scholarly journals Towards Al3+-Induced Manganese-Containing Superoxide Dismutase Inactivation and Conformational Changes: An Integrating Study with Docking Simulations

2011 ◽  
Vol 2011 ◽  
pp. 1-7
Author(s):  
Jiang-Liu Yang ◽  
Shang-Jun Yin ◽  
Yue-Xiu Si ◽  
Zhi-Rong Lü ◽  
Xiangrong Shao ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Conformational Changes ◽  
Tertiary Structure ◽  
Kinetic Studies ◽  
Computational Prediction ◽  
Enzyme Inactivation ◽  
Dependent Manner ◽  
Inhibitory Effects ◽  
Docking Simulations ◽  
Dose Dependent

Superoxide dismutase (SOD, EC 1.15.1.1) plays an important antioxidant defense role in skins exposed to oxygen. We studied the inhibitory effects of Al3+ on the activity and conformation of manganese-containing SOD (Mn-SOD). Mn-SOD was significantly inactivated by Al3+ in a dose-dependent manner. The kinetic studies showed that Al3+ inactivated Mn-SOD follows the first-order reaction. Al3+ increased the degree of secondary structure of Mn-SOD and also disrupted the tertiary structure of Mn-SOD, which directly resulted in enzyme inactivation. We further simulated the docking between Mn-SOD and Al3+ (binding energy for Dock 6.3: −14.07 kcal/mol) and suggested that ASP152 and GLU157 residues were predicted to interact with Al3+, which are not located in the Mn-contained active site. Our results provide insight into the inactivation of Mn-SOD during unfolding in the presence of Al3+ and allow us to describe a ligand binding via inhibition kinetics combined with the computational prediction.

scholarly journals Identification and Evaluation of Flavone-glucosides Isolated from Barley Sprouts and their Inhibitory Activity against Bacterial Neuraminidase

2014 ◽  
Vol 9 (10) ◽  
pp. 1934578X1400901
Author(s):  
Mi Jin Park ◽  
Ji-Eun Ra ◽  
Kyung Hye Seo ◽  
Ki-Chang Jang ◽  
Sang-Ik Han ◽  
...  
Keyword(s):  
Inhibitory Activity ◽  
Competitive Inhibition ◽  
Food Additives ◽  
Kinetic Studies ◽  
Dependent Manner ◽  
Health Food ◽  
Inhibitory Effects ◽  
Inhibitory Activities ◽  
The Individual ◽  
Dose Dependent

Neuraminidase (NA) is one of the key enzymes responsible for bacterial infection and pathogenesis. This study aimed to gain deeper insights into the inhibitory effects of flavone-glucosides (1–9) isolated from barley sprouts (BS) on neuraminidase activity. The isolated compounds were identified as, lutonarin (1), saponarin (2), isoorientin (3), orientin (4), isovitexin (5), isoscoparin-7- O-[6-sinapoyl]-glucoside (6), isoscoparin-7- O-[6-feruloyl]-glucoside (7), isovitexin-7- O-[6-sinapoyl]-glucoside (8), and isovitexin-7- O-[6-feruloyl]-glucoside (9). Among them, compounds 1–5 exhibited neuraminidase-inhibitory activities in a dose-dependent manner, with IC50 values ranging from 20.1 to 32.7 μM, in a non-competitive inhibition mode according to kinetic studies. Moreover, the individual flavone-glucoside levels differed notably, in particular, lutonarin (1) and saponarin (2) were shown to be present in the greatest amounts, according to UPLC analysis. Consequently, our results suggest that BS may be utilized as an effective NA inhibitor in human health food, additives, and feed.

Effect of ethanol on peptidases of hamster jejunal brush-border membrane

1982 ◽  
Vol 242 (5) ◽  
pp. G442-G447
Author(s):  
P. K. Dinda ◽  
I. T. Beck
Keyword(s):  
Conformational Changes ◽  
Brush Border ◽  
Brush Border Membrane ◽  
Kinetic Studies ◽  
Inhibitory Effect ◽  
Time Dependent ◽  
Peptidase Activity ◽  
Dependent Manner ◽  
Dose Dependent ◽  
Hydrolysis Of

This study was undertaken to investigate the effect of ethanol on the brush-border activity of the small intestine. Brush-border membrane isolated from hamster jejunum was incubated with L-phenylalanylglycine (Phe-Gly), L-leucylglycine (Leu-Gly), or glycyl-L-tyrosine (Gly-Tyr) in the absence and presence of 1-5% (wt/vol) ethanol, and the L-amino acids liberated were determined. Ethanol was found to depress the hydrolysis of all peptides in a dose-dependent manner. The inhibitory effect of ethanol on the peptidases does not appear to be time dependent. The ethanol-induced inhibition of peptidase activity is completely reversible. Kinetic studies indicate that ethanol caused a decrease in the Vmax of the enzymes responsible for the hydrolysis of the Phe-Gly and Gly-Tyr but did not have any effect on their Km. In the hydrolysis of Leu-Gly, two enzymes were involved, and ethanol depressed the Vmax of both without affecting the Km of either. These findings suggest that ethanol produces conformational changes of the peptidases involved in the hydrolysis of these three dipeptides.

scholarly journals Effect of lemon peel flavonoids on anti-fatigue and anti-oxidation capacities of exhaustive exercise mice

2020 ◽  
Vol 63 (1) ◽  
Author(s):  
Guili Bao ◽  
Yinglong Zhang ◽  
Xiaoguang Yang
Keyword(s):  
Skeletal Muscle ◽  
Superoxide Dismutase ◽  
Manganese Superoxide Dismutase ◽  
Fatty Acid Content ◽  
Hepatic Tissue ◽  
Control Group ◽  
Dependent Manner ◽  
Lemon Peel ◽  
Tnf Α ◽  
Dose Dependent

AbstractIn this study, lemon peel flavonoids (LPF) were administered to investigate its effect on the anti-fatigue and antioxidant capacity of mice that undergo exercise until exhaustion. LPF (88.36 min in LPFH group mice) significantly increased the exhaustion swimming time compare to the untreated mice (40.36 min), increased the liver glycogen and free fatty acid content in mice and reduce lactic acid and BUN content in a dose-dependent manner. As the concentration of lemon peel flavonoids increased, the serum creatine kinase, aspartate aminotransferase, and alanine aminotransferase levels of mice gradually decreased. LPF increases superoxide dismutase (SOD) and catalase (CAT) levels in mice and reduces malondialdehyde levels in a dose-dependent manner. And LPF raises hepatic tissue SOD, CAT activities and reduces skeletal muscle tissue iNOS, TNF-α levels of mice compared to the control group. LPF also enhanced the expression of copper/zinc-superoxide dismutase (Cu/Zn-SOD), manganese-superoxide dismutase (Mn-SOD), and CAT mRNA in mouse liver tissue. LPF also enhanced the expression of alanine/serine/cysteine/threonine transporter 1 (ASCT1) mRNA and attenuate the expression of syncytin-1, inducible nitric oxide synthase (iNOS), and tumor necrosis factor (TNF)-α in mouse skeletal muscle. According to high-performance liquid chromatography (HPLC) analysis, it was found that LPF contains flavonoids such as rutin, astragalin, isomangiferin, naringin, and quercetin. Our experimental data show that LPF has good anti-fatigue effects and anti-oxidation ability. In summary, LPF has high prospects to be developed and added to nutritional supplements.

Activation of Phosphatidylinositol-Linked Novel D1 Dopamine Receptors Inhibits High-Voltage-Activated Ca2+ Currents in Primary Cultured Striatal Neurons

2009 ◽  
Vol 101 (5) ◽  
pp. 2230-2238 ◽  
Author(s):  
Li-Qun Ma ◽  
Chao Liu ◽  
Fang Wang ◽  
Na Xie ◽  
Jun Gu ◽  
...  
Keyword(s):  
Dopamine Receptor ◽  
High Voltage ◽  
Dependent Manner ◽  
Striatal Neurons ◽  
Inhibitory Effects ◽  
Patch Clamp Technique ◽  
Whole Cell Patch Clamp ◽  
Intracellular Ca ◽  
Dose Dependent

Recent evidences indicate the existence of a putative novel phosphatidylinositol (PI)-linked D1 dopamine receptor that mediates excellent anti-Parkinsonian but less severe dyskinesia action. To further understand the basic physiological function of this receptor in brain, the effects of a PI-linked D1 dopamine receptor-selective agonist 6-chloro-7,8-dihydroxy-3-methyl-1-(3-methylphenyl)-2,3,4,5-tetrahydro-1H-3-benzazepine (SKF83959) on high-voltage activated (HVA) Ca2+ currents in primary cultured striatal neurons were investigated by whole cell patch-clamp technique. The results indicated that stimulation by SKF83959 induced an inhibition of HVA Ca2+ currents in a dose-dependent manner in substance-P (SP)-immunoreactive striatal neurons. Application of D1 receptor, but not D2, α1 adrenergic, 5-HT receptor, or cholinoceptor antagonist prevented SKF83959-induced reduction, indicating that a D1 receptor-mediated event assumed via PI-linked D1 receptor. SKF83959-induced inhibitory modulation was mediated by activation of phospholipase C (PLC), mobilization of intracellular Ca2+ stores and activation of calcineurin. Furthermore, the inhibitory effects were attenuated significantly by the L-type calcium channel antagonist nifedipine, suggesting that L-type calcium channels involved in the regulation induced by SKF83959. These findings may help to further understand the functional role of the PI-linked dopamine receptor in brain.

scholarly journals The Effects of Salacia reticulata on Anti-Cellular Oxidants and Melanogenesis Inhibition in α-MSH-stimulated and UV Irradiated B16 Melanoma Cells

2014 ◽  
Vol 9 (4) ◽  
pp. 1934578X1400900
Author(s):  
Prasit Sirwannalert ◽  
Ryusho Kariya ◽  
Ikuko Suzu ◽  
Seiji Okada
Keyword(s):  
Melanoma Cells ◽  
Pharmaceutical Products ◽  
B16 Melanoma ◽  
Tyrosinase Activity ◽  
Root Extract ◽  
Dependent Manner ◽  
Inhibitory Effects ◽  
B16 Melanoma Cells ◽  
Dose Dependent ◽  
Salacia Reticulata

The purposes of this study were to investigate the inhibitory effects of Salacia reticulata Tul. root extract on cellular oxidants and melanogenesis in B16 melanoma cells. Cells treated with non-toxic doses of S. reticulata root extract were investigated for their effects on melanogenesis, cellular tyrosinase activity and cellular oxidant scavenging activity. The results indicated that S. reticulata extract inhibited melanin synthesis and tyrosinase activity in α-MSH-induced or UV-irradiated B16 melanoma cells in a dose dependent manner. Additionally, the extract also exhibited anti-cellular oxidants in UV-induced radical melanoma cells. Altogether, these results suggested that S. reticulata root extract has roles in suppression of melanogenesis and oxidant inhibition. S. reticulata root extract may be a potential source for the development of pharmaceutical products for treatment of skin hyperpigmentation disorders.

Interaction between perchlorate and nifedipine on insulin secretion from mouse pancreastic islets

1993 ◽  
Vol 13 (2) ◽  
pp. 107-117 ◽  
Author(s):  
Gerd Larsson-Nyrén ◽  
Janove Sehlin
Keyword(s):  
Insulin Secretion ◽  
Insulin Release ◽  
Specific Effect ◽  
Maximum Effect ◽  
Dependent Manner ◽  
Inhibitory Effects ◽  
Maximum Inhibition ◽  
Second Phases ◽  
Dose Dependent ◽  
Higher Sensitivity

In order to elucidate the mechanisms responsible for the stimulatory effect of perchlorate (ClO4−) on insulin secretion, we have investigated the interaction between this chaotropic anion and the organic calcium antagonist nifedipine. This drug, known as a blocker of L-type calcium channels, was chosen as a tool to test the idea that ClO4− acts on insulin secretion by stimulating the gating of voltage-controlled Ca2+ channels. ClO4− amplified the stimulatory effect of D-glucose on insulin release from perfused pancreas (first and second phases) as well as from isolated islets incubated in static incubations for 60 min. This indicates that ClO4− amplifies physiologically regulated insulin secretion. Nifedipine reduced D-glucose-induced (20 mM) insulin release in a dose-dependent manner with half-maximum effect at about 0.8 μM and apparent maximum effect at 5 μM nifedipine. In the presence of 20 mM D-glucose, the inhibitory effects of 0.5, 1 or 5 μM nifedipine were only slightly, if at all, counteracted by perchlorate. When 12 mM ClO4− and 20 mM D-glucose were combined, calculation of the specific effect of ClO4− revealed that nifedipine produced almost maximum inhibition already at 0.05 μM. Thus, the perchlorate-induced amplification of D-glucose-stimulated insulin release shows higher sensitivity to nifedipine than the D-glucose-effect as such. This supports the hypothesis that perchlorate primarily affects the voltage-sensitive L-type calcium channel in the β-cell.

scholarly journals Kinetics of Mushroom Tyrosinase and Melanogenesis Inhibition byN-Acetyl-pentapeptides

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Ching-Yi Lien ◽  
Ching-Yu Chen ◽  
Shih-Ting Lai ◽  
Chin-Feng Chan
Keyword(s):  
Kojic Acid ◽  
Lag Time ◽  
Melanoma Cells ◽  
Dependent Manner ◽  
Mushroom Tyrosinase ◽  
Inhibitory Effects ◽  
B16f10 Melanoma ◽  
B16f10 Melanoma Cells ◽  
Kinetics Of ◽  
Dose Dependent

We investigated the kinetics of 4N-acetyl-pentapeptides, Ac-P1, Ac-P2, Ac-P3, and Ac-P4, regarding inhibition of mushroom tyrosinase activity. The peptides sequences of Ac-P1, Ac-P2, Ac-P3, and Ac-P4 were Ac-RSRFK, Ac-KSRFR, Ac-KSSFR, and Ac-RSRFS, respectively. The 4N-acetyl-pentapeptides were able to reduce the oxidation ofL-DOPA by tyrosinase in a dose-dependent manner. Of the 4N-acetyl-pentapeptides, only Ac-P4 exhibited lag time (80 s) at a concentration of 0.5 mg/mL. The tyrosinase inhibitory effects of Ac-P4 (IC500.29 mg/mL) were more effective than those of Ac-P1, Ac-P2, and Ac-P3, in which IC50s were 0.75 mg/mL, 0.78 mg/mL, and 0.81 mg/mL, respectively. Kinetic analysis demonstrated that all 4N-acetyl-pentapeptides were mixed-type tyrosinase inhibitors. Furthermore, 0.1 mg/mL of Ac-P4 exhibited significant melanogenesis inhibition on B16F10 melanoma cells and was more effective than kojic acid. The melanogenesis inhibition of Ac-P4 was dose-dependent and did not induce any cytotoxicity on B16F10 melanoma cells.

scholarly journals Rainbow trout hypocalcin stimulates bone resorption in embryonic mouse calvaria in vitro in a PTH-like fashion

1989 ◽  
Vol 143 (1) ◽  
pp. 165-175
Author(s):  
F. P. Lafeber ◽  
M. P. Herrmann-Erlee ◽  
G. Flik ◽  
S. E. Wendelaar Bonga
Keyword(s):  
Bone Resorption ◽  
Cyclic Amp ◽  
Tertiary Structure ◽  
Lactate Production ◽  
Dependent Manner ◽  
Embryonic Mouse ◽  
Molar Basis ◽  
Mouse Calvaria ◽  
Dose Dependent

Hypocalcin, the major hormone with hypocalcaemic action in fish, was isolated from trout corpuscles of Stannius (SCs). The bioactivity of hypocalcin was assessed in a parathyroid hormone (PTH) bioassay involving bone resorption in embryonic mouse calvaria. Calcium and phosphate release and lactate production were stimulated in a dose-dependent manner by hypocalcin. On a molar basis about equal amounts of hypocalcin and PTH were required to obtain similar effects in this assay. Hypocalcin did not stimulate cyclic AMP production either in mouse calvaria or in cultured osteoblasts. In this respect hypocalcin resembles shortened or N-terminus-modified PTH molecules that induce bone resorption without increasing cyclic AMP levels. Since hypocalcin and PTH have comparable bioactivity in this mammalian bioassay (as well as in fish bioassays), we tentatively suggest that both hormones are structurally similar and that both hormones may act via the same receptors. The two hormones show no resemblance to one another in primary structure, so we suggest that they have similarities in tertiary structure.

Acetate Suppresses Lipopolysaccharide-stimulated Nitric Oxide Production in Primary Rat Microglia but not in BV-2 Microglia Cells

2020 ◽  
Vol 14 (2) ◽  
pp. 253-260
Author(s):  
Mitsuaki Moriyama ◽  
Yasunori Nishimura ◽  
Ryosuke Kurebayashi ◽  
Tomoki Minamihata ◽  
Kenji Kawabe ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Ethics Committees ◽  
No Production ◽  
Dependent Manner ◽  
Intraventricular Administration ◽  
Ros Production ◽  
Primary Microglia ◽  
Inhibitory Effects ◽  
Intracellular Ros ◽  
Dose Dependent

Aims: To show that acetate attenuates neuroinflammatory responses in activated microglia. Background: Dietary acetate supplementation alleviates neuroglial activation in a rat model of neuroinflammation induced by intraventricular administration of lipopolysaccharide (LPS). However, the precise mechanism(s) underlying the anti-inflammatory effect of acetate is not fully understood. Objective: To determine whether acetate has inhibitory effects on LPS-induced neuroinflammatory responses in microglia. Methods: We examined LPS-stimulated nitric oxide (NO) production in primary rat microglia and BV-2 cells. Protein expression of inducible NO synthase (iNOS) was determined by western blot analysis. The intracellular generation of reactive oxygen species (ROS) and glutathione (GSH) were also evaluated. Results: In primary microglia, acetate decreased LPS-stimulated NO production in a dose-dependent manner, reaching significance at greater than 10 mM, and cell viability was not affected. Acetate suppressed LPS-induced expression of iNOS protein concomitantly with the decrease in NO. The LPS-induced increase in intracellular ROS production was attenuated by acetate. In addition, acetate prevented LPSinduced reduction of GSH. Notably, such suppressive effects of acetate on NO and ROS production were not observed in BV-2 cells. Conclusion: These findings suggest that acetate may alleviate neuroinflammatory responses by attenuating NO and ROS production in primary microglia but not in BV-2 cells. Other: All animals received humane care and the animal protocols used in this study were approved by the Ethics Committees for Animal Experimentation.

Effects of removing heat and phlegm prescription on the proliferation and autoantigens expression of esophageal carcinoma cell.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e16510-e16510
Author(s):  
Fuchun Si
Keyword(s):  
Esophageal Carcinoma ◽  
G1 Phase ◽  
Dependent Manner ◽  
Inhibitory Effects ◽  
Ethanol Extraction ◽  
Phase Arrest ◽  
G1 Phase Arrest ◽  
M Phase ◽  
Ic50 Values ◽  
Dose Dependent

e16510 Background: o explore the effects of removing heat and phlegm prescription (RHPP) on the proliferation and autoantigens expression of esophageal carcinoma(EC) cell, so as to provide basis for the molecular pathogenesis and clinical medication of EC. Methods: RHPP was developed by us for treating EC, EC autoantigens CK13, CK16, CaD, ACTG2 were identified in our previous studies. The effects of RHPP and and its ethanol extraction on the proliferation, cell cycle and autoantigen protein expression of Eca109 cell, EC9706 cell and TE-1 cell were investigated by MTT assay, flow cytometry and western blot analysis. Results: RHPP and its removing heat (RH) and removing phlegm (RP) separated prescriptions all have inhibitory effects on the proliferation of EC9706, EC109 and TE-1 cells in dose-dependent and time-dependent manner, changed morphology of four esophageal carcinoma cells, which appeared as round with rough edges, karyopyknosis, and karyorrhexis. Ic50 values of RHPP for Ec9706, Eca109 and TE1 cell were 33.31 ug·ml−1, 20.70 ug·ml−1, 21.93 ug·ml−1 respectively, while Ic50 values of RHPP’s ethanol extraction for Ec9706, Eca109, TE1 were 0.653 ug·ml−1, 0.082 ug·ml−1, 0.172 ug·ml−1 respectively. RHPP and RP induced G2/M phase arrest in EC109 and TE-1 cells, while RH induced G0/G1 phase arrest in EC109 and TE-1 cells; RHPP and RP induced G0/G1 phase arrest in EC9706 cells, while RH induced S phase arrest in EC9706 cells. RHPP and its two separated prescription could downregulate CK16, CaD, ACTG2 expression and upregulate CK13 expression. Conclusions: Autoantigens CK13, CK16, CaD and ACTG2 were expressed in EC cell, RHPP could regulate these four autoantigens expression. This study provides new basis for the EC mlecular mechanism and development of anti-esophageal carcinoma drugs in traditional Chinese medicine.

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