• Journal of Ginseng Research
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• v.47 no.4
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• pp.524-533
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• 2023

Background: Obesity is a risk factor for aging and many diseases, and the disorder of lipid metabolism makes it prominent. This study aims to investigate the effect of ginsenoside Rg1 on aging, lipid metabolism and stress resistance Methods: Rg1 was administered to Caenorhabditis elegans (C. elegans) cultured in NGM or GNGM. The lifespan, locomotory activity, lipid accumulation, cold and heat stress resistance and related mRNA expression of the worms were examined. Gene knockout mutants were used to clarify the effect on lipid metabolism of Rg1. GFP-binding mutants were used to observe the changes in protein expression Results: We reported that Rg1 reduced lipid accumulation and improved stress resistance in C. elegans. Rg1 significantly reduced the expression of fatty acid synthesis-related genes and lipid metabolism-related genes in C. elegans. However, Rg1 did not affect the fat storage in fat-5/fat-6 double mutant or nhr-49 mutant. Combined with network pharmacology, we clarified the possible pathways and targets of Rg1 in lipid metabolism. In addition, Rg1-treated C. elegans showed a higher expression of anti-oxidative genes and heat shock proteins, which might contribute to stress resistance Conclusion: Rg1 reduced fat accumulation by regulating lipid metabolism via nhr-49 and enhanced stress resistance by its antioxidant effect in C. elegans.

• Journal of environmental and Sanitary engineering
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• v.19 no.1
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• pp.50-56
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• 2004

Dibutyl phthalate (DBP) is used extensively in the plastic industry and has been known as an endocrine disruptor. Present study was undertaken to examine whether DBP can induce oxidative stress in mice. In this study, oxidative stress was measured in terms of the modification of lipid peroxidation and gamma-glutamyl transferase (GGT) activity. The serum toxicity index, level of lipid peroxidation and triglyceride (TG), and activity of GGT were measured in male ICR mice after a single administration of DBP (5 g/kg, po). DBP did not alter serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine, glucose and cholesterol level. However, the treatment with DBP was found to significantly increase the level of lipid peroxidation in liver and lung. The TG content and activity of GGT in the liver of DBP-exposed animals was also increased. These results indicate that DBP can induce mild oxidative stress in mice. The GGT activity is considered to be increased as one of the adaptive defense mechanisms to oxidative stress induced by DBP.

• Applied Chemistry for Engineering
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• v.28 no.3
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• pp.306-312
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• 2017

Changes in the cell growth and lipid accumulation of marine microalga Dunaliella tertiolecta were investigated in response to the combination of different stress factors including the variation of iron supply as a primary stress factor and different options in light irradiation and $CO_2$ supply as a secondary stress factor. High or limited Fe conditions could act as a stress for lipid synthesis. As a secondary stress factor, non-$CO_2$ condition was good for lipid accumulation, but the overall cell growth was sacrificed significantly after a long-time cultivation. Dark condition as a secondary stress factor also favored lipid accumulation and the extent of cell density reduction at the early period in the dark was small compared to other stress conditions. The two-stage cultivation strategy was necessary to maximize lipid production because tendencies of the cell growth and lipid content were not identical under the chosen stress condition. The first stage was for preparing a high cell density under the normal growth-favoring condition and the second stage was the stress condition to induce lipid accumulation in a short time. The short-term (12 h) incubation under the 5X Fe (3.25 mg/L) and dark conditions resulted in the best lipid productivity of 1.44 g/L/d providing 2 g/L inoculum at the second stage.

• Nutritional Sciences
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• v.6 no.2
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• pp.94-99
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• 2003

The purpose of this study was to investigate in vivo lipid peroxidation in rats under conditions of streptozotocin-induced oxidative stress and the antioxidant effects of probucol. In vivo lipid peroxidation was observed by measuring low molecular weight aldehydes and related carbonyl compounds in rat urine. Three groups of male Wistar rats weighing 165-190 g were used: normal (N), streptozotocin-induced oxidative stress (OS) and oxidative stress plus probucol treatment (P). following streptozotocin treatment of the rats, a variety of secondary lipid peroxidation products were increased. The levels of butanal, hexanal, hex-2-enal, kept-2-enal, octanal, non-2-enal, deca-2,4-dienal, 4-hydroxyhex-2-enal, 4-hydroxyno n-2-enal, malondi aldehyde(MDA), and unknown carbonyl compounds were significantly increased in the oxidative stress group compared to the control group. Treatment with probucol resulted in significant decreases in buoal, hexanal, hex-2-enal, octanal, deca-2,4-dienal, 4-hydroxyhex-2-enal, MDA and unknown carbonyl compounds. Hept-2-enal, hepta-2,4-dienal and non-2-enal appeared to have a tendency to decrease due to pobucol treatment.

• Journal of Environmental Science International
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• v.16 no.12
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• pp.1345-1353
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• 2007

The effect of salicylic acid(SA) on antioxidant system and protective mechanisms against UV-B induced oxidative stress was investigated in cucumber(Cucumis sativus L.) leaves. UV-B radiation and SA were applied separately or in combination to first leaves of cucumber seedlings, and dry matter accumulation, lipid peroxidation and activities of antioxidant enzymes were measured in both dose and time-dependant manner. UV-B exposure showed reduced levels of fresh weight and dry matter production, whereas SA treatment significantly increased them. SA noticeably recovered the UV-B induced inhibition of biomass production. UV-B stress also affected lipid peroxidation and antioxidant enzyme defense system. Malondialdehyde(MDA), a product of lipid peroxidation, was greatly increased under UV-B stress, showing a significant enhancement of a secondary metabolites, which may have antioxidative properties in cucumber leaves exposed to UV-B radiation. Combined application of UV-B and SA caused a moderate increase in lipid peroxidation. These results suggest that SA may mediate protection against oxidative stress. UV-B exposure significantly increased SOD, APX, and GR activity compared with untreated control plants. Those plants treated with 1.0 mM SA showed a similar pattern of changes in activities of antioxidant enzymes. SA-mediated induction of antioxidant enzyme activity may involve a protective accumulation of $H_2O_2$ against UV-B stress. Moreover, their activities were stimulated with a greater increase by UV-B+SA treatment. The UV-B+SA plants always presented higher values than UV-B and SA plants, considering the adverse effects of UV-B on the antioxidant cell system. ABA and JA, second messengers in signaling in response to stresses, showed similar mode of action in UV-B stress, supporting that they may be important in acquired stress tolerance. Based on these results, it can be suggested that SA may participates in the induction of protective mechanisms involved in tolerance to UV-B induced oxidative stress.

• Journal of Microbiology and Biotechnology
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• v.33 no.3
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• pp.310-318
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• 2023

Microalgae are attracting much attention as promising, eco-friendly producers of bioenergy due to their fast growth, absorption of carbon dioxide from the atmosphere, and production capacity in wastewater and salt water. However, microalgae can only accumulate large quantities of lipid in abiotic stress, which reduces productivity by decreasing cell growth. In this study, the strategy was investigated to increase cell viability and lipid production by overexpressing S-adenosylmethionine (SAM) synthetase (SAMS) in the microalga Chlamydomonas reinhardtii. SAM is a substance that plays an important role in various intracellular biochemical reactions, such as cell proliferation and stress response, and the overexpression of SAMS could allow cells to ithstand the abiotic stress and increase productivity. Compared to wild-type C. reinhardtii, recombinant cells overexpressing SAMS grew 1.56-fold faster and produced 1.51-fold more lipids in a nitrogen-depleted medium. Furthermore, under saline-stress conditions, the survival rate and lipid accumulation were 1.56 and 2.04 times higher in the SAMS-overexpressing strain, respectively. These results suggest that the overexpression of SAMS in recombinant C. reinhardtii has high potential in the industrial-scale production of biofuels and various other high-value-added materials.

• Food Science of Animal Resources
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• v.40 no.5
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• pp.734-745
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• 2020

Commercially sterilized ultra high temperature (UHT) milk was manufactured at different homogenization pressures (20, 25, and 30 MPa), and changes in fat particle size, mechanical stress-induced fat aggregation, plasmin activity, and lipid oxidation were monitored during ambient storage of the UHT milk for up to 16 wk. The particle sizes of milk fat globules were significantly decreased as homogenization pressure increased from 20 to 30 MPa (p<0.05). The presence of mechanical stress-induced fat aggregates in milk produced at 20 MPa was significantly higher than for UHT milk produced at either 25 or 30 MPa. This difference was maintained all throughout the storage. There were no significant differences in plasmin activity, trichloroacetic acid (12%, w/v) soluble peptides, and the extent of lipid oxidation. Based on these results, an increase of homogenization pressure from 20 (the typical homogenization pressure employed in the Korea dairy industry) to 25-30 MPa significantly decreased mechanical stress-induced fat aggregation without affecting susceptibility to lipid oxidation during storage.

• Archives of Pharmacal Research
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• v.27 no.3
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• pp.340-345
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• 2004

Our work in this study was made in the microsomal fraction to evaluate the lipid peroxidation by measuring superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and malondialdehyde (MDA) and to elucidate the preventive role of CS in the $CCl_4$-induced oxidative stress. The excessive lipid peroxidation by free radicals derived from $CCl_4$ leads to the condition of oxidative stress which results in the accumulation of MDA. MDA is one of the end-products in the lipid peroxidation process and oxidative stress. MDA, lipid peroxide, produced in this oxidative stress causes various diseases related to aging and hepatotoxicity, etc. Normal cells have a number of enzymatic and nonenzymatic endogenous defense systems to protect themselves from reactive species. The enzymes in the defense systems, for example, are SOD, CAT, and GPx. They quickly eliminate reactive oxygen species (ROS) such as superoxide anion free radicalㆍO$^{[-10]}$ $_2$, hydrogen peroxide $H_2O$$_2$ and hydroxyl free radicalㆍOH. CS inhibited the accumulation of MDA and the deactivation of SOD, CAT and GPx in the dose-dependent and preventive manner. Our study suggests that CS might be a potential scavenger of free radicals in the oxidative stress originated from the lipid peroxidation of the liver cells of $CCl_4$-treated rats.

• Journal of Nutrition and Health
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• v.30 no.9
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• pp.1061-1066
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• 1997

This study was undertaken to evaluate the effect of 4 weeks of $\alpha$-tocopherol(800 I.U./d) supplementation on oxidant stress of eleven female aerobic -majoring students during rest and exercise. Changes in the activity of the antioxidant enzyme glutathione peroxidase were also studied. Serum $\alpha$-tocopherol concentration was significantly increased with vitamin E supplementation(710.1$\pm$113.8$\mu\textrm{g}$/dl vs. 1,485,8$\pm$105.2$\mu\textrm{g}$/dl). In addition, serum MDA concentration, an index of lipid peroxidation, significantly decreased after vitamin E supplementation. However, MDA values after exercise increased to pre-supplementation levels. Serum glutathione peroxidase activity significantly increased with vitamin E supplementation. The enzyme activity showed a trend toward decrease after exercise. Serum cholesterol values were not significantly affected by vitamin E supplementation. However, serum triglycerides significantly increased after supplementation against oxidative stress during resting periods. These supplements appraently work by decreasing lipid peroxidation and increasing glutathione peroxidase activity. However, vitamin E supplementation did not prevent exercise-induced increases in lipid peroxidation.

• BMB Reports
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• v.35 no.3
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• pp.297-301
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• 2002

Membrane lipid peroxidation processes yield products that may react with DNA and proteins to cause oxidative modifications. The oxyR gene product regulates the expression of enzymes and proteins that are needed for cellular protection against oxidative stress. Upon exposure to tert-butylhydroperoxide (t-BOOH) and 2,2'-azobis (2-amidinopropane) hydrochloride (AAPH), which induce lipid peroxidation in membranes, the Escherichia coli oxyR overexpression mutant was much more resistant to lipid peroxidation-mediated cellular damage, when compared to the oxyR deletion mutant in regard to growth kinetics, viability, and DNA damage. The deletion of the oxyR gene in E. coli also resulted in increased susceptibility of superoxide dismutase to lipid peroxidation-mediated inactivation. The results indicate that the peroxidation of lipid is probably one of the important intermediary events in free radical-induced cellular damage. Also, the oxyR regulon plays an important protective role in lipid peroxidation-mediated cellular damage.