Free radicals in disease processes: a compilation of cause and consequence

Oxidative stress involvement in the molecular pathogenesis and progression of multiple sclerosis: a literature review

Multiple sclerosis (MS) is an autoimmune debilitating disease of the central nervous system caused by a mosaic of interactions between genetic predisposition and environmental factors. The pathological hallmarks of MS are chronic inflammation, demyelination, and neurodegeneration. Oxidative stress, a state of imbalance between the production of reactive species and antioxidant defense mechanisms, is considered one of the key contributors in the pathophysiology of MS. This review is a comprehensive overview of the cellular and molecular mechanisms by which oxidant species contribute to the initiation and progression of MS including mitochondrial dysfunction, disruption of various signaling pathways, and autoimmune response activation. The detrimental effects of oxidative stress on neurons, oligodendrocytes, and astrocytes, as well as the role of oxidants in promoting and perpetuating inflammation, demyelination, and axonal damage, are discussed. Finally, this review also points out the therapeutic potential of various synthetic antioxidants that must be evaluated in clinical trials in patients with MS.

Quantitative determination of potential genotoxic impurities in metformin hydrochloride and empagliflozin tablets through ultra-performance liquid chromatographymass spectrometry

An increasing number of drug research institutions consider genotoxic impurity research a core task in drug research and development. Peroxides in drugs may directly or indirectly attack and damage cell DNA, posing a potential carcinogenic risk to the human body. Currently, the literature only studies hydroperoxide impurities, and benzyl peroxide has not been studied yet. In this study, an effective method for ultra-performance liquid chromatographymass spectrometry (UPLCMS/MS) was established and verified to detect and quantify the potential genotoxic impurity (PGI), empagliflozin benzyl peroxide, in metformin-empagliflozin combination formulations, which has not been reported thus far. A Waters ACQUITY UPLC HSS T3 (3.0 ×100 mm, 1.8 µm) column was used to achieve chromatographic separation with gradient elution. The mass spectrometry conditions were optimized using electrospray ionization in the negative mode. Following the International Conference of Harmonization (ICH) guidelines, this methodology can quantify PGIs at 1.35 ng/mL (5.4 ppm) in samples. This validated method exhibited good linearity over a concentration range of 5.4 to 36 ppm, and the accuracy of this method was in the range of 83.2-95.0% for empagliflozin benzyl peroxide. This approach fills the gap in the detection method for benzyl peroxide impurities in metformin hydrochloride and empagliflozin tablets, providing technical support for the quality control of the drug.

Beeswax Alcohol Prevents Low-Density Lipoprotein Oxidation and Demonstrates Antioxidant Activities in Zebrafish Embryos and Human Subjects: A Clinical Study

Oxidative stress is one of the primary instigators of the onset of various human ailments, including cancers, cardiovascular diseases, and dementia. Particularly, oxidative stress severely affects low-density lipid & protein (LDL) oxidation, leading to several detrimental health effects. Therefore, in this study, the effect of beeswax alcohol (BWA) was evaluated in the prevention of LDL oxidation, enhancement of paraoxonase 1 (PON-1) activity of high-density lipid & protein (HDL), and zebrafish embryo survivability. Furthermore, the implication of BWA consumption on the oxidative plasma variables was assessed by a preliminary clinical study on middle-aged and older human subjects (n = 50). Results support BWA augmentation of PON-1 activity in a dose-dependent manner (10-30 μM), which was significantly better than the effect exerted by coenzyme Q10 (CoQ10). Moreover, BWA significantly curtails LDL/apo-B oxidation evoked by CuSO4 (final 0.5 μM) and a causes a marked reduction in lipid peroxidation in LDL. The transmission electron microscopy (TEM) analysis revealed a healing effect of BWA towards the restoration of LDL morphology and size impaired by the exposure of Cu2+ ions (final 0.5 μM). Additionally, BWA counters the toxicity induced by carboxymethyllysine (CML, 500 ng) and rescues zebrafish embryos from development deformities and apoptotic cell death. A completely randomized, double-blinded, placebo-controlled preliminary clinical study on middle- and older-aged human subjects (n = 50) showed that 12 weeks of BWA (100 mg/day) supplementation efficiently diminished serum malondialdehyde (MDA) and total hydroperoxides and enhanced total antioxidant status by 25%, 27%, and 22%, respectively, compared to the placebo-control and baseline values. Furthermore, the consumption of BWA did not exhibit any noteworthy changes in physical variables, lipid profile, glucose levels, and biomarkers pertinent to kidney and liver function, thus confirming the safety of BWA for consumption. Conclusively, in vitro, BWA prevents LDL oxidation, enhances PON-1 activity in HDL, and positively influences oxidative variables in human subjects.

Verbascoside-Rich Plant Extracts in Animal Nutrition

In recent years, the search for dietary intervention with natural products able to sustain animal health and decrease environmental impact, has raised the number of studies pertaining to the use of plants' secondary metabolites. In fact, in livestock, there is a clear relationship between the animals' antioxidant status and the onset of some diseases that negatively affect animal welfare, health, and productive performance. An interesting compound that belongs to the secondary metabolites family of plants, named phenylpropanoids, is verbascoside. The genus Verbascum, which includes more than 233 plant species, is the genus in which this compound was first identified, but it has also been found in other plant extracts. Verbascoside exhibits several properties such as antioxidant, anti-inflammatory, chemopreventive, and neuroprotective properties, that have been evaluated mainly in in vitro studies for human health. The present work reviews the literature on the dietary integration of plant extracts containing verbascoside in livestock. The effects of dietary plant extracts containing verbascoside on the productive performance, antioxidant status, blood parameters, and meat quality in several animal species were evaluated. The present data point out that dietary plant extracts containing verbascoside appear to be a favorable dietary intervention to enhance health, antioxidant status, and product quality in livestock.

Cardioprotective effect of Justicia gendarussa on doxorubicin induced toxicity in mice

Justicia gendarussa Burm.f, belonging to the family Acanthaceae, is widely used for various ailments traditionally. Antioxidant, anti-arthritic, anti-inflammatory, analgesic, anticancerous, properties of the plant have been widely reported. The present study analyzed the cardioprotective effect of J. gendarussa on doxorubicin (DOX) induced toxicity in mice. Ethanolic extract of J. gendarussa was administered orally for 7 consecutive days. The alterations in oxido-reduction status, biochemical and histopathological parameters were analyzed in heart tissue. DOX increased superoxide dismutase (SOD) and catalase activities to 3.4 ± 0.5 and 3.68 ± 1 from their normal values 2.43 ± 0.8 and 2.72 ± 0.88, respectively. The increased activities of both the enzymes were found reduced to 3.12 ± 0.24 and 3.41 ± 0.65 by the treatment of the extract. Similarly, DOX elevated glutathione peroxidase (GPx) activity to 44.6 ± 3.71 from the normal level 32.33 ± 3.41. DOX decreased the glutathione (GSH) level to 15.66 ± 2.51 from the normal values 31.66 ± 4.05. Upon treatment, GPx activity and GHS level found restored. The increased lipid peroxidation 2.53 ± 0.25 of DOX was also decreased to 2.0 ± 0.34 by the extract. Histopathology observations substantiate the protective effect of J. gendarussa extract. In conclusion, DOX-induced disturbance of oxido-reduction status and histopathology of heart attenuated closer to the normal indicating the protective effect of J. gendarussa against DOX-induced toxicity in cardiomyocytes.

Mitochondrial Oxidative Metabolism: An Emerging Therapeutic Target to Improve CKD Outcomes

Chronic kidney disease (CKD) predisposes one toward end-stage renal disease (ESRD) and its associated morbidity and mortality. Significant metabolic perturbations in conjunction with alterations in redox status during CKD may induce increased production of reactive oxygen species (ROS), including superoxide (O₂^●-) and hydrogen peroxide (H₂O₂). Increased O₂^●- and H₂O₂ may contribute to the overall progression of renal injury as well as catalyze the onset of comorbidities. In this review, we discuss the role of mitochondrial oxidative metabolism in the pathology of CKD and the recent developments in treating CKD progression specifically targeted to the mitochondria. Recently published results from a Phase 2b clinical trial by our group as well as recently released data from a ROMAN: Phase 3 trial (NCT03689712) suggest avasopasem manganese (AVA) may protect kidneys from cisplatin-induced CKD. Several antioxidants are under investigation to protect normal tissues from cancer-therapy-associated injury. Although many of these antioxidants demonstrate efficacy in pre-clinical models, clinically relevant novel compounds that reduce the severity of AKI and delay the progression to CKD are needed to reduce the burden of kidney disease. In this review, we focus on the various metabolic pathways in the kidney, discuss the role of mitochondrial metabolism in kidney disease, and the general involvement of mitochondrial oxidative metabolism in CKD progression. Furthermore, we present up-to-date literature on utilizing targets of mitochondrial metabolism to delay the pathology of CKD in pre-clinical and clinical models. Finally, we discuss the current clinical trials that target the mitochondria that could potentially be instrumental in advancing the clinical exploration and prevention of CKD.

High Fischer ratio peptide of hemp seed: Preparation and anti-fatigue evaluation in vivo and in vitro

The high Fischer (F) ratio hemp peptide (HFHP) was prepared by enrichment using activated carbon adsorption, ultrafiltration, and Sephadex G-25 gel filtration chromatography. The OD₂₂₀/OD₂₈₀ ratio reached 47.1 with a molecular weight distribution from 180 to 980 Da, a peptide yield up to 21.7 %, and the F value was 31.5. HFHP had high scavenging ability of DPPH, hydroxyl free radicals, and superoxide. Mice experiments showed that the HFHP increased the activity of superoxide dismutase and glutathione peroxidase. The HFHP had no effect on the body weight of mice, but prolonged their weight-bearing swimming time. The lactic acid, serum urea nitrogen, and malondialdehyde of the mice after swimming was reduced, and the liver glycogen increased. The correlation analysis indicated that the HFHP had significant anti-oxidation and anti-fatigue properties.

Fifty Years of the Fluid–Mosaic Model of Biomembrane Structure and Organization and Its Importance in Biomedicine with Particular Emphasis on Membrane Lipid Replacement

The Fluid–Mosaic Model has been the accepted general or basic model for biomembrane structure and organization for the last 50 years. In order to establish a basic model for biomembranes, some general principles had to be established, such as thermodynamic assumptions, various molecular interactions, component dynamics, macromolecular organization and other features. Previous researchers placed most membrane proteins on the exterior and interior surfaces of lipid bilayers to form trimolecular structures or as lipoprotein units arranged as modular sheets. Such membrane models were structurally and thermodynamically unsound and did not allow independent lipid and protein lateral movements. The Fluid–Mosaic Membrane Model was the only model that accounted for these and other characteristics, such as membrane asymmetry, variable lateral movements of membrane components, cis- and transmembrane linkages and dynamic associations of membrane components into multimolecular complexes. The original version of the Fluid–Mosaic Membrane Model was never proposed as the ultimate molecular description of all biomembranes, but it did provide a basic framework for nanometer-scale biomembrane organization and dynamics. Because this model was based on available 1960s-era data, it could not explain all of the properties of various biomembranes discovered in subsequent years. However, the fundamental organizational and dynamic aspects of this model remain relevant to this day. After the first generation of this model was published, additional data on various structures associated with membranes were included, resulting in the addition of membrane-associated cytoskeletal, extracellular matrix and other structures, specialized lipid–lipid and lipid–protein domains, and other configurations that can affect membrane dynamics. The presence of such specialized membrane domains has significantly reduced the extent of the fluid lipid membrane matrix as first proposed, and biomembranes are now considered to be less fluid and more mosaic with some fluid areas, rather than a fluid matrix with predominantly mobile components. However, the fluid–lipid matrix regions remain very important in biomembranes, especially those involved in the binding and release of membrane lipid vesicles and the uptake of various nutrients. Membrane phospholipids can associate spontaneously to form lipid structures and vesicles that can fuse with various cellular membranes to transport lipids and other nutrients into cells and organelles and expel damaged lipids and toxic hydrophobic molecules from cells and tissues. This process and the clinical use of membrane phospholipid supplements has important implications for chronic illnesses and the support of healthy mitochondria, plasma membranes and other cellular membrane structures.

Dietary Antioxidant Indices in Relation to All-Cause and Cause-Specific Mortality Among Adults With Diabetes: A Prospective Cohort Study

Background

The potential beneficial effect of individual antioxidants on mortality has been reported. However, the association of overall intakes of dietary antioxidants with all-cause and cause-specific mortality among adults with diabetes remained unclear.

Methods

A total of 4,699 US adults with diabetes were enrolled in 2003–2014 in the National Health and Nutrition Examination Survey (NHANES) and followed for mortality until 31 December 2015. The Dietary Antioxidant Quality Score (DAQS) and the Dietary Antioxidant Index (DAI), which indicate the total antioxidant properties, were calculated based on the intakes of vitamins A, C, E, zinc, selenium, and magnesium. The Cox proportional hazards regression models were used to investigate the associations of the DAQS or the DAI with all-cause and cause-specific mortality.

Results

A total of 913 deaths occurred during 27,735 person-years of follow-up, including 215 deaths due to cardiovascular disease (CVD) and 173 deaths due to cancer. The higher intakes of antioxidant vitamins A, E, magnesium, and selenium were associated with lower all-cause mortality. The adjusted hazard ratios (HRs) (95% CIs) comparing the highest DAQS (5–6) to the lowest DAQS (0–2) were 0.70 (0.53–0.92) for all-cause mortality, 0.56 (0.35–0.90) for CVD mortality, and 0.59 (0.33–1.04) for cancer mortality. Consistent inverse associations were found between the DAI and mortality.

Conclusion

Higher intake of overall dietary antioxidants was associated with lower risk of death from all-cause and CVD in adults with diabetes. Future dietary intervention studies are needed to determine whether increasing overall antioxidant micronutrients intake could prevent premature death among adults with diabetes.

Isolation of the hemeoxygenase-1 inducer from rice-derived peptide

Bioactive peptides with various health benefits have been reported from rice protein hydrolysates. We previously showed that rice-derived peptides (RP) increased intracellular glutathione levels and induced the expression of γ-glutamylcysteine synthetase, which is regulated by nuclear transcription factor-erythroid 2-related factor 2 (Nrf2). Heme oxygenase-1 (HO-1) is an important Nrf2 downstream antioxidant enzyme that protects against oxidative stress. This study aimed to investigate the protective effects of RP on hydrogen peroxide (H₂O₂)-induced oxidative stress in human hepatoblastoma cell line HepG2 and identified HO-1 induced peptides from RP. Pretreatment of cells with RP reduced the cytotoxicity caused by H₂O₂ in a dose-dependent manner. Moreover, RP induced HO-1 expression in a concentration- and time-dependent manner. Next, we attempted to isolate the HO-1 inducer from RP by bioactivity-guided fractionation. Purification of the active peptides using a Sep-Pak C18 cartridge and reversed-phase HPLC, followed by sequence analysis by mass spectrometry, led to the identification of the three peptides. These peptides effectively reduced H₂O₂-induced oxidative stress. Among them, only P3 (peptide sequence: RSAVLLSH) increased HO-1 protein expression. Additionally, the knockdown of Nrf2 suppressed the induction of HO-1 expression by P3. Our results indicated that P3 identified from RP induced HO-1 by activating the Nrf2 signaling pathway.

Hyperbaric oxygen influences chronic wound healing – a cellular level review

Chronic wound is a serious medical issue due to its high prevalence and complications; hyperbaric oxygen therapy (HBOT) is also considered in comprehensive treatment. Clinical trials, including large meta-analyses bring inconsistent results about HBOT efficacy. This review is summarizing the possible effect of HBOT on the healing of chronic wound models at the cellular level. HBOT undoubtedly escalates the production of reactive oxygen and nitrogen radicals (ROS and RNS), which underlie both the therapeutic and toxic effects of HBOT on certain tissues. HBOT paradoxically elevates the concentration of Hypoxia inducible factor (HIF) 1 by diverting the HIF-1 degradation to pathways that are independent of the oxygen concentration. Elevated HIF-1 stimulates the production of different growth factors, boosting the healing process. HBOT supports synthesis of Heat shock proteins (HSP), which are serving as chaperones of HIF-1. HBOT has antimicrobial effect, increases the effectiveness of some antibiotics, stimulates fibroblasts growth, collagen synthesis and suppresses the activity of proteolytic enzymes like matrix metalloproteinases. All effects of HBOT were investigated on cell cultures and animal models, the limitation of their translation is discussed at the end of this revie

Royal Jelly Proteins and Their Derived Peptides: Preparation, Properties, and Biological Activities

Royal jelly, also called bee milk, is a source of high-quality proteins. Royal jelly proteins serve as not only a rich source of essential amino acids and functional donors but also an excellent substrate for preparing bioactive peptides. Most naturally occurring bioactive peptides in royal jelly are antibacterial, while peptides derived from proteolytic reactions are shown to exert antihypertensive, antioxidative, and anti-aging activities. Further studies are warranted to characterize the functional properties of major royal jelly proteins and peptides, to explore the preparation of bioactive peptides and the potential novel activities, to improve their bioavailability, to enhance the production efficiency for commercial availability, and finally to open up new applications for royal jelly as a functional food and potential therapeutic agent.

Fundamentals of Membrane Lipid Replacement: A Natural Medicine Approach to Repairing Cellular Membranes and Reducing Fatigue, Pain, and Other Symptoms While Restoring Function in Chronic Illnesses and Aging

Membrane Lipid Replacement (MLR) uses natural membrane lipid supplements to safely replace damaged, oxidized lipids in membranes in order to restore membrane function, decrease symptoms and improve health. Oral MLR supplements contain mixtures of cell membrane glycerolphospholipids, fatty acids, and other lipids, and can be used to replace and remove damaged cellular and intracellular membrane lipids. Membrane injury, caused mainly by oxidative damage, occurs in essentially all chronic and acute medical conditions, including cancer and degenerative diseases, and in normal processes, such as aging and development. After ingestion, the protected MLR glycerolphospholipids and other lipids are dispersed, absorbed, and internalized in the small intestines, where they can be partitioned into circulating lipoproteins, globules, liposomes, micelles, membranes, and other carriers and transported in the lymphatics and blood circulation to tissues and cellular sites where they are taken in by cells and partitioned into various cellular membranes. Once inside cells, the glycerolphospholipids and other lipids are transferred to various intracellular membranes by lipid carriers, globules, liposomes, chylomicrons, or by direct membrane-membrane interactions. The entire process appears to be driven by 'bulk flow' or mass action principles, where surplus concentrations of replacement lipids can stimulate the natural exchange and removal of damaged membrane lipids while the replacement lipids undergo further enzymatic alterations. Clinical studies have demonstrated the advantages of MLR in restoring membrane and organelle function and reducing fatigue, pain, and other symptoms in chronic illness and aging patients.

α-Amyrin and β-Amyrin Isolated from Celastrus hindsii Leaves and Their Antioxidant, Anti-Xanthine Oxidase, and Anti-Tyrosinase Potentials

Celastrus hindsii is a popular medicinal plant in Vietnam and Southeast Asian countries as well as in South America. In this study, an amount of 12.05 g of an α-amyrin and β-amyrin mixture was isolated from C. hindsii (10.75 g/kg dry weight) by column chromatography applying different solvent systems to obtain maximum efficiency. α-Amyrin and β-amyrin were then confirmed by gas chromatography-mass spectrometry (GC-MS), electrospray ionization-mass spectrometry (ESI-MS), and nuclear magnetic resonance (NMR). The antioxidant activities of the α-amyrin and β-amyrin mixture were determined via 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,20-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays with IC₅₀ of 125.55 and 155.28 µg/mL, respectively. The mixture exhibited a high potential for preventing gout by inhibiting a relevant key enzyme, xanthine oxidase (XO) (IC₅₀ = 258.22 µg/mL). Additionally, an important enzyme in skin hyperpigmentation, tyrosinase, was suppressed by the α-amyrin and β-amyrin mixture (IC₅₀ = 178.85 µg/mL). This study showed that C. hindsii is an abundant source for the isolation of α-amyrin and β-amyrin. Furthermore, this was the first study indicating that α-amyrin and β-amyrin mixture are promising in future therapies for gout and skin hyperpigmentation.

Myrcene-What Are the Potential Health Benefits of This Flavouring and Aroma Agent?

Myrcene (β-myrcene) is an abundant monoterpene which occurs as a major constituent in many plant species, including hops and cannabis. It is a popular flavouring and aroma agent (food additive) used in the manufacture of food and beverages. This review aims to report on the occurrence, biological and toxicological profile of β-myrcene. The main reported biological properties of β-myrcene-anxiolytic, antioxidant, anti-ageing, anti-inflammatory, analgesic properties-are discussed, with the mechanisms of activity. Here we also discuss recent data regarding the safety of β-myrcene. Overall, β-myrcene has shown promising health benefits in many animal studies. However, studies conducted in humans is lacking. In the future, there is potential for the formulation and production of non-alcoholic beers, functional foods and drinks, and cannabis extracts (low in THC) rich in β-myrcene.

Telomere Shortening and Psychiatric Disorders: A Systematic Review

Telomeres are aging biomarkers, as they shorten while cells undergo mitosis. The aim of this study was to evaluate whether psychiatric disorders marked by psychological distress lead to alterations to telomere length (TL), corroborating the hypothesis that mental disorders might have a deeper impact on our physiology and aging than it was previously thought. A systematic search of the literature using MeSH descriptors of psychological distress ("Traumatic Stress Disorder" or "Anxiety Disorder" or "depression") and telomere length ("cellular senescence", "oxidative stress" and "telomere") was conducted on PubMed, Cochrane Library and ScienceDirect databases. A total of 56 studies (113,699 patients) measured the TL from individuals diagnosed with anxiety, depression and posttraumatic disorders and compared them with those from healthy subjects. Overall, TL negatively associates with distress-related mental disorders. The possible underlying molecular mechanisms that underly psychiatric diseases to telomere shortening include oxidative stress, inflammation and mitochondrial dysfunction linking. It is still unclear whether psychological distress is either a cause or a consequence of telomere shortening.

Changes of Intestinal Oxidative Stress, Inflammation, and Gene Expression in Neonatal Diarrhoea Kids

Diarrhea and disorders in young goats are serious threats to the animals' health, influencing the profitability of the goat industry. There is a need to better understand the potential biomarkers that can reflect the mortality and morbidity in neonatal diarrhea goats. Ten pairs of twin kid goats from the same does (one healthy and the other diagnosed as diarrhea) with the same age under 14 days after birth were used in this study. Since gastrointestinal infection is probably the first ailment in neonatal goats, we aimed to investigate the changes in oxidative stress, inflammation, and gene expression in the gastrointestinal tract of neonatal diarrhea goats based on an epidemiological perspective. The results showed the activity of glutathione peroxidase (GSH-Px) was less (P < 0.05) in the jejunum in neonatal diarrhea goats compared with control goats. However, the malondialdehyde (MDA) activities in the jejunum and ileum were higher (P < 0.05) in neonatal diarrhea goats. There was no significant difference in the super-oxide dismutase (SOD) and catalase (CAT) activity observed between the two groups (P > 0.05). For the concentrations of intestinal interleukin-2 (IL2) and interleukin-6 (IL6), only the IL-2 in ileum of neonatal diarrhea goats was higher than that from healthy control goats. The transcriptomic analysis of the jejunum showed a total of 364 differential expression genes (DEGs) identified in neonatal diarrhea goats compared with control goats. The Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analysis of up-regulated DEGs was mainly related to the ECM–receptor interaction and axon guidance, and the down-regulated DEGs mainly related to the Arachidonic acid metabolism, complement and coagulation cascades, and alpha-Linolenic acid metabolism. Real-time PCR results showed that the expression of most toll-like receptor-4-(TLR4) pathway-related genes and intestinal barrier function-related genes were similar in the two groups. These results suggest that neonatal diarrhea goats experienced a higher intestinal oxidative stress compared with control goats. Thus, it is possible that the antioxidant capacity of young ruminants acts as an indicator of health status and the measurements of oxidation stress may be useful as diagnostic biomarkers, reflecting the mortality and morbidity in neonatal diarrhea goats.

Tricarboxylic Acid (TCA) Cycle Intermediates: Regulators of Immune Responses

The tricarboxylic acid cycle (TCA) is a series of chemical reactions used in aerobic organisms to generate energy via the oxidation of acetylcoenzyme A (CoA) derived from carbohydrates, fatty acids and proteins. In the eukaryotic system, the TCA cycle occurs completely in mitochondria, while the intermediates of the TCA cycle are retained inside mitochondria due to their polarity and hydrophilicity. Under cell stress conditions, mitochondria can become disrupted and release their contents, which act as danger signals in the cytosol. Of note, the TCA cycle intermediates may also leak from dysfunctioning mitochondria and regulate cellular processes. Increasing evidence shows that the metabolites of the TCA cycle are substantially involved in the regulation of immune responses. In this review, we aimed to provide a comprehensive systematic overview of the molecular mechanisms of each TCA cycle intermediate that may play key roles in regulating cellular immunity in cell stress and discuss its implication for immune activation and suppression.

Antioxidant and Cytoprotective Potential of the Essential Oil Pistacia lentiscus var. chia and Its Major Components Myrcene and α-Pinene

The antioxidant, cytoprotective, and wound-healing potential of the essential oil from the resin of Pistacia lentiscus var. chia (mastic oil) was evaluated, along with that of its major components, myrcene and α-pinene. Antioxidant potential was monitored as: (i) direct antioxidant activity as assessed by 2,2-di-phenyl-1-picrylhydrazyl (DPPH), 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), and ABTS assays; (ii) DNA damage protection activity; and (iii) cytoprotective activity as assessed via induction of transcription of genes related to the antioxidant response in human keratinocyte cells (HaCaT). The cytoprotective potential of the test substances was further evaluated against ultraviolet radiation B (UVB)- or H₂O₂-induced oxidative damage, whereas their regenerative capability was accessed by monitoring the wound closure rate in HaCaT. Μastic oil and major components did not show significant direct antioxidant activity, however they increased the mRNA levels of antioxidant response genes, suggesting indirect antioxidant activity. Treatment of HaCaT with the test substances before and after UVB irradiation resulted in increased cell viability in the cases of pre-treatment with mastic oil or post-treatment with myrcene. Increased cytoprotection was also observed in the case of cell treatment with mastic oil or its major components prior to H₂O₂ exposure. Finally, mastic oil and myrcene demonstrated a favorable dose-dependent effect for cell migration and wound closure. Collectively, mastic essential oil may exert its promising cytoprotective properties through indirect antioxidant mechanisms.

Heamanetic Effects of a Dioxidovanadium(V) Complex in STZ-Induced Diabetic Male Sprague Dawley Rats

BACKGROUND

Despite the effective maintenance of glucose homeostasis by insulin in type 1 diabetes mellitus, the drug has been implicated as one of the causes of haematological disturbances, which give rise to cardiovascular complications. As a result, research into alternative therapies for diabetes is needed. In our laboratory, an anti-hyperglycaemic novel vanadium complex has been synthesized using organic heterocyclic ligands. The complex has been shown and improve glycaemic control. The effects of this complex on haematological function, however, have not yet been established. Therefore, this study sought to investigate the haematological effects of dioxidovanadium(V) complex in (STZ)-induced diabetic rats.

METHODS

Diabetic rats received vanadium complex (40 mg kg ^-1 p.o), diabetic untreated (H₂O) and insulin treated (0.175 mg kg^-1 s.c), groups acted as a negative and positive control, respectively. Vanadium complex was administered twice daily, and blood glucose concentration was monitored weekly for 5 weeks. Thereafter, the animals were sacrificed followed by blood and kidneys collection for haematological (full blood count and Annexin V), hormonal (EPO) and oxidative status (SOD and GPx) analysis.

RESULTS

After 5 weeks, untreated diabetic rats presented with hyperglycaemia compared to non-diabetic rats which was attenuated by vanadium complex administration. Furthermore, vanadium treated groups presented with an augmented RBC count, haematocrit, haemoglobin concentration, MCHC, MCV, and (EPO) levels compared to diabetic control. An increase in annexin V expression hence cell survival was observed in vanadium complex treated rats. Lastly, the administration of the complex improved antioxidant status as evidenced by increases in SOD and GPx concentration in plasma and in the kidneys.

CONCLUSION

The administration of the anti-hyperglycaemic dioxidovanadium(V) complex improved haematological parameters, cell survival and the antioxidant status displayed by the diabetic rats. These results give an indication that the complex might be an effective alternative therapeutic drug for the treatment of hyperglycaemia in DM.

Effects of butylparaben on antioxidant enzyme activities and histopathological changes in rat tissues

Butyl p-hydroxybenzoic acid, also known as butylparaben (BP), is one of the most common parabens absorbed by the skin and gastrointestinal tract and metabolised in the liver and kidney. Recent in vivo and in vitro studies have raised concern that BP causes reproductive, development, and teratogenic toxicity. However, BP-induced oxidative stress and its relation to tissue damage has not been widely investigated before. Therefore, we aimed to investigate the effects of butyl 4-hydroxybenzoate on enzyme activities related to the pentose phosphate pathway and on glutathione-dependent enzymes such as glucose 6-phosphate dehydrogenase (G6PD), 6-phosphogluconate dehydrogenase (6-PGD), glutathione reductase (GR), glutathione peroxidase (GPx), and glutathione-S-transferase (GST) in kidney, liver, brain, and testis tissues. Male rats were randomly divided into four groups to orally receive corn oil (control) or 200, 400, or 800 mg/kg/day of BP for 14 days. Then we measured G6PD, GR, GST, 6-PGD, and GPx enzyme activities in these tissues and studied histopathological changes. BP treatment caused imbalance in antioxidant enzyme activities and tissue damage in the liver, kidney, brain, and testis. These findings are the first to show the degenerative role of BP on the cellular level. The observed impairment of equivalent homeostasis and antioxidant defence points to oxidative stress as a mechanism behind tissue damage caused by BP.

Toxicological impact of sodium benzoate on inflammatory cytokines, oxidative stress and biochemical markers in male Wistar rats

Sodium benzoate is a widely used food and pharmaceutical preservative due to its antibacterial and antifungal activity. In the present study effect of different concentrations of sodium benzoate on hepatic antioxidants, inflammatory cytokines (TNF-α, IFN-γ, IL-1β and IL-6), biochemical markers and histopathology of liver was evaluated. Twenty five adult rats (aged 1-2 months) with 5 rats per group were randomly distributed into 5 groups. Group 1 rats were used as control and all groups (1-5) were provided with water and fed ad libitum. In addition to usual water and food, rats of group 2, 3, 4 and 5 were treated with 70, 200, 400 and 700 mg/kg b.wt of sodium benzoate once a day via oral gavage for 30 days. Our results showed that activity of glutathione peroxidase (GPx), catalase (CAT), glutathione-s-transferase (GST), glutathione reductase (GR) and superoxide dismutase (SOD) in rats decreased significantly when treated with 200, 400 and 700 mg/kg b.wt of sodium benzoate. Increase in the concentration of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, serum total protein, albumin, globulin, urea and creatinine was found to be dose dependent. Severe histopathological damage was observed in the hepatic tissue at higher concentrations of sodium benzoate. It was noticed that high concentrations of sodium benzoate (200, 400 and 700 mg/kg b.wt) produce significant increase in inflammatory cytokine markers (TNF-α, IFN-γ, IL-1β and IL-6) in comparison to control. Sodium benzoate at concentration of 70 mg/kg b.wt did not produce any significant changes in any of the above studied parameters.

Osteochondritis dissecans (OCD) in Horses - Molecular Background of its Pathogenesis and Perspectives for Progenitor Stem Cell Therapy

Osteochondrosis (osteochondrosis dissecans; OCD) is a disease syndrome of growing cartilage related to different clinical entities such as epiphysitis, subchondral cysts and angular carpal deformities, which occurs in growing animals of all species, including horses. Nowadays, these disorders are affecting increasing numbers of young horses worldwide. As a complex multifactorial disease, OCD is initiated when failure in cartilage canals because of existing ischemia, chondrocyte biogenesis impairment as well as biochemical and genetic disruptions occur. Recently, particular attention have been accorded to the definition of possible relations between OCD and some metabolic disorders; in this way, implication of mitochondrial dysfunctions, endoplasmic reticulum disruptions, oxidative stress or endocrinological affections are among the most considered axes for future researches. As one of the most frequent cause of impaired orthopaedic potential, which may result in a sharp decrease in athletic performances of the affected animals, and lead to the occurrence of complications such as joint fragility and laminitis, OCD remains as one of the primary causes of considerable economic losses in all sections of the equine industry. It would therefore be important to provide more information on the exact pathophysiological mechanism(s) underlying early OC(D) lesions, in order to implement innovative strategies involving the use of progenitor stem cells, which are considered nowadays as a promising approach to regenerative medicine, with the potential to treat numerous orthopaedic disorders, including osteo-degenerative diseases, for prevention and reduction of incidence of the disease, not only in horses, but also in human medicine, as the equine model is already widely accepted by the scientific community and approved by the FDA, for the research and application of cellular therapies in the treatment of human conditions.

Ribosomal protein gene RPL9 variants can differentially impair ribosome function and cellular metabolism

Variants in ribosomal protein (RP) genes drive Diamond-Blackfan anemia (DBA), a bone marrow failure syndrome that can also predispose individuals to cancer. Inherited and sporadic RP gene variants are also linked to a variety of phenotypes, including malignancy, in individuals with no anemia. Here we report an individual diagnosed with DBA carrying a variant in the 5′UTR of RPL9 (uL6). Additionally, we report two individuals from a family with multiple cancer incidences carrying a RPL9 missense variant. Analysis of cells from these individuals reveals that despite the variants both driving pre-rRNA processing defects and 80S monosome reduction, the downstream effects are remarkably different. Cells carrying the 5′UTR variant stabilize TP53 and impair the growth and differentiation of erythroid cells. In contrast, ribosomes incorporating the missense variant erroneously read through UAG and UGA stop codons of mRNAs. Metabolic profiles of cells carrying the 5′UTR variant reveal an increased metabolism of amino acids and a switch from glycolysis to gluconeogenesis while those of cells carrying the missense variant reveal a depletion of nucleotide pools. These findings indicate that variants in the same RP gene can drive similar ribosome biogenesis defects yet still have markedly different downstream consequences and clinical impacts.

An In Vitro and In Vivo Cholinesterase Inhibitory Activity of Pistacia khinjuk and Allium sativum Essential Oils

Objectives

Alzheimer’s disease (AD), an overwhelming neurodegenerative disease, has deleterious effects on the brain that consequently causes memory loss and language impairment. This study was intended to investigate the neuroprotective activity of the two essential oils (EOs) from Iranian Pistacia khinjuk (PK) leaves and Allium sativum (AS) cloves against β-Amyloid 25–35 (Aβ25-35) induced elevation of cholinesterase enzymes in AD.

Methods

The EOs of PK (PKEO) and AS (ASEO) were prepared and analyzed in terms of extraction yield, phenolic content, and cholinergic markers in vitro. Moreover, both were administered orally to adult male Wistar rats at concentrations of 1, 2, and 3%. The inhibitory potential of PKEO and ASEO was compared with Donepezil (0.75 mg/kg) against the high activities of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes.

Results

PKEO reached an inhibition rate of 83.6% and 81.4% against AChE and BChE, respectively. ASEO had lower anti-cholinesterase activity (65.4% and 31.5% for the inhibition AChE and BChE). PKEO was found to have more phenolic content than ASEO. A significantly positive correlation was observed between the total phenolics and anti-cholinesterase potential. In rats, both EOs decreased the enzyme activity in a concentration-dependent manner. As compared with Donepezil, the significant difference in the AChE and BChE inhibition occurred as rats were treated with PKEO 3% (p < 0.05).

Conclusion

It could be concluded that PKEO and ASEO are potent inhibitors of AChE and BChE in rats that hold promise to be used for the treatment of AD.

Exploring the Chemistry and Therapeutic Potential of Triazoles: A Comprehensive Literature Review

:

Triazole is a valuable platform in medicinal chemistry, possessing assorted pharmacological properties, which could play a major role in the common mechanisms associated with various disorders like cancer, infections, inflammation, convulsions, oxidative stress and neurodegeneration. Structural modification of this scaffold could be helpful in the generation of new therapeutically useful agents. Although research endeavors are moving towards the growth of synthetic analogs of triazole, there is still a lot of scope to achieve drug discovery break-through in this area. Upcoming therapeutic prospective of this moiety has captured the attention of medicinal chemists to synthesize novel triazole derivatives. The authors amalgamated the chemistry, synthetic strategies and detailed pharmacological activities of the triazole nucleus in the present review. Information regarding the marketed triazole derivatives has also been incorporated. The objective of the review is to provide insights to designing and synthesizing novel triazole derivatives with advanced and unexplored pharmacological implications.

Identification of DNA and glutathione adducts in male Sprague-Dawley rats exposed to 1-bromopropane

Occupational exposure of workers to 1-bromopropane (1-BP) has raised concerns in industry for many years. Despite the known toxicity of this chemical, molecular events attributed to exposure to 1-BP have not been extensively studied. The aim of the present study was to examine the effects of 1-BP exposure on adduct formation with DNA and glutathione (GSH) in male Sprague-Dawley rats in an attempt to determine the early stages of toxicity. Following 6 h after either single or daily exposure to 1-BP for 3 days, N⁷-propyl guanine and S-propyl GSH were quantified in several organs by using liquid chromatography-mass spectrometry (LC-MS/MS). The results showed that N⁷-propyl guanine was maximally formed in liver followed by spleen, testes, and lung in both dose- and time-dependent manners. However, DNA adduct was not detected in cardiac tissue. In the case of S-propyl GSH, this compound was formed in the following order in various organs: liver > testes > spleen > kidney > lung > heart. In a subsequent in vitro study, formation of N⁷-propyl guanine initiated by 1-BP in calf thymus DNA was not markedly affected by addition of liver homogenates, which indicated that this chemical may be acting as a direct alkylating agent. In contrast, an in vitro study with free GSH demonstrated that 1-BP reduced GSH and elevated production of S-propyl GSH, and that the production of this adduct was significantly higher in the presence of active liver homogenates. Data indicated that formation of GSH adducts initiated by 1-BP might be associated with an enzyme-driven process. Although further characterization is necessary, it would appear that N⁷-propyl guanine and S-propyl GSH might serve as useful markers in cases of exposure assessment of 1-BP.

Determination of macro, micro, trace essential, and toxic elements in Garcinia cambogia fruit and its anti-obesity commercial products

BACKGROUND

Garcinia (Clusiaceae) species are traditionally used as flavoring agents in curries and to cure several human health complications. This study investigated 31 macro, micro, and trace elements in microwave-assisted digested samples of Garcinia cambogia fruit and its anti-obesity commercial products by inductively coupled plasma-optical emission spectroscopy (ICP-OES) and inductively coupled plasma-mass spectrometric (ICP-MS) techniques. The methods were also validated using the coefficient of determination (R² ), limits of detection and quantification (LOD, LOQ), precision (CV%), analysis of certified reference materials, spiking recovery experiments, and participation in an accredited laboratory proficiency test organized by Food Analysis Performance Assessment Scheme (FAPAS).

RESULTS

Quality assurance confirmed that the methods were efficient and in accordance with criteria set by the Association of Official Analytical Chemists (AOAC). In the elemental analysis, the analyzed macro, micro, and trace essential elements were present in appreciable concentrations, which could meet the human nutritional requirements. Traces of toxic elements were within safe limits.

CONCLUSION

From the results of the current study, the fruit and its commercial products could be considered potential sources of mineral elements without posing any threats to consumers. © 2018 Society of Chemical Industry.

Total Phenolic Content and In vitro Antioxidant Activity of Endophytic Fungi Isolated from Calotropis procera L

Background:

Endophytic fungi are microorganisms that colonize inside the plant tissues without causing any disease symptoms. Endophytic fungi isolated from medicinal plants have emerged as an interesting source for the isolation of bioactive compounds. In this study, we selected Calotropis procera, a member of the Asclepiadaceae family commonly called ‘Aak’ to evaluate the antioxidant potential of isolated endophytic fungi. </P><P> Objective: The aim of this study was to assess the total phenolic content (TPC), antioxidant capacity by using different assay and phytochemical screening of endophytic fungi isolated from Calotropis procera (leaves, stem and root). </P><P> Method: Crude ethyl acetate extracts of 20 different endophytic fungi isolated from Calotropis procera were tested for their preliminary phytoconstituents presence, TPC estimation (by Folin–Ciocalteu colorimetric assay) and antioxidant potential [1, 1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay, hydrogen peroxide (H2O2) free radical scavenging assay, β-carotene-linoleic free radical scavenging assay, metal chelating assay and xanthine oxidase inhibitory assay].

Results:

Phenols, carbohydrates, saponins, tannins, alkaloids and flavanoids were the main phytoconstituents present in the endophytic fungi. Among the endophytes, Aspergillus nomius showed the highest TPC [72.71±1.67 µg GAE (gallic acid equivalent) /mg dry weight of fungi] and antioxidant activity for DPPH free radical scavenging assay (68.86±0.19%). A high positive linear correlation was found between TPC and xanthine oxidase inhibitory assay (R2-0.890) and between TPC and DPPH free radical scavenging assay (R2-0.839). Aspergillus and Fusarium genus species showed significant antioxidant activity by the different assay.

Conclusion:

The present study revealed some endophytic fungi from Calotropis procera could be a potential source of novel natural antioxidant compounds.

Deletion of the Mitochondrial Complex-IV Cofactor Heme A:Farnesyltransferase Causes Focal Segmental Glomerulosclerosis and Interferon Response

Mutations in mitochondrial DNA as well as nuclear-encoded mitochondrial proteins have been reported to cause tubulointerstitial kidney diseases and focal segmental glomerulosclerosis (FSGS). Recently, genes and pathways affecting mitochondrial turnover and permeability have been implicated in adult-onset FSGS. Furthermore, dysfunctioning mitochondria may be capable of engaging intracellular innate immune-sensing pathways. To determine the impact of mitochondrial dysfunction in FSGS and secondary innate immune responses, we generated Cre/loxP transgenic mice to generate a loss-of-function deletion mutation of the complex IV assembly cofactor heme A:farnesyltransferase (COX10) restricted to cells of the developing nephrons. These mice develop severe, early-onset FSGS with innate immune activation and die prematurely with kidney failure. Mutant kidneys showed loss of glomerular and tubular epithelial function, epithelial apoptosis, and, in addition, a marked interferon response. In vitro modeling of Cox10 deletion in primary kidney epithelium compromises oxygen consumption, ATP generation, and induces oxidative stress. In addition, loss of Cox10 triggers a selective interferon response, which may be caused by the leak of mitochondrial DNA into the cytosol activating the intracellular DNA sensor, stimulator of interferon genes. This new animal model provides a mechanism to study mitochondrial dysfunction in vivo and demonstrates a direct link between mitochondrial dysfunction and intracellular innate immune response.

The effect of rutin on ovarian ischemia-reperfusion injury in a rat model

The effect of rutin on ovarian ischemia-reperfusion (I/R) injury was investigated in this experimental study. Eighteen Wistar albino female rats were divided into three groups as follows: I/R group (IRG; n = 6), 50 mg/kg rutin + I/R group (RG; n = 6), and a healthy control group scheduled for a sham operation (SG; n = 6). 2 h of ischemia and following 2 h of reperfusion were created in the IRG and RG by using a torsion model involving atraumatic vascular clips. Rutin, a flavonoid glycoside, was injected intraperitoneally at the dose of 50 mg/kg to RG group 1 h before reperfusion. Then, rats were euthanized and their ovaries were removed for biochemical and histopathological examination and also assessment of the gene expressions. IRG group had a significant increase in malondialdehyde (MDA) levels, in the expressions of tumor necrosis factor alpha (TNF-α) and interleukin 1 beta (IL-1β), and also in the activity of cyclooxygenase 2 (COX-2) unlike the significant decrease in total glutathione (tGSH) levels and the activity of COX-1 when compared to the SG group. However, rutin significantly decreased MDA levels, the expressions of TNF-α and IL-1β, and also the activity of COX-2 while it increased significantly tGSH levels and the activity of COX-1 in the RG group in comparison with the IRG group. Rutin ameliorated the I/R-induced ovarian injury in rats via its possible antioxidative and anti-inflammatory effects.

Recombinant buckwheat glutaredoxin intake increases lifespan and stress resistance via hsf-1 upregulation in Caenorhabditis elegans

Glutaredoxin (Grx) is a polypeptide with low molecular weight, which has been extracted from buckwheat and has been suggested to have multiple functions revolving around oxidative stress responses and cell signaling. Here, we report the antioxidant activity of recombinant buckwheat Grx (rbGrx) to reduce aging effects in Caenorhabditis elegans (C. elegans) as well as the mechanism involved. Our results showed that rbGrx beneficially affected the health span of C. elegans, including pharyngeal-pumping rate, locomotion, and lipofuscin accumulation. Furthermore, stress assay showed that rbGrx could extend the lifespan under both oxidative and heat stress. Further studies indicated that the longevity-extending effects of rbGrx could be attributed to its in vitro and in vivo antioxidant activities. After treatment with rbGrx, SOD activity, CAT activity, GSH content, and GSH/GSSG ratio were increased, while MDA content was decreased, which led to low intracellular levels of reactive oxygen species in C. elegans. Moreover, rbGrx up-regulated hsf-1 mRNA level and could not expand the lifespan of the hsf-1 mutant C. elegans (sy441); however, this had no effect on the transcription of daf-16 and skn-1 and could expand the lifespan of both daf-16 and skn-1 mutants. These results suggested dependency of the rbGrx effect on the heat shock transcription factor (HSF-1) and independency on both DAF-16 and SKN-1. In summary, our results demonstrated the anti-aging activity of rbGrx, which increased resistance to cellular stress and improved the health span of C. elegans. These results are very important for the use of rbGrx in anti-aging research.

Extender Supplementation with Antioxidants Selected after the Evaluation of Sperm Susceptibility to Oxidative Challenges in Goats

This study aimed to detect the most deleterious ROS for goat sperm and then supplemented the extender with a proper antioxidant. For this, 12 adult goats (aged 1-7) were used. Fresh samples were submitted to challenge with different ROS (superoxide anion, hydrogen peroxide, and hydroxyl radical) and malondialdehyde (MDA-toxic product of lipid peroxidation). After experiment 1, sperms were cryopreserved in extenders supplemented to glutathione peroxidase (Control: 0 UI/mL; GPx1: 1 UI/mL; GPx5: 5 UI/mL, and GPx10: 10 UI/mL) and catalase (Control: 0 UI/mL; CAT60: 60 UI/mL; CAT120: 120 UI/mL, and CAT240: 240 UI/mL). Each sample was evaluated by motility, plasma membrane integrity (eosin/nigrosin), acrosome integrity (fast green/rose bengal), sperm morphology, assay of the sperm chromatin structure, mitochondrial activity (3,3-diaminobenzidine), and measurement of lipid peroxidation (thiobarbituric acid reactive substances [TBARS]). It was possible to observe a mitochondrial dysfunction (DAB-Class IV) and low membrane integrity after hydrogen peroxide action. However, the high rates of TBARS were observed on hydroxyl radical. CAT240 presents the lower percentage of plasma membrane integrity. It was possible to attest that hydrogen peroxide and hydroxyl radical are the more harmful for goat sperm. Antioxidant therapy must be improving perhaps using combination between antioxidants.

Antioxidant Activity of the Essential Oil and its Major Terpenes of Satureja macrostema (Moc. and Sessé ex Benth.) Briq

BACKGROUND

The aim of this study was to investigate the in vitro antioxidant activity of Satureja macrostema (Moc. and Sessé ex Benth.) Briq. (Lamiaceae) essential oil, a Mexican medicinal plant known as nurite.

MATERIALS AND METHODS

Fresh aerial parts of S. macrostema plants cultivated in greenhouse for 3 months were subjected to hydrodistillation in a Clevenger apparatus to obtain essential oil. Volatile compounds were identified by gas chromatography (GC) and GC/mass spectrometry. Antioxidant effectiveness of essential oil and its major terpenes of S. macrostema was examined by three different radical scavenging methods: 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and total antioxidant capacity (TAC). The concentrations tested were 0.001, 0.01, 0.1, and 1 mg/mL.

RESULTS

The major volatile compounds were caryophyllene, limonene, linalool, pulegone, menthone, and thymol. S. macrostema essential oil showed the highest free radical scavenging activity with DPPH and ABTS methods (53.10% and 92.12%, respectively) at 1 mg/mL and 98% with TAC method at 0.1 mg/mL. Thymol exerted the highest antioxidant capacity with 0.1 mg/mL, reaching 83.38%, 96.96%, and 98.57% by DPPH, ABTS, and TAC methods. Caryophyllene, limonene, linalool, pulegone, and menthone exhibited an antioxidant capacity <25% with the DPPH and ABTS methods; however, limonene showed a TAC of 85.41% with 0.01 mg/mL.

CONCLUSION

The essential oil of S. macrostema and thymol showed a free radical scavenging activity close to that of the synthetic butylated hydroxytoluene.

SUMMARY

The major volatile compounds of essential oil of Satureja macrostema were caryophyllene, limonene, linalool, pulegone, menthone and thymolThe essential oil of S. macrostema showed a high free radical scavengingThymol exerted the highest antioxidant capacity by DPPH, ABTS and TAC methods. Abbreviations used: GC: Gas Chromatography; DPPH: 2,2-diphenyl-1-picrylhydrazyl; ABTS: 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid; TAC: Total antioxidant capacity.

The impact of hypoxic conditions on apoptosis and Toll-like receptor 4 expression in polymorphonuclear neutrophils

Many patients are admitted to the emergency department due to trauma. Trauma patients suffer from hypoxia due to massive hemorrhage, respiratory failure, and hypovolemic shock. Further damage is caused by reduced immune function and over-expression of inflammatory response. We conducted an experiment to determine the effects of hyperoxia and hypoxia on apoptosis and expression of Toll-like receptor 4 (TLR4) in polymorphonuclear neutrophils (PMNs). Initially, the PMNs were placed in normoxic and hypoxic conditions, and these PMNs were divided into two groups as stimulated or not stimulated with lipopolysaccharide (LPS). Levels of apoptosis and TLR4 expression were measured under normoxic, hypoxic, and hyperoxic conditions. Apoptosis decreased in the hypoxic group than in the normoxic group. With LPS stimulation, apoptosis was decreased in all three treatment groups and even more reduced in the hypoxic group. TLR4 expression increased in all three treatment groups with LPS stimulation, increased further in the hypoxic group, and to a lesser degree in the hyperoxic group. Unlike the cells exposed to hypoxic conditions, the cells exposed to the hyperoxic condition reacted similarly to the cells in the control (normoxic) group. Therefore, the inflammatory reactions can be stronger in the hypoxic group than in the other two groups.

The non-stop decay mRNA surveillance pathway is required for oxidative stress tolerance

Reactive oxygen species (ROS) are toxic by-products of normal aerobic metabolism. ROS can damage mRNAs and the translational apparatus resulting in translational defects and aberrant protein production. Three mRNA quality control systems monitor mRNAs for translational errors: nonsense-mediated decay, non-stop decay (NSD) and no-go decay (NGD) pathways. Here, we show that factors required for the recognition of NSD substrates and components of the SKI complex are required for oxidant tolerance. We found an overlapping requirement for Ski7, which bridges the interaction between the SKI complex and the exosome, and NGD components (Dom34/Hbs1) which have been shown to function in both NSD and NGD. We show that ski7 dom34 and ski7 hbs1 mutants are sensitive to hydrogen peroxide stress and accumulate an NSD substrate. We further show that NSD substrates are generated during ROS exposure as a result of aggregation of the Sup35 translation termination factor, which increases stop codon read-through allowing ribosomes to translate into the 3΄-end of mRNAs. Overexpression of Sup35 decreases stop codon read-through and rescues oxidant tolerance consistent with this model. Our data reveal an unanticipated requirement for the NSD pathway during oxidative stress conditions which prevents the production of aberrant proteins from NSD mRNAs.

Oxidative toxicity in diabetes and Alzheimer's disease: mechanisms behind ROS/ RNS generation

Reactive oxidative species (ROS) toxicity remains an undisputed cause and link between Alzheimer’s disease (AD) and Type-2 Diabetes Mellitus (T2DM). Patients with both AD and T2DM have damaged, oxidized DNA, RNA, protein and lipid products that can be used as possible disease progression markers. Although the oxidative stress has been anticipated as a main cause in promoting both AD and T2DM, multiple pathways could be involved in ROS production. The focus of this review is to summarize the mechanisms involved in ROS production and their possible association with AD and T2DM pathogenesis and progression. We have also highlighted the role of current treatments that can be linked with reduced oxidative stress and damage in AD and T2DM.

Mitochondrial energetics in the kidney

The kidney requires a large number of mitochondria to remove waste from the blood and regulate fluid and electrolyte balance. Mitochondria provide the energy to drive these important functions and can adapt to different metabolic conditions through a number of signalling pathways (for example, mechanistic target of rapamycin (mTOR) and AMP-activated protein kinase (AMPK) pathways) that activate the transcriptional co-activator peroxisome proliferator-activated receptor-γ co-activator 1α (PGC1α), and by balancing mitochondrial dynamics and energetics to maintain mitochondrial homeostasis. Mitochondrial dysfunction leads to a decrease in ATP production, alterations in cellular functions and structure, and the loss of renal function. Persistent mitochondrial dysfunction has a role in the early stages and progression of renal diseases, such as acute kidney injury (AKI) and diabetic nephropathy, as it disrupts mitochondrial homeostasis and thus normal kidney function. Improving mitochondrial homeostasis and function has the potential to restore renal function, and administering compounds that stimulate mitochondrial biogenesis can restore mitochondrial and renal function in mouse models of AKI and diabetes mellitus. Furthermore, inhibiting the fission protein dynamin 1-like protein (DRP1) might ameliorate ischaemic renal injury by blocking mitochondrial fission.

Biological Relevance of Free Radicals and Nitroxides

Nitroxides are stable, kinetically-persistent free radicals which have been successfully used in the study and intervention of oxidative stress, a critical issue pertaining to cellular health which results from an imbalance in the levels of damaging free radicals and redox-active species in the cellular environment. This review gives an overview of some of the biological processes that produce radicals and other reactive oxygen species with relevance to oxidative stress, and then discusses interactions of nitroxides with these species in terms of the use of nitroxides as redox-sensitive probes and redox-active therapeutic agents.