scholarly journals Enhancement of Enduracidin Accumulation from Sweet Sorghum Juice via Alleviation of Oxidative Damage in Streptomyces Fungicidicus M30

2020 ◽  
Author(s):  
Lu Liu ◽  
Wei Hu ◽  
Jihong Chen ◽  
Wenjian Li ◽  
Libin Zhou
Keyword(s):  
Cell Growth ◽  
Vitamin C ◽  
Sweet Sorghum ◽  
Cell Damage ◽  
Inhibitory Effect ◽  
Antioxidant Enzyme Activities ◽  
Methyl Paraben ◽  
Sweet Sorghum Juice ◽  
Long Term Storage ◽  
Chemical Preservative

Abstract Background: Sweet sorghum juice is the preferred feedstock for enduracidin production, but the fermentation efficiency still need to be further enhanced. Oxygen-mediated microbial cell damage is an effective way to boost cell growth and metabolite accumulation in aerobic fermentation. However, this strategy on enduracidin production from sweet sorghum juice has not been reported yet. Results: In this study, enduracidin production titer was significantly enhanced when 90 mM Vitamin C was added at 4 d of fermentation. The enhanced T-AOC and antioxidant enzyme activities may help to further understand the mechanism of Vitamin C effect on regulation of enduracidin accumulation in S. fungicidicus M30. The effects of chemical preservative methyl paraben on cell growth and enduracidin production were also evaluated, and 0.04 g/L of methyl paraben had no significant inhibitory effect on cell growth and enduracidin production, indicating that the concentrated sweet sorghum juice assisted by methyl paraben for a long-term storage can be used as the substrate for enduracidin production effectively. Finally, based on the group with 0.04 g/L of methyl paraben and 90 mM Vitamin C, a final enduracidin concentration of 1.14 g/L was achieved from clarificated sweet sorghum juice by M30 strain. Conclusions: This work provided a promising strategy to enhance enduracidin production using sweet sorghum juice via adding the antioxidant to boost antioxidant capacity in S. fungicidicus.

Neuroprotective Effects of Extracts from the Radix Curcuma aromatica on H2O2-induced Damage in PC12 Cells

2018 ◽  
Vol 21 (8) ◽  
pp. 571-582 ◽  
Author(s):  
Juxiang Liu ◽  
Lianli Zhang ◽  
Dan Liu ◽  
Baocai Li ◽  
Mi Zhang
Keyword(s):  
Oxidative Stress ◽  
Pc12 Cells ◽  
Caspase 3 ◽  
Cell Damage ◽  
Positive Control ◽  
Neuroprotective Activity ◽  
Antioxidant Enzyme Activities ◽  
Morphologic Change ◽  
Neuroprotective Effects ◽  
Etoh Extract

Aim & Objectives: Curcuminoids are characteristic constituents in Curcuma, displaying obviously neuroprotective activities against oxidative stress. As one of the Traditional Chinese Medicines from Curcuma, the radix of Curcuma aromatica is also rich in those chemicals, but its neuroprotective activity and mechanism remain unknown. The aim of the current study is to evaluate the neuroprotective effects of extracts from the radix of C. aromatica (ECAs) on H2O2-damaged PC12 cells. Material and Methods: The model of oxidative stress damage was established by treatment of 400 µM H2O2 on PC12 to induce cell damage. After the treatment of ECWs for 24 h, the cell viability, LDH, SOD, CAT and GSH were measured to evaluate the neuroprotection of ECAs on that model. The potential action mechanism was studied by measurement of level of ROS, cell apoptosis rate, mitochondrial membrane potential (MMP), morphologic change, the intracellular Ca2+ content (F340/F380) and the expressions of Bcl-2, Bax and Caspase-3. Additionally, the constituents from tested extracts were analyzed by HPLC-DAD-Q-TOF-MS method. Results: Compared with a positive control, Vitamin E, 10 µg/ml of 95% EtOH extract (HCECA) and 75% EtOH extract (MCECA) can markedly increase the rate of cell survival and enhance the antioxidant enzyme activities of SOD, CAT, increase the levels of GSH, decrease LDH release and the level of ROS, attenuate the intracellular Ca2+ overloading, reduce the cell apoptotic rate and stabilize MMP, down-regulate Bcl-2 expression, up-regulate Bax and caspase-3 expression, and improve the change of cell morphology. The chemical analysis showed that diarylheptanoids and sesquiterpenoids are the major chemicals in tested extracts and the former were richer in HCECA and MCECA than others. Conclusions: These findings indicated that the effects of HCECA and MCECA on inhibiting the cells damage induced by H2O2 in PC12 are better than other extracts from the radix of C. aromatica, and the active constituents with neuroprotective effects consisting in those two active extracts are diarylheptanoids.

Amperometric assay of vitamin C using an ascorbate oxidase enzyme electrode

1979 ◽  
Vol 44 (11) ◽  
pp. 3395-3404 ◽  
Author(s):  
Pavel Posádka ◽  
Lumír Macholán
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Oxygen Electrode ◽  
Ascorbate Oxidase ◽  
Current Response ◽  
Reaction Conditions ◽  
Long Term Storage ◽  
Oxidase Enzyme ◽  
Optimal Reaction

An oxygen electrode of the Clark type, coated by a thin, active layer of chemically insolubilized ascorbate oxidase from squash peelings specifically detects by measuring oxygen uptake 10 to 400 μg of ascorbic acid in 3 ml of phosphate buffer. The record of current response to substrate addition lasts 1-2 min. The ascorbic acid values determined in various samples of fruit juices are in good agreement with the data obtained by titration and polarography. The suitable composition of the membrane and its lifetime and stability during long-term storage are described; optimal reaction conditions of vitamin C determination and the possibilities of interference of other compounds are also examined. Of the 35 phenols, aromatic amines and acids tested chlorogenic acid only can cause a positive error provided that the enzyme membrane has been prepared from ascorbate oxidase of high purity.

scholarly journals Effect of Cell Growth on Hepatitis C Virus (HCV) Replication and a Mechanism of Cell Confluence-Based Inhibition of HCV RNA and Protein Expression

2006 ◽  
Vol 80 (3) ◽  
pp. 1181-1190 ◽  
Author(s):  
Heather B. Nelson ◽  
Hengli Tang
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Cell Growth ◽  
De Novo ◽  
Physiological State ◽  
Inhibitory Effect ◽  
Cell Number ◽  
Serum Starvation ◽  
Hcv Rna ◽  
Cell Growth Arrest

ABSTRACT An intimate relationship between hepatitis C virus (HCV) replication and the physiological state of the host liver cells has been reported. In particular, a highly reproducible and reversible inhibitory effect of high cell density on HCV replication was observed: high levels of HCV RNA and protein can be detected in actively growing cells but decline sharply when the replicon cells reach confluence. Arrested cell growth of confluent cells has been proposed to be responsible for the inhibitory effect. Indeed, other means of arresting cell growth have also been shown to inhibit HCV replication. Here, we report a detailed study of the effect of cell growth and confluence on HCV replication using a flow cytometry-based assay that is not biased against cytostasis and reduced cell number. Although we readily reproduced the inhibitory effect of cell confluence on HCV replication, we found no evidence of inhibition by serum starvation, which arrested cell growth as expected. In addition, we observed no inhibitory effect by agents that perturb the cell cycle. Instead, our results suggest that the reduced intracellular pools of nucleosides account for the suppression of HCV expression in confluent cells, possibly through the shutoff of the de novo nucleoside biosynthetic pathway when cells become confluent. Adding exogenous uridine and cytidine to the culture medium restored HCV replication and expression in confluent cells. These results suggest that cell growth arrest is not sufficient for HCV replicon inhibition and reveal a mechanism for HCV RNA inhibition by cell confluence.

scholarly journals Effect of Aspirin on Cell Growth of Human MG-63 Osteosarcoma Line

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
E. De Luna-Bertos ◽  
J. Ramos-Torrecillas ◽  
O. García-Martínez ◽  
L. Díaz-Rodríguez ◽  
C. Ruiz
Keyword(s):  
Cell Cycle ◽  
Cell Growth ◽  
Cell Line ◽  
Bone Tissue ◽  
Tissue Repair ◽  
Mg63 Cell ◽  
Pharmacological Action ◽  
Inhibitory Effect ◽  
Cell Cycle Analysis ◽  
Inflammatory Drugs

Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used in bone tissue repair treatment for their pharmacological action. The objective of this study was to determine the effect of aspirin, on osteoblast growth, using MG63 cell line as osteoblast model. MTT spectrophotometry results showed that 20, 100, and 1000 μM aspirin doses have an inhibitory effect on growth. Cell cycle analysis revealed that aspirin doses of 100 and 1000 μM arrest the cell cycle in phase GO/G1. Parallel apoptosis/necrosis studies showed no changes in comparison to control cells after treatment with 1 or 10 μM aspirin but a significantly increased percentage of cells in apoptosis at doses of 20, 100, and 1000 μM. We highlight that treatment of osteoblast-like cells with 1000 μM aspirin increased not only the percentage of cells in apoptosis but also the percentage of necrotic cells, which was not observed in aspirin treatments at lower doses.

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