Antioxidant Enzymes and Related Trace Elements in Aging Brain Capillaries and Choroid Plexus

The activities of superoxide dismutase (SOD), glutathione peroxidase, glutathione reductase, and catalase were measured in isolated brain capillaries, choroid plexus, cerebrum, and cerebellum from rats of 2, 6, 12, and 24 months. The contents of copper, zinc, and manganese were determined in capillaries, cerebrum, and cerebellum, and the profile of fatty acids was studied in brain capillaries. In brain capillaries, the activities of glutathione peroxidase and glutathione reductase did not change with age. The activities of the two enzymes increased in cerebrum and cerebellum. In choroid plexus, glutathione peroxidase activity increased, but glutathione reductase activity remained unchanged. Catalase activity in brain capillaries declined, whereas in choroid plexus, cerebrum, and cerebellum, it did not change. The activities of the three enzymes were significantly higher in brain capillaries and choroid plexus than in cerebrum and cerebellum. SOD activity increased in the four tissues. Copper content in the capillaries increased initially and then levelled off, whereas it continued to increase in cerebrum and cerebellum. Zinc increased in brain capillaries, but did not vary in cerebrum and cerebellum. Manganese content remained constant in all tissues studied. The percent of saturated fatty acids in brain capillaries did not change with age, whereas those of mono- and polyunsaturated fatty acids increased and decreased, respectively. The possibility that a deficiency of enzymes protective against free radicals causes blood-brain barrier and blood-cerebrospinal fluid barrier degeneration is ruled out.     

Antioxidant Defense Systems in the Brains of Type II Diabetic Mice

Abstract: The specific activities of superoxide dismutase, catalase, and glutathione S -transferase (μ subtype) were significantly lower in the brains of mice with type II diabetes than in the brains of control mice. On the other hand, the specific activity of glutathione peroxidase was unaltered. The concentration of vitamin E, but not that of total glutathione and ascorbate, was increased in the brains of the type II diabetic mice. The relative amount of polyunsaturated fatty acids (as determined with soybean lipoxygenase) was increased in whole brains and crude synaptosomal membranes of the type II diabetic mice. Endogenous levels of thiobarbituric acid-positive material were decreased in both whole brain homogenates and crude synaptosomal membranes of the db/db mice. Susceptibility of lipids within whole brain homogenates and crude synaptosomal membranes of mice with type II diabetes to peroxidation with iron/ascorbate was also markedly decreased compared with that of controls. Vitamin E is known to quench lipid peroxidation. Therefore, decreased lipid peroxidation in the type II mouse brain may be due to increased vitamin E content.     

Predominant Low-Molecular-Weight Proteins in Isolated Brain Capillaries Are Histones

Blood-brain barrier (BBB) function is endowed by the expression of unique proteins within the brain capillary endothelium. In the absence of knowing the function of BBB-specific proteins, one strategy for identification of these proteins is the purification and amino acid sequencing of proteins within the brain capillary that are not found in other cells. Earlier studies have shown that a 16-18K triplet of low-molecular-weight proteins in isolated brain capillaries is not found in either erythrocytes or in capillary-free preparations of synaptosomal proteins. Therefore, the present studies describe the purification of the 16-18K triplet of proteins as well as a 14K protein in isolated brain capillaries using sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE) and C4 reverse-phase HPLC. Amino acid sequencing of the N-terminus of the 14K, 17K, and 18K proteins and of two tryptic peptides of the 16K protein showed that these proteins are alpha-globin, histone 2B, histone 3, and histone 2A, respectively. SDS-PAGE of subcellular fractions of bovine brain capillaries demonstrated that the 16-18K triplet of histone proteins migrated in the nuclear fraction. In addition, a 34K doublet and a 200K protein were localized in the nuclear pellet. Therefore, the present studies demonstrate that the predominant 14-18K proteins seen on SDS-PAGE of isolated brain capillaries are known proteins and provide a general scheme for purification of brain capillary proteins isolated following SDS-PAGE.     

Alterations in Protective Enzymes Against Peroxidation in the Central and Peripheral Nervous System of Control and Dysmyelinating Mutant Mice

The activities of peroxide-detoxifying enzymes such as superoxide dismutase (SOD), glutathione peroxidase, glutathione reductase, and catalase were measured in the nervous system of neurological dysmyelinating mutants: quaking (Qk), shiverer (Shi), and trembler (Tr) mice. Cu/Zn-SOD activity was higher in the cerebellum of Qk and Shi mice (by 53% and 106%, respectively) in comparison with controls, but it was the same in the cerebellum of Tr mice and their corresponding controls. In contrast, there was no difference in the level of Cu/Zn-SOD activity in the cerebrum of Qk, Shi, and Tr mice and their respective controls. Mn-SOD activity was the same among all the mutants compared to control animals in both cerebrum and cerebellum. In Shi cerebellum, glutathione peroxidase and glutathione reductase activities were slightly decreased (a 21.6% and a 13.2% diminution, respectively), whereas catalase activity in cerebrum and cerebellum was the same among mutants and control mice. In the sciatic nerve from Tr mice, all the enzymatic activities were enhanced: sixfold increase for total SOD, and 2.4-fold, 3.5-fold, and 1.8-fold increase for glutathione peroxidase, glutathione reductase, and catalase, respectively.     

Effect of MPTP and l-Deprenyl on Antioxidant Enzymes and Lipid Peroxidation Levels in Mouse Brain

Abstract: Excessive free radical formation or antioxidant enzyme deficiency can result in oxidative stress, a mechanism proposed in the toxicity of MPTP and in the etiology of Parkinson's disease (PD). However, it is unclear if altered antioxidant enzyme activity is sufficient to increase lipid peroxidation in PD. We therefore investigated if MPTP can alter the activity of the antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-PX) and the level of lipid peroxidation. l -Deprenyl, prior to MPTP administration, is used to inhibit MPP⁺ formation and its subsequent effect on antioxidant enzymes. MPTP induced a threefold increase in SOD activity in the striatum of C57BL/6 mice. No parallel increase in GSH-PX or CAT activities was observed, while striatal lipid peroxidation decreased. At the level of the substantia nigra (SN), even though increases in CAT activity and reduction in SOD and GSH-PX activities were detected, lipid peroxidation was not altered. Interestingly, l -deprenyl induced similar changes in antioxidant enzymes and lipid peroxidation levels, as did MPTP. Taken together, these results suggest that an alteration in SOD activity, without compensatory increases in CAT or GSH-PX activities, is not sufficient to induce lipid peroxidation.     

Sodium Transport in Capillaries Isolated from Rat Brain

Abstract: Brain capillary endothelial cells form a bloodbrain barrier (BBB) that appears to play a role in fluid and ion homeostasis in brain. One important transport system that may be involved in this regulatory function is the Na⁺,K⁺-ATPase that was previously demonstrated to be present in isolated brain capillaries. The goal of the present study was to identify additional Na⁺ transport systems in brain capillaries that might contribute to BBB function. Microvessels were isolated from rat brains and ²²Na ⁺ uptake by and efflux from the cells were studied. Total ²²Na ⁺ uptake was increased and the rate of ²²Na ⁺ efflux was decreased by ouabain, confirming the presence of Na⁺,K⁺-ATPase in capillary cells. After inhibition of Na⁺,K⁺-ATPase activity, another saturable Na ⁺ transport mechanism became apparent. Capillary uptake of ²²Na ⁺ was stimulated by an elevated concentration of Na ⁺or H⁺ inside the cells and inhibited by extracellular Na⁺, H⁺, Li⁺, and NH₄⁺. Amiloride inhibited ²²Na ⁺ uptake with a K_i between 10^?5 and 10^?6M but there was no effect of 1 mM furosemide on ²²Na⁺ uptake by the isolated microvessels. These results indicate the presence in brain capillaries of a transport system capable of mediating Na ⁺/ Na ⁺ and Na ⁺/H ⁺ exchange. As a similar transport system does not appear to be present on the luminal membrane of the brain capillary endothelial cell, it is proposed that Na ⁺/H ⁺ exchange occurs primarily across the antiluminal membrane.     

Ouabain-Sensitive Choline Transport System in Capillaries Isolated from Bovine Brain

In physiological conditions, there is a net transport of choline from brain to blood, despite the fact that the choline concentration is higher in plasma than in CSF. Because of the blood-brain barrier characteristics, such passage against the concentration gradient takes place necessarily through endothelial cells. To get a better understanding of this phenomenon, [3H]choline uptake properties have been analyzed in capillaries isolated from bovine brain. [3H]Choline uptake was linear with time for up to 1 h. Nonlinear regression analysis of the uptake rates at different substrate concentrations gave the best fit to a system of two components, one of which was saturable (Km = 17.8 +/- 4.8 microM; Vmax = 11.3 +/- 3.4 pmol/min/mg of protein) and the other of which was nonsaturable at concentrations up to 200 microM. The [3H]choline transport was significantly reduced in the absence of sodium and after incubation with 10(-4) M ouabain for 30 min. Ouabain also inhibited choline uptake in purified cerebral endothelial cells, but not in the endothelium isolated from bovine aorta. Accordingly, cerebral endothelial cells were able to concentrate [3H]choline, with this effect being abolished by ouabain, whereas in aortic endothelial cells the [3H]choline intracellular concentration was never higher than that of the incubation medium. These results suggest that the blood-brain barrier endothelium is specifically provided with an energy-dependent choline transport system, which may explain the choline efflux from the brain and the maintenance of a low choline concentration in the cerebral extracellular space.     

不同剂量白藜芦醇对糖尿病性白内障大鼠晶状体抗氧化酶活力的影响

目的:探究不同剂量白藜芦醇对糖尿病性白内障大鼠晶状体抗氧化酶活力的影响。方法:75只5周龄健康SPF级雄性SD大鼠按照随机数字表法分为正常对照组、模型组,白藜芦醇低剂量组,白藜芦醇中剂量组和白藜芦醇高剂量组,每组各15只。五组大鼠均给予常规适应性喂养,模型组和白藜芦醇低、中、高剂量组大鼠采用链脲佐菌素(STZ)以60 mg/kg的给药剂量制作糖尿病大鼠模型,成模后白藜芦醇低剂量组按20 mg/kg、白藜芦醇中剂量组按50 mg/kg、白藜芦醇高剂量组按100 mg/kg的给药剂量每日给予白藜芦醇灌胃。观察12周后5组大鼠晶状体的混浊程度,检测血糖、体重后处死大鼠,检测晶状体内超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)以及过氧化氢酶(CAT)的活性改变。结果:随着白藜芦醇剂量的升高,白藜芦醇低、中、高剂量组大鼠的血糖逐渐降低而体重逐渐升高,且组间比较均具有统计学差异(P0.05)。三组不同剂量白藜芦醇干预组大鼠晶状体的浑浊程度均低于模型组,且白藜芦醇高剂量组大鼠晶状体的浑浊程度最低,差异均具有统计学意义(P0.05)。白藜芦醇低、中、高剂量组大鼠SOD、GSH-PX和CAT酶活力与模型组大鼠相比均明显升高,而与正常对照组相比均明显降低(均P0.05)。随着白藜芦醇剂量的升高,白藜芦醇低、中、高剂量组大鼠SOD、GSH-PX和CAT酶活力逐渐升高,且组间比较均具有统计学差异(P0.05)。结论:高剂量白藜芦醇可更为明显地降低血糖浓度,提高晶状体SOD、GSH-Px及CAT酶活力,改善糖尿病性白内障晶状体的浑浊程度。     

Stage-specific distribution of oxidative radicals and antioxidant enzymes in the midgut of Leptinotarsa decemlineata

The titers of reactive oxygen species (ROS) represented by superoxide anion and general peroxides, and the activities of antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), are regulated in the midgut of the Colorado potato beetle (CPB) relative to the gut compartment, developmental stage, and food intake. ROS concentration is low in the potato leaves but it is very high in their digest in insect's anterior midgut. It is proposed that intensive ROS production in this gut region is linked to the processing of allelochemicals. SOD and CAT activities, low oxygen tension, and unidentified redox systems that maintain a slightly reducing milieu in the midgut lumen (pe+pH=6.95 declining to 5.36), obviously contribute to the decrease of ROS concentration along the gut length to a minimum in the wall of posterior midgut region. SOD and CAT activities are higher in the potato leaves than in the midgut tissues but the role of plant enzymes in ROS elimination within the gut lumen remains to be shown. A lower level of ROS and a higher antioxidant potential in the adult than in the larval midgut indicate stage specificity in the management of oxidative stress. The antioxidant defense is high in the diapausing adults that contain no detectable superoxide and about ten times less peroxides than the reproducing adults.     

A polysaccharide–peptide complex from abalone mushroom (Pleurotus abalonus) fruiting bodies increases activities and gene expression of antioxidant enzymes and reduces lipid peroxidation in senescence-accelerated mice

The antioxidant effects of a polysaccharide–peptide complex (F22) from mushroom (Pleurotus abalonus)-fruiting bodies were studied. The activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in the liver, kidney, and brain of senescence-accelerated mice showed a marked increase after treatment with the polysaccharide–peptide complex. Concurrently, the gene expression levels of SOD, CAT, and GPx, as determined with real-time polymerase chain reaction, were up-regulated in the liver, kidney, and brain, whereas the MDA content in these organs declined. The maximal lifespan of the mice was prolonged.     

动物抗氧化系统中主要抗氧化酶基因的研究进展

抗氧化系统是机体清除体内多余的活性氧、保护自身免受氧化损伤的重要体系,其中超氧化物歧化酶、过氧化氢酶、谷胱甘肽过氧化物酶等起主要作用。本文将对动物抗氧化系统中,超氧化物歧化酶、过氧化氢酶和谷胱甘肽过氧化物酶基因的种类、分布、结构及表达进行综述。     

Differential response of the antioxidant system in wild and cultivated genotypes of chickpea

Two chickpea cultivars PBG-1 and PDG-3 along with a wild species Cicer judaicum were investigated to compare the activities of their antioxidant enzymes in mature seeds and roots, as well as shoots and cotyledons of seedlings germinated under dark and continuous illumination of 40 μmol m⁻² s⁻¹ photosynthetically active radiation (PAR). Seedling biomass of C. judaicum was lower as compared to cultivars of PBG-1 and PDG-3 both under dark and light conditions. Light reduced the biomass of seedlings. Activities of glutathione reductase (GR) and ascorbate peroxidase (APX) were higher in shoots and roots of C. judaicum compared to the cultivars PBG-1 and PDG-3. In mature seeds, the activities of GR and APX were higher in the cultivated genotypes whereas catalase (CAT) and peroxidase were higher in C. judaicum. Under illumination, a general upregulation of CAT in both shoots and cotyledons and of GR in shoots was observed in all the three genotypes. However, superoxide dismutase (SOD) increased in C. judaicum and APX in PBG-1 and PDG-3. The differences in antioxidant enzyme system between wild and cultivated genotypes possibly contribute to better tolerance of wild Cicer species against abiotic and biotic stresses.     

Enzymatic response to cadmium by Impatiens glandulifera: A preliminary investigation

This paper aims to develop our understanding of the effect of cadmium (Cd) on Impatiens glandulifera, a recently identified potential Cd hyperaccumulator. Impatiens glandulifera plants were exposed to three concentrations of Cd (20, 60 and 90 mg/kg) and were sampled at two timepoints (one and seven days) to investigate the stress response of I. glandulifera to Cd. Cd can induce oxidative stress in plants, triggering overproduction of reactive oxygen species (ROS). The level of activity of catalase (CAT) and ascorbate peroxidase (APX), two crucial antioxidant enzymes responsible for detoxifying ROS, were found to increase in a concentration dependent manner. Though there was no change observed in the level of superoxide dismutase (SOD) activity, the activity of glutathione S-transferase (GST), involved in detoxifying and sequestering Cd, increased after exposure to Cd. Cd did not appear to impact the levels of proline and photosynthetic pigments, indicating the plants weren't stressed by the presence of Cd. These results suggest that the rapid response observed in enzyme activity aid the efficacious mitigation of the toxic effects of Cd, preventing significant physiological stress in I. glandulifera.     

Superoxide Dismutase, Catalase, and Glutathione Peroxidase Activities in Copper/Zinc-Superoxide Dismutase Transgenic Mice

Copper/zinc-superoxide dismutase (CuZn-SOD) transgenic mice overexpress the gene for human CuZn-SOD. To assess the effects of the overexpression of CuZn-SOD on the brain scavenging systems, we have measured the activities of manganese-SOD (Mn-SOD), catalase, and glutathione peroxidase (GSH-Px) in various regions of the mouse brain. In nontransgenic mice, cytosolic CuZn-SOD activity was highest in the caudate-putamen complex; this was followed by the brainstem and the hippocampus. The lowest activity was observed in the cerebellum. In transgenic mice, there were significant increases of cytosolic CuZn-SOD activity in all of these regions, with ratios varying from a twofold increase in the brainstem to 3.42-fold in the cerebellum in comparison with nontransgenic mice. Particulate Mn-SOD was similarly distributed in all brain regions, and its levels also were significantly increased in superoxide dismutase (SOD)-transgenic mice. In the brains of nontransgenic mice, cytosolic catalase activity was similar in all brain regions except the cortex, which showed less than 50% of the activity observed in the other regions. In transgenic mice, cytosolic catalase activity was significantly increased, with the cortex showing the greatest changes (133%) in comparison with nontransgenic mice. The smallest increases were observed in the hippocampus (34%). In contrast to what was observed for SOD and catalase, there were no significant changes in cytosolic GSH-Px activity in any of the brain regions examined. The present results indicate that, in addition to displaying marked increases in the levels of brain CuZn-SOD activity, SOD-transgenic mice also exhibit increases in other enzymes that scavenge oxygen-based radicals.(ABSTRACT TRUNCATED AT 250 WORDS)     

Oral exposure to Microcystis increases activity-augmented antioxidant enzymes in the liver of loach (Misgurnus mizolepis) and has no effect on lipid peroxidation

Recently, eutrophication has induced severe cyanobacterial blooms in the Naktong River, the second largest river of Korea. In the present study, lipid peroxidation and the antioxidant enzymes superoxide dismutase, catalase, and glutathione peroxidase, were evaluated in the liver of loach (Misgurnus mizolepis) that were orally exposed to a low dose of Microcystis through dietary supplementation with bloom scum. Loach received 75 mg of dry cells/kg body weight mass (equal to 10 microg microcystin-RR/kg body mass), for 28 days under controlled conditions. Antioxidant enzymatic activity and lipid peroxidation were measured after termination of exposure. The activities of antioxidant enzyme were significantly increased in the livers of toxin-exposed loach after 28 days of exposure, as compared to control fish. However, lipid peroxidation remained stable in both groups. These results suggest that antioxidant enzymes were able to eliminate oxidative stress induced by low concentrations of microcystins and to prevent increased lipid peroxidation in the liver of loach.     

Increased Permeability of Superoxide Dismutase at the Blood-Nerve and Blood-Brain Barriers with Retained Enzymatic Activity After Covalent Modification with the Naturally Occurring Polyamine, Putrescine

Abstract: Our previous studies have demonstrated that modification of superoxide dismutase (SOD) with the naturally occurring polyamines—putrescine (PUT), spermidine, and spermine—dramatically increases the permeability-coefficient surface area (PS) product at the blood-brain barrier and blood-nerve barrier after parenteral administration. Because of this increased permeability, the efficient delivery of polyamine-modified SOD (pSOD) across these barriers may enhance its therapeutic usefulness in treating ischemic neuronal degeneration, neurodegenerative disease, or even aging as an important antioxidant therapeutic strategy. Because PUT-SOD had the highest PS values, SOD was modified in the present experiments by activating carboxylic acid groups to the reactive ester with water-soluble carbodiimide and then reacted with PUT as the nucleophilic reagent. Preservation of SOD enzyme activity while maximizing the permeability was accomplished by adjusting the ionization of the protein carboxylic acid with pH. Both sodium dodecyl sulfate-polyacrylamide gel electrophoresis and isoelectric focusing analyses demonstrated graded conversion of SOD to its polyamine-modified derivative when performed at different pH. Although modification at pH 4.7 resulted in only 6.6% retained SOD activity and the highest PS value (43.35 ± 3.81 × 10^?6 ml/g/s for the hippocampus), modification at pH 5.7 resulted in 50.1% retained activity with a PS value of 24.48 ± 1.30 × 10^?6 ml/g/s for nerve endoneurium and 21.95 ± 1.62 × 10^?6 ml/g/s for hippocampus. This contrasts with a PS of 1.8–3.2 × 10^?6 ml/g/s for native SOD in nerve and various brain regions. Reaction conditions are therefore defined that titrate enzyme activity of PUT-SOD with PS changes in the intact animal after intravenous administration. These studies will allow an evaluation of the therapeutic usefulness of pSOD in animal models of neuronal degeneration.     

Alteration in Fatty Acid Composition of Adult Rat Brain Capillaries and Choroid Plexus Induced by a Diet Deficient in n-3 Fatty Acids: Slow Recovery After Substitution with a Nondeficient Diet

Wistar rats were fed for three generations with a semisynthetic diet containing either 1.5% sunflower oil (940 mg% of C18:2n-6, 6 mg% of C18:3n-3) or 1.9% soya oil (940 mg% of C18:2n-6, 130 mg% of C18:3n-3). At 60 days of age, the male offspring of the third generation were killed. The fatty acyl composition of isolated capillaries and choroid plexus was determined. The major changes noted in the fatty acid profile of isolated capillaries were a reduction (threefold) in the level of docosahexaenoic acid and, consequently, a fourfold increase in docosapentaenoic acid in sunflower oil-fed animals. The total percentage of polyunsaturated fatty acids was close to that in the soya oil-fed rats, but the ratio of n-3/n-6 fatty acids was reduced by threefold. In the choroid plexus, the C22:6n-3 content was also reduced, but by 2.6-fold, whereas the C22:5n-6 content was increased by 2.3-fold and the ratio of n-3/n-6 fatty acids was reduced by 2.4-fold. When the diet of sunflower oil-fed rats was replaced with a diet containing soya oil at 60 days of age, the recovery in content of n-6 and n-3 fatty acids started immediately after diet substitution; it progressed slowly to reach normal values after 2 months for C22:6n-5 and 2.5 months for C22:6n-3. The recovery in altered fatty acids of choroid plexus was also immediate and very fast. Recovery in content of C22:5n-6 and C22:6n-3 was complete by 46 days after diet substitution.     

Redox imbalance in peripheral blood of type 1 myotonic dystrophy patients

Objectives: The aim of our study was to determine if redox imbalance caused by the activities of antioxidant enzymes existed in erythrocytes of type 1 myotonic dystrophy (DM1) patients.

Methods: The activities of erythrocyte superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase were measured in 30 DM1 patients and 15 healthy controls (HCs). The obtained values were correlated with the Muscular Impairment Rating Scale (MIRS) score and creatine kinase (CK).

Results: Superoxide dismutase and catalase activities were lower in DM1 patients compared to HCs. A positive correlation was found between disease duration and MIRS score as well as with glutathione reductase activity. In DM1 patients, there were positive correlations between catalase, glutathione peroxidase, and glutathione reductase activities. After sub-dividing DM1 patients according to CK levels, superoxide dismutase activity was still statistically different from HCs. However, catalase activity was significantly lower only in DM1 patients with increased CK.

Discussion: Undesirable alterations in antioxidant enzyme activities during DM1 disease progression may result in conditions favoring oxidative stress and changes in metabolism which together could contribute to muscle wasting.     

The Functional Significance of the Pentose Phosphate Pathway in Synaptosomes: Protection Against Peroxidative Damage by Catecholamines and Oxidants

Abstract: Catecholamines added in vitro in rat brain synaptosomes activate the decarboxylation of glucose radioactively labelled on carbon 1, suggesting an effective activation of the pentose phosphate pathway. Stimulation also occurred with phenazine methosulphate, reduced glutathione and hydrogen peroxide. The activation of the pentose phosphate pathway by 5-hydroxytryptamine, noradrenaline and dopamine is ascribed to the activation of monoamine oxidase, producing both the respective biogenic aldehyde and hydrogen peroxide. Evidence is presented that the further metabolism of the aldehyde by aldehyde reductase and the removal of hydrogen peroxide by glutathione peroxidase both release the limitation of N ADP⁺ availability for the pentose phosphate pathway by leading to the oxidation of NADPH. The relevance of the maintenance of reduced NADP⁺ on brain is discussed in relation to the metabolism of glutathione and to lipid peroxidation.     

Effects of genistein on early-stage cutaneous wound healing

Wound healing occurs in three sequential phases: hemostasis and inflammation, proliferation, and remodeling. Inflammation, the earliest phase, is considered a critical period for wound healing because immune cells remove damaged tissues, foreign debris, and remaining dead tissue. Wound healing would be delayed without inflammation, and this phase is affected by antioxidation capacity. Therefore, we hypothesized that genistein, which has an antioxidant effect, might modulate the wound healing process by altering the inflammatory response. After three days of acclimation, mice were divided into three groups: control, 0.025% genistein, and 0.1% genistein. After two weeks of an experimental diet, skin wounds were induced. Wounded skin areas were imaged, and the healing rate calculated. To measure lipid peroxidation, antioxidant enzyme expression and activity, and pro-inflammatory cytokine expression, skin and liver tissues were harvested at 12, 24, 48, and 72 h. Genistein did not affect body weight. The rate of wound closure in mice fed genistein was significantly faster than in the control group during the early stage of wound healing, especially in first three days. Cu, Zn-SOD and Mn-SOD expression in wound skin tissue in the 0.1% genistein group was lower than in the control group. However, CAT expression did not differ among groups. We also found that genistein modulated NF-κB and TNF-α expression during the early stage of wound healing. The genistein group had significantly lower hepatic lipid peroxidation and higher SOD, CAT, and GPx activities than the control group. These results suggest that genistein supplementation reduces oxidative stress by increasing antioxidant capacity and modulating proinflammatory cytokine expression during the early stage of wound healing.