2.Effects of alpha-Lipoic Acid on the Antioxidant System in Prostate Cancer Cells.
Sunghyup CHOI ; Kweonsik MIN ; Ikjoon CHOI ; Dongil KANG
Korean Journal of Urology 2009;50(1):72-80
PURPOSE: Overproduction of lipid peroxidation byproducts and disturbances in the antioxidant defense system have been implicated in the pathogenesis of several diseases, including prostate cancer. Although several studies have investigated the level of lipid peroxidation and antioxidants in prostate cancer, there are no reports on alpha-lipoic acid (ALA) in prostate cancer. Here we assessed the effects of ALA on the antioxidant system in prostate cancer cells. MATERIALS AND METHODS: PC-3, LNCaP, and RWPE-2 cell lines were used in this study. Redox factor (Ref)-1 protein was measured by Western blot analysis after treatment with ALA. Real-time polymerase chain reaction (RT-PCR) was performed to detect superoxide dismutase (SOD)-1 and -2, catalase, and glutathione peroxidase (GSH-Px) mRNA expression. RESULTS: Ref-1 was expressed in the PC-3, LNCaP, and RWPE-2 cell lines. The expression of Ref-1 protein was increased after treatment with 125, 250, and 500 microM ALA in the PC-3 (p<0.05) and LNCaP (p>0.05) cells compared with the RWPE-2 cells at 48 hours. In PC-3 cells, the mRNA expression of SOD-1, SOD-2, catalase, and GSH-Px decreased at 24 and 48 hours dose-dependently compared with that in RWPE-2 cells (p<0.05). The mRNA expression of SOD-2, catalase, and GSH-Px in LNCaP cell decreased at 48 hours dose-dependently (p<0.05). CONCLUSIONS: The expression of Ref-1 protein and antioxidant enzymes changed after ALA exposure in prostate cancer cells. Our findings suggest that ALA affects the antioxidant system in prostate cancer cells and may be related to compensatory changes in the antioxidant defense system of the cells.
Antioxidants
;
Blotting, Western
;
Catalase
;
Cell Line
;
Glutathione Peroxidase
;
Lipid Peroxidation
;
Oxidation-Reduction
;
Prostate
;
Prostatic Neoplasms
;
Real-Time Polymerase Chain Reaction
;
RNA, Messenger
;
Superoxide Dismutase
;
Thioctic Acid
4.Total phenolic, total flavonoid content, and antioxidant capacity of the leaves of Meyna spinosa Roxb., an Indian medicinal plant.
Saikat SEN ; Biplab DE ; N DEVANNA ; Raja CHAKRABORTY
Chinese Journal of Natural Medicines (English Ed.) 2013;11(2):149-157
AIM:
The objective of the present study was to determine the total phenolic and total flavonoid contents, and to evaluate the antioxidant potential of different leaf extracts of Meyna spinosa Roxb. ex Link, a traditional medicinal plant of India.
METHODS:
Free radical scavenging and antioxidant potential of the methanol, ethyl acetate, and petroleum ether extracts of Meyna spinosa leaves were investigated using several in vitro and ex vivo assays, including the 2, 2-diphenyl-picrylhydrazyl radical scavenging, superoxide anion scavenging, hydroxyl radical scavenging, nitric oxide radical scavenging, hydrogen peroxide scavenging activity, metal chelating assay, and reducing power ability method. Total antioxidant activity of the extracts was estimated by the ferric thiocyanate method. Inhibition assay of lipid peroxidation and oxidative hemolysis were also performed to confirm the protective effect of the extracts. Total phenolic and total flavonoid contents of the extracts were estimated using standard chemical assay procedures.
RESULTS:
Methanol extracts showed the highest polyphenolic content and possessed the better antioxidant activity than the other two extracts. Total phenolic and total flavonoid contents in the methanol extract were (90.08 ± 0.44) mg gallic acid equivalents/g and (58.50 ± 0.09) mg quercetin equivalents/g, respectively. The IC50 of the methanol extract in the DPPH(·), superoxide anion, hydroxyl radical, nitric oxide radical, hydrogen peroxide scavenging activity and metal chelating assays were (16.4 ± 0.41), (35.9 ± 0.19), (24.1 ± 0.33), (23.7 ± 0.09), (126.8 ± 2.92), and (117.2 ± 1.01) μg·mL(-1), respectively. The methanol extract showed potent reducing power ability, total antioxidant activity, and significantly inhibit lipid peroxidation and oxidative hemolysis which was similar to that of standards.
CONCLUSION
The results indicated a direct correlation between the antioxidant activity and the polyphenolic content of the extracts, which may the foremost contributors to the antioxidant activity of the plant. The present study confirmed that the methanol extract of Meyna spinosa leaves is a potential source of natural antioxidants.
Antioxidants
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chemistry
;
Celastraceae
;
chemistry
;
Flavonoids
;
chemistry
;
India
;
Lipid Peroxidation
;
Medicine, East Asian Traditional
;
Oxidation-Reduction
;
Phenols
;
chemistry
;
Plant Extracts
;
chemistry
;
Plant Leaves
;
chemistry
;
Plants, Medicinal
;
chemistry
5.Construction of sugar-based microbial fuel cells by dissimilatory metal reduction bacteria.
Zhi-Dan LIU ; Jing LIAN ; Zhu-Wei DU ; Hao-Ran LI
Chinese Journal of Biotechnology 2006;22(1):131-137
Dissimilatory Metal Reduction Bacteria play an important role in the anaerobic environment. This kind of bacteria gains energy by coupling the oxidation of organic acid or sugars to the reduction of metal oxides. The graphite electrode rode can also be used as the final electron acceptor due to its similarity to solid metal oxides. Based on this biological mechanism, Dissimilatory Metal Reduction Bacteria Rhodoferaxferrireducens was used to construct a suit of microbial fuel cells with sugars as fuel, and the process and mechanism of electricity generation was studied. Rhodoferax ferrireducens was inoculated into the anode chamber in which a graphite electrode served as the final electron acceptor and glucose as the sole electron donor. It was showed that current density was up to 158mA/m2 with the resistance of 510omega at the normal temperature (platform voltage was around 0.46V, the effectual electrode surface was 57cm2). Following 20days' growth a large amount of bacteria cells attached to the electrode surface had been observed through the SEM images. The plandtonic cell protein concentration was 140mg/L and the attached biomass of electrode surface was 1180mg/m2 determined by the Bradford method, which indicated quite a few bacteria attached to the electrode. By analyzing the voltage value measured by the data acquisition system, it was proved that microbial electricity generation attributed mainly to the electrochemically and biologically active cells attached to the electrode, while the planktonic cells had no ability to catalyze electricity generation and almost had not electrochemically and biologically active. Furthermore, this kind of microbial fuel cells exhibited a good electrochemical cycle property and proved to be efficient in biomass utilization and energy restore since other sugars like fructose, sucrose, even xylose, could be oxidized and finally decomposed. Vast waste biomass in the form of carbohydrates is discarded in the environment. Not only is contamination of the environment caused by the discarded biomass, but also abundant energy stored in the biomass is drained away in vain. The sugar-based microbial fuel cells constructed by Rhodoferax ferrireducens could effectively transform the energy stored in sugars into electricity. Meanwhile, the microbial fuel cells presented in this paper, which could work cleanly at normal temperature with a good cycle property, showed a promising future application in this field.
Bioelectric Energy Sources
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microbiology
;
Comamonadaceae
;
metabolism
;
Electricity
;
Electron Transport
;
Equipment Failure
;
Glucose
;
metabolism
;
Oxidation-Reduction
6.Molecular ecological network reveals the response of metallurgical microorganisms to energy substrates.
Junming XIONG ; Liyuan MA ; Shanshan HUANG ; Xiangliang LI ; Hongmei WANG
Chinese Journal of Biotechnology 2020;36(12):2674-2684
By analyzing the shift of microbial communities under different iron/sulfur ratios, the response of metallurgical microorganisms to energy substrates was investigated based on molecular ecological networks. High-throughput sequencing of microbial samples from different domesticated batches was conducted to analyze the changes in community composition, alpha and beta diversity. Based on the molecular ecological network, the interactions between microorganisms under different iron/sulfur ratios were explored. Keystones were identified to analyze the community response to energy substrates. In the process of domestication based on different energy substrates, the dominant species in the in iron-rich and sulfur-less community were Acidithiobacillus ferrooxidans and A. ferriphilus. A. thiooxidans accounted for up to 90% in the sulfur-rich and iron-less community after 3 domesticating batches. The results of alpha and beta diversity analysis show that the domestication process of sulfur-rich and iron-less substrates reduced the diversity of microbial communities. Molecular ecological network analysis shows that the keystones were all rare species with low abundance. During the domestication by sulfur-rich and iron-less energy substrates, the bacterial species had a closer symbiotic relationship and the community was more stable. Through this domestication experiment, the impact of different energy substrates on microbial aggregation was clarified. Domesticating metallurgical microorganisms by using sulfur-rich and iron-less energy substrates made the microbial colonies to be more stable, which was conducive to the oxidation of iron and sulfur, promoting the dissolution of sulfide minerals. Our findings provide a reference for the directional domestication of metallurgical microorganisms.
Acidithiobacillus/genetics*
;
Iron
;
Minerals
;
Oxidation-Reduction
;
Sulfur
7.Bioconversion of methane by metabolically engineered methanotrophs.
Chinese Journal of Biotechnology 2021;37(3):816-830
Due to abundant availability of shale gas and biogas, methane has been considered as one of the most potential carbon sources for industrial biotechnology. Methanotrophs carrying the native methane monooxygenase are capable of using methane as a sole energy and carbon source, which provides a novel strategy for reducing greenhouse gas emission and substituting edible substrates used in bioconversion processes. With the rapid development of genetic engineering tools and biosynthesis techniques, various strategies for improving the efficiency of methane bioconversion have been achieved to produce a variety of commodity bio-based products. Herein, we summarize several important aspects related with methane utilization and metabolic engineering of methanotrophs, including the modification of methane oxidation pathways, the construction of efficient cell factories, and biosynthesis of chemicals and fuels. Finally, the prospects and challenges of the future development of methane bioconversion are also discussed.
Biofuels
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Biotechnology
;
Metabolic Engineering
;
Methane
;
Oxidation-Reduction
8.Chemical synthesis of a synthetically useful L-galactosaminuronic acid building block.
Chun-Jun QIN ; Hong-Li HOU ; Mei-Ru DING ; Yi-Kuan QI ; Guang-Zong TIAN ; Xiao-Peng ZOU ; Jun-Jie FU ; Jing HU ; Jian YIN
Chinese Journal of Natural Medicines (English Ed.) 2022;20(5):387-392
Most bacterial cell surface glycans are structurally unique, and have been considered as ideal target molecules for the developments of detection and diagnosis techniques, as well as vaccines. Chemical synthesis has been a promising approach to prepare well-defined oligosaccharides, facilitating the structure-activity relationship exploration and biomedical applications of bacterial glycans. L-Galactosaminuronic acid is a rare sugar that has been only found in cell surface glycans of gram-negative bacteria. Here, an orthogonally protected L-galactosaminuronic acid building block was designed and chemically synthesized. A synthetic strategy based on glycal addition and TEMPO/BAIB-mediated C6 oxidation served well for the transformation of commercial L-galactose to the corresponding L-galactosaminuronic acid. Notably, the C6 oxidation of the allyl glycoside was more efficient than that of the selenoglycoside. In addition, a balance between the formation of allyl glycoside and the recovery of selenoglycoside was essential to improve efficiency of the NIS/TfOH-catalyzed allylation. This synthetically useful L-galactosaminuronic acid building block will provide a basis for the syntheses of complex bacterial glycans.
Carbohydrates
;
Glycosides
;
Oligosaccharides
;
Oxidation-Reduction
;
Polysaccharides/chemistry*
9.Oxidative Damage to Macromolecules in Atopic Dermatitis Patients.
Eunil LEE ; Eun Ha OH ; Hae Jun SONG ; Won Jun CHOI ; Jin Ok BAEK ; Jong Rok LEE ; Joo Young ROH
Korean Journal of Dermatology 2015;53(6):456-461
BACKGROUND: Excessive exposure to reactive oxygen species (ROS) or decreased antioxidants leads to damage of proteins, lipids, and DNA. Previous studies suggest that oxidative stress may be important in the pathogenesis of atopic dermatitis. OBJECTIVE: To investigate whether oxidative stress is increased in atopic dermatitis patients compared to a normal control group, we examined DNA damage, lipid peroxidation, ROS production and antioxidant expression. METHODS: Patients with atopic dermatitis (n=16; mean Scoring Atopic Dermatitis [SCORAD] index=53.06) were investigated compared to a normal control group (n=25). To examine DNA damage in the cellular level, we performed comet assays on lymphocytes and granulocytes taken from patients and control group. To measure lipid peroxidation products, urine and plasma malondialdehyde (MDA) levels were analyzed. To examine intracellular redox in lymphocytes, ROS were measured using flow cytometry. Expression of superoxide dismutase (SOD) 1, 2 antioxidants were analyzed using reverse transcription polymerase chain reaction (RT-PCR). RESULTS: Atopic dermatitis patients showed severe DNA damage compared to the control group in both lymphocytes (1.89 and 1.51, respectively, p<0.05) and granulocytes (2.07 and 1.58, respectively, p<0.05). While urine MDA levels were not significantly different between groups (1.64 and 1.13 microM/g respectively, p>0.05), plasma MDA levels were significantly increased in atopic dermatitis patients compared to controls (1.45 and 0.80 microM/g respectively, p<0.005). ROS production by activated lymphocytes was increased in atopic dermatitis patients compared to controls. SOD 1, 2 were expressed in all atopic dermatitis patients without significant increase compared to controls. CONCLUSION: Increased DNA damage, lipid peroxidation and ROS production in lymphocytes as indices of oxidative stress were observed in moderate to severe atopic dermatitis patients compared to normal control. Although precise mechanism of oxidative stress on the pathogenesis of atopic dermatitis is not defined yet, decreasing ROS exposure or augmenting antioxidant defenses may be alternative therapeutic approaches for atopic dermatitis.
Antioxidants
;
Comet Assay
;
Dermatitis, Atopic*
;
DNA
;
DNA Damage
;
Flow Cytometry
;
Granulocytes
;
Humans
;
Lipid Peroxidation
;
Lymphocytes
;
Malondialdehyde
;
Oxidation-Reduction
;
Oxidative Stress
;
Plasma
;
Polymerase Chain Reaction
;
Reactive Oxygen Species
;
Reverse Transcription
;
Superoxide Dismutase
10.Redox Regulating Protein APE1/Ref-1 Expression is Increased in Abdominal Aortic Coarctation-induced Hypertension Rats.
Sun Heon SONG ; Eun Jung CHO ; Myoung Soo PARK ; Yu Ran LEE ; Hee Kyoung JOO ; Gun KANG ; Shin Kwang KANG ; Sunga CHOI ; Byeong Hwa JEON
Journal of the Korean Society of Hypertension 2012;18(3):126-135
BACKGROUND: Aim of study is designed to investigate whether apurinic/apyrimidinic endonuclease-1/redox factor-1 (APE1/Ref-1) expression is changed in abdominal aortic coarctation models. METHODS: Male Sprague-Dawley rats were randomly assigned with abdominal aortic coarctation, repaired group, sham, and control groups. Endothelial function was assessed with endothelium-dependent relaxations. Detection of superoxide anion and lipid peroxidation was performed by lucigenin chemiluminescence and thiobarbituric acid-reactive substances assay. APE1/Ref-1 expression was measured with Western blot and immunohistochemistry. RESULTS: In anesthetized condition, the abdominal aortic coarctation rats showed hypertension as systolic/diastolic arterial pressure of 171/114 mm Hg, compared with 114/94 mm Hg of control. Endothelium-dependent relaxations were significantly impaired in the aortic coarctation which was recovered in 1 week after coarctation repair. Superoxide production and lipid peroxidation were elevated in aortic coarctation rats. In immunohistochemistry, APE1/Ref-1 expressions were increased at aorta and kidney in aortic coarctation rats. Increased APE1/Ref-1 expression in aorta was recovered by repair of coarctation. CONCLUSIONS: Taken together, it suggests that APE1/Ref-1 expression was increased in aortic coarctation-induced hypertensive rats, suggesting a biomarker for hypertension. Impaired endothelium dependent relaxation in the aortic coarctation can be modulated by repair of coarctation or the modulation of blood pressure.
Acridines
;
Animals
;
Aorta
;
Aortic Coarctation
;
Arterial Pressure
;
Blood Pressure
;
Blotting, Western
;
Endothelium
;
Humans
;
Hypertension
;
Immunohistochemistry
;
Kidney
;
Lipid Peroxidation
;
Luminescence
;
Male
;
Oxidation-Reduction
;
Oxidative Stress
;
Rats
;
Rats, Sprague-Dawley
;
Relaxation
;
Salicylamides
;
Superoxides