EGF receptor and MMP-2 were significantly reduced by riccardin D as estimated by Western blot assay and real-time quantitative PCR analysis. The decrease of VEGF was also detected in riccardin D-treated human lung cancer H460 cells. The anticancer activity of riccardin D was then evaluated in a mouse model in which riccardin D delayed the growth of H460 xenografts without obvious toxicity to animals after three weeks injection. To evaluate the role of antiangiogenesis of riccardin D in mice, CD34 immunohistochemical staining was employed to analyze the mean vascular density in H460 xenograft tissues. The number of blood vessels was significantly decreased after riccardin D treatment. These results suggest that riccardin D display the inhibitory effect on growth of human lung carcinoma cells and that the inhibition of angiogenesis may involve in anticancer activity of riccardin D.

[The analgesic effect of plexus anesthesia with buprenorphine in patients].

OBJECTIVE: To study the anesthetic effect of brachial plexus block by adding buprenorphine in local anesthetics and patients with intramuscular injection, and observe the anesthesia effects, the anesthesia maintenance time, postoperative analgesia effects. METHODS: 60 cases of upper limb to line, hand surgery patients from Sep. 2009 to Dec. 2009 in Tianjin Hospital were randomly divided into 3 groups. A (local anesthetics without buprenorphine, n = 20); B group (plus 2 µg/kg buprenorphine in local anesthetics, n = 20); C group (intramuscular injection 2 µg/kg buprenorphine before anesthesia, n = 20). With B/BRAMN-STIMMPLEX-DIG nerve stimulator guided positioning of brachial plexus block of axillary line. 3 groups of patients recorded (1) the onset time of narcotic; (2) the duration of anesthesia; (3) the surgery time; (4) the pain score of postoperative 4, 8, 12, 24, 36, 48, 72 h; (5) the incidence of nausea and vomiting; (6) observed other side effects. RESULTS: the patients' age, weight, sex, operation time of the 3 groups had no significant difference between the comparison (P > 0.05); anesthesia onset time between the 3 groups showed no significant difference (P > 0.05). Duration of anesthesia: A, C group was significantly shorter than the B group (P < 0.01); pain score at 4 h, A and B, C no significant difference between groups (P > 0.05); 8, 12, 24 h, when group A was significantly higher than the B, C group (P < 0.01), 36, 48, 72 h when the A group and B, C no significant difference between groups (P > 0.05); the incidence of nausea A group 10%, B group 20%, C group 20%. Vomiting, the incidence of A, B group was 0, C group 30%. CONCLUSION: Buprenorphine adding local anesthetics in brachial plexus block or intramuscular injection buprenorphine before a block can be to achieve a satisfactory effect of postoperative analgesia, buprenorphine adding local anesthetics in brachial plexus block Narcotic maintenance of anesthesia time can be extended and have a significant effect and fewer adverse reactions.