• Analytical Science and Technology
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• v.24 no.6
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• pp.460-466
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• 2011

The activity of an antimicrobial peptide, magainin 2, on lipid membranes was investigated using solid-state NMR and a new sampling method that employed mechanically aligned bilayers between thin glass plates. The experiments were performed at two hydration levels. At 95% hydration about 15% of the lipid bilayers were disrupted and at full hydration 20% were disrupted. From the comparison of two equilibrium states established by two sampling methods the importance of peptide binding to the lipid bilayer for whole membrane disruption was demonstrated.

• YAKHAK HOEJI
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• v.37 no.3
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• pp.270-277
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• 1993

It is well known that lipidperoxide, formed in vivo, induced the denaturation of enzyme and destruction of cell membrane to acute injury of tissue. Aralia elata have physiological activates, the improvement of lipid metabolism, antidiabetic activity etc., which was thought to have the relationship to lipid peroxidation. The anti-lipidperoxidative effect of Aralia elata have not yet established. In this study, we examined the anti-lipidperoxidative effects of Aralia elata (Butanol fraction) on CCI$_{4}$ induced lipidperoxidation in rats, and elucidated the anti-lipidperoxidative mechanism. In rat liver homogenate intoxicated with CCI$_{4}$ (0.5 ml/100g), BuOH fraction of Aralia elata (80 mg/Kg/day) exhibited 85.41% anti-lipidperoxidative effect but in serum 69.63% inhibitory effects, respectively. In mitochondrial and microsomal fraction showed inhibition of 55.85% and 69.30%, respectively. In order to elucidate the mechanism of anti-lipidperoxidation effects of Aralia elata, enzymatic (NADPH dependent) and non-enzymatic (Ascorbic acid catalyzed) reaction, in vitro, were performed. In enzymatic reation, Aralia elata exhibited 59.43% anti-lipidperoxidation effects, but in non-enzymatic reaction exhibited 43.27% inhibition. Therefore, it is noteworthy that antioxidative power of them may mainly results from the inhibition by enzymatic reaction.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.4
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• pp.367-376
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• 1997

The effect of an organic peroxide, t-butylhydroperoxide (t-BHP), on glutamate uptake was studied in synaptosomes prepared from cerebral cortex. t-BHP inhibited the $Na^+-dependent$ glutamate uptake with no change in the $Na^+-independent$ uptake. This effect of t-BHP was not altered by addition of $Ca^{2+}$ channel blockers (verapamil, diltiazem and nifedipine) or $PLA_2$ inhibitors (dibucaine, butacaine and quinacrine). However, the effect was prevented by iron chelators (deferoxamine and phenanthroline) and phenolic antioxidants (N,N'-diphenyl-phenylenediamine, butylated hydroxyanisole, and butylated hydroxytoluene). At low concentrations (＜1.0 mM), t-BHP inhibited glutamate uptake without altering lipid peroxidation. Moreover, a large increase in lipid peroxidation by $ascorbate/Fe^{2+}$ was not accompanied by an inhibition of glutamate uptake. The impairment of glutamate uptake by t-BHP was not intimately related to the change in $Na^+-K+-ATPase$ activity. These results suggest that inhibition of glutamate uptake by t-BHP is not totally mediated by peroxidation of membrane lipid, but is associated with direct interactions of glutamate transport proteins with t-BHP metabolites. The $Ca^{2+}$ influx through $Ca^{2+}$ channel or $PLA_2$ activation may not be involved in the t-BHP inhibition of glutamate transport.

• Journal of Ginseng Research
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• v.16 no.2
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• pp.129-137
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• 1992

This study was carried out to investigate the localization of lipids and lipase activity with lipid staining and cytochemical technique in endosperm cells of Panax ginseng C.A. Meyer seed. In endosperm cells of indehiscent seed, protein bodies facing the umbiliform layer are different in electron density during the various degraded processes. Gradually, protein matrix near the cell wall was lysed and electron lucent inclusions appeared on umbiliform layer. The protein body with high electron density and the spherosome with low electron density were observed in endosperm cells. As a result of lipid staining, electron density of spherosome is more intense than those of the protein matrix within the protein body in endosperm cells of indehiscent seed. Free spherical spherosomes within the umbiliform layer have a high electron density. The spherical spherosomes were more electron densed and were uniform in comparison with the cytoplasmic proteinaceous granules in endosperm cells of seed with red seed coat. The major component of spherosome was determined to be lipid. Lipase activity occurs in the spherosome and near the endosperm cell wall facing the umbiliform layer. Cytochemical reaction products of lipase were observed in the spherosome membrane and in the inner regions of spherosome. After protein bodies were digested, lipase activities were observed in free spherosomes and near the cell wall of endosperm cells. Umbiliform layer composing of fibrillized wall and digested materials of the endosperm cell showed a little lipase reaction products.

• BMB Reports
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• v.41 no.8
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• pp.560-567
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• 2008

The importance of lipids in cell signaling and tissue physiology is demonstrated by the many CNS pathologies involving deregulated lipid metabolism. One such critical metabolic event is the activation of phospholipase $A_2$ ($PLA_2$), which results in the hydrolysis of membrane phospholipids and the release of free fatty acids, including arachidonic acid, a precursor for essential cell-signaling eicosanoids. Reactive oxygen species (ROS, a product of arachidonic acid metabolism) react with cellular lipids to generate lipid peroxides, which are degraded to reactive aldehydes (oxidized phospholipid, 4-hydroxynonenal, and acrolein) that bind covalently to proteins, thereby altering their function and inducing cellular damage. Dissecting the contribution of $PLA_2$ to lipid peroxidation in CNS injury and disorders is a challenging proposition due to the multiple forms of $PLA_2$, the diverse sources of ROS, and the lack of specific $PLA_2$ inhibitors. In this review, we summarize the role of $PLA_2$ in CNS pathologies, including stroke, spinal cord injury, Alzheimer's, Parkinson's, Multiple sclerosis-Experimental autoimmune encephalomyelitis and Wallerian degeneration.

• YAKHAK HOEJI
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• v.43 no.6
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• pp.756-761
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• 1999

Lipid peroxidation mediated by hydroxyl radicals which are generated during myocardial ischermia has suggested as a possible mechanism of ischemic myocardial damage. Recently, it has been reported that anti-arrhythmic action of lidocaine, a local anesthetic, is attributed to its "membrane-stabilizing" properties through scavenging free radicals, thus, inhibiting lipid peroxidation. Aldehyde oxidase and xanthine oxidase which catalyze the oxidation of many purine, pyrimidine and pteridine derivatives are known as free radical generating systems. In this experiment, we studied the effect of lidocaine and procainamide on the hepatic aldehyde and xanthine oxidase activity and antioxidative activities. It was found that lidocaine and procainamide inhibited both NADPH-dependent and independent lipid peroxidation. Both of tested compounds were found to be ineffective in inhibiting xanthine oxidase. Lidocaine and procainamide, however, inhibited aldehyde oxidase activity in vitro as well as in vivo. Based on the above results, lidocaine and procainamide could be employed as a therapeutic agent for aldehyde oxidaserelated disease.d disease.

• Journal of Nutrition and Health
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• v.30 no.10
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• pp.1123-1131
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• 1997

This study examined the effect of dietary lipids and guar gum on lipid metabolism in ovariectomized rats. The experimental animals received ovarietomy (OVX). Lipids sources were divided into 3 groups (soybean oil(SB), beef tallow(BT)) and fish oil(FO)) and guar gum was supplemented to each lipid diet (SBG, BTG, FOG). Experimental diets were fed to therats for 16 weeks. Serum triglyceride (TG) levels were higher in the BT group and lower in the FO group as compared to the SB group .Serum total cholesterol (Tc) and HDL-C levels were lower in the FO group as compared to the SB group. Serum LDL-C and phospholipid levels were lower in the FO group as compared to the SB group. Serum lipids levels were lowered by guar gum supplement. Serum SFA(saturated fatty acids) contents were not significantly influenced by dietary lipids and guar gum. Serum MUFA(monounsaturated fatty acids) contents were the lowest in the SB group. Fecal weight was highest in the beef tallow group and lowest in the fish oil group. Fecal weight was increased by guar gum supplement in all lipid groups. Total bile acid content in feces was increased by guar gum supplement in the soybean oil and beef tallow groups. The endothelial cells of the beef tallow group changed from a flat shape to distorted round and enlarged shapes. The subendothelial layer was the thickness the thickest in the beef tallow group ; the interspace between elastic lamina was widened and elastic lamina was straightened and partly disrupted . The fish oil group showed more porminient endothelial cells and subendothelial layer. Internal elastic membrane and elastic lamina exhibited regularly wavy shapes. Guar gum supplement showed positive effects in all lipids groups. Based on the above results , it is suggested that beef tallow increased serum TG levels and injured the wall of the aorta. On the other hand, fish oil , which decreased serum lipid levels, has a positive effect on the walls of the aorta. Guar gum protects the aorta from injury by reducing the serum lipid levels. Therefore, it is suggested that soybean oil and beef tallow consumed with guar gum is beneficial.

• The Journal of Korean Medicine
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• v.18 no.1
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• pp.375-384
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• 1997

This study was undertaken to determine Juglandis Semen extraction (JS) has a protective effect against the cell injury caused by oxidants, t-butylhydroperoxide (t-BHP) and $H_{2}O_2$ in rabbit lung slices. Cell injury was estimated by measuring tissue water content and peroxidation of membrane lipids was assessed by measuring malondialdehyde (MDA), an end-product of lipid peroxidation. t-BHP significantly increased water content in lung tissues over concentrations of 2-10 mM, and such effects were prevented by 5% JS. JS exerted the beneficial effect in a dose-dependent manner. $H_{2}O_2$ (100 mM) also increased water content in tissues, which was almost completely prevented by 5% JS. t-BHP induced lipid peroxidation in a dose-dependent fashion in lung tissues over concentrations of 0.5-10 mM. JS significantly reduced t-BHP induced lipid peroxidation and oxidant-independent endogenous lipid peroxidation, and such effects were dose-dependent at concentration of 0.5-10%. JS prevented $H_{2}O_2$ (100 mM)-dependent lipid peroxidation. These results suggest that JS prevents ceil injury induced by oxidants in the lung, and such effects may be attributed to inhibition of lipid peroxidation. The precise mechanisms remains to be explored.

• Reproductive and Developmental Biology
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• v.40 no.2
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• pp.15-22
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• 2016

As a one of unsaturated fatty acid, polyunsaturated fatty acids (PUFAs) have multiple actions: as precursor of prostaglandins (PGs), steroid hormone synthesis and energy production in animal reproduction. PUFAs, which include omega-3 (n-3) and omega-6 (n-6), are derived from the diet and changed by diet, species, breed and season. The plasma membrane of spermatozoa in mammals contain various PUFAs. These composition of PUFAs regulate the membrane fluidity and cause lipid peroxidation via generation of reactive oxygen species (ROS). Induced lipid peroxidation by ROS decreased viability and motility of spermatozoa, and it is reduced by addition of antioxidant and low concentration of PUFAs. Because oocytes of animal have a high lipid components, process of oocyte maturation and embryo development are influenced by PUFAs. In in vitro study, oocyte maturation, embryo development, intracellular cAMP and MAPK activity were increased by treatment of n-3 ${\alpha}$-linolenic acid (ALA) during maturation, whereas n-6 linoleic acid (LA) negatively influenced. Also, inhibition of fatty acid metabolism in oocyte influenced blastocyst formation of cattle. PGs are synthesized from PUFAs and various PUFAs influence PGs via regulation of PG-endoperoxide synthase (PTGS). Steroid hormone synthesis from cholesterol is regulated by expression of steroid acute regulator (StAR) protein and mRNA. Exogenous n-3 and n-6 PUFAs altered sex hormone in animal through stimulate or inhibit StAR activity. Because PUFAs altered PG and steroid hormone synthesis, follicular development was influenced by PUFAs. This effect of unsaturated fatty acid could provide information for improvement of reproductive ability in animals.

• Fisheries and Aquatic Sciences
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• v.6 no.3
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• pp.155-159
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• 2003

Lipid composition and fatty acid composition were characterized in the membrane of a marine ciliate protozoan (Uronema marinum). Phospholipids accounted for 70% of total lipid, and the remainder was neutral lipids. Total phospholipids were separated as phosphatidylcholine $(24.26\%)$, phosphatidylethanolamine $(22.21\%)$, phosphatidylinositol $(6.14\%)$, phosphatidyl­serne $(5.11\%)$, cardiolipin $(3.07\%)$ and unidentified phospholipids $(28.72\%)$ through high performance liquid chromatography (HPLC). Fatty acid composition of neutral lipids and phospholipids was determined by gas chromatography (GC), based solely on comparision of retention times. In neutral lipids, the most abundant fatty acid group was monounsaturated fatty acid $(48.3\% of total fatty acids)$ with oleic acid (18:1) and nervonic acid (24:1). Saturated fatty acids comprised $29.6\%$ of total fatty acids, with palmitic acid (16:0), stearic acid (18:0) ane myristic acid (14:0), and polyunsaturated fatty acid accounted for $33.0\%$ with $Di-homo-\gamma-linolenic$ acid (20:3) and linoleic acid (18:2). Wherease phospholipids predominantly contained the fatty acid group in the following order: polyunsaturated fatty acids $(52.7\%\;of\;total\;fatty\;acids)$ with linoleic acid (18:2) and $\gamma-linolenic$ acid (18:3) > monounsaturated fatty acids $(28.5\%\;of\;total\;fatty\;acids)$ with oleic acid (18:1) and palmitoleic acid (16:1) > saturated fatty acids $(25.5\%\;of\;total\;fatty\;acids)$ with palmitic acid (16:0), stearic acid (18:0) and myristic acid (14:0).