Reactive oxygen species (ROS) and aging: Do we need them — can we measure them — should we block them?

The Over-Irradiation Metabolite Derivative, 24-Hydroxylumister-ol3, Reduces UV-Induced Damage in Skin

The hormonal form of vitamin D₃, 1,25(OH)₂D₃, reduces UV-induced DNA damage. UV exposure initiates pre-vitamin D₃ production in the skin, and continued UV exposure photoisomerizes pre-vitamin D₃ to produce "over-irradiation products" such as lumisterol₃ (L₃). Cytochrome P450 side-chain cleavage enzyme (CYP11A1) in skin catalyzes the conversion of L₃ to produce three main derivatives: 24-hydroxy-L₃ [24(OH)L₃], 22-hydroxy-L₃ [22(OH)L₃], and 20,22-dihydroxy-L₃ [20,22(OH)L₃]. The current study investigated the photoprotective properties of the major over-irradiation metabolite, 24(OH)L₃, in human primary keratinocytes and human skin explants. The results indicated that treatment immediately after UV with either 24(OH)L₃ or 1,25(OH)₂D₃ reduced UV-induced cyclobutane pyrimidine dimers and oxidative DNA damage, with similar concentration response curves in keratinocytes, although in skin explants, 1,25(OH)₂D₃ was more potent. The reductions in DNA damage by both compounds were, at least in part, the result of increased DNA repair through increased energy availability via increased glycolysis, as well as increased DNA damage recognition proteins in the nucleotide excision repair pathway. Reductions in UV-induced DNA photolesions by either compound occurred in the presence of lower reactive oxygen species. The results indicated that under in vitro and ex vivo conditions, 24(OH)L₃ provided photoprotection against UV damage similar to that of 1,25(OH)₂D₃.

Growth Hormone Stimulates Murine Macrophage Migration during Aging

BACKGROUND

Age-related impairments in macrophage functions have important consequences for the health of the elderly population. The aging process is also accompanied by a reduction in several hormones, including growth hormone (GH). Previous studies have shown that this hormone can affect macrophage activity in young individuals; however, the biological effects of GH stimulation on macrophages during aging have not yet been elucidated.

OBJECTIVE

The aim of this work was to investigate the in vitro effects of GH on peritoneal macrophages from aged mice.

METHODS

Peritoneal macrophages isolated from young (4 months-old) and old (12-15 months-old) mice were treated in vitro with 100 ng/mL of GH for 24 hours. After treatment, cells were analysed for cell morphology, reactive oxygen species (ROS) production, expression of integrins, cell adhesion to extracellular matrix molecules, and migration in transwell chambers.

RESULTS

Although GH-treated cells from old mice exhibited decreased ROS production, we did not observe the effects of GH on macrophage morphology or macrophage phagocytic activity in young and old mice-derived cell cultures. Macrophages from old mice had increased adhesion to laminin and fibronectin substrates, as did cells obtained from young mice treated with GH, but no change was observed in the expression of integrin receptors. Furthermore, cells from old mice exhibited increased migration compared to young mice and a significant increase in macrophage migration was observed under GH stimulation.

CONCLUSION

Our results showed that GH can interfere with the motility of macrophages from old mice, advancing our understanding of the interactions between the immune and neuroendocrine systems during aging.

Improvement on blood pressure and skin using roselle drink: A clinical trial

Roselle (Hibiscus sabdariffa L.) is an increasingly attractive plant for its health and pharmaceutical, beverage, and cosmetic applications. The purpose of this study was to investigate the clinical effects of roselle drink on antioxidant activity, blood pressure, and skin condition. Roselle drink used in this study contained rich phenolics (1.96 g of gallic acid equivalent/100 ml) and anthocyanins (1.65 g of cyanidin-3-glucoside equivalent/100 ml). In a randomized, cross-over, double-blind, placebo-controlled clinical study, 39 healthy adults received drank 200 ml of roselle drink or placebo-control drink for 6 months. A significant reduction in the blood pressure was observed in the roselle drink treated group when compared with preintervention values. After 6 months of treatment with roselle drink, serum phenolics contents, the levels of Trolox equivalent antioxidant capacity (TEAC), glutathione, superoxide dismutase (SOD), glucose-6-phosphate dehydrogenase (G-6-PDH), glutathione peroxidase (GSH-Px), and glutathione reductase (GSH-Rd) were significantly increased in healthy subjects. However, a significant increment in skin redness and skin moisture was observed in the facial skin of roselle drink-treated participants. Oral administration of roselle drink for 6 months significantly lowered the blood pressure, improved antioxidation level, and positively regulated skin redness as well as moisture. Phenolics and anthocyanins in roselle could be the major potential contributors to such health effects. PRACTICAL APPLICATIONS: Roselle is a typical plant. Continuous administration of roselle drink clearly improved antioxidation levels, reduced blood pressure and positively regulated skin redness and moisture. Phenloics and anthocyanins in roselle could be the major potentila contributors of such health benefits.

Nanocomposites containing titanium dioxide for environmental remediation

Titania is considered to be one of the most versatile material in its nanoform. Scientific community looks towards it to address various pressing global problems. One such problem is aquatic pollution arising from organic chemicals such as dyes, pesticides, antibiotics etc. due to industrial, domestic and agricultural activities. Titania proves to be very effective to address this problem owing to its superior photocatalytic properties. In this review, we will review the recent advances in titania-based nanocomposites. The recent advances discussed in this review include synthesis of titania, modification of titania, exploration of various supports such as silica, carbon, graphene etc., that is documented to enhance its environmental remediation properties.

Protection from Ultraviolet Damage and Photocarcinogenesis by Vitamin D Compounds

Exposure of skin cells to UV radiation results in DNA damage, which if inadequately repaired, may cause mutations. UV-induced DNA damage and reactive oxygen and nitrogen species also cause local and systemic suppression of the adaptive immune system. Together, these changes underpin the development of skin tumours. The hormone derived from vitamin D, calcitriol (1,25-dihydroxyvitamin D₃) and other related compounds, working via the vitamin D receptor and at least in part through endoplasmic reticulum protein 57 (ERp57), reduce cyclobutane pyrimidine dimers and oxidative DNA damage in keratinocytes and other skin cell types after UV. Calcitriol and related compounds enhance DNA repair in keratinocytes, in part through decreased reactive oxygen species, increased p53 expression and/or activation, increased repair proteins and increased energy availability in the cell when calcitriol is present after UV exposure. There is mitochondrial damage in keratinocytes after UV. In the presence of calcitriol, but not vehicle, glycolysis is increased after UV, along with increased energy-conserving autophagy and changes consistent with enhanced mitophagy. Reduced DNA damage and reduced ROS/RNS should help reduce UV-induced immune suppression. Reduced UV immune suppression is observed after topical treatment with calcitriol and related compounds in hairless mice. These protective effects of calcitriol and related compounds presumably contribute to the observed reduction in skin tumour formation in mice after chronic exposure to UV followed by topical post-irradiation treatment with calcitriol and some, though not all, related compounds.

Metabolomic Profiling Reveals the Difference on Reproductive Performance between High and Low Lactational Weight Loss Sows

Sows suffering excess weight loss during lactation may delay weaning to estrus interval (WEI) and have a detrimental effect on subsequent reproductive performance, however, the underlying mechanism is not completely clear. Therefore, the goal of this study was to investigate physiological profiles manifested in plasma originating from high (HWL) and low lactational weight loss (LWL) sows. The plasma biochemical parameters, hormones, antioxidant parameters, and milk compositions were assessed. Furthermore, plasma metabolites were analyzed using ultrahigh-performance liquid chromatography/time-of-flight mass spectrometry in positive and negative ion modes. Results showed that HWL sows had a lower feed intake and higher lactational weight loss and prolonged WEI, but had similar litter performance and milk composition compared to LWL sows. These changes were associated with lower plasma insulin-like growth factor 1 and higher fibroblast growth factor 21 levels in the HWL sows. Moreover, HWL led to a severe oxidative stress and metabolic damage, as accompanied by excessive protein breakdown and lipids mobilization at weaning. Metabolomic analysis revealed differences in 46 compounds between HWL and LWL sows, and the identified compounds were enriched in metabolic pathways related to amino acids metabolism, fatty acids oxidation metabolism, bile acids biosynthesis, and nucleoside metabolism. These results provide the evidence for physiological mechanism in sows with excessive lactational weight loss that delayed the WEI. Metabolomic data provides essential information and gives rise to potential targets for the development of nutritional intervention strategies.

The effects of inflammation, aging and oxidative stress on the pathogenesis of diabetes mellitus (type 2 diabetes)

Diabetes mellitus is seen to be prevalent among the different epidemics. The prevalence rate of the diabetes mellitus is seen to be increasing in different regions of the world. Type 2 diabetes mellitus is the most common form of the disease that causes the defect in the production of insulin. It is associated with the disruption in the metabolism of fat, proteins and carbohydrates. Different complications that are associated with T2DM includes the retinopathy, neuropathy, nephropathy and weakness and other issues. Due to the loss of the function of the insulin, the metabolism is disturbed. . It is needed to consider the effects of inflammation aging and the oxidative stress on the diabetes mellitus. Therefore this review has dealt with this particular issue in great detail. The predominant aim of this review was to evaluate the effects of inflammation aging and oxidative stress on the T2DM. It was achieved through correlating and comparing the studies of different researchers. This review article has reviewed this topic in great detail considering the different researches related to the inflammation aging, oxidative stress and their impact on the diabetes mellitus.

ROS-Responsive Biomaterial Design for Medical Applications

Stimuli-responsive biomaterials undergo significant alterations in material structure and property in response to changes of local environmental factors (e.g. pH, temperature, enzyme activation, and water absorption). In particular, reactive oxygen species (ROS) is considered as a major stimulus because over-production of ROS involves most types of major pathogenesis. The application of ROS-responsive biomaterials requires suitable material designs to program user-defined changes of their structure and property in response to a sudden change in the local ROS level. This chapter summarizes the progress in designing and applying major types of ROS-responsive biomaterials within the past 10 years.

Systematic evaluation of bioactive components and antioxidant capacity of some new and common bayberry cultivars using an in vitro gastrointestinal digestion method

This study was aimed to investigate the impact of in vitro gastrointestinal digestion on some common and new bayberry cultivars. The contents of total phenolics (246-669mg gallic acid equivalents/kg FW (fresh weight)), flavonoids (116-689mg quercetin-3-O-rutinoside equivalents/kg FW), procyanidins (28-133mg catechin equivalents/kg FW) and anthocyanins (1-7mg cyaniding-3-O-glucoside equivalents/kg FW) were detected in digested cultivars. HPLC-TOF-MS analysis identified 17 phenolic compounds in digested sample. Among all digested cultivars, the new cultivars Anhaizaomei (ABTS, IC₅₀=2.95mg/mL; FRAP, 401.32mg vitamin C equivalents (VCE)/kg FW) and Yingsi (ABTS, IC₅₀=3.28mg/mL; FRAP, 400.81mg VCE/kg FW) showed better in vitro antioxidant capacity. Further cellular assay indicated that the common cultivar Dongkui (2mg/mL) possessed the strongest ROS scavenging activity. The comprehensive evaluation of bioactive components and antioxidant properties using principal component analysis suggests that common cultivar Dongkui, new cultivars Yingsi and Anhaizaomei could be considered as dietary supplements.

Effect of social ranks and gestation housing systems on oxidative stress status, reproductive performance, and immune status of sows

Ninety-six multiparous sows were randomly assigned into 2 different gestation housing systems on d 35 of gestation: individual gestational crates (n = 24) or small groups with 3 sows in gestational pens (n = 24). Sows were classified into 4 treatments based on gestation housing systems and social ranks within each gestational pen: sows housed in individual gestational crates were in control treatment (CON), and sows destined to high, middle, or low social ranks within each pen were classified into high social rank treatment (HR), middle social rank treatment (MR), and low social rank treatment (LR). The social rank of sows within a pen was determined by their winning percentage during aggressive interactions observed for a 4-d period after mixing on d 35 of gestation. Plasma samples collected from each sow on d 35, 60, 90, and 109 of gestation and d 1 and 18 of lactation were used to determine concentrations of malondialdehyde (MDA), protein carbonyls, 8-hydroxy-deoxyguanosine (8-OHdG), IgG, and IgM. Sows in HR had higher (P < 0.05) body weight during gestation and lactation, smallest (P < 0.05) litter weight at birth, increased (P < 0.05) number of stillborn than sows in MR and LR, and tended to have decreased (P = 0.073, P = 0.064) number of born alive compared with sows in CON and LR. Sows in LR had lower farrowing rate compared with sows in MR. Plasma concentration of protein carbonyl in HR was higher (P < 0.05) than that in MR on d 3 of lactation. Plasma concentrations of 8-OHdG in LR was greater (P < 0.05) than that in HR on d 90 of gestation, d 3 and 18 of lactation, and greater (P < 0.05) than CON on d 18 of lactation. The reproductive performance of sows from all of the social ranks was related to their oxidative stress status during gestation and lactation. Collectively, the reproductive performance, oxidative stress status, and immune status did not differ between sows housed in gestational crates (CON) and pens (HR + MR + LR). Sows in CON and MR did not show inferior reproductive performance during gestation and lactation. Sows in HR and LR had increased oxidative damage during late gestation and lactation which could contribute to the reduced litter size and litter weight in HR and lower farrowing rate in LR.

Zinc oxide nanoflowers make new blood vessels

It is well established that angiogenesis is the process of formation of new capillaries from pre-existing blood vessels. It is a complex process, involving both pro- and anti-angiogenic factors, and plays a significant role in physiological and pathophysiological processes such as embryonic development, atherosclerosis, post-ischemic vascularization of the myocardium, tumor growth and metastasis, rheumatoid arthritis etc. This is the first report of zinc oxide (ZnO) nanoflowers that show significant pro-angiogenic properties (formation of new capillaries from pre-existing blood vessels), observed by in vitro and in vivo angiogenesis assays. The egg yolk angiogenesis assay using ZnO nanoflowers indicates the presence of matured blood vessels formation. Additionally, it helps to promote endothelial cell (EA.hy926 cells) migration in wound healing assays. Formation of reactive oxygen species (ROS), especially hydrogen peroxide (H(2)O(2))-a redox signaling molecule, might be the plausible mechanism for nanoflower-based angiogenesis. Angiogenesis by nanoflowers may provide the basis for the future development of new alternative therapeutic treatment strategies for cardiovascular and ischemic diseases, where angiogenesis plays a significant role.

Reactive oxygen species driven angiogenesis by inorganic nanorods

The exact mechanism of angiogenesis by europium hydroxide nanorods was unclear. In this study we have showed that formation of reactive oxygen species (H(2)O(2) and O(2)·-) is involved in redox signaling pathways during angiogenesis, important for cardiovascular and ischemic diseases. Here we used single-walled carbon nanotube sensor array to measure the single-molecule efflux of H(2)O(2) and a HPLC method for the determination of O(2)·- from endothelial cells in response to proangiogenic factors. Additionally, reactive oxygen species-mediated angiogenesis using inorganic nanorods was observed in transgenic (fli1a:EGFP) zebrafish embryos.

The carboxyproxyl-derived spin trap (CP-H) is an appropriate detector-compound for oxidative stress

Reperfusion of ischemic tissue disturbs the balance between reactive oxygen species (ROS) and the cellular antioxidative defense. This imbalance is known as oxidative stress. In this study the spin trap 3-carboxy-2,2,5,5-tetramethylpyrrolin-1-hydroxide (CP-H) with its ESR-detectable paramagnetic analogue 3-carboxy-2,2,5,5-tetramethylpyrrolin-1-oxyl (*CP) was analyzed in vitro and in vivo. In preliminary in vitro experiments we studied the interaction of CP-H with reactive compounds like hydroxyl radicals (*OH) and alkylperoxyl radicals (ROO*) which are formed during organ reperfusion or tissue reoxygenation. The increase in the peak intensity of the ESR signal of the *CP-radical was used as a measure for CP-H oxidation by the above-mentioned oxidizing radicals. It could be clearly shown that *OH as well as ROO* induce CP-H oxidation. The intensity of the ESR signal (*CP) depends on the concentration of the applied oxidant. In a further set of in vitro experiments we analyzed some factors influencing the stability of the generated *CP. Cellular reductants are able to interact with many radicals whereby their paramagnetic signal intensity decreases. We could show that glutathione (GSH) up to 5 mM does not influence *CP concentration. On the other hand, ascorbate at a concentration of 0.6 mM significantly reduces 55% of *CP within 60 min to the ESR-silent CP-H. At 1 mM ascorbate the *CP derived ESR signal is reduced within 60 min by 90%. Lower concentrations of ascorbate (0.1-0.3 mM) do not significantly decrease signal intensity within 1 h. Homogenization of ischemic rat kidney in the presence of an air-equilibrated buffer obviously induces the formation of oxidizing radicals which in turn are able to convert diamagnetic CP-H into paramagnetic *CP. The intensity of the formed *CP was analyzed in a 600 g supernatant with ESR spectroscopy at 25 degrees C. It could be demonstrated that at least 3.0 +/- 0.5 microM *CP is formed 15 min after starting tissue homogenization and reoxygenation. Subsequent measurements of the *CP concentration indicated that its signal intensity continuously decreases. After 75 min a residual *CP concentration of 0.7 +/- 0.3 microM was monitored. Removal of mitochondria from the homogenate by centrifugation at 6,000g decelerates the disappearance of *CP but does not block it completely. In summary it could be shown that the marker (CP-H) is able to indicate the formation of oxidizing radicals during reoxygenation of ischemic tissue. This method underestimates the amount of produced oxidizing radicals. One reason for this is the reduction of *CP by some cellular reductants. Other reasons will be discussed. We assume that the used method allows a nearly real-time determination of radical production during organ reoxygenation.

Aggregation and toxicity of titanium dioxide nanoparticles in aquatic environment--a review

The use of nanoparticles--particles with size approximately 1-100 nm is increasing worldwide. This is particularly the case for applications of titanium dioxide nanoparticles (nano-TiO(2)) in consumer products, which have expanded at a fast rate in the last decade. The properties of nano-TiO(2) differ significantly from bulk-TiO(2) of the same composition because of an increase in surface area. A release of nano-TiO(2) from application sources to the aquatic environment may pose possible risks due to their bioavailability and toxicity. The aggregation of nano-TiO(2) plays an important role in the environmental effects of nanoparticles because the size and shape of nanoparticles will determine the magnitude of any potentially toxic effect. Aggregation is affected by pH, ionic strength, and ionic identity (inorganic and organic) of aqueous suspensions and is reviewed in this paper. The current information on the evaluation of ecotoxicological hazards of nano-TiO(2) to bacteria, algae, invertebrates, nematodes, and rainbow trout is also given.

Cytotoxicity of titanium dioxide nanoparticles in mouse fibroblast cells

Nanotitanium dioxide (TiO2) is an important industrial material that is widely used as an additive in cosmetics, pharmaceuticals, and food colorants. Although the small size of the TiO2 nanoparticle is useful in various applications, the biosafety of this material needs to be evaluated. In this study, mouse fibroblast (L929) cells were used to evaluate the cytotoxicity of different concentrations (3-600 microg/mL) of homogeneous and weakly aggregated TiO2 nanoparticles in aqueous solution. The L929 cells became round and even shrank as the concentration of TiO2 nanoparticles increased. Moreover, TiO2 nanoparticle-treated cells had condensed fragmented chromatin or were directly necrosed, as observed by acridine orange (AO) staining. The transmission electron microscopy (TEM) analysis showed that in cells cultured in a medium containing 300 microg/mL TiO2, the number of lysosomes increased, and some cytoplasmic organelles were damaged. In addition, there was a significant increase in oxidative stress at higher TiO2 nanoparticle concentrations (>60 microg/mL). As the concentration of TiO2 nanoparticles increased in the culture medium, the levels of reactive oxygen species (ROS) and lactate dehydrogenase (LDH) increased, while those of methyl tetrazolium cytotoxicity (MTT), glutathione (GSH), and superoxide dismutase (SOD) decreased. A possible mechanism for the cytotoxicity of TiO2 nanoparticles is also discussed.

Potential biomarkers of ageing

Life span in individual humans is very heterogeneous.Thus, the ageing rate, measured as the decline of functional capacity and stress resistance, is different in every individual. There have been attempts made to analyse this individual age, the so-called biological age, in comparison to chronological age. Biomarkers of ageing should help to characterise this biological age and, as age is a major risk factor in many degenerative diseases,could be subsequently used to identify individuals at high risk of developing age-associated diseases or disabilities. Markers based on oxidative stress, protein glycation,inflammation, cellular senescence and hormonal deregulation are discussed.

DCFH2 interactions with hydroxyl radicals and other oxidants--influence of organic solvents

The oxidation of 2',7'-dichlorofluorescin (DCFH(2)) is widely used as a measure to detect the generation of reactive oxygen species (ROS) and to analyze oxidative stress. Other factors beside commonly known radicals may influence the results of such measurements. Therefore, the effects of H(2)O(2), KMnO(4,) decomposition products of AAPH, ethanol and DMSO, antioxidants like ascorbic acid, different ferrous ion chelates, and heme-containing proteins like cytochrome c, myoglobin, hemoglobin, and horseradish-peroxidase were comparatively analyzed with respect to their impact on DCFH(2) oxidation. The study evaluates the effects of various oxidants with different oxidative potentials regarding their ability to induce DCF-fluorescence. Furthermore, we analyzed the inhibitory effect of organic solvents like ethanol or DMSO on the oxidation of DCFH(2) by hydroxyl radicals. The results of our study indicate that the potential of an oxidant does not always correlate with its efficiency to generate DCF-fluorescence.