The involvement of free radicals in burn injury: a review

Assessment of the Anti-Acne Properties of Some Medicinal Plants and Development of an Herbal Anti-Acne Formulation

Background: Acne is a prevalent dermatological condition characterized by the blockage of hair follicles and sebaceous glands, leading to the formation of acne. The anaerobe pathogen Cutibacterium acnes (formerly known as Propionibacterium acnes) plays an essential role in the pathogenesis of acne, for which generally antimicrobial treatment is required. Acne is a substantial health concern, and continuing research is being conducted to discover novel and efficacious remedies. The antimicrobial activity of plants has been demonstrated in numerous studies, and they are still targeted organisms in drug development. Studies showing that plants are effective against acne pathogens have also been reported. Methods: The antimicrobial activity of the hydroethanolic extracts prepared from 30 plant species was determined against C. acnes standard strains (C. acnes Scholz and Kilian ATCC 11827 and ATCC 11828) and 30 clinical isolates in our preliminary screening. Since acne is an inflammatory skin disease, the anti-inflammatory effect of six active extracts against C. acnes was determined through the in vitro inhibition of collagenase, lipoxygenase (LOX), hyaluronidase and xanthine oxidase (XO) enzymes. Results: Cotinus coggygria Scop. leaf extract displayed the highest hyaluronidase and collagenase inhibition (79.75% and 52.52%, respectively), while the extract from the aerial parts of Helichrysum arenarium (L.) Moench demonstrated a potent XO inhibitory effect (82.51%). Therefore, these two extracts have been chosen for further studies, and LC/MS-MS was used to determine the phenolic profiles of these extracts. Conclusions: Subsequently, nanoemulgels were formulated with the active extracts to develop a prototype herbal anti-acne product, and characterization studies of the formulations were conducted.

Advances in ionic liquid-based antimicrobial wound healing platforms

Wound infections, marked by the proliferation of microorganisms at surgical sites, necessitate the development of innovative wound dressings with potent bactericidal properties to curb microbial growth and prevent bacterial infiltration. This study explores the recent strides in utilizing ionic liquid-based polymers as highly promising antimicrobial agents for advanced wound healing applications. Specifically, cationic polymers containing quaternary ammonium, imidazolium, guanidinium, pyridinium, triazolium, or phosphonium groups have emerged as exceptionally effective antimicrobial compounds. Their mechanism of action involves disrupting bacterial membranes, thereby preventing the development of resistance and minimizing toxicity to mammalian cells. This comprehensive review not only elucidates the intricate dynamics of the skin's immune response and the various stages of wound healing but also delves into the synthesis methodologies of ionic liquid-based polymers. By spotlighting the practical applications of antimicrobial wound dressings, particularly those incorporating ionic liquid-based materials, this review aims to lay the groundwork for future research endeavors in this burgeoning field. Through a nuanced examination of these advancements, this article seeks to contribute to the ongoing progress in developing cutting-edge wound healing platforms that can effectively address the challenges posed by microbial infections in surgical wounds.

Superoxide dismutase-contained solid lipid nanoparticles: Formulation development and In-vivo evaluation for second-degree burn wound healing in rats

INTRODUCTION

Superoxide dismutase (SOD), a natural enzyme with high antioxidant activity, reduces injury and accelerates wound healing by scavenging superoxide radicals. This enzyme plays an important role in cellular defense against oxidative stress such as burn injury. The aim of this study was to load SOD into solid lipid nanoparticles for the treatment of rat burn wounds.

METHODS

Solid lipid nanoparticles were prepared by Solvent Emulsification Diffusion method and evaluated for particle size, enzyme activity and enzyme entrapment efficiency. Twenty-seven rats in 3 different groups were induced with deep second-degree burns and then treated with SOD-loaded solid lipid nanoparticles, solid lipid nanoparticles without enzyme, or SOD solution. After the treatment period, the wounds were evaluated macroscopically for the area of healing and microscopically for indices of re-epithelialization, granulation tissue and angiogenesis.

RESULTS

The optimized SOD-loaded solid lipid nanoparticles showed a particle size of 35-85 ± 2.41 nm, 78.4 ± 4.31 % entrapment efficiency and 90 % initial enzyme activity. Macroscopic examination showed that the best recovery rate belonged to the solid lipid nanoparticle group. Pathological studies also showed that angiogenesis and granulation tissue were significantly better in this group. Compared to the other two groups, SOD-loaded solid lipid nanoparticles showed a significant improvement in pathological factors, particularly angiogenesis and granulation tissue, as well as a faster reduction in the number of inflammatory cells.

CONCLUSION

Based on this study, solid lipid nanoparticles could be used as an effective delivery system for SOD in the treatment of second-degree burns.

Polymer-Based Wound Dressings Loaded with Essential Oil for the Treatment of Wounds: A Review

Wound healing can result in complex problems, and discovering an effective method to improve the healing process is essential. Polymeric biomaterials have structures similar to those identified in the extracellular matrix of the tissue to be regenerated and also avoid chronic inflammation, and immunological reactions. To obtain smart and effective dressings, bioactive agents, such as essential oils, are also used to promote a wide range of biological properties, which can accelerate the healing process. Therefore, we intend to explore advances in the potential for applying hybrid materials in wound healing. For this, fifty scientific articles dated from 2010 to 2023 were investigated using the Web of Science, Scopus, Science Direct, and PubMed databases. The principles of the healing process, use of polymers, type and properties of essential oils and processing techniques, and characteristics of dressings were identified. Thus, the plants Syzygium romanticum or Eugenia caryophyllata, Origanum vulgare, and Cinnamomum zeylanicum present prospects for application in clinical trials due to their proven effects on wound healing and reducing the incidence of inflammatory cells in the site of injury. The antimicrobial effect of essential oils is mainly due to polyphenols and terpenes such as eugenol, cinnamaldehyde, carvacrol, and thymol.

Effects of traditional artiri La Li formulation on experimental models of vitiligo and mechanisms of melanogenesis

ETHNOPHARMACOLOGICAL RELEVANCE

Artiri La Li Honey Pill (ALLHP) is a traditional medicinal formula that is widely used in Xinjiang, China, for the treatment of vitiligo. Since the cause of vitiligo has not been determined, no satisfactory treatment is available. Clinical interventions include pharmacological treatment with psoralen, usually in conjunction with ultraviolet A (UVA) radiation, but toxic side effects limit this application. Studies on the activity and mechanisms of ALLHP are scarce.

AIM OF THE STUDY

To verify the therapeutic effect of ALLHP on vitiligo and determine its effectiveness as a theoretical and experimental basis for the development of innovative drugs with independent intellectual property rights and the effective use of local resources.

MATERIALS AND METHODS

The experimental animal model of vitiligo was established by chemical decoloring. Rats were treated with gradient doses of ALLHP. The therapeutic effect was judged by gross observation. The contents of TYR, MAO, AchE and MDA in serum and skin tissue, the number of hair follicles containing melanin in skin tissue, the distribution of epidermal melanin, and the weight index of immune organs were detected, and the therapeutic effect of ALLHP on vitiligo was evaluated. In addition, certain monomer components in ALLHP were used to intervene in the zebrafish juvenile melanin suppression model, and the melanin-activating activities of some monomer components in ALLHP were screened by counting the melanin area ratio.

RESULTS

ALLHP increased the number of melanin-containing hair follicles and the epidermal melanin content in the skin of experimental vitiligo animals, repaired the skin cell morphology to a certain extent, increased the content of TYR in serum and skin, and reduced the content of MDA, AchE and MAO. Carvone, Luteolin, Psoralen and Psoraleae phenol and Bakuchiol could increase the melanin area of experimental melanin inhibition in zebrafish.

CONCLUSION

According to the results of this study, ALLHP can increase the number of melanin-containing hair follicles and the epidermal melanin content in the skin of vitiligo animals and restore skin cell morphology to a certain extent by reducing oxidative stress in epidermal tissue. A wide range of active ingredients may promote melanogenesis with ALLHP.

Effect of Copper on the Function of Isolated Porcine Kidneys Stored Using Simple Hypothermia

Renal ischemia in the peri-transplant period causes a number of changes that adversely affect the initiation of normal vital functions in grafts after transplantation. To minimise the extent of ischemic damage, organs are stored in preservation fluid. The components of the fluid are supposed to ensure stabilisation of the cell cytoskeleton, protect against oxygen free radicals, reduce cell swelling, and ensure endothelial cell integrity. The aim of this study was to analyse the protective effect of Cu2+, as a component of Biolasol preservative fluid, in the prevention of nephron damage occurring during the graft storage period. Analyses of the effectiveness of copper in the presence of prolactin added to Biolasol fluid were also carried out. Forty isolated pig slaughter kidneys were used in the study, avoiding the use of laboratory animals. The kidneys were stored using simple hypothermia. After 2 h and 48 h of graft storage, selected biochemical indicators of renal function were determined in the collected perfusates. The addition of Cu2+ at a dose of 1 µg/L to the composition of Biolasol fluid was found to affect the generation of ischemic damage in the isolated pig kidney. The intensity of the occurrence of these processes is exacerbated by the presence of prolactin at a dose of 0.1 µg/L.

Antioxidant and multi-sensitive PNIPAAm/keratin double network gels for self-stripping wound dressing application

Hydrogel is a potential wound dressing material due to its ability to maintain a humid environment, the strong absorptive capacity of exuded tissue fluid, and gas exchange function. Herein, poly(N-isopropyl acrylamide)/keratin double network (PNIPAAm/keratin DN) gels were fabricated through covalent and ionic double cross-linking strategy. The effects of PNIPAAm/keratin ratios on the morphology and swelling rate of gels were characterized. The DN gels could swell up from 2600% to 4600% in proportion to the keratin content, demonstrating their great ability to absorb tissue fluid. The gels possessed thermo-sensitiveness, imparting self-stripping property. Moreover, the antibacterial chlorhexidine acetate (CHX) was loaded into gels with a post-fabrication drug-loading strategy. The release behavior showed that CHX-loaded DN gels exhibited multiple responsive characteristics (temperature, pH, and ROS). Furthermore, the drug-loaded gels showed greater antibacterial activity than free CHX due to the sustained drug release effect. Meanwhile, the antioxidant efficiency of PNIPAAm/keratin DN gels was ca. 33.1%, while the PNIPAAm gel was just ca. 18.2%, indicating the strong oxidation resistance of DN gels. In the Sprague Dawley (SD) rat skin defect model, the hydrogel had better tissue regeneration ability than the commercial film. Taken together, the multifunctional PNIPAAm/keratin DN gels are potential candidates for clinical wound treatment.

The effect of Myrtus communis L. ethanol extract on the small intestine and lungs in experimental thermal burn injury

Thermal trauma can damage organs away from the skin burn site and lead to multiple organ dysfunction. Following thermal injury, all tissues are exposed to ischemia, and as a result, resuscitation and reperfusion occur during the burning shock. Burn damage starts systemic inflammatory reactions that produce toxins and reactive oxygen radicals that lead to peroxidation. This study aimed to investigate, for the first time, the possible antioxidant effects of Myrtus communis ethanol extract on burn-induced oxidative distant organ injury orally. The thermal trauma was generated under ether anesthesia by exposing the dorsum of rats to 90 ^°C water bath for 10 s. 100 mg/kg/day Mrytus communis ethanol extract was applied orally for two days. Malondialdehyde (MDA) and glutathione (GSH) levels, glutatinone-S-transferase (GST), superoxidedismutase (SOD) and catalase (CAT) activities were determined to detect the possible antioxidant effects of myrtle on small intestine and lung tissues. Burn damage significantly increased MDA levels in lung and small intestine tissues, and significantly decreased GSH levels, CAT and GST activities in the small intestine and lung tissues compared to control group. Mrytus communis ethanol extract decreased MDA level and increased GSH level, SOD, CAT and GST activities significantly in either small intestine or lung tissues. Mrytus communis extract may be an ideal candidate to be used as an antioxidant adjunct to improve oxidative distant organ damage to limit the systemic inflammatory response and decreasing the recovery time after thermal injury.

The Estimation of Blood Paramagnetic Center Changes during Burns Management with Biodegradable Propolis-Nanofiber Dressing

The evolution of the paramagnetic center system in blood during the healing of skin burn wounds dressed with a biodegradable apitherapeutic nanofiber dressing was examined. The aim of this study was to determine the changes in paramagnetic centers in blood during the influence of apitherapeutic nanofiber dressings on the healing process. The blood samples were tested before burn infliction (day 0) and, respectively, on the 10^th and 21^st days of the experiment. Paramagnetic centers in the blood of the pig used as the model animal were examined with an X-band (9.3 GHz) electron paramagnetic resonance spectroscopy. The EPR spectra were measured with Bruker spectrometer at 230 K with a modulation frequency of 100 kHz. The EPR lines of the high spin Fe³⁺ in methemoglobin, high spin Fe³⁺ in transferrin, Cu²⁺ in ceruloplasmin, and free radicals were observed in the multicomponent spectra of blood. For the application of the apitherapeutic nanofiber dressing, the amplitudes of the EPR signals of Fe³⁺ in methemoglobin were similar up to 10 days. For the experiment with the apitherapeutic formulation, the heights of EPR signals of Fe³⁺ in transferrin were lower after 10 days and 21 days of therapy, compared to day 0. For the application of the apitherapeutic formulation the signals of Cu²⁺ in ceruloplasmin and free radicals, strongly decreased after 10 days of therapy, and after 21 days it increased to the initial values characteristic for day 0. The apitherapeutic formulation caused that after 21 days the EPR spectrum of Cu²⁺ in ceruloplasmin and free radicals was considerably high. The apitherapeutic formulation interaction after 10 days and after 21 days of therapy resulted in the low EPR lines of Fe³⁺ in methemoglobin. EPR spectra of blood may be useful for presentation of the changes in its paramagnetic centers during the healing process of the burn wounds.

Evaluation of Systemic Oxidative Stress in Patients with Premature Canities and Correlation of Severity of Hair Graying with the Degree of Redox Imbalance

Context:

Premature canities etiopathogenesis is unclear, and approach to its therapy remains arbitrary. Reactive oxygen species generated during melanin biosynthesis in anagen hair bulb have been implicated in melanocyte apoptosis and hair graying. Extraneous factors, namely environmental pollution, stressful lifestyle, may compound the melanogenesis-induced endogenous oxidative stress.

Aims:

We aimed to investigate the role of systemic oxidative stress in causation of premature canities and its correlation with the severity of hair graying.

Settings and Design:

This was a tertiary care hospital-based cross-sectional study.

Materials and Methods:

Consecutive 50 patients with premature hair graying, aged <25 years, and 30 age and sex-matched healthy controls were recruited. Severity of premature canities was graded based on the total number of gray hair on the scalp. Redox status was evaluated in cases and controls, by malondialdehyde (MDA), reduced glutathione (rGSH), and superoxide dismutase (SOD) measurement in serum, by enzyme-linked immunosorbent assay.

Results:

Serum MDA concentration, an oxidative stress marker, was significantly higher (P < 0.01), while serum rGSH and SOD levels, both indicators of antioxidant potential, were significantly lower (P < 0.0001 and P < 0.01 respectively) in premature canities patients compared to controls. A novel observation was the significant correlation of serum MDA rise and serum rGSH decline with increasing severity of hair graying (P < 0.01 and P = 0.01, respectively).

Conclusion:

Systemic redox imbalance is present in premature canities patients, with the severity of hair graying varying in parallel to the degree of oxidative stress. Antioxidants supplementation is likely to yield therapeutic benefit in premature canities.

Does oxidative stress correlate with disease activity and severity in vitiligo? An analytical study

BACKGROUND

Oxidative damage to melanocytes, resulting from an imbalance between the damaging oxidative pathways and the protective anti-oxidants likely plays a pathogenic role in vitiligo.

AIM

To evaluate three parameters related to the oxidative stress (OS) pathway namely malondialdehyde (MDA), a marker of oxidative damage, and superoxide dismutase (SOD) and reduced glutathione (rGSH) (both antioxidants) in patients with active and stable vitiligo with either localized or generalized disease.

PATIENTS/METHODS

Sixty clinically diagnosed vitiligo patients were categorized into generalized (n = 30) or localized vitiligo (n = 30) and were further sub-grouped according to their disease activity into active and stable groups. Thirty healthy volunteers were included in the control group. ELISA was used for the evaluation of MDA, SOD, and r GSH.

RESULTS

The patient group demonstrated significantly raised levels of MDA and significantly decreased levels of SOD and rGSH compared with the control group. Further, the OS parameters were significantly more deranged in patients with generalized disease (all three-MDA, rGSH, and SOD) and an active disease (MDA) as compared to those with localized and stable disease, respectively.

CONCLUSION

Our findings suggest an important role of OS in relation to vitiligo activity and severity. Although the OS parameters were deranged in all subsets of patients, with respect to controls, the derangement of oxidative damage marker (MDA) in generalized and active disease groups was most marked. Disease remains active when the oxidative damage becomes higher but is unmatched with the anti-oxidant reserve which does not proportionately increase.

Wound healing and antimicrobial effect of active secondary metabolites in chitosan-based wound dressings: A review

Wound healing can lead to complex clinical problems, hence finding an efficient approach to enhance the healing process is necessary. An ideal wound dressing should treat wounds at reasonable costs, with minimal inconveniences for the patient. Chitosan is one of the most investigated biopolymers for wound healing applications due to its biocompatibility, biodegradability, non-toxicity, and antimicrobial activity. Moreover, chitosan and its derivative have attracted numerous attentions because of the accelerating wound healing, and easy processability into different forms (gels, foams, membranes, and beads). All these properties make chitosan-based materials particularly versatile and promising for wound dressings. Besides, secondary natural metabolites could potentially act like the antimicrobial and anti-inflammatory agents and accelerate the healing process. This review collected almost all studies regarding natural compounds applications in wound healing by focusing on the chitosan-based bioactive wound dressing systems. An accurate analysis of different chitosan formulations and the influence of bioactive compounds on their wound healing properties are reported.

EPR Spectroscopic Examination of Different Types of Paramagnetic Centers in the Blood in the Course of Burn Healing

The multicomponent electron paramagnetic resonance spectra of the blood during healing of skin burned wounds treated with a new generation biodegradable dressings containing poly(lactide-co-glycolide) were analysed. The evolution of different types of paramagnetic centers in the blood with time of healing was determined. The EPR spectra of the blood samples at 230 K temperature were measured at 1, 10, and 21 days after burning of the pig skin. The EPR lines of the following paramagnetic centers: the high-spin Fe³⁺ in methemoglobin (line I), high-spin Fe³⁺ in transferrin (line II), and Cu²⁺ in ceruloplasmin and free radicals (line III) were observed in the X-band (9.3 GHz) spectra of the blood. The multicomponent structure of the EPR spectra of the tested blood samples depended on the time of the healing of the burned wounds. The amount of the high-spin Fe³⁺ in methemoglobin (line I) in the blood decreased after 21 days of the healing of the burned wounds. The amount of the high-spin Fe³⁺ in transferrin (line II) slightly increased after 21 days of therapy with the basis. The amount of Cu²⁺ in ceruloplasmin and free radicals (line III) in the blood was very high after 10 days of therapy. At the first day of the healing of the burned wounds, the highest amount of the high-spin Fe³⁺ in methemoglobin (line I), the relatively lower amounts of the high-spin Fe³⁺ in transferrin (line II), and Cu²⁺ in ceruloplasmin and free radicals (line III) existed in the blood. In the medium phase (after 10 days) of the healing of the burned wounds, the extremely higher amounts of Cu²⁺ in ceruloplasmin and free radicals (line III) appeared in the blood. In the last phase (after 21 days), only the low differences between the amounts of the high-spin Fe³⁺ in methemoglobin (line I), the high-spin Fe³⁺ in transferrin (line II), and Cu²⁺ in ceruloplasmin and free radicals (line III) were observed. The present study may serve as a starting point for the development of a new technique for monitoring molecular complexes containing iron Fe³⁺ (methemoglobin, transferrin) or copper Cu²⁺ ions (ceruloplasmin) and free radicals in the blood during wound healing.

Prevention of Burn Wound Progression by Mesenchymal Stem Cell Transplantation: Deeper Insights Into Underlying Mechanisms

INTRODUCTION

Burns are dynamic wounds that may present a progressive expansion of necrosis into the initially viable zone of stasis. Therefore, salvage of this zone is a major subject of focus in burn research. The beneficial effects of mesenchymal stem cells (MSCs) on the survival of the zone of stasis have been previously documented. However, many gaps still exist in our knowledge regarding the underlying protective mechanisms. Hence, this study was designed to evaluate the pathophysiological basis of MSCs in the prevention of burn wound progression.

METHODS

Wistar rats received thermal trauma on the back according to the "comb burn" model. Animals were randomly divided into sham, control, and stem cell groups with sacrifice and analysis at 72 hours after the burn. The stasis zones were evaluated using histochemistry, immunohistochemistry, biochemistry, real-time polymerase chain reaction assay, and scintigraphy to evaluate the underlying mechanisms.

RESULTS

Gross evaluation of burn wounds revealed that vital tissue percentage of the zone of stasis was significantly higher in the stem cell group. Semiquantitative grading of the histopathologic findings showed that MSCs alleviated burn-induced histomorphological alterations in the zone of stasis. According to CC3a staining and expression analysis of Bax (B-cell leukemia 2-associated X) and Bcl-2 (B-cell leukemia 2) genes, MSCs attenuated increases in apoptosis postburn. In addition, these transplants showed an immunomodulatory effect that involves reduced neutrophilic infiltration, down-regulation of proinflammatory cytokines (tumor necrosis factor α, interleukin 1β [IL-1β], and IL-6), and up-regulation of the anti-inflammatory cytokine IL-10 in the zone of stasis. Burn-induced oxidative stress was significantly relieved with MSCs, as shown by increased levels of malondialdehyde, whereas the expression and activity of the antioxidant enzyme superoxide dismutase were increased. Finally, MSC-treated interspaces had enhanced vascular density with higher expression levels for vascular endothelial growth factor A, platelet-derived growth factor, fibroblast growth factor, and transforming growth factor β. Gamma camera images documented better tissue perfusion in animals treated with MSCs.

CONCLUSIONS

The protective effects of MSCs are mediated by the inhibition of apoptosis through immunomodulatory, antioxidative, and angiogenic actions.

Mesenchymal Stromal Cell Preconditioning: The Next Step Toward a Customized Treatment For Severe Burn

Over the last century, the clinical management of severe skin burns significantly progressed with the development of burn care units, topical antimicrobials, resuscitation methods, early eschar excision surgeries, and skin grafts. Despite these considerable advances, the present treatment of severe burns remains burdensome, and patients are highly susceptible to skin engraftment failure, infections, organ dysfunction, and hypertrophic scarring. Recent researches have focused on mesenchymal stromal cell (MSC) therapy and hold great promises for tissue repair, as reported in several animal studies and clinical cases. In the present review, we will provide an up-to-date outlook of the pathophysiology of severe skin burns, clinical treatment modalities and current limitations. We will then focus on MSCs and their potential in the burn wound healing both in in vitro and in vivo studies. A specific attention will be paid to the cell preconditioning approach, as a means of improving the MSC efficacy in the treatment of major skin burns. In particular, we will debate how several preconditioning cues would modulate the MSC properties to better match up with the burn pathophysiology in the course of the cell therapy. Finally, we will discuss the clinical interest and feasibility of a MSC-based therapy in comparison to their paracrine derivatives, including microvesicles and conditioned media for the treatment of major skin burn injuries.

Comparative Analysis of Mesenchymal Stem Cells from Bone Marrow, Adipose Tissue, and Dental Pulp as Sources of Cell Therapy for Zone of Stasis Burns

Introduction: The implantation of mesenchymal stem cells (MSCs) has been shown to exert benefits for the survival of the zone-of-stasis. However, the clinical experience indicates the importance of selecting the right source and type of stem cells. Therefore, we planned the current study to perform a quantitative comparison of MSCs isolated from three different sources to provide information useful in selection of the optimal source and to see whether critical mechanisms are conserved between different populations. Methods: The protective effects of MSCs derived from bone marrow, adipose tissue and dental pulp were compared in a rat model of thermal trauma. The stasis zones were evaluated 72 h after the burn using histochemistry, immunohistochemistry and biochemistry. Results: Gross evaluation of burn wounds revealed that the differences between the mean percentages of the calculated necrotic areas weren't statistically significant. Semi-quantitative grading of the histopathological findings revealed that there were no significant differences between damage scores. Immunohistochemical assessment of apoptotic and necrotic cell deaths revealed that the differences between the mean numbers of apoptotic and necrotic cells weren't statistically significant. Myeloperoxidase activity was found to be significantly lower in the adipose tissue group. Biochemical and immunohistochemical assessment of tissue malondialdehyde revealed that the differences between the groups weren't statistically significant. Finally, the number of neo-vessels in the dental pulp group was found to be significantly higher. Conclusion: Our findings suggest that bone marrow, adipose tissue and dental pulp may serve as a universal donor MSC source for the prevention of burn wound progression.

Application of Numerical Analysis of the Shape of Electron Paramagnetic Resonance Spectra for Determination of the Number of Different Groups of Radicals in the Burn Wounds

Background. The evidence exists that radicals are crucial agents necessary for the wound regeneration helping to enhance the repair process. Materials and methods. The lineshape of the electron paramagnetic resonance (EPR) spectra of the burn wounds measured with the low microwave power (2.2 mW) was numerically analyzed. The experimental spectra were fitted by the sum of two and three lines. Results. The number of the lines in the EPR spectrum corresponded to the number of different groups of radicals in the natural samples after thermal treatment. The component lines were described by Gaussian and Lorentzian functions. The spectra of the burn wounds were superposition of three lines different in shape and in linewidths. The best fitting was obtained for the sum of broad Gaussian, broad Lorentzian, and narrow Lorentzian lines. Dipolar interactions between the unpaired electrons widened the broad Gaussian and broad Lorentzian lines. Radicals with the narrow Lorentzian lines existed mainly in the tested samples. Conclusions. The spectral shape analysis may be proposed as a useful method for determining the number of different groups of radicals in the burn wounds.

Astaxanthin protects against early burn-wound progression in rats by attenuating oxidative stress-induced inflammation and mitochondria-related apoptosis

Burn-wound progression can occur in the initial or peri-burn area after a deep burn injury. The stasis zone has a higher risk of deterioration mediated by multiple factors but is also considered salvageable. Astaxanthin (ATX), which is extracted from some marine organisms, is a natural compound with a strong antioxidant effect that has been reported to attenuate organ injuries caused by traumatic injuries. Hence, we investigated the potential effects of ATX on preventing early burn-wound progression. A classic "comb" burn rat model was established in this study for histological and biological assessments, which revealed that ATX, particularly higher doses, alleviated histological deterioration in the stasis zone. Additionally, we observed dose-dependent improvements in oxidative stress and the release of inflammatory mediators after ATX treatment. Furthermore, ATX dose-dependently attenuated burn-induced apoptosis in the wound areas, and this effect was accompanied by increases in Akt and Bad phosphorylation and a downregulation of cytochrome C and caspase expression. In addition, the administration of Ly 294002 further verified the effect of ATX. In summary, we demonstrated that ATX protected against early burn-wound progression in a rat deep-burn model. This protection might be mediated by the attenuation of oxidative stress-induced inflammation and mitochondria-related apoptosis.

Antioxidant Micronutrients in Major Trauma and Burns: Evidence and Practice

There has been a growing interest in micronutrients as a result of their essential role in endogenous antioxidant defense mechanisms and immunity. Critically ill burn and trauma patients are characterized by an increased free radical production, which is proportional to the severity of the injury. In addition, they are at high risk of negative trace element balances, which contribute to the imbalance in endogenous antioxidant capacity and the extension of primary lesions. Although selenium, zinc, and vitamin C and E status are altered in all injured patients, patients with major burns are unique for having copper deficiency. In major burns, high-dose ascorbic acid for 24 hours achieves reduction of resuscitation fluid requirements by endothelial antioxidant mechanisms both in animal models and in 1 human trial. Supplementation trials in trauma and burns including selenium and zinc have shown that early provision of micronutrients improves recovery. Vitamin supplementation trials without selenium have not achieved definitive effects. The human studies show that reinforcing antioxidant defenses early in the course of major injury is rational and that substituting the large initial micronutrient losses of selenium and zinc is safe in trauma, as is the addition of copper in burns. The IV route seems the only way to deliver the doses required to obtain a clinical effect.

Oxidative Stress Biomarkers and Adenosine Deaminase over the Alopecic Area of the Patients with Alopecia Areata

BACKGROUND

Alopecia areata (AA) is an autoimmune, T-cell mediated, and chronic inflammatory disorder. The pathological mechanisms of disease are unclear, but oxidative stress may be involved. To our knowledge, no studies have examined the oxidative stress levels or biomarkers within the lesional area and skin surface in patients with AA. Similarly, adenosine deaminase (ADA) has not been characterized in AA.

AIMS

Therefore, we aimed to define ADA levels and the factors involved in oxidative stress from scalp-scrapes of patients with AA.

STUDY DESIGN

Case-control study.

METHOD

A total of 60 patients (30 diagnosed AA patients and 30 healthy controls) were included in the study. ADA as well as oxidative stress factors, including malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) were analyzed from scalp-scrapes in both groups and quantified by spectrophotometry.

RESULTS

Activities of SOD (p=0.000), CAT (p=0.033), and ADA (p=0.004) as well as levels of GSH (p=0.000) and MDA (p=0.032) in patients with AA were higher than the controls statistically significant.

CONCLUSION

Based on these results, factors associated with oxidative stress were elevated in AA patient scalp-scrapes compared to controls and may have a defined role the disease pathogenesis. Alterations in the activities of antioxidant enzymes from AA patient scraping samples may be a local effect of elevated oxidative stress levels. In this disease, oxidative stress may affect not only hair follicle but also any layers of the skin.

Current concepts on burn wound conversion-A review of recent advances in understanding the secondary progressions of burns

Burn wound conversion describes the process by which superficial partial thickness burns convert into deeper burns necessitating surgical intervention. Fully understanding and thus controlling this phenomenon continues to defy burn surgeons. However, potentially guiding burn wound progression so as to obviate the need for surgery while still bringing about healing with limited scarring is the major unmet challenge. Comprehending the pathophysiologic background contributing to deeper progression of these burns is an essential prerequisite to planning any intervention. In this study, a review of articles examining burn wound progression over the last five years was conducted to analyze trends in recent burn progression research, determine changes in understanding of the pathogenesis of burn conversion, and subsequently examine the direction for future research in developing therapies. The majority of recent research focuses on applying therapies from other disease processes to common underlying pathogenic mechanisms in burn conversion. While ischemia, inflammation, and free oxygen radicals continue to demonstrate a critical role in secondary necrosis, novel mechanisms such as autophagy have also been shown to contribute affect significantly burn progression significantly. Further research will have to determine whether multiple mechanisms should be targeted when developing clinical therapies.

Assessment of Oxidative Stress in Patients with Premature Canities

Context:

Premature canities is a common, yet unexplored disorder. Oxidative stress levels have been evaluated within the greying hair follicle but not in the sera of patients with premature canities.

Aims:

To evaluate the oxidative stress parameters in the sera of patients with premature canities.

Settings and Design:

A pilot case-controlled study, conducted in a tertiary care setup in Delhi during November 2011 to December 2012.

Materials and Methods:

Fifty-two self-reporting cases of premature canities (age of onset <20 years) and 30 healthy controls were recruited from outpatient Department of Dermatology. Oxidative stress parameters (serum malonaldehyde (MDA), whole blood reduced glutathione (rGSH) and serum ferric reducing antioxidant potential [FRAP]) were assessed in cases and controls. Mann–Whitney test was used to compare the oxidative stress parameters between the two groups (SPSS version 17.0, SPSS Inc, Chicago, USA; P < 0.05 considered as significant).

Results:

The age and sex distribution of cases and controls was comparable. The mean serum levels of MDA were higher in cases than controls (3.7 ± 1.6 nmol/ml vs. 2.8 ± 1.5 nmol/ml; P = 0.01). The GSH levels were lower in the cases than controls (31.5 ± 8.9 mg/dl vs. 36.6 ± 16.9 mg/dl; P = 0.064). Similarly, the mean FRAP levels were lower in the cases than controls (400 ± 70 nmol/ml vs. 430 ± 80 nmol/ml; P = 0.038).

Conclusions:

Patients with premature canities had a higher level of pro-oxidants and lower levels of antioxidants than controls. This is the first humble attempt to document the oxidative stress parameters in sera of patients with premature canities, further studies with larger sample size are required to reach a definite conclusion.

Fictitious hyperglycemia: point-of-care glucose measurement is inaccurate during high-dose vitamin C infusion for burn shock resuscitation

The use of high-dose vitamin C (hdVC, 66 mg/kg/hour × 18 hours) infusion is a useful adjunct to reducing fluid requirements during resuscitation of burn shock. Routine point-of-care glucose (POCG) analysis has been inaccurately high in observed patients undergoing hdVC. Inaccurate POCG could potentially lead to iatrogenic hypoglycemia if the fictitious hyperglycemia is treated with insulin. This study is a retrospective analysis of plasma glucose measurements from a central laboratory (LG) compared with POCG during and 24 hours after hdVC infusion. Records of adult patients receiving hdVC infusions during burn resuscitation over 1 year were reviewed. Charts selected for analysis included those with glucose measurements using POCG and LG that were taken simultaneously, during hdVC infusion, and 24 hours after completion. All specimens were drawn from arterial lines. POCG was measured with Accu-Chek Inform (Roche, Indianapolis, IN) and LG was measured by Siemens Dimension Vista 500 (Siemens, Deerfield, IL) using biochromic analysis. Nonparametric statistical analysis was performed using Wilcoxon's matched pairs test and Spearman correlation with significance at P < .05. Of 18 adult patients undergoing burn resuscitation with hdVC infusion, 5 were chosen for analysis (%TBSA 40 ± 15; age 51 ± 18). All data were pooled with 11 comparisons both during and after hdVC. The mean POCG (225 ± 71) was significantly higher than mean LG (138 ± 41) on hdVC (P = .002). There was no difference between POCG (138 ± 30) and LG (128 ± 23) after hdVC was finished (P = .09). There was a negative correlation between POCG and LG on hdVC (-0.64, P = .04) and a positive correlation off hdVC (0.89, P = .0005). POCG analysis during hdVC infusion is significantly higher than laboratory glucose measurements. Once the hdVC infusion is complete, POCG and laboratory glucose measurements are not statistically different. Treating erroneously high glucose based on POC testing is potentially dangerous and could lead to hypoglycemia and seizures.

A comparative study to evaluate the effect of limited access dressing (LAD) on burn wound healing

Biochemical and histopathological analyses are commonly used objective parameters in research and clinical fields to assess the healing status of burn wounds. In this study, the effect of newer intermittent negative-pressure wound therapy in combination with moist environment [limited access dressing (LAD)] on burn wound healing is studied. Various biochemical parameters like hydroxyproline, hexosamine and total protein, and antioxidants like reduced glutathione (GSH), glutathione peroxidase (GPx) and oxidative biomarker malondialdhyde (MDA) were measured in the granulation tissue. Histopathologically, necrotic tissue, amount of inflammatory infiltrate, angiogenesis and extracellular matrix deposition (ECM) were studied to determine wound healing. A total of 55 patients were divided into two groups as follows: LAD group (n = 28) and conventional dressing group (n = 27). Patients treated with LAD have shown significant increase in the mean levels of (±SD) hydroxyproline (75·2 ± 26·30 versus 27·8 ± 15·5; P = 0·010), hexosamine (9·0 ± 1·99 versus 8·0 ± 1·18; P = 0·038), total protein (15·6 ± 8·23 versus 10·26 ± 4·94; P = 0·003), GSH (7·40 ± 1·91 versus 5·1 ± 1·28; P = 0·037), GPx (112·6 ± 46·4 versus 92 ± 32·4; P = 0·016), and decrease in MDA (6·5 ± 2·24 versus 1 0·6 ± 3·8; P = 0·002). Histopathologically, between LAD and conventional dressing groups, there was a significant difference after 10 days of treatment (mean±SE) in necrotic tissue of (LAD versus conventional dressing groups = 10 ± 1·8 versus 11·9 ± 2·6; P = 0·033), inflammatory cells (8·4 ± 1·9 versus 13 ± 3·46; P = 0·021), new blood vessels (12·5 ± 2·87 versus 9·4 ± 1·7; P = 0·047), ECM deposit (12·9 ± 2·41 versus 9·68 ± 1·3; P = 0·018) and showed comparatively fewer inflammatory cells, increased and well-organised extracellular matrix deposit, more angiogenesis in LAD group as compared with that in conventional dressing group. To conclude, LAD exerts its beneficial effects on wound healing by reducing oxidative stress, decreasing necrotic tissue and amount of inflammatory infiltrate, and increasing ECM deposition and angiogenesis.

Investigation of oxidative stress in patients with alopecia areata and its relationship with disease severity, duration, recurrence and pattern

BACKGROUND

Alopecia areata (AA) is an inflammatory autoimmune disease that causes hair loss on the scalp or trunk without scarring. Although the precise aetiopathogenesis of alopecia areata remains unknown, oxidative stress is thought to play a role.

AIM

To investigate the relationship between severity and the role of oxidative stress in AA, by measuring plasma oxidant levels and antioxidant enzyme activities in erythrocytes.

METHODS

In total, 62 patients with AA (24 males and 38 females), and 62 sex- and age-matched healthy controls (HCs) were enrolled in the study. We investigated the levels of plasma malondialdehyde (MDA) and the activities of erythrocyte catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). The relationship between oxidative stress and AA was also investigated with regard to disease pattern, severity, duration and recurrence.

RESULTS

The mean erythrocyte GSH-Px and SOD activities were significantly reduced (P < 0.001 and P < 0.001 respectively) compared with the control group. Plasma MDA levels were increased but statistically insignificant (P = 0.08) in patients with AA compared with controls. No significant difference between erythrocyte CAT activities was observed between patients and controls (P = 0.2). In addition, we observed no statistically significant difference in patient plasma MDA levels or erythrocyte CAT, GSH-Px or SOD activities with regard to AA severity, duration, recurrence or pattern (P > 0.05).

CONCLUSIONS

Patients with AA displayed reduced erythrocyte SOD and GSH-Px activities and enhanced plasma MDA levels. These findings support the possible role of oxidative stress in the pathogenesis of AA.

Micronutrients after burn injury: a review

Supplementation of micronutrients after burn injury is common practice in order to fight oxidative stress, support the immune system, and optimize wound healing. Assessing micronutrient status after burn injury is difficult because of hemodilution in the resuscitation phase, redistribution of nutrients from the serum to other organs, and decreases in carrier proteins such as albumin. Although there are many preclinical data, there are limited studies in burn patients. Promising research is being conducted on combinations of micronutrients, especially via the intravenous route.

Oxidative stress in alopecia areata: a case-control study

BACKGROUND

Increased reactive oxygen species (ROS) and lipid peroxidation are seen in many dermatologic disorders, including atopic dermatitis, psoriasis, vitiligo, acne vulgaris, pemphigus vulgaris, and lichen planus. In alopecia areata (AA), there is increased production of ROS from perifollicular inflammatory cells.

OBJECTIVE

The aim of this study was to determine the oxidative stress index (OSI) and lipid peroxidation by studying serum total oxidant capacity (TOC), total antioxidant capacity (TAC), and malondialdehyde (MDA) values in AA patients.

METHODS

The study included 35 AA patients and a control group consisting of 30 age- and sex-matched healthy volunteers. The serum TOC, TAC, and MDA values were measured, and the OSIs were calculated and compared in both groups.

RESULTS

The mean serum TOC (p < 0.001), MDA (p < 0.001), and OSI (p < 0.001) values were found to be significantly higher in AA patients than in the control group. The mean serum TAC value was significantly lower (p < 0.05) in cases than in controls. Significantly higher MDA (p < 0.001), TOC (p < 0.001), and OSI values (p < 0.001) and lower TAC values (p < 0.01) were found in severe AA than in mild or moderate AA.

CONCLUSION

The demonstrated results confirmed the presence of oxidative stress and lipid peroxidation in AA. Whether these changes play a role in disease pathogenesis or result from the inflammatory process requires further investigation.

Melatonin protection against burn-induced liver injury. A review

Severe thermal injury may be complicated by dysfunction of organs distant from the original burn wound, including the liver, and represents a serious clinical problem. Although pathophysiology of burn-induced liver injury remains unclear, increasing evidence implicate activation of inflammatory response, oxidative stress, endothelial dysfunction and microcirculatory disorders as the main mechanisms of hepatic injury. Several studies suggest melatonin as a multifunctional indolamine that counteracts some of the pathophysiologic steps and displays significant beneficial effects against burn-induced cellular injury. This review summarizes the role of melatonin in restricting the burn-induced hepatic injury and focuses on its effects on oxidative stress, inflammatory response, endothelial dysfunction and microcirculatory disorders as well as on signaling pathways such as regulation of nuclear erythroid 2-related factor 2 (Nrf2) and nuclear factor-kappaB (NF-kB). Further studies are necessary to elucidate the modulating effect of melatonin on the transcription factor responsible for the regulation of the pro-inflammatory and antioxidant genes involved in burn injuries.

The pathogenesis of vitiligo

BACKGROUND

Vitiligo is a commonly encountered pigmentary disorder. Numerous studies and investigations from all over the world have attempted to determine the mechanisms behind this disease; however, the pathogenesis of vitiligo remains elusive.

OBJECTIVE

n this comprehensive review article, we present the findings behind the five overarching theories of what causes this disfiguring and psychologically debilitating disease.

METHOD

We begin our discussion with the role of genetic predisposition and move onward to the neural theory first proposed in the 1950s. Next we discuss the autoimmune hypothesis, followed by the reactive oxygen species model, and conclude by describing the findings of the more recent melanocytorrhagy hypothesis.

CONCLUSION

Although the exact pathogenesis of vitiligo is uncertain, each of these theories likely plays a role. Understanding each theory would pave the way for therapeutic advances for this disease.

Targeting the redox balance in inflammatory skin conditions

Reactive oxygen species (ROS) can be both beneficial and deleterious. Under normal physiological conditions, ROS production is tightly regulated, and ROS participate in both pathogen defense and cellular signaling. However, insufficient ROS detoxification or ROS overproduction generates oxidative stress, resulting in cellular damage. Oxidative stress has been linked to various inflammatory diseases. Inflammation is an essential response in the protection against injurious insults and thus important at the onset of wound healing. However, hampered resolution of inflammation can result in a chronic, exaggerated response with additional tissue damage. In the pathogenesis of several inflammatory skin conditions, e.g., sunburn and psoriasis, inflammatory-mediated tissue damage is central. The prolonged release of excess ROS in the skin can aggravate inflammatory injury and promote chronic inflammation. The cellular redox balance is therefore tightly regulated by several (enzymatic) antioxidants and pro-oxidants; however, in case of chronic inflammation, the antioxidant system may be depleted, and prolonged oxidative stress occurs. Due to the central role of ROS in inflammatory pathologies, restoring the redox balance forms an innovative therapeutic target in the development of new strategies for treating inflammatory skin conditions. Nevertheless, the clinical use of antioxidant-related therapies is still in its infancy.

Stimulation of production of reactive oxygen and nitrogen species in endothelial cells by unmodified and Fenton-modified ultradisperse detonation diamond

In recent years, the development of nanotechnology opens up new prospects for biomedical applications of unmodified and chemically modified diamond nanoparticles (DNPs). The problem of biocompatibility of DNPs is thus of primary importance. The first step in the modification of DNPs is usually the introduction of -OH groups, which can bind other functional groups. One of the basic methods to introduce -OH groups onto DNPs is the Fenton reaction. The aim of this study was to compare the effect of unmodified DNPs and nanoparticles modified by the Fenton reaction on human endothelial cells. Ultradisperse diamond (UDD) was modified by the Fenton reaction introducing surface -OH groups. Immortalized human umbilical cord endothelial cells (HUVEC-ST) were incubated with 2-100 µg/mL nanopowders in the opti-MEM medium. For comparison, graphite powder (GRAF and GRAF+OH) was also employed. UDD and GRAF augmented generation of reactive oxygen species in the cells after 24 H incubation, estimated by oxidation of 2',7'-dichlorofluorescin diacetate (H2DCF-DA). Cellular production of nitric oxide, estimated with DAF-FM-DA (3-amino-4-aminomethyl 2',7'-dichlorofluorescein diacetate), was also affected by UDD and GRAF after 24 H. Fenton-modified OH, in contrast to unmodified diamond, decreased NO production. Detonation nanoparticles also affected the cellular content of glutathione and activities of main antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, and glutathione S-transferase). This article was published online on 5 February 2013. Errors in the byline and affiliation line were subsequently identified. This notice is included in the online and print versions to indicate that both have been corrected 18 April 2013.

Propagation of cutaneous thermal injury: a mathematical model

Cutaneous burn wounds represent a significant public health problem with 500,000 patients per year in the USA seeking medical attention. Immediately after skin burn injury, the volume of the wound burn expands due to a cascade of chemical reactions, including lipid peroxidation chain reactions. Such expansion threatens life and is therefore highly clinically significant. Based on these chemical reactions, the present paper develops for the first time a three-dimensional mathematical model to quantify the propagation of tissue damage within 12 hours post initial burn. We use the model to investigate the effect of supplemental antioxidant vitamin E for intercepting propagation. We show, for example, that if tissue levels of vitamin E tocotrienol are increased, postburn, by five times then this would slow down the lipid peroxide propagation by at least 50%. We chose the alpha-tocotrienol form of vitamin E as it is a potent inhibitor of 12-lipoxygenase, which is known to propagate oxidative lipid damage. Our model is formulated in terms of differential equations, and sensitivity analysis is performed on the parameters to ensure the robustness of the results.

Paraoxonase and arylesterase activity and total oxidative/anti-oxidative status in patients with chronic adenotonsillitis

OBJECTIVES

The aim of this study was to investigate serum paraoxonase, arylesterase activities along with determination of oxidative status via measurement of total oxidant status (TOS), total antioxidant status (TAS) and oxidative stress index (OSI) in children with recurrent adenotonsillitis during pre- and post-adenotonsillectomy period and to compare results with data from healthy subjects.

METHODS

We performed a prospective controlled trial on adenoidectomy and/or tonsillectomy patients. A total of 47 subjects, including 22 patients with recurrent adenotonsillitis and 25 healthy controls were enrolled in this study. Peripheral venous blood samples were taken from patients before adenotonsillectomy and a second sample was obtained in first month postoperatively. In the control group, blood samples from healthy volunteers were collected for one time only. Serum paraoxonase, arylesterase activities, TOS, TAS and OSI levels were measured.

RESULTS

Paraoxonase, arylesterase activity, TAS and TOS levels were significantly higher in preoperative group compared to control group (P<0.001, P=0.003, 0.003 and 0.005, respectively). However, OSI level was similar in preoperative group compared to control group (P=0.25). In the post-operative group, paraoxonase, arylesterase activities, TAS and OSI levels were lower as compared to preoperative group but differences were statistically insignificant (P=0.483, 0.265, 0.149 and 0.090, respectively). TOS level in post-operative group was significantly lower than the preoperative group (P<0.001). In the post-operative group, paraoxonase and arylesterase activities were significantly higher as compared to control group (P=0.004 and 0.02, respectively). TOS and OSI levels were significantly lower in post-operative group compared to control group (P=0.001 and 0.02, respectively). However, TAS was similar between post-operative and control groups (P=0.464).

CONCLUSIONS

Based on data obtained from this study, we may state that paraoxonase, arylesterase activities with TAS, TOS and OSI levels of patients with chronic adenotonsillitis shows alterations due to oxidant/antioxidant imbalance induced by frequent infections.

The Angiotensin-converting enzyme inhibitor captopril inhibits poly(adp-ribose) polymerase activation and exerts beneficial effects in an ovine model of burn and smoke injury

We investigated the effect of the angiotensin-converting enzyme (ACE) inhibitor captopril in a clinically relevant ovine model of smoke and burn injury, with special reference to oxidative stress and activation of poly(ADP-ribose) polymerase, in the lung and in circulating leukocytes. Female, adult sheep (28-40 kg) were divided into three groups. After tracheostomy and under deep anesthesia, both vehicle-control-treated (n = 5) and captopril-treated (20 mg/kg per day, i.v., starting 0.5 h before the injury) (n = 5) groups were subjected to 2 × 20%, third-degree burn injury and were insufflated with 48 breaths of cotton smoke. A sham group not receiving burn/smoke was also studied (n = 5). Animals were mechanically ventilated and fluid resuscitated for 24 h in the awake state. Burn and smoke injury resulted in an upregulation of ACE in the lung, evidenced by immunohistochemical determination and Western blotting. Burn and smoke injury resulted in pulmonary dysfunction, as well as systemic hemodynamic alterations. Captopril treatment of burn and smoke animals improved PaO2/FiO2 ratio and pulmonary shunt fraction and reduced the degree of lung edema. There was a marked increase in PAR levels in circulating leukocytes after burn/smoke injury, which was significantly decreased by captopril. The pulmonary level of ACE and the elevated pulmonary levels of transforming growth factor β in response to burn and smoke injury were significantly decreased by captopril treatment. Our results suggest that the ACE inhibitor captopril exerts beneficial effects on the pulmonary function in burn/smoke injury. The effects of the ACE inhibitor may be related to the prevention of reactive oxygen species-induced poly(ADP-ribose)polymerase overactivation. Angiotensin-converting enzyme inhibition may also exert additional beneficial effects by inhibiting the expression of the profibrotic mediator transforming growth factor β.

Burn and smoke injury activates poly(ADP-ribose)polymerase in circulating leukocytes

The nuclear enzyme poly(ADP-ribose)polymerase (PARP) plays a significant role in the pathogenesis of various forms of critical illness. DNA strand breaks induced by oxidative and nitrative stress trigger the activation of PARP, and PARP, in turn, mediates cell death and promotes proinflammatory responses. Until recently, most studies focused on the role of PARP in solid organs such as heart, liver, and kidney. We investigated the effect of burn and smoke inhalation on the levels of poly(ADP-ribosylated) proteins in circulating sheep leukocytes ex vivo. Adult female merino sheep were subjected to burn injury (2× 20% each flank, 3 degrees) and smoke inhalation injury (insufflated with a total of 48 breaths of cotton smoke) under deep anesthesia. Arterial and venous blood was collected at baseline, immediately after the injury and 1 to 24 h after the injury. Leukocytes were isolated with the Histopaque method. The levels of poly(ADP-ribosyl)ated proteins were determined by Western blotting. The amount of reactive oxygen species was quantified by the OxyBlot method. To examine whether PARP activation continues to increase ex vivo in the leukocytes, blood samples were incubated at room temperature or at 37°C for 3 h with or without the PARP inhibitor PJ34. To investigate whether the plasma of burn/smoke animals may trigger PARP activation, burn/smoke plasma was incubated with control leukocytes in vitro. The results show that burn and smoke injury induced a marked PARP activation in circulating leukocytes. The activity was the highest immediately after injury and at 1 h and decreased gradually over time. Incubation of whole blood at 37°C for 3 h significantly increased poly(ADP-ribose) levels, indicative of the presence of an ongoing cell activation process. In conclusion, PARP activity is elevated in leukocytes after burn and smoke inhalation injury, and the response parallels the time course of reactive oxygen species generation in these cells.

Oxidative stress in acne vulgaris

BACKGROUND

Acne vulgaris is one of the common dermatological diseases and its pathogenesis is multifactorial. In this study, we aimed to determine the effects of oxidative stress in acne vulgaris.

MATERIALS AND METHODS

The study involved 32 patients with acne vulgaris in the patient group and 34 healthy adults in the control group. The parameters of oxidative stress such as catalase (CAT), superoxide dismutase (SOD), xanthine oxidase (XO), nitric oxide (NO) and malondialdehyde (MDA) in the venous blood of patients were measured spectrophotometrically. The values were compared with those of the control group.

RESULTS

The serum levels of MDA and XO activity in the patients with acne vulgaris were significantly higher than those of the controls. A significantly lower SOD and CAT activity was found in the patient group than in the control group. Although the patient group had higher serum levels of NO than the control group, the difference was not statistically significant.

CONCLUSION

These results suggest that oxidative damage may play a role in the pathogenesis of acne; therefore, significant alterations may occur in the antioxidant defence system.

Response of vitiligo to narrowband ultraviolet B and oral antioxidants

Narrowband ultraviolet B phototherapy (NB-UVB) is the most widely and effective therapeutic option in vitiligo. Antioxidant supplementation has also been reported to be useful. The purpose of this study was to determine the efficacy of oral antioxidants with NB-UVB in the treatment of vitiligo. Twenty-four patients with stable vitiligo were recruited and divided randomly into 2 groups. They were treated with NB-UVB plus oral vitamin E in group A and with NB-UVB only in group B. Improvement was recorded according to the extent of repigmentation in the existing lesions. Both plasma malondialdehyde (MDA; product of lipid peroxidation) and reduced glutathione (GSH) were measured before and after treatment. Twenty patients completed the study. Marked to excellent repigmentation was noted in 72.7% and 55.6% of the patients in group A and group B, respectively. Of the patients, 70% in group A and 85% in group B experienced mild erythema. After treatment, there was a significant reduction in plasma MDA in group A than in group B, but the increase in plasma GSH was not significant. In conclusion, oral vitamin E may represent a valuable adjuvant therapy, preventing lipid peroxidation in the cellular membrane of melanocytes and increasing the effectiveness of NB-UVB.

Effect of melatonin on burn-induced gastric mucosal injury in rats

We studied the effect of melatonin treatment on gastric mucosal damage induced by experimental burns and its possible relation to changes in gastric lipid peroxidation status. Melatonin was intraperitoneally applied immediately after third-degree burns over 30% of total body skin surface area of rats. Malondialdehyde (MDA), uric acid (UA) and sulphydril (SH) levels were determined in gastric mucosa and blood plasma and used as biomarkers of the oxidative stress. The results showed that the skin burn caused oxidative stress evidenced by accumulation of MDA and UA as well as the depletion of SHs in gastric mucosa. Plasma MDA concentrations were elevated, while plasma SH concentrations were decreased after burns. Melatonin (10 mg per kg body weight) protected gastric mucosa from oxidative damage by suppressing lipid peroxidation and activating the antioxidant defence. It may be hypothesised that melatonin restores the redox balance in the gastric mucosa and protects it from burn-induced oxidative injury. Melatonin has no significant influence on the concentrations of plasma MDA and antioxidants after burn; therefore, it should largely be considered as a limiting factor for tissue-damage.