The ratio of lipidperoxides to superoxide dismutase activity in the skin lesions of patients with severe skin diseases: an accurate prognostic indicator

Attenuation of dermal wounds via downregulating oxidative stress and inflammatory markers by protocatechuic acid rich n-butanol fraction of Trianthema portulacastrum Linn. in wistar albino rats

Oxidative stress and inflammation contribute as a key factor for retarding the process of dermal wound healing. Trianthema portulcastrum Linn. (TP) leaves reported to possess antioxidant, antifungal, anti-inflammatory and antibacterial properties, which could make TP a promising wound healing agent. The current study was aimed to estimate the antioxidant potential of the fractionated hydroethanolic extract of TP leaves and evaluate wound healing activity by excision and incision wound models along with the assessment of possible underlying mechanism. Ethyl acetate, chloroform and n-butanol fractions of the hydroethanolic extract of TP leaves were examined for in vitro antioxidant ability by DPPH method. Strongest antioxidant activity bearing n-butanol fraction (nBuTP) was further analyzed quantitatively by High Performance Liquid Chromatography coupled with Diode Array Detector (HPLC-DAD). Wound healing potential of nBUTP using excision and incision wound model was studied. Wistar albino rats were randomly divided into four groups, containing six animals in each group; group I served as control treated with simple ointment base, group II was standard group, treated with povidone-iodine ointment USP (5%), group III treated with nBuTP 5% w/w ointment, and group IV treated with nBuTP 10%w/w ointment. All the groups were topically applied their respective ointments, once daily, till the complete healing achieved. Wound healing was assessed by analyzing % wound closure, hydroxyproline content, epithelialization period, tensile strength, enzymatic antioxidative status and inflammatory markers. Total phenolic and flavonoid content of the extract was estimated to be 112.32±1.12 and 84.42±0.47mg/g, respectively. HPLC-DAD of nBuTP confirmed the presence of chlorogenic acid (20.74±0.03), protocatechuic acid (34.45±0.02mg/g), caffeic acid (4.31±0.03mg/g) and ferulic acid (1.43±0.01mg/g). 5% and 10%w/w nBuTP ointment significantly accelerated the wound healing process dose-dependently in both wound models, evidenced by the faster rate of wound contraction, epithelialization, increased hydroxyproline content, high tensile strength, increased antioxidant enzyme activity, decreased the level of inflammatory markers compared to the control group. Histopathological studies also revealed the dose-dependant amelioration of wound healing by re-epithelialization, collagenation and vascularization of wounded skin sample in nBuTP treated groups. These results implicate potential medicinal value of nBuTP to heal dermal wounds.

The Role of Oxidative Stress in the Clinical Manifestations of Childhood Asthma

INTRODUCTION

The significance of oxidative stress in pathogenesis of childhood asthma was recognized, but its role in the clinical manifestations of disease is still unclear.

MATERIALS AND METHODS

The study was conducted in 96 asthmatic children. The urinary biomarker of oxidative stress, 8-oxo-7,8-dihydro-2-deoxyguanosine (8-oxodG/creatinine) was determined by using HPLC-MS/MS. ELISA was performed to measure myeloperoxidase (MPO) and Cu,Zn- superoxide dismutase (Cu,Zn-SOD) in serum.

RESULTS

Logistic regression analysis revealed that female gender, tobacco smoke exposure, and increased 8-oxodG/creatinine were associated with risk for intermittent asthma, while the positive allergy test and increased Cu,Zn-SOD were associated with eczema in asthmatic children. Higher MPO (p = 0.033), and percent of granulocytes (p = 0.030) were found in severe persistent asthma in comparison to intermittent or mild persistent asthma.

CONCLUSION

The main findings that TSE-induced oxidative stress is a risk for intermittent asthma and eczema may be clinically significant for the disease prevention and therapeutic improvements.

Cutaneous Wound Healing after Topical Application of Pistacia atlantica Gel Formulation in Rats

Objectives

This study has been undertaken to investigate the antioxidant activity of the gel formulation from Pistacia atlantica oil extraction on enzymatic antioxidants in experimental wound created in rats.

Materials and Methods

Under anesthesia, a square-shaped skin defect (2x2 cm) was created aseptically by surgical incision. Then, animals were randomly allocated to four groups (I- untreated controls, II- topically treated with base gel, III- topically treated with 5% gel, IV- topically treated with 10% gel).

Results

The results suggest that topical application of Pistacia atlantica oil gels improved reepithelialization with continuous stratum basalis and a mature granulation tissue and adnexa (hair follicles and sweat gland) compared with control and base gel groups. Treatment with 10% oil gel significantly enhanced the tensile strength, ultimate stress, yield strength and stiffness in this group compared with the control and base gel groups at 21 days post injury. The collagen fibers showed a more organized pattern and the tissue alignment was greater as compared to the control and base gel-treated groups at the same stage.

Conclusion

The results suggest that topical application of Pistacia atlantica oil gel improved the morphological, biochemical and biomechanical properties of experimentally-induced wound defects in rats.

Innovative approaches in wound healing: trajectory and advances

Wound is one of the oldest suffering associated with the mankind and its history is as old as humanity. Advances in the field of medical sciences created a pile of knowledge and paved the path for the development of a separate branch specifically devoted for wound healing. The understanding and treatment strategies for wound healing have gone through a great revolution. This article reviews all the aspects of wound healing including the pathway, types and recent advances made in the wound care management in particular moist wound dressings using natural polymers, skin grafts, debridement, growth factor and drug delivery.

Evaluation of antimicrobial, antioxidant and wound-healing potentials of Holoptelea integrifolia

The methanolic extracts of Holoptelea integrifolia (Roxb.) (Urticaceae) leaves (MLE) and stem bark (MSBE) were studied for the wound-healing potential. Since wound healing is severely hampered by microbial infection and reactive oxygen species (ROS), this study was undertaken to evaluate antimicrobial and antioxidant activity apart from wound-healing activity. The antimicrobial property of the Holoptelea was studied against the six bacterial and five fungal strains using the agar well diffusion method and minimum microbicidal concentration and minimum inhibitory concentration were determined for each strain, in which methanolic extract of stem bark (MSBE) has shown bigger zone of inhibition (11.3-20.4 mm) than methanolic extract of leaves (MLE) (9.6-14.9 mm). The anti-oxidant activity was evaluated by DPPH free radical scavenging activity using HPLC method. The IC(50) values obtained for MSBE (TPC: 78.53+/-1.26 mg/g) and MLE (TPC: 57.71+/-1.45 mg/g) were 37.66+/-0.48 and 50.36+/-0.59 microg/well, respectively. In excision wound model, more than 90% wound healing was recorded in treated groups by 14 days of post surgery, where as only 62.99% was observed in the control group. In incision model, higher breaking strengths and higher hydroxyproline content in treated groups suggested higher collagen re-deposition than the control group. Finally, histopathology studies conformed wound-healing activity of Holoptelea integrifolia.

Influence of desloratadine on oxidative stress markers in patients with chronic idiopathic urticaria

BACKGROUND

Recent findings suggest the involvement of oxidative stress in the pathogenesis of chronic idiopathic urticaria (CIU). It has been demonstrated that desloratadine has an antioxidant activity in vitro. We evaluated the effects of desloratadine on markers of oxidative stress in patients with CIU.

METHODS

Blood samples were obtained from 10 patients with CIU before and after 4 weeks of treatment with desloratadine. Blood samples from 10 healthy volunteers were used as controls. In platelets from both patients and controls, radical oxygen species (ROS) production was measured using spectrofluorimetric detection of dichloro-fluorescein oxidation, and superoxide dismutase (SOD) activity was determined by means of the xanthine-xanthine oxidase system.

RESULTS

Radical oxygen species concentrations and SOD activity were significantly elevated in patients with CIU at baseline as compared with control subjects. Treatment with desloratadine caused a relevant reduction of ROS levels and SOD activity (P<0.005).

CONCLUSIONS

These preliminary results suggest that desloratadine exerts antioxidant effects also in vivo.

Age-dependent generation of reactive oxygen species in the skin of live hairless rats exposed to UVA light

Aging proceeds by highly complicated biochemical processes, in which the involvement of the reactive oxygen species (ROS) and free radicals has been implicated. Although the relationship between UV-induced photoaging and ROS generation has been proposed, it has been difficult to establish direct proof of the generation of ROS in the skin under UV exposure. Recently, we reported finding endogenously generated ROS in the skin of live mice after UVA light exposure by a method of in vivo chemiluminescent detection, in which superoxide anion radical (*O2-) and singlet oxygen species (1O2) are contributed. In light of the results, we tried to understand the age-dependent changes in ROS generation in the skin of hairless rats under UVA exposure. Chemiluminescent levels due to ROS in the untreated and UVA-exposed skin decreased age dependently, and the signal intensities in old rats were significantly lower than those in young rats. However, the ratios of chemiluminescent intensities in the UVA-exposed skin to those in the untreated skin were significantly enhanced in an age-dependent manner. These results suggest that the antioxidative ability against ROS generation in the skin, possessed by antioxidant enzymes and low molecular weight antioxidants, is lowered age dependently.

Protein oxidative damage in the stratum corneum: Evidence for a link between environmental oxidants and the changing prevalence and nature of atopic dermatitis in Japan

BACKGROUND

The incidence of atopic dermatitis (AD) has increased in Japan, along with the number of patients with severe and treatment-resistant AD in urban and industrial areas. We hypothesize that these changes could be due to increased reactive oxygen species (ROS) generated from environmental pollution and solar radiation.

OBJECTIVES

To demonstrate whether direct oxidative protein damage of the stratum corneum of the biopsied skin from AD patients is increased when compared with controls.

PATIENTS AND METHODS

Carbonyl moieties in skin biopsies from 75 patients with AD were assessed using both spectrophotometric and immunohistochemical detection of the formation of dinitrophenylhydrazone (DNP) from dinitrophenylhydrazine (DNPH). These were compared with diseased and normal controls. Lipid peroxidation was also assessed by staining with antibody to 4-hydroxy-2-nonenal (4-HNE), an aldehyde product of oxidized omega-6-fatty acids. In addition, the activity of superoxide dismutase (SOD), an effective scavenger of ROS, was assessed and compared with controls.

RESULTS

The level of protein carbonyl moieties in patients' skin was elevated and correlated directly with the severity of the disease. In contrast, DNP formation was not significantly increased in diseased controls, when compared with healthy volunteers, and no statistical significance was found between the two control groups. SOD activity was increased except for those with extra-severe disease. Positive staining with anti-DNP antibody and anti-4-HNE antibody were found in the most superficial layers of the stratum corneum.

CONCLUSIONS

This study has found an association between AD severity and markers of ROS-associated damage, adding weight to the hypothesis that environmentally generated ROS may induce oxidative protein damage in the stratum corneum, leading to the disruption of barrier function and exacerbation of AD.

Over-expression of Mn-superoxide dismutase as a marker of oxidative stress in lesional skin of chronic idiopathic urticaria

We studied the involvement of oxidative stress in chronic idiopathic urticaria (CIU), assessing the activities of superoxide dismutase (SOD) and glutathione and the levels of malondialdeyde (MDA), a marker of lipid peroxidation, in samples taken from lesional skin (n = 16) and nonlesional skin (n = 11) of CIU patients. The activity of SOD and glutathione and the levels of MDA were markedly increased in lesional skin as compared with skin of healthy subjects, whereas no differences were detected between nonlesional skin of CIU patients and control samples. Immuno-dot blot assay revealed an up-regulation of Mn-SOD expression in lesional skin. These findings show that oxidative stress is crucially involved in CIU. The evidence of lipid peroxidation and compensatory increase of Mn-SOD and glutathione activities in lesional skin, in the absence of any alteration in uninvolved skin, suggests that oxidative stress is secondary to the development of inflammation.

Plant self-defense mechanisms against oxidative injury and protection of the forest by planting trees of triploids and tetraploids

The depletion of the ozone layer, and the resulting substantial increase in incident ultraviolet (UV) irradiation and subsequent oxygen radical formation on the Earth, have caused an extensive variety of damage to the world's forests. Superoxide dismutase (SOD), catalase, and glutathione peroxidase (GSH-Px), which scavenge harmful oxygen radicals and inhibit lipid peroxides, were examined in two types of Japanese cedars, black pines, and cypresses, namely those with leaves showing premature withering, shedding, or dying and those with leaves not showing these effects prematurely. The effect of homogenates from these trees on lipid peroxide formation in a reaction system which UV light induces was also studied. The results indicate that strong black pines have significantly higher SOD activities than ordinary black pines, the leaves of which prematurely wither or die. Remarkably, trees that had triploid or tetraploid chromosomes showed higher SOD levels than diploid trees and markedly inhibited lipid peroxide formation since the SOD gene resides on a chromosome. This was especially true of plus trees of Japanese cypress, some of which had five times higher SOD activities than common Japanese cypresses although GSH-Px appears to play less of a role in this regard. Rice leaves and osmunda which are resistant to UV damage showed markedly higher SOD and GSH-Px activity. Our experiments suggest that the trees that have high SOD can protect themselves by scavenging oxygen radicals induced by UV irradiation and inhibit harmful lipid peroxide formation. In order to protect forests from oxidative damage by UV light, we should plant trees of natural mutants and artificially crossed triploids and tetraploids.

Antioxidant status during cutaneous wound healing in immunocompromised rats

The present investigation was undertaken to investigate the endogenous status of free radical scavengers during cutaneous wound healing in immunocompromised rats. Antioxidant contents and lipid peroxidation product in terms of malondialdehyde (MDA) have been monitored in the wound tissues of immunosuppressed rats at different time intervals (2, 7 and 14 days) following cutaneous injury. A significant increase in MDA content and decrease in glutathione and vitamin C content was observed in the skin of immunocompromised rats as compared to control subjects. Further, a significant decrease in vitamin C, vitamin E content, catalase and glutathione peroxidase activity was observed at 2 days postwounding in immunocompromised rats. A significant and time-dependent decrease in glutathione content was also observed at 7 and 14 days postwounding. However, the healing tissue on 2 and 7 days postwounding exhibited significantly elevated superoxide dismutase activity. The MDA content was augmented only at 2 days postwounding in immunosuppressed rats. Thus significant alterations in the antioxidant profile accompanied by elevated levels of MDA, a marker of free radical damage may be contributory to impaired wound healing in immunocompromised rats.

The effects of EGb 761 on lipid peroxide levels and superoxide dismutase activity in sunburn

BACKGROUND/PURPOSE

Free oxygen radicals are involved in inflammatory skin reactions induced by ultraviolet B (UVB). In this study, the effect of a herbal antioxidant Ginkgo biloba extract (EGb 761) was investigated in UVB irradiated mice skin.

METHODS

The study was carried out on four groups of mice (n = 6 in each group). The first group was a control group (G1). The second group (G2) was only exposed to acute UVB irradiation. The third group (G3) received 100 mg/kg/day of EGb 761 orally for 5 days before UVB irradiation and the fourth group (G4) was given only a single dose of EGb 761 immediately after UVB irradiation. Eighteen hours after exposing to UVB, lipid peroxide levels, and superoxide dismutase (SOD) activities were studied and UVB damage was evaluated histopathologically according to "sun-burn cell count".

RESULTS

The SOD activities and Malondialdehyde (MDA) levels in G2, G3 and G4 were found to be decreased significantly when compared with G1 (P < 0.05). The SOD activities of G3 and G4 were higher when compared with G2 (P < 0.05). The number of sunburn cells (SBCs) was the highest in G2.

CONCLUSIONS

Our results suggest that EGb 761 may have an important effect, both as a protective and therapeutic agent, in sunburn after UVB irradiation.

Asiaticoside-induced elevation of antioxidant levels in healing wounds

Asiaticoside derived from the plant Centella asiatica is known to possess good wound healing activity. Enhanced healing activity has been attributed to increased collagen formation and angiogenesis. Since antioxidants have been reported to play a significant role in the wound healing process we studied the effect of asiaticoside on the levels of certain antioxidants in the wound so as to explore the possible involvement of such a mechanism in the asiaticoside induced wound healing. Asiaticoside application (0.2%, topical) twice daily for 7 days to excision-type cutaneous wounds in rats led to increased enzymatic and non-enzymatic antioxidants, namely superoxide dismutase (35%), catalase (67%), glutathione peroxidase (49%), vitamin E (77%) and ascorbic acid (36%) in newly formed tissues. It also resulted in a several fold decrease in lipid peroxide levels (69%) as measured in terms of thiobarbituric acid reactive substance. However, continued application for 14 days showed no significant difference in these antioxidants compared with their values in vehicle treated wound tissue. It appears from the present study that asiaticosides enhanced induction of antioxidant levels at an initial stage of healing which may be an important contributory factor in the healing properties of this substance.

Erythrocyte antioxidant activity and trace element levels in Behçet's disease

Selenium (Se), zinc (Zn), copper (Cu), and antioxidant enzyme (superoxide dismutase [SOD] and glutathione peroxidase [GSH-Px]) levels in sera were detected in Behçet patients. Age and sex matched controls were used to find out if oxidative stress takes place in the etiopathogenesis of Behçet's disease. Superoxide dismutase levels were found to be lower in the whole patients group when compared to controls. In whole patients and inactive patients' group Zn and Se levels were found to be higher, but not different in the active patients group when compared to controls. No significant difference was found between the groups as Cu and glutathione peroxidase levels were taken into consideration. According to the results of the present study, SOD level is low in Behçet's disease patients' sera independent from the phase of the disease, and as a result of decreased SOD activity, increased production of free oxygen radicals may play a role in the etiopathogenesis of the disease.

Depletion of reduced glutathione, ascorbic acid, vitamin E and antioxidant defence enzymes in a healing cutaneous wound

In the present investigation the involvement of free radicals in a self-healing cutaneous wound has been demonstrated. The levels of different enzymatic and non-enzymatic antioxidants have been studied in 2,4,7 and 14 days old wounds and compared with normal skin. Except for glutathione reductase (GR), all other enzymatic and non-enzymatic antioxidants were found to decrease following wounding. The decrease was 60-70% in superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) at 2, 4 and 7 days, while in the case of catalase (CAT) the decrease was 40-60% during this period. Although a complete recovery in the activity of CAT was observed, SOD and GPx did not recover completely and GST was found to be slightly elevated on 14th day post wounding. Non-enzymatic antioxidants viz, ascorbic acid, vitamin E and glutathione were also found to decrease to about 60-70% and except glutathione none of them was found to recover completely at 14th day postwounding. Interestingly thiobarbituric acid reactive substance (TBARS) expressed as malondialdehyde (MDA) equivalent, a marker of lipid peroxidation, decreased following wounding which could be because of meagre availability of lipid substrate and/or of ascorbic acid. The results indicate that wounding results in loss of different free radical scavengers both enzymatic and non-enzymatic which either partially or completely recover following healing.

Suppression of UV-induced erythema by topical treatment with melatonin (N-acetyl-5-methoxytryptamine). A dose response study

Oxygen-centred free radicals play an important role in the pathogenesis of acute and chronic UV-induced skin damage as well as in skin aging. In this double-blind randomized study the efficacy of topically applied melatonin (N-acetyl-5-methoxytryptamine), a potent free radical scavenger, in the suppression of UV-induced erythema was assessed. A group of 20 healthy volunteers were irradiated with 0.099 J/cm2 UVB on four 5-cm2 areas on the lower back and topically treated with various concentrations of melatonin (0.05, 0.1, 0.5%) in a nanocolloid gel as carrier or with carrier alone. The UV-induced erythema was examined 8 and 24 h after irradiation by visual scoring and chromametry. A distinct dose response relationship was observed between the topical dose of melatonin and the degree of UV-induced erythema. Significant differences (P < 0.05) were found in redness (chromameter a-value and visual scoring) 8 h after irradiation between the areas treated with melatonin at 0.5% and those treated with melatonin at 0.05% or with the carrier. These results might open a new approach in the prevention and control of free radical-influenced skin diseases.

Treatment of actinic prurigo in Chimila Indians

BACKGROUND

Actinic prurigo has a high prevalence in women of child-bearing age. Its treatment has been, among others, with thalidomide. To avoid the deleterious effects of this drug on the embryo, therapeutic alternatives have been sought. Among these, tetracycline and vitamin E have been investigated as to their influence on the symptoms of actinic prurigo. Both these drugs affect superoxide radicals that are thought to be involved in the pathogenesis of actinic prurigo.

MATERIALS AND METHODS

Patients (Chimila Indians with a high prevalence of actinic prurigo) received either (a) tetracycline, 500 mg three times daily, for 6 months, or (b) vitamin E, 100 IU daily, for 6 months. The patients were seen once monthly. There were eight patients in each group.

RESULTS

Both drugs used were effective. Pruritus was remarkably improved by either treatment. None of the side effects were severe enough to lead to interruption of treatment, but the observation period posttreatment was relatively short, 4 months for tetracycline and 2 months for vitamin E. The improvement occurred in spite of the continuation of extensive exposure to the sun.

CONCLUSIONS

Tetracycline and vitamin E are efficacious in relieving the pruritus of actinic prurigo. Preliminary trials of a combination treatment with these two drugs is a new avenue which has shown in preliminary trials to yield synergistic effects which might allow the dosage of tetracycline to be reduced.

Hypothesis: spermine may be an important epidermal antioxidant

Spermine has been identified as a potent antioxidant and an anti-inflammatory agent. The compound is present in all organisms and all organs. The concentration is exceptionally high in skin, and I propose that spermine constitutes a prime defence against radiation damage. This hypothesis is substantiated by the fact that ornithine decarboxylase (ODC), the rate-controlling enzyme of spermine biosynthesis, is induced by UVB-irradiation and oxidative stress. On the contrary, inhibition of ODC makes cells more sensitive to radiation damage. The antioxidative effect of spermine may be due to metal chelation and/or to prevention of superoxide generation from stimulated neutrophils. This paper reviews the antioxidative and anti-inflammatory effects of spermine, and suggests that spermine is an important antioxidant of epidermis.

Mechanism of inhibitory effects of chelating drugs on lipid peroxidation in rat brain homogenates

The mechanism of the inhibitory effects of chelators (desferrioxamine, EDTA, rutin, phenanthroline and ADP) on the production of oxygen radicals in the Fenton reaction and on lipid peroxidation of rat brain homogenates has been studied. It was found that the inhibitory effects of the chelators correlated well with their abilities to oxidize ferrous ions in solution and brain homogenates. On these grounds, it was concluded that the oxidation of Fe2+ ions inside a ferrous ion-chelator complex is a major mechanism of inhibitory effects of these chelators on free radical processes. It is proposed that this mechanism is also realized during therapeutic treatment with chelators of patients with "free radical" pathologies such as Fanconi anemia, beta-thalassemia and Diamond-Blackfan anemia.

Long-term follow-up study of changes in lipid peroxide levels and the activity of superoxide dismutase, catalase and glutathione peroxidase in mouse skin after acute and chronic UV irradiation

Lipid peroxide levels, the activities of superoxide dismutase (SOD), catalase and glutathione peroxidase (GSH-Px), and the development of tanning in the skin of C57 BL/6 mice were assessed for long periods, from very early to late stages, after acute or chronic UVB irradiation. Acute UVB irradiation produced an increase in lipid peroxide levels that peaked 18 h after irradiation, after which the levels declined to a minimum 2-3 days after irradiation and then gradually rose to baseline. Chronic irradiation caused the lipid peroxide level to fall to a minimum at 0.5-1.0 weeks, after which it gradually returned to baseline by the third week. SOD and GSH-Px activities decreased sharply after acute irradiation, reaching a minimum 18 h after irradiation. Following chronic irradiation, these enzyme levels peaked after 0.5 weeks, and thereafter declined gradually to the original levels 3 weeks after irradiation. In contrast, catalase activity did not change significantly. Tanning began to increase at 1.5 weeks after irradiation, with an accelerated rate of increase from the third week.(ABSTRACT TRUNCATED AT 250 WORDS)

Development and characterization of hydrogen peroxide-resistant Chinese hamster ovary cell variants--I. Relationship between catalase activity and the induction/stability of the oxidant-resistant phenotype

Hydrogen peroxide (H2O2)-resistant sublines of Chinese hamster ovary (CHO) cells were isolated by in vitro exposure to the oxidant (treatment for 1 hr followed by 3 days of growth in peroxide-free medium). Stepwise increase in low level H2O2 concentrations produced variants which were progressively more resistant to the growth inhibitory effect elicited by the oxidant. Removal from H2O2 decreased resistance and the curve describing this process was biphasic in nature. In addition, the rate of loss of the H2O2-resistant phenotype was more rapid for the toxicity elicited by low concentrations of hydrogen peroxide, compared to that produced by high concentrations. Changes in total cell proteins were found to parallel the variations in sensitivity to the oxidant, since the protein content constantly increased during the adaptation process and decreases upon removal from H2O2. Catalase activity did not show large variations in resistant sublines with respect to the parental cell line, and these changes were at least partially related to differences in cell size/amount of total cell proteins of the sublines. In addition, the minor changes observed for catalase activity did not correlate with the degree of resistance to growth inhibition elicited by the oxidant. It may therefore be suggested that the H2O2-resistant phenotype of mammalian cells, initially adapted to low--then gradually increased--concentrations of the oxidant, is the result of a complex phenomenon which only partially involves over-expression of catalase.

The effect of lipid peroxides and superoxide dismutase on systemic lupus erythematosus: a preliminary study

Serum lipid peroxide (LPO) levels, superoxide dismutase (SOD) activity in peripheral blood erythrocytes, serum ANA, anti-dsDNA, and C3 were measured in 83 patients with systemic lupus erythematosus (SLE) and in 29 healthy controls. Compared to the controls, LPO levels were significantly increased in active SLE patients while SOD activity was markedly decreased. From the active phase to the inactive phase, a gradual decline in LPO levels and an increase in SOD activity were observed. There was a close correlation between LPO levels and disease activity or the parameters including ANA titers, anti-DNA titers, and C3 levels; a significant negative correlation was found between SOD activity and LPO levels or these parameters. Further, a marked difference in SOD activity was found in untreated active cases with and without nephritis. As the SLE patients improved, LPO levels gradually declined and SOD activity increased. The present study indicates that free radicals and resultantly formed lipid peroxide levels are higher in patients with SLE than those in normal persons, probably contributing to the production of autoantibodies, nephritis, and vasculitis of other organs, and that excessively generated free radicals may play an important role in the pathogenesis of SLE, which is possibly due to diminished SOD activity.

The role of iron in an acute model of skin inflammation induced by reactive oxygen species (ROS)

The effect of iron was studied in rats in a ROS-initiated model of acute skin inflammation. Iron dextran was administered i.v. 24 h before the induction of the inflammatory response by intradermal injection of glucose oxidase attached to polyethylene glycol (GOD-PEG). Iron exacerbated the response at 24 and 48 h (P greater than 0.001). Histologically, a similar picture was seen to that without iron except for an increase in tissue oedema and matrix destruction including the skin glands. Associated with iron loading was an increase in Perls stainable iron in the skin (P greater than 0.025) and liver (P greater than 0.001). However, skin inflammation without iron loading also increased skin iron levels (P greater than 0.025). Total serum iron was decreased in iron-loaded and GOD-PEG animals (P greater than 0.01) and the unbound iron binding capacity (UIBC) increased (P greater than 0.01).

Changes in lipid peroxide levels and activity of reactive oxygen scavenging enzymes in skin, serum and liver following UVB irradiation in mice

The effect of acute UVB on the generation of reactive oxygen species (ROS) in the skin and the induction of ROS scavenging enzymes in situ was examined. Lipid peroxide levels and the activities of superoxide dismutase (SOD), catalase, glutathione peroxidase (GSH-Px) and D-glucose-6-phosphate dehydrogenase (G-6-P-D) were determined in the skin, serum, and liver of ICR mice subjected to 1400 mJ/cm2 of acute UVB irradiation. In irradiated skin, lipid peroxides were increased at 3 and 24 hr after irradiation, whereas the four ROS scavenging enzymes were generally decreased during the first 48 hr after irradiation. In the serum, lipid peroxides showed an increase at 3 hr, but enzyme activities remained negligible. In the liver, lipid peroxides showed similar behaviour to that in skin. GSH-Px activity in the liver was decreased during the first 24 hr, whereas G-6-P-D showed substantial fluctuation and SOD and catalase activities showed no change. These data are consistent with a model in which lipid peroxides generated in the UVB-irradiated lesions are transported to the liver and there metabolized by the scavenging enzymes induced in situ.

Histochemical detection of burn-induced lipid peroxidation in sebaceous glands of rat skin

Increased lipid peroxide levels both in skin and serum have been reported after cutaneous thermal injury. However, it still remains unclear where lipid peroxides are produced at the site of burned skin. In the present study, a histochemical method using cold Schiff's reagent was applied in order to detect the localization of lipid peroxide. Schiff positivity was detected in sebaceous glands, and the extent of positivity seemed to correlate with the serum lipid peroxide levels. These results may suggest that lipid peroxides produced in sebaceous glands after thermal injury enter the blood stream and are partially responsible for the elevated serum lipid peroxide levels.

Impairment of enzymic and nonenzymic antioxidants in skin by UVB irradiation

Antioxidants may play a significant role in ameliorating or preventing photobiologic damage in skin that could lead to cutaneous disorders such as cancer and premature aging. The objective of this study was to assess the acute cutaneous enzymic and nonenzymic antioxidant response to a single exposure of large fluence (300 mJ/cm2) ultraviolet radiation (greater than 280 nm) in hairless mice. This treatment caused an immediate and statistically significant inhibition of glutathione reductase and catalase activity. Glutathione peroxidase and superoxide dismutase were not affected. Glutathione levels decreased and, conversely glutathione disulfide concentrations increased. A slight depletion of the total glutathione was observed, while the content of total ascorbic acid did not change. The lipophilic antioxidants alpha-tocopherol, ubiquinol 9 and ubiquinone 9 also decreased significantly, and the concentration of malondialdehyde remained constant. The free radical scavenging activity of epidermis, as assessed by reduction of the stable, cationic nitroxide radical [2,2,6,6-tetramethyl-1-piperidinoxy-4-(2',4',6'-trimethyl) methylpyridinium perchlorate] was considerably inhibited. The study indicates that immediately after exposure to a large fluence of ultraviolet radiation the enzymic and nonenzymic antioxidant capacity of skin decreases significantly.

Is postburn dermal ischaemia enhanced by oxygen free radicals?

The accumulated data suggest that oxygen free radicals are actively involved in the pathophysiology of the wound healing process. Since OH. and O2- directly correlate with the release of arachidonic acid and catalyse some of the enzymes participating in its cascade, their involvement in the enhancement of dermal ischaemia in the stasis zone is postulated. Experimental data using topically applied scavengers of superoxide have shown their beneficial effects on the burn wound healing process.

Significance of reactive oxygen species in distal flap necrosis and its salvage with liposomal SOD

In an attempt to elucidate whether reactive oxygen species (ROS) have a role in causing distal necrosis of random pattern flaps, and to develop measures to prevent necrosis, three experiments were made using a rat flap model. The flap-salvaging effect of liposomal superoxide dismutase (L-SOD) was assessed. The results were as follows: (1) Measurements of changes in cutaneous blood flow in a flap, with time, revealed an initial remarkable decrease followed by gradual but significant increase in the distal portion 24 hours after operation. (2) The SOD activity in the flap continued to decrease gradually with time until 24 hours after operation both in L-SOD treated and control groups. However, SOD activity in L-SOD treated flaps was always significantly higher than in the control. (3) S-D value (survival length minus dye distance) was significantly greater in the L-SOD treated flap than in the control flap, indicating a significant effect of L-SOD in preventing the expected flap necrosis. These results suggest a possible role, in causing flap necrosis, of ROS which are generated by reperfusion following ischaemia, and the effectiveness of L-SOD in salvaging distal flap necrosis.

Neutrophil chemotaxis, phagocytosis and parameters of reactive oxygen species in human aging: cross-sectional and longitudinal studies

To assess the effect of aging on neutrophil (PMN) functions and the parameters related to reactive oxygen species (ROS), we measured the following in blood samples from 166 asymptomatic aged individuals: PMN activities including chemotaxis, phagocytosis and generation of ROS; the activity of superoxide dismutase (SOD) of blood cell; and serum lipid peroxide levels. Compared with non-aged adults, the older individuals showed markedly attenuated PMN chemotaxis, and slightly elevated serum lipid peroxide levels. Other parameters were not significantly different between the two aged groups. In contrast both to the elderly group as a whole and to the subgroup 65 to 79 years old, the subjects over greater than or equal to 80 years old showed normal PMN chemotaxis and serum lipid peroxide levels, as defined by the young adult control group. Thirty-two subjects who entered the study at ages 69 to 72 years were followed with serial assays for seven years; twenty-one of these subjects died during this observation period. There was a striking and significant difference between the survivors and nonsurvivors with regard to PMN chemotaxis and serum lipid peroxide levels; even when asymptomatic upon initial examination, the nonsurvivors showed diminished PMN chemotaxis and elevated lipid peroxide levels. It seems from both the cross-sectional and longitudinal parts of our study that PMN chemotaxis and serum lipid peroxide levels correlate with survival to advanced age.

Experimental burn-induced changes in lipid peroxide levels, and activity of superoxide dismutase and glutathione peroxidase in skin lesions, serum, and liver of mice

The lipid peroxide levels and the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in skin lesions, liver, and serum of mice were measured from the 15th min to 6th day after burns were inflicted on their skin. The lipid peroxide levels in the skin lesions were increased at the 24th h and on the 3rd day after the burns were inflicted. However, the SOD activity did not increase but was significantly decreased from the 30th min to 24th h. GSH-Px activity was almost undetectable in both skin and serum. The lipid peroxide levels in the serum were significantly increased and SOD activity slightly increased at the 4th h. The lipid peroxide levels in the liver were elevated at the 4th h and on the 3rd day although a slight decrease was observed at the 8th h. SOD and GSH-Px activities in the liver increased from the 4th to 24th h. The present study illustrates the changes in both burn-induced lipid peroxides in each organ and the induction mechanisms of the activities of oxygen radical scavenging enzyme, SOD, and lipid peroxide processing enzyme, GSH-Px, which responded to oxygen stress.

The effect of aging on cutaneous lipid peroxide levels and superoxide dismutase activity in guinea pigs and patients with burns

Cutaneous lipid peroxide levels and superoxide dismutase (SOD) activity in non-aged and aged guinea pigs were measured between 15 min and 7 days after experimental infliction of burns. Skin burns on non-aged and aged patients were also subjected to these assays. In non-aged guinea pig skin burns, lipid peroxide levels increased from 24 hr to the fourth day after the burn infliction, while SOD activity did not increase but showed a slight decrease 12 hr and 24 hr post-burn. On the other hand, while the aged group showed a more increase in skin lipid peroxide levels compared to that seen in non-aged mice, skin SOD activity began to decrease from 30 min post-burn, the maximum decrease being reached on the second day. The activity did not return to normal by the 7th day. In non-aged patients skin burns showed increases in both lipid peroxide levels and SOD activity, while in aged patients, though they showed a marked increase in lipid peroxide levels, SOD activity remained unchanged. The present study indicated that, although in our recent study, skin SOD activity of healthy elderly people was found to be comparable to that in non-aged individuals, the capacity for induction of SOD activity under oxygen stress differed with age in both guinea pig and human burn sufferers. Furthermore, this induction capacity seemed to vary from species to species.

Follow-up study of lipid peroxides, superoxide dismutase and glutathione peroxidase in the synovial membrane, serum and liver of young and old mice with collagen-induced arthritis

Because reactive oxygen species (ROS) are generally believed to play an important role in tissue injury in rheumatoid arthritis, we examined the levels of lipid peroxides, superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) in the synovial membrane, serum and liver of young (8 wk) and old (12 mo) mice with collagen-induced arthritis. In the synovial membrane, serum and liver, lipid peroxide levels of both young and old mice were increased beginning on the 3rd day after the onset of arthritis. SOD activity, which scavenges O2- and inhibits lipid peroxidation, rose markedly in the synovial membrane of young mice in parallel with the increase in lipid peroxide levels, but not so markedly in old mice. Liver GSH-Px activity, which metabolizes already formed lipid peroxides, also rose in young arthritic mice to a greater degree than in old mice. This study suggests that in inflammatory synovial lesions, lipid peroxides are generated due to an increase in ROS concentration, with resultant cytotoxicity, and that younger animals or humans can prevent this unfavorable reaction more effectively than aged ones by enzyme induction. The hypothesis that lipid peroxides formed in the oxidative lesions of the primary organ are released into the serum, trapped by the liver and metabolized there is further supported by the present study.

Antioxidant activity of synovial fluid, hyaluronic acid, and two subcomponents of hyaluronic acid. Synovial fluid scavenging effect is enhanced in rheumatoid arthritis patients

To test the scavenging of reactive oxygen species (ROS), we added synovial fluids from patients with rheumatoid arthritis (RA) and osteoarthritis, as well as hyaluronic acid (HA) and its 2 subcomponents, D-glucuronic acid and N-acetyl-D-glucosamine, to 2 ROS-generating systems, activated neutrophils and xanthine-xanthine oxidase. Synovial fluid from RA patients, HA, and D-glucuronic acid markedly decreased the O2-, H2O2, OH., and chemiluminescence measured in both systems. HA and synovial fluid, which are known to be susceptible to degradation by excessive ROS in RA patients, also seem to play an active role in protecting articular tissues from oxidative damage.

Decreased skin superoxide dismutase activity by a single exposure of ultraviolet radiation is reduced by liposomal superoxide dismutase pretreatment

The effect of a single exposure to UV radiation on skin superoxide dismutase (SOD) activity was examined in mice. A significant decrease in SOD activity was observed 24 and 48 h after UV irradiation, returning to the normal level by 72 h after irradiation. Decreased SOD activity after UV exposure was reduced by pretreatment with liposomal SOD (L-SOD). This protective effect of L-SOD may have potential clinical application for photodermatologic reactions.