Assay for lipid peroxides in animal tissues by thiobarbituric acid reaction

Lipid peroxidation can be described generally as a process under which oxidants such as free radicals attack lipids containing carbon-carbon double bond(s), especially polyunsaturated fatty acids (PUFAs). Over the last four decades, an extensive body of literature regarding lipid peroxidation has shown its important role in cell biology and human health. Since the early 1970s, the total published research articles on the topic of lipid peroxidation was 98 (1970–1974) and has been increasing at almost 135-fold, by up to 13165 in last 4 years (2010–2013). New discoveries about the involvement in cellular physiology and pathology, as well as the control of lipid peroxidation, continue to emerge every day. Given the enormity of this field, this review focuses on biochemical concepts of lipid peroxidation, production, metabolism, and signaling mechanisms of two main omega-6 fatty acids lipid peroxidation products: malondialdehyde (MDA) and, in particular, 4-hydroxy-2-nonenal (4-HNE), summarizing not only its physiological and protective function as signaling molecule stimulating gene expression and cell survival, but also its cytotoxic role inhibiting gene expression and promoting cell death. Finally, overviews of in vivo mammalian model systems used to study the lipid peroxidation process, and common pathological processes linked to MDA and 4-HNE are shown.

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Lipid peroxidation: production, metabolism, and signaling mechanisms of malondialdehyde and 4-hydroxy-2-nonenal.

EDDINGTON'S “Internal Constitution of the Stars” was published in 1926 and gives what now ranks as a classical account of his own researches and of the general state of the theory at that time. Since then, a tremendous amount of work has appeared. Much of it has to do with the construction of stellar models with different equations of state applying in different zones. Other parts deal with the effects of varying chemical composition, with pulsation and tidal and rotational distortion of stars, and with the precise relations between the interior and the atmosphere of a star. The striking feature of all this work is that so much can be done without assuming any particular mechanism of stellar energy-generation. Only such very comprehensive assumptions are made about the distribution and behaviour of the energy sources that we may expect future knowledge of their mechanism to lead mainly to more detailed results within the framework of the existing general theory. An Introduction to the Study of Stellar Structure By S. Chandrasekhar. (Astrophysical Monographs sponsored by The Astrophysical Journal.) Pp. ix+509. (Chicago: University of Chicago Press; London: Cambridge University Press, 1939.) 50s. net.

An Introduction to the Study of Stellar Structure

A marked increase in interest has occurred over the last few years in the role that mammalian heme peroxidase enzymes, primarily myeloperoxidase, eosinophil peroxidase, and lactoperoxidase, may play in both disease prevention and human pathologies. This increased interest has been sparked by developments in our understanding of polymorphisms that control the levels of these enzymes, a greater understanding of the basic chemistry and biochemistry of the oxidants formed by these species, the development of specific biomarkers that can be used in vivo to detect damage induced by these oxidants, the detection of active forms of these peroxidases at most, if not all, sites of inflammation, and a correlation between the levels of these enzymes and a number of major human pathologies. This article reviews recent developments in our understanding of the enzymology, chemistry, biochemistry and biologic roles of mammalian peroxidases and the oxidants that they generate, the potential role of these oxidants in human disease, and the use of the levels of these enzymes in disease prognosis.

Mammalian heme peroxidases: from molecular mechanisms to health implications.

Redox degenerative reactions of the biological system inevitably produce reactive oxygen species (ROS) and their derivatives. Oxidative stress is the result of an imbalance in pro-oxidant/antioxidant homeostasis that leads to the generation of toxic reactive oxygen species (ROS), such as hydrogen peroxide, organic hydro peroxides, nitric oxide, superoxide and hydroxyl radicals etc. Information are accumulating steadily, supporting the general importance of oxidative damage of tissue and cellular components as a primary or secondary causative factor in many different human diseases and aging processes. Many of the recent landmarks in scientific research have shown that in human beings, oxidative stress has been implicated in the progression of major health problems by inactivating the metabolic enzymes and damaging important cellular components, oxidizing the nucleic acids, leading to cardiovascular diseases, eye disorders, joint disorders, neurological diseases (Alzheimer’s disease, Parkinson’s disease and amyotrophic lateral sclerosis), atherosclerosis, lung and kidney disorders, liver and pancreatic diseases, cancer, ageing, disease of the reproductive system including the male and female infertility etc. The advent of a growing number of in vitro and in vivo models for evaluating the human disease pathology is aiding scientists in deciphering the detailed mechanisms of the point of intersection of the oxidative stress with other cellular components or events in the growing roadmap leading to different human disorders. The toxic effect of reactive oxygen and nitrogen species in human is balanced by the antioxidant action of non-enzymatic antioxidants, as well as by antioxidant enzymes. Such antioxidant defences are extremely important as they represent the direct removal of free radicals (prooxidants), thus providing maximal protection for biological sites. These systems not only assert with the problem of oxidative damage, but also play a crucial role in wellness, health maintenance, and prevention of chronic and degenerative diseases. In this review we have tried to generate a gross picture on the critical role of ROS in deteriorating human health and the importance of antioxidative defense system in ameliorating the toxicity of ROS.

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Oxidative stress and human health

Background and Objective
Therapeutic ultrasound (US) and laser (L) treatments accelerate and facilitate wound healing, and also have beneficial effects on tendon healing. This randomized control study was designed to evaluate the effects of low-intensity US and low-level laser therapy (LLLT) on tendon healing in rats.

Study Design/Materials and Methods
Eighty-four healthy male Swiss-Albino rats were divided into three groups consisting of 28 rats, the left Achilles tendons were used as treatment and the right Achilles tendons as controls. The right and left Achilles tendons of rats were traumatized longitudinally. The treatment was started on postinjury day one. We applied the treatment protocols including low-intensity US treatment in Group I (US Group), Sham US in Group II (SUS Group), LLLT in Group III (L Group), Sham L in Group IV (SL Group), US and LLLT in Group V (US + L Group), and Sham US and Sham L in Group VI (SUS + SL Group). The US treatment was applied with a power of 0.5 W/cm2, a frequency of 1 MHz, continuously, 5 minutes daily. A low-level Ga–As laser was applied with a 904 nm wavelength, 6 mW average power, 1 J/ cm2 dosage, 16 Hz frequency, for 1 minute duration, continuously. In the control groups, the similar procedures as in the corresponding treatment groups were applied with no current (Sham method). The treatment duration was planned for 9 days (sessions) in all groups, except the rats used for biochemical evaluation on the 4th day of treatment, which were treated for 4 days. We measured the levels of the tissue hydroxyproline for biochemical evaluation on the 4th, 10th, and 21st days following the beginning of treatment and the tendon breaking strength on the 21st day following the beginning of treatment for biomechanical evaluation. Seven rats in each group were killed on the 4th, 10th, and 21st days for biochemical evaluation and on the 21st day for biomechanical evaluation.

Results
The hydroxyproline levels were found to be significantly increased in the treatment groups on the 10th and 21st days compared to their control groups (P   0.05). In comparison of the tendon breaking strengths, it was found as significantly increased in the treatment groups compared with their control groups (P < 0.05), although there was no significant difference between the treatment groups.

Conclusions
Although US, L, and combined US + L treatments increased tendon healing biochemically and biomechanically more than the control groups, no statistically significant difference was found between them. Also we did not find significantly more cumulative positive effects of combined treatment. As a result, both of these physical modalities can be used successfully in the treatment of tendon healing. Lasers Surg. Med. 35:84–89, 2004. © 2004 Wiley-Liss, Inc.

Comparison of the effects of laser, ultrasound, and combined laser + ultrasound treatments in experimental tendon healing.

We investigated the effects of electrical stimulation (ES) and laser treatment on wound healing in rats. A randomized-controlled trial, conducted at the Experimental and Clinical Research Centre of Erciyes University (Kayseri, Turkey), divided 124 healthy female Swiss-Albino rats into four groups. A 6 cm linear incision was made at the dorsal skin of all rats. Group 1 was given a constant direct current of 300 microA for 30 min per day. The current was applied in negative polarity for the first 3 days and in positive polarity for the next 7 days. Group 3 received a full-contact, continuous gallium-arsenide (GaAs) laser therapy, with a wavelength of 904 nm, an energy density of 1 J/cm2, and an average power of 6 mW for 10 min per day. The remaining two groups (Groups 2 and 4) were considered the control groups and received sham treatment. All groups were treated for 10 days. Histopathologic and biochemical evaluations were conducted on 10 rats from each group on the 4th and 10th days, and wound breaking strength was measured for biomechanical evaluation on the 25th day of the study. Both ES and laser treatment proved significantly effective in the inflammatory phase compared with control groups (p 0.05). Although ES and laser treatment both were effective in the maturation phase, increasing wound breaking strength compared with their control groups (p 0.05). We conclude that ES and laser treatment both have beneficial effects during the inflammatory, proliferation, and maturation phases of a wound. Both ES and laser treatment can be used successfully in decubitis ulcers and chronic wounds, in combination with conventional therapies such as daily care and debridement of wounds; however, ES has more beneficial effects during the inflammatory phase in some parameters than laser treatment.

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A comparative study of the effects of electrical stimulation and laser treatment on experimental wound healing in rats.

We aimed to determine the importance of neutrophil activation and the source of oxidative stress in the pathogenesis of rheumatoid arthritis (RA) by quantification of advanced oxidation protein products (AOPP) and total thiol levels as markers of oxidative protein damage, malondialdehyde (MDA) levels as a marker of lipid peroxidation and myeloperoxidase (MPO) activity as a marker of neutrophil activation in patients with RA. Fifty-seven rheumatoid arthritis patients were included in the study and sub-grouped according to disease activity (active, n = 31; inactive, n = 26) and compared with healthy controls (n = 25). Serum MPO activity, AOPP, MDA, and thiol levels were measured by an enzymic spectrophotometric method. Serum MPO activity (p < 0.001), AOPP (p < 0.001), MDA (p < 0.001) and levels of thiol (p < 0.002), were higher in the patient group than the controls. Active and inactive RA groups were compared with the control group and there were significant differences between each parameter. MPO activity, AOPP, MDA and thiol levels were significantly higher in both active and inactive RA patients than the controls. On the other hand, when a comparison was made between active and the inactive stage, a statistically significant difference was present only in MDA (p < 0.05) and AOPP levels (p < 0.05). There was also a significant positive correlation between all parameters. These data strongly suggest that neutrophils, which constitute the most important source of chlorinated oxidants due to their high MPO content, may be involved in serum AOPP formation and therefore the production of a novel class of pro-inflammatory mediators of oxidative stress in RA patients and that protein oxidation could play an important role in the pathogenesis of RA as does lipid peroxidation.

Investigation of protein oxidation and lipid peroxidation in patients with rheumatoid arthritis

Assessment of paraoxonase 1 activity and malondialdehyde levels in patients with rheumatoid arthritis.

The aim of this study was to compare the efficacy of sodium hyaluronate (SH) injection with the most common treatment methods, intraarticular steroid injection and physical therapy modalities in patients with adhesive capsulitis (AC). A total of 95 shoulders of 90 patients were included in the study and were randomized in four groups. The patients were treated with SH injection (group 1), triamsinolone acetonide (group 2) or physical therapy modalities (group 3). Group 4 patients were served as controls. Pain severity, passive ranges of motion and functional considerations were measured before, and 15 days and 3 months after the treatments. In all treatment groups, there were significant improvements at both the 15th day and third month in all parameters (for each, p<0.001). The passive abduction values on the 15th day was found significantly higher in group 3 when compared with group 1 and controls (for each, p<0.001). At the third month, the passive abduction values of the groups 2 and 3 were improved when compared with the control group (p<0.001). Constant score was higher in group 3 on 15th day when compared with group 1. At the third month, all treatment groups were improved significantly compared with control group (p<0.001). We provided the best results in physical therapy modalities applied group for AC treatment. However, we think that SH injection may be administered as an alternative treatment method.

Hüseyin Demir

Papers

Comparison of the effects of laser, ultrasound, and combined laser + ultrasound treatments in experimental tendon healing.

A comparative study of the effects of electrical stimulation and laser treatment on experimental wound healing in rats.

Investigation of protein oxidation and lipid peroxidation in patients with rheumatoid arthritis

Assessment of paraoxonase 1 activity and malondialdehyde levels in patients with rheumatoid arthritis.

Is intraarticular sodium hyaluronate injection an alternative treatment in patients with adhesive capsulitis