Chemical Compounds, Antioxidant Activities, and Inhibitory Activities Against Xanthine Oxidase of the Essential Oils From the Three Varieties of Sunflower (Helianthus annuus L.) Receptacles.

Background/Aim: Essential oils of sunflower receptacles (SEOs) have antibacterial and antioxidant potential. However, the differences of biological activities from the different varieties of sunflowers have not been studied till now. The purpose of this study was to compare the differences of chemical compounds, antioxidant activities, and inhibitory activities against xanthine oxidase (XO) of SEOs from the three varieties of sunflowers including LD5009, SH363, and S606. Methods: SEOs were extracted by using the optimal extraction conditions selected by response surface methodology (RSM). Chemical compounds of SEOs were identified from the three varieties of sunflowers by gas chromatography-mass spectrometry (GC-MS). Antioxidant activities of SEOs were detected by 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and iron ion reduction ability. Inhibitory activities of SEOs against XO were measured by using UV spectrophotometer. XO inhibitors were selected from the main chemical compounds of SEOs by the high-throughput selections and molecular simulation docking. Results: The extraction yields of SEOs from LD5009, SH363, and S606 were 0.176, 0.319, and 0.580%, respectively. A total of 101 chemical compounds of SEOs were identified from the three varieties of sunflowers. In addition, the results of inhibitory activities against XO showed that SEOs can reduce uric acid significantly. Eupatoriochromene may be the most important chemical compounds of SEOs for reducing uric acid. The results of antioxidant activities and inhibitory activities against XO showed that SEOs of LD5009 had the strongest antioxidant and XO inhibitory activities. The Pearson correlation coefficient (r > 0.95) showed that γ-terpinene, (E)-citral, and L-Bornyl acetate were highly correlated with the antioxidant activities and XO inhibitory ability. Conclusion: SEOs had antioxidant activities and XO inhibitory ability. It would provide more scientific information for utilization and selection of varieties of sunflowers, which would increase the food quality of sunflowers and incomes of farmers.

Chemical Composition and Antimicrobial and Antioxidant Activities of Essential Oil of Sunflower (Helianthus annuus L.) Receptacle.

Sunflower (Helianthus annuus L.) contains active ingredients, such as flavonoids, alkaloids and tannins. Nevertheless, few studies have focused on essential oil from the receptacle of sunflower (SEO). In this work, we investigated the chemical composition and antimicrobial and antioxidant activities of SEO. The yield of SEO was about 0.42% (v/w) by hydrodistillation. A total of 68 volatile components of SEO were putatively identified by gas chromatography-mass spectrometry (GC-MS). The main constituents of SEO were α-pinene (26.00%), verbenone (7.40%), terpinolene (1.69%) and α-terpineol (1.27%). The minimum inhibitory concentration (MIC) of SEO against P. aeruginosa and S. aureus was 0.2 mg/mL. The MIC of SEO against S. cerevisiae was 3.2 mg/mL. The MIC of SEO against E. coli and Candida albicans was 6.4 mg/mL. The results showed that SEO had high antibacterial and antifungal activities. Three different analytical assays (DPPH, ABTS and iron ion reducing ability) were used to determine the antioxidant activities. The results showed that SEO had antioxidant activities. To summarize, the results in this study demonstrate the possibility for the development and application of SEO in potential natural preservatives and medicines due to its excellent antimicrobial and antioxidant activities.

Hypoglycemic effect and mechanism of isoquercitrin as an inhibitor of dipeptidyl peptidase-4 in type 2 diabetic mice.

Glucagon-like peptide (GLP)-1 is a potent glucose-dependent insulinotropic gut hormone released from intestinal L cells. The aim of this study was to investigate isoquercitrin as an inhibitor of dipeptidyl peptidase IV (DPP-IV) and determine whether it affects GLP-1 release in normal mice and NCI-H716 cells. In vitro, we used chromogenic substrate method detection methods to measure DPP-IV. We found that isoquercitrin was a competitive inhibitor, with IC50 and K i values of 96.8 and 236 µM, respectively. Isoquercitrin and sitagliptin also stimulated GLP-1 release in NCI-H716 cells. In vivo, a type 2 diabetic mouse model was established, and oral treatment with different concentration of isoquercitrin and sitagliptin for 8 weeks significantly decreased the fasting blood glucose level. The weight and the levels of serum GLP-1 and insulin of the mice in the isoquercitrin group were higher than those in the model group (P < 0.001). An oral glucose tolerance test showed that the isoquercitrin significantly inhibited postprandial blood glucose changes in a dose-dependent manner. These findings demonstrated the hypoglycemic effects of isoquercitrin and indicated that isoquercitrin improved insulin sensitivity by targeting DPP-IV.

Identification of key genes associated with the effect of estrogen on ovarian cancer using microarray analysis.

PURPOSE: To identify key genes related to the effect of estrogen on ovarian cancer. METHODS: Microarray data (GSE22600) were downloaded from Gene Expression Omnibus. Eight estrogen and seven placebo treatment samples were obtained using a 2 × 2 factorial designs, which contained 2 cell lines (PEO4 and 2008) and 2 treatments (estrogen and placebo). Differentially expressed genes were identified by Bayesian methods, and the genes with P < 0.05 and |log2FC (fold change)| ≥0.5 were chosen as cut-off criterion. Differentially co-expressed genes (DCGs) and differentially regulated genes (DRGs) were, respectively, identified by DCe function and DRsort function in DCGL package. Topological structure analysis was performed on the important transcriptional factors (TFs) and genes in transcriptional regulatory network using tYNA. Functional enrichment analysis was, respectively, performed for DEGs and the important genes using Gene Ontology and KEGG databases. RESULTS: In total, 465 DEGs were identified. Functional enrichment analysis of DEGs indicated that ACVR2B, LTBP1, BMP7 and MYC involved in TGF-beta signaling pathway. The 2285 DCG pairs and 357 DRGs were identified. Topological structure analysis showed that 52 important TFs and 65 important genes were identified. Functional enrichment analysis of the important genes showed that TP53 and MLH1 participated in DNA damage response and the genes (ACVR2B, LTBP1, BMP7 and MYC) involved in TGF-beta signaling pathway. CONCLUSION: TP53, MLH1, ACVR2B, LTBP1 and BMP7 might participate in the pathogenesis of ovarian cancer.

Epigallocatechin-3-gallate (EGCG) inhibits 3-hydroxy-3-methylglutaryl-CoA reductase in the presence of glycerol.

The inhibition of 3-hydroxy-3-methylglutaryl CoA reductase (HMGCR) is considered able to decrease serum cholesterol levels and dramatically reduce the risk for cardiovascular and cerebrovascular diseases. The statins, competitive inhibitors of HMGCR, have been employed to control hypercholesterolemia. But their side effects, especially their safety of long-term administration have attracted great attention. Therefore, there is still an urgent requirement for the development of safer inhibitors of HMGCR with less serious side effects. In this study, we cloned and purified the catalytic domain of human HMGCR (△HMGCR), and applied the method of Ultra Performance Liquid Chromatography (UPLC) to assay △HMGCR activity and screen its inhibitors from natural products. The results indicated that EGCG can inhibit △HMGCR in the presence of some glycerol in vitro and can decrease cellular total cholesterol in HepG2 cells. As a consequence, it is promising to put EGCG into the development of hypolipidemic health product.

Synthesis of silane surface modified ZnO quantum dots with ultrastable, strong and tunable luminescence.

Surface modified ZnO quantum dots (QDs) with ultrastable, strong and tunable luminescence have been successfully prepared via silanization during the growth process by (3-(2,3-epoxypropoxy)propyl)trimethoxysilane. The as-prepared ZnO QDs are demonstrated to be promising for anti-counterfeit applications in expensive high-end liquors, etc.