Creatine supplementation exacerbates ethanol-induced hepatic damage in mice.

OBJECTIVE: The aim of this study was to investigate the effects of creatine supplementation on early stages of ethanol-induced hepatic damage. METHODS: Male Swiss mice were divided into three groups (n = 12/group): control (C), ethanol (E), and ethanol supplemented with creatine (EC). The control group received a diet containing 15.8% of total calories from proteins, 46.3% from carbohydrates, and 37.9% from lipids. The ethanol and ethanol and creatine groups received diets containing 15.8% of total calories from proteins, 16.2% from carbohydrates, and 34.5% from lipids; the remaining calories were obtained from the addition of 5% of 95% ethanol. Creatine (1%; weight/vol) was added to the diet of EC mice. After 14 and 28 d, six animals from each group were sacrificed, generating subdivisions in each group: C14 and C28, E14 and E28, EC14 and EC28. After sacrifice, the liver was removed, weighed, and prepared for histologic, biochemical, and molecular analysis, and blood was collected. RESULTS: Ethanol intake induced mild cell degeneration, liver damage, oxidative lesions, and inflammation. Surprisingly, ethanol intake combined with creatine exacerbated cell degeneration and fat accumulation, hepatic expression of genes related to ethanol metabolism, oxidative stress and inflammation, and promoted oxidative stress and elevated plasma alanine aminotransferase (P < 0.05). CONCLUSION: Creatine supplementation associated with ethanol is able to interfere in the alcohol metabolism and oxidative stress and to exacerbate ethanol-induced hepatic damage. These new findings are opposite to those observed in several studies where protective effects of creatine in a wide variety of injury models, including non-alcoholic fatty liver disease, were described.

Short infusion of paclitaxel imbalances plasmatic lipid metabolism and correlates with cardiac markers of acute damage in patients with breast cancer.

PURPOSE: Although paclitaxel-based chemotherapy is widely used for treating breast cancer, paclitaxel therapy has been associated with several adverse effects. Such adverse effects have primarily been associated with long-term regimens, but some acute effects are being increasingly reported in the literature. In this context, the present study analyzed the systemic proteomic profiles of women diagnosed with breast cancer at the first cycle of short paclitaxel infusion (n = 30). Proteomic profiles thus obtained were compared with those of breast cancer patients without chemotherapy (n = 50), as well as with those of healthy controls (n = 40). METHODS: Plasma samples were evaluated by label-free LC-MS to obtain systemic proteomic profiles. Putative dysregulated pathways were identified and validated by in silico analysis of proteomic profiles. RESULTS: Our results identified 188 proteins that were differentially expressed in patients who received a single short paclitaxel infusion when compared to patients who did not receive the infusion. Gene ontology analysis indicated that the cholesterol pathway may be dysregulated by paclitaxel in these patients. Validation analysis showed that paclitaxel treatment significantly reduced plasma high-density lipoprotein levels and increased plasma hydroperoxide levels when compared to breast cancer patients without chemotherapy. Furthermore, augmented C-reactive protein and creatine kinase fraction MB were found to be significantly higher in paclitaxel-treated patients in comparison with healthy controls. CONCLUSIONS: Taken together, these data suggest that a single dose of short paclitaxel infusion is sufficient to trigger significant alterations in lipid metabolism, which puts breast cancer patients at risk for increased incidence of cardiovascular disease.

Can Breast Tumors Affect the Oxidative Status of the Surrounding Environment? A Comparative Analysis among Cancerous Breast, Mammary Adjacent Tissue, and Plasma.

In this paper, we investigated the oxidative profile of breast tumors in comparison with their normal adjacent breast tissue. Our study indicates that breast tumors present enhanced oxidative/nitrosative stress, with concomitant augmented antioxidant capacity when compared to the adjacent normal breast. These data indicate that breast cancers may be responsible for the induction of a prooxidant environment in the mammary gland, in association with enhanced TNF-α and nitric oxide.

Trastuzumab-based chemotherapy modulates systemic redox homeostasis in women with HER2-positive breast cancer.

Trastuzumab is an immunotargeting therapeutic against breast tumors with amplification of the human epithelial growth factor receptor 2 (HER2). HER2 patients naturally exhibit disruption in the pro-oxidant inflammatory profiling; however, the impact of trastuzumab-based chemotherapy in modulating this process is still unknown. Here we determined the systemic pro-inflammatory profile of women diagnosed with HER2-amplified tumors, undergoing trastuzumab-based chemotherapy (TZ), and compared the results with that of healthy controls (CTR) and untreated patients with HER2-amplified breast cancer (CA). The plasmatic inflammatory profile was assessed by evaluating pro-oxidant parameters such as lipid peroxidation, total antioxidant capacity (TRAP), levels of advanced oxidation protein products (AOPPs), nitric oxide (NO), C-reactive protein (CRP), and total thiol content. Markers of cardiac damage were also assessed. Our findings showed increased NO levels in TZ than that in either CA or CTR groups. Furthermore, TZ augmented TRAP and reduced total thiol than that of the CA group. Our data also revealed that AOPP levels were significantly higher in the TZ than the CA group. AOPP and the MB fraction of creatine-kinase (CKMB) levels were positively correlated in TZ patients. These findings suggest that trastuzumab-associated chemotherapy can modulate the pro-inflammatory markers of HER2-positive breast cancer patients to the levels found in healthy controls.

Genistein prevents ultraviolet B radiation-induced nitrosative skin injury and promotes cell proliferation.

Nitric oxide (NO) levels increase considerably after 24h of exposure of skin to ultraviolet B (UVB) radiation, which leads to nitrosative skin injury. In addition, increased NO levels after exposure to UVB radiation are associated with inhibition of cell proliferation. Compared to the UV-control group, UV-genistein at 10 mg/kg (UV-GEN10) group showed tissue protection, decreased lipid peroxide and nitrotyrosine formation, and low CAT activity. Furthermore, NO levels and iNOS labeling remained high. In this group, the reduction in lipid peroxides and nitrotyrosine was accompanied by upregulation of cell proliferation factors (Ki67 and PCNA), which indicated that prevention of nitrosative skin injury promoted cell proliferation and DNA repair. Genistein also prevented nitrosative events, inhibited ONOO(-) formation, which leads to tissue protection and cell proliferation. The UV-GEN15 group did not result in a greater protective effect compared to that with UV-GEN10 group. In the UV-GEN15 group, histological examination of the epidermis showed morphological alterations without efficient protection against lipid peroxide formation, as well as inhibition of Ki67 and PCNA, and VEGF labeling, which suggested inhibition of cell proliferation. These results help to elucidate the mechanisms underlying the photoprotective effect of genistein and reveal the importance of UVB radiation-induced nitrosative damage.

Oxidative and proteolytic profiles of the right and left heart in a model of cancer-induced cardiac cachexia.

Cardiac cachexia is a syndrome that has received increased attention in recent years. Although an association between proteolysis and cardiac cachexia has been proposed, the direct influence of oxidative stress on the process has not been demonstrated. In the present study, the right (RH) and left (LH) hearts (atrium and ventricle of each side of the heart) were collected from rats at the 5th and 10th days after phosphate buffer (control) orWalker-256 solid tumour implantation. Immediately after sacrifice, cachexia was determined in tumour-bearing animals by the formula: [(inicial body weight-final body weight+tumour weight+weight gain of control group)/(initial body weight+body mass gain of control group)]×100%; RH and LH were stored until use. Oxidative stress and proteolysis were determined in each collected sample. In addition, heart samples were collected from a separate set of animals to determine the thickness of the left and right ventricles. Cachexia values increased over time after tumour implantation from 6.85% at the 5th day to 17.76% at the 10th day. There was no significant difference in LH wet weight and ventricle thickness compared with the control, where as RH wet weight (0.109±0.09g at the 5th day and 0.093±0.09g at the 10th day) and thickness (420±16µm at the 5th day and 279±08µm at the 10th day) were significantly decreased at both time points when compared with control values (0.153±0.06g and 607±21µm, respectively). tert-Butyl-stimulated chemiluminescence analysis revealed a significant increase in the LH and decrease in the RH oxidative stress profiles. Carbonylated proteins increased in the LH (140%, p<0.05) and RH (100%, p<0.05) at the 5th day, and significantly decreased in both sides on the 10th day compared to controls. Chemotrypsin-like, caspase-like, and calpain-like activities were evaluated by chemiluminescence, and only calpain-like activity was found to increase at the 5th day in the RH. In the LH, all proteolytic activities systems were decreased when compared with controls. Together, these results demonstrate that oxidative stress appears to play a different role in mass modulation on the LH and RH. The proteolytic systems evaluated herein also appear to have different effects on the responses developed during cardiac cachexia in the two sides of the heart.

Hypertension is associated with serologically active disease in patients with systemic lupus erythematosus: role of increased Th1/Th2 ratio and oxidative stress.

OBJECTIVES: To determine whether disease activity verified by laboratorial parameters is associated with a higher frequency of hypertension in patients with systemic lupus erythematosus (SLE) without renal impairment and to investigate factors that could influence this hypertension. METHOD: This study included 102 controls, 70 patients with inactive SLE, and 53 patients with active SLE without renal impairment. We evaluated T helper type 1 (Th1)/Th2 lineage cytokines, nitric oxide (NO), insulin resistance (IR), and oxidative stress. RESULTS: Patients with active SLE had a higher probability of developing hypertension compared to controls [odds ratio (OR) 3.833, 95% confidence interval (CI) 1.806-8.137, p < 0.0003] and patients with inactive SLE (OR 2.215, 95% CI 1.032-4.752, p = 0.0394). Active SLE patients had a higher interleukin (IL)-12/IL-4 ratio (p < 0.05) than both controls and inactive SLE patients. Protein oxidation was significantly higher in patients with active SLE than in the control group and in patients with inactive SLE (p < 0.01 and p < 0.05, respectively). Multivariate analysis revealed an association between the presence of hypertension and he levels of glucose (p = 0.0276), insulin (p = 0.0498), hydroperoxides (p = 0.0221), IFN-γ (p = 0.0494), IL-17 (p = 0.0272), IL-12/IL-10 (p = 0.0373), IFN-γ/IL-10 (p = 0.0142), IFN-γ/IL-4 (p = 0.0320), and adiponectin (p = 0.0433). CONCLUSIONS: Patients with active SLE without renal impairment had an increased frequency of high blood pressure (43.4%) compared with patients with inactive SLE (25.7%) and controls (16.7%). Hypertension was associated with serologically active disease and was influenced by an increased Th1/Th2 ratio and oxidative stress.

Clinical insights from adiponectin analysis in breast cancer patients reveal its anti-inflammatory properties in non-obese women.

Adiponectin is a cytokine reported as a determinant of poor prognosis in women with breast cancer. However, because data regarding its role in breast cancer have been obtained primarily from studies employing overweight or obese women, the adiponectin profile in non-obese women is poorly understood. In this study, we determined adiponectin levels in plasma from non-obese women with breast cancer and investigated a possible correlation with systemic inflammatory status. We determined the plasma adiponectin levels as well as biochemical and oxidative stress parameters in 80 women. Our results revealed that plasma adiponectin levels were affected by chemotherapy, estrogen receptor status, and disease progression. Adiponectin was positively correlated with antioxidant levels, without affecting either the metastatic behavior of disease or patient outcome. These findings highlight adiponectin as a novel player in the endocrine signaling that modulates the oxidative inflammatory response in human breast cancer, and contribute to the understanding of the role of adiponectin in pathological conditions in non-obese women.

Relationship between iron metabolism, oxidative stress, and insulin resistance in patients with systemic lupus erythematosus.

OBJECTIVE: The aim of the present study was to assess oxidative stress and iron metabolism in systemic lupus erythematosus (SLE) patients with and without insulin resistance (IR). METHOD: This study included 236 subjects (125 controls and 111 SLE patients). Patients with SLE were divided in two groups: with (n = 72) or without (n = 39) IR. RESULTS: SLE patients with IR showed higher advanced oxidation protein product (AOPP) levels (p = 0.030) and gamma-glutamyltransferase (GGT) levels (p = 0.001) and lower sulfhydryl groups of proteins (p = 0.0002) and total radical-trapping antioxidant parameter (TRAP) corrected by uric acid (UA) levels (p = 0.04) when compared to SLE patients without IR. However, SLE patients with IR presented lower serum 8-isoprostane (p = 0.05) and carbonyl protein levels (p = 0.04) when compared to SLE patients without IR. Serum ferritin levels were significantly higher in SLE patients (p = 0.0006) than in controls, and SLE patients with IR presented higher serum ferritin levels (p = 0.01) than SLE patients without IR. Patients with SLE showed that IR was inversely correlated to TRAP/UA (r = -0.2724, p = 0.0008) and serum ferritin was positively correlated to AOPP (r = 0.2870, p = 0.004). CONCLUSIONS: This study found that oxidative stress was higher in the group of SLE patients with IR, and increased ferritin, whether caused by the inflammatory process per se or hyperinsulinaemia, can favour the redox process. In addition, the preset data reinforce the need to measure oxidative stress with several methodologies with different assumptions.

Decreased oxidant profile and increased antioxidant capacity in naturally postmenopausal women.

Recent works have shown a dual side of estrogens, and research on the relationship between oxidative stress and menopausal status remains unclear and has produced controversial results. In this work, we aimed to evaluate by sensitive methods the oxidant and antioxidant changes that develop after natural menopause. Thirty premenopausal and 28 naturally postmenopausal women volunteered for this study. Blood was collected and plasma used. 17-OH estradiol levels in plasma were estimated. Plasma levels of advanced oxidation protein products (AOPP), lipid peroxidation products (such as hydroperoxides and malondialdehyde (MDA)), and nitrites were measured, and total radical antioxidant parameter testing was performed to determine the oxidant and antioxidant profiles, respectively. Estrogen levels were significantly increased (p < 0.02) in premenopausal women (54.28 ± 9.34 pg/mL) as compared with postmenopausal women (18.10 ± 1.49 pg/mL). Postmenopausal women had lower levels of lipid hydroperoxide oxidation (p < 0.0001), lipid hydroperoxide levels evaluated by the area under the curve (AUC; 1,366,000 ± 179,400 AUC; p < 0.01), and hydroperoxides as measured by the ferrous oxidation-xylenol orange method (31.48 ± 2.7 µM; p < 0.0001). The MDA levels did not differ between pre- and postmenopausal women whether measured by thiobarbituric acid-reactive substances or high-performance liquid chromatography assays. No differences in AOPP and nitrite levels were observed between pre- and postmenopausal women. Postmenopausal women also exhibited a higher total radical antioxidant level (0.89 ± 0.08 µM Trolox; p < 0.0001). Postmenopausal women demonstrated lower levels of oxidative damage and a higher antioxidant capacity than premenopausal women.

Molecular subtype is determinant on inflammatory status and immunological profile from invasive breast cancer patients.

Breast cancer consists in a chronic inflammatory disease with multiple biological and clinical behaviors. Based on high throughput technologies data, this disease is currently classified according to the molecular expression of estrogen (ER), progesterone (PR) and human epidermal growth factor (HER-2) receptors. In this study, we defined the inflammatory profile of the main molecular subtypes of breast cancer patients: luminal (ER and PR positive, HER-2 negative), HER-2 enriched (HER-2 positive) and triple negative (ER, PR and HER-2 negative). Cytokines panel was assessed by measurement of TNF-α, TGF-ß, IL-1, IL-10 and IL-12 plasmatic levels. Oxidative profile was assessed by determination of lipid peroxidation, total antioxidant capacity of plasma, malondialdehyde levels, carbonyl content and nitric oxide (NO). Clinical data were correlated with inflammatory findings. Our findings demonstrated that patients bearing the luminal subtype displayed high TNF-α, TGF-ß and enhanced oxidative stress levels associated with reduced IL-12. HER-2-enriched group exhibited higher levels of TNF-α, IL-12 and TGF-ß associated with enhanced oxidative stress. Triple-negative subtype exhibited the most aggressive profile of disease behavior, with reduction in both TNF-α and TGF-ß, with high levels of lipid peroxidation and NO. The clinical importance of our findings lies in the fact that the inflammatory status varies in distinct ways due to molecular subtype of breast cancer, opening potential therapeutic targets to future therapies.

Time-dependent reactive species formation and oxidative stress damage in the skin after UVB irradiation.

This study provides evidence that skin oxidative stress injury caused by UVB irradiation is mediated predominantly by reactive oxygen species immediately after irradiation and by reactive nitrogen species at later time points. Animals were pre-treated with free radical scavengers (deferrioxamine, histidine), α-tocopherol, or inhibitors of nitric oxide synthase (NOS) (L-NAME or aminoguanidine) or left untreated and subjected to UVB irradiation. α-Tocopherol inhibited the increase in lipid peroxidation, as evaluated by chemiluminescence at 0 h and 24 h after UVB irradiation. Immediately after UVB irradiation, lipid peroxidation increased moderately and was abolished by free radical scavengers but not by NOS inhibitors. Likewise, the reduction of antioxidant capacity was not reversed by NOS inhibitors. Nitric oxide augmentation was not observed at this time point. Twenty-four hours after irradiation, increased lipid peroxidation levels and nitric oxide elevation were observed and were prevented by NOS inhibitors. Low concentrations of GSH and reduced catalase activity were also observed. Altogether, these data indicate that reactive oxygen species (singlet oxygen and hydroxyl radicals) are the principal mediators of immediate damage and that reactive nitrogen species (*NO and possibly ONOO(-)) seem to be involved later in skin oxidative injury induced by UVB radiation. The reduced catalase activity and low level of GSH suggest that *NO and H(2)O(2) may react to generate ONOO(-), a very strong lipid peroxidant species.

Oxidative stress and hematological profiles of advanced breast cancer patients subjected to paclitaxel or doxorubicin chemotherapy.

Several adverse effects of chemotherapy treatments have been described, and most of these effects are associated with direct interactions between blood cells and indirect effects generated during the oxidative metabolism of antineoplastic drugs. In this study we evaluated the oxidative systemic status and hematological profiles of breast cancer patients with advanced ductal infiltrative carcinoma treated with doxorubicin (DOX) or paclitaxel (PTX) within 1 h after chemotherapy. Blood analyses included evaluation of hemogram, pro-oxidative markers, and antioxidant status. The results showed that advanced breast cancer diseased (AD) patients without previous chemotherapy presented anemia and high oxidative stress status characterized by elevated levels of lipid peroxidation and nitric oxide, and reduced catalase activity when compared with controls. DOX-treated patients exhibited increased anemia and reduced antioxidant status, which was revealed by decreases in reduced glutathione levels and the total antioxidant capacity of plasma; however, these changes did not lead to further increases in lipid peroxidation or carbonyl proteins when compared with the AD group. PTX-treated patients also showed increased anemia, lactate dehydrogenase leakage, and enhanced lipid peroxidation. These data reveal for the first time that patients subjected to chemotherapy with DOX or PTX present immediate systemic oxidative stress and red blood cell oxidative injury with anemia development. These findings provide a new perspective on the systemic redox state of AD and patients subjected to chemotherapy regarding oxidative stress enhancement and its possible involvement in the aggravation of chronic anemia.

An international round-robin calibration protocol for nanoindentation measurements.

Nanoindentation has become a common technique for measuring the hardness and elastic-plastic properties of materials, including coatings and thin films. In recent years, different nanoindenter instruments have been commercialised and used for this purpose. Each instrument is equipped with its own analysis software for the derivation of the hardness and reduced Young's modulus from the raw data. These data are mostly analysed through the Oliver and Pharr method. In all cases, the calibration of compliance and area function is mandatory. The present work illustrates and describes a calibration procedure and an approach to raw data analysis carried out for six different nanoindentation instruments through several round-robin experiments. Three different indenters were used, Berkovich, cube corner, spherical, and three standardised reference samples were chosen, hard fused quartz, soft polycarbonate, and sapphire. It was clearly shown that the use of these common procedures consistently limited the hardness and reduced the Young's modulus data spread compared to the same measurements performed using instrument-specific procedures. The following recommendations for nanoindentation calibration must be followed: (a) use only sharp indenters, (b) set an upper cut-off value for the penetration depth below which measurements must be considered unreliable, (c) perform nanoindentation measurements with limited thermal drift, (d) ensure that the load-displacement curves are as smooth as possible, (e) perform stiffness measurements specific to each instrument/indenter couple, (f) use Fq and Sa as calibration reference samples for stiffness and area function determination, (g) use a function, rather than a single value, for the stiffness and (h) adopt a unique protocol and software for raw data analysis in order to limit the data spread related to the instruments (i.e. the level of drift or noise, defects of a given probe) and to make the H and E(r) data intercomparable.

Immunological effects of taxol and adryamicin in breast cancer patients.

Antineoplastic chemotherapy still consists in the major first-line therapeutics against cancer. Several reports have described the immunomodulatory effects of these drugs based on in vitro treatment, but no previous data are known about these effects in patients and its association with immunological-mediated toxicity. In this study, we first characterize the immunological profile of advanced breast cancer patients treated with doxorubicin and paclitaxel protocols, immediately after chemotherapy infusion. Our findings included an immediate plasmatic reduction in IL-1, IL-10, and TNF-α levels in doxorubicin-treated patients, as well as high levels of IL-10 in paclitaxel patients. Further, it was demonstrated that both drugs led to leukocytes oxidative burst impairment. In vitro analysis was performed exposing healthy blood to both chemotherapics in the same concentration and time of exposition of patients, resulting in low IL-10 and high IL-1ß in doxorubicin exposition, as low TNF-α and high IL-1 in paclitaxel treatment. Nitric oxide levels were not altered in both in vivo and in vitro treatments. In conclusion, our data revealed for the first time that the immediate effects of chemotherapy could be mediated by cytokines signaling in patients and that the results observed in patients could be a resultant of host immune cells activation.

Differential oxidative status and immune characterization of the early and advanced stages of human breast cancer.

Breast cancer is the malignant neoplasia with the highest incidence in women worldwide. Chronic oxidative stress and inflammation have been indicated as major mediators during carcinogenesis and cancer progression. Human studies have not considered the complexity of tumor biology during the stages of cancer advance, limiting their clinical application. The purpose of this study was to characterize systemic oxidative stress and immune response parameters in early (ED; TNM I and II) and advanced disease (AD; TNM III and IV) of patients diagnosed with infiltrative ductal carcinoma breast cancer. Oxidative stress parameters were evaluated by plasmatic lipoperoxidation, carbonyl content, thiobarbituric reactive substances (TBARS), nitric oxide levels (NO), total radical antioxidant parameter (TRAP), superoxide dismutase, and catalase activities and GSH levels. Immune evaluation was determined by TNF-α, IL-1ß, IL-12, and IL-10 levels and leukocytes oxidative burst evaluation by chemiluminescence. Tissue damage analysis included heart (total CK and CKMB), liver (AST, ALT, GGT), and renal (creatinine, urea, and uric acid) plasmatic markers. C-reactive protein (CRP) and iron metabolism were also evaluated. Analysis of the results verified different oxidative stress statuses occur at distinct cancer stages. ED was characterized by reduction in catalase, 8-isoprostanes, and GSH levels, with enhanced lipid peroxidation and TBARS levels. AD exhibited more pronounced oxidative status, with reduction in catalase activity and TRAP, intense lipid peroxidation and high levels of NO, TBARs, and carbonyl content. ED patients presented a Th2 immune pattern, while AD exhibited Th1 status. CRP levels and ferritin were increased in both stages of disease. Leukocytes burst impairment was observed in both the groups. Plasma iron levels were significantly elevated in AD. The data obtained indicated that oxidative stress enhancement and immune response impairment may be necessary to ensure cancer progression to advanced stages and may result from both host and tumor inflammatory mediators.

Antioxidant activity of Spathodea campanulata (Bignoneaceae) extracts / Atividade antioxidante de extratos de Spathodea campanulata (Bignoneaceae)

Spathodea campanulata is used in traditional medicine in Africa as diuretic and anti-inflammatory. Although few studies have reported the mechanism of antioxidant action, this study evidenced the antioxidant activity of S. campanulata bark and flower extracts and their possible mechanism of action. Ethanol extracts of S. campanulata bark and flowers showed antioxidant activity on lipid peroxidation of liver microsome induced by Fe3+-ascorbic acid. Bark extract was 5 times more efficient than flower extract. The antioxidant activity of flower extract, previously complexed with increasing concentrations of Fe3+ (20 - 100 µM) which resulted in antioxidant activity loss, was shown to be related to iron complex formation. In contrast, the antioxidant activity of bark extract was not inhibited by the previous incubation with Fe3+, although complexation was demonstrated by spectral analysis of the solution. These results suggest an antioxidant mechanism other than Fe3+ complex formation. Therefore, the antioxidant mechanisms of S. campanulata flower and bark extracts are distinct from each other, reflecting the extract heterogeneous composition and the mechanism of action.

Spathodea campanulata é usada na medicina popular na África como diurético e antiinflamatório. Embora poucos estudos relatem o mecanismo de ação antioxidante, neste trabalho foi evidenciado a atividade antioxidante dos extratos da casca e da flor da S. campanulata e o possível mecanismo de ação. Os extratos etanólicos da casca e da flor da S. campanulata mostrou possuir atividade antioxidante sobre a lipoperoxidação de microssoma hepático induzida por Fe3+-ácido ascórbico. O extrato da casca foi 5 vezes mais eficiente que da flor. O extrato da flor foi previamente complexado com concentrações crescentes de Fe3+ (20 - 100 µM) o qual resultou na perda da atividade antioxidante, demonstrando que esta está relacionada com a formação de complexo com o ferro. Por outro lado, a atividade antioxidante do extrato da casca não foi inibida pela prévia incubação com o ferro, embora haja a formação do complexo evidenciado pela análise espectral da solução. Estes resultados sugerem que o mecanismo antioxidante seja outro que não a complexação com o Fe3+. Portanto, o mecanismo antioxidante dos extratos da flor e da casca da S. campanulata é distinto entre si o que reflete a composição heterogênica do extrato e o mecanismo de ação.

Oxidative stress is associated with liver damage, inflammatory status, and corticosteroid therapy in patients with systemic lupus erythematosus.

Oxidative stress exerts an important role on the pathophysiological mechanisms of systemic lupus erythematosus (SLE). This study investigated oxidative stress in patients with SLE and its correlation with disease activity, corticosteroid therapy, and liver function biomarkers. The study included 58 patients with SLE and 105 healthy volunteers. Patients showed oxidative stress increase evaluated by tert-butyl hydroperoxide-initiated chemiluminescence (CL-LOOH), advanced oxidation protein products (AOPP), and nitric oxide metabolites. C-reactive protein (CRP) was associated with CL-LOOH and with AOPP. Aspartate aminotransferase correlated significantly with CL-LOOH and with AOPP. Patients with disease activity showed an inverse significant correlation of daily prednisone doses and CL-LOOH and a direct correlation with total antioxidant capacity. In conclusion, patients with SLE have persistent lipoperoxidation and protein oxidation even with inactive disease or mild disease activity. The significant correlation between oxidative stress and CRP suggests that, despite clinical remission, the persistence of an inflammatory condition favors oxidative stress. Oxidative stress was associated with liver enzymes, and this relationship seems to support the hypothesis of drug-induced oxidative stress with consequent liver injury. In relation to non-active disease, patients with active SLE did not present oxidative stress and antioxidant capacity changes, due to the antioxidant drugs used in SLE treatment, especially prednisone.

Inflammatory biomarkers and oxidative stress measurements in patients with systemic lupus erythematosus with or without metabolic syndrome.

The aims of the present study were to report the frequency of metabolic syndrome in systemic lupus erythematosus (SLE); to verify differences in inflammatory biomarkers and oxidative stress in SLE patients with or without metabolic syndrome; and to assess which metabolic syndrome components are associated with oxidative stress and disease activity. The study included 58 SLE patients and 105 controls. SLE patients were divided in two groups, with and without metabolic syndrome. 41.4% patients met the criteria for metabolic syndrome compared with 10.5% controls. Patients with SLE and metabolic syndrome had significantly raised serum uric acid, C-reactive protein (CRP), lipid hydroperoxides, and protein oxidation when compared with patients with SLE without metabolic syndrome. Lipid hydroperoxides were correlated with CRP, whereas protein oxidation was associated with waist circumference and uric acid. There was a positive association between serum C3 and C4 and glucose and between C3 and CRP. SLE disease activity index (SLEDAI) scores were positively correlated with body mass index (BMI) and waist circumference (WC). In conclusion, SLE patients have a high prevalence of metabolic syndrome and this syndrome directly contributes to increase inflammatory status and oxidative stress. Inflammatory processes, being overweight/obese, and uric acid may favor oxidative stress increases in patients with SLE and metabolic syndrome. C3 and C4 may have a positive acute-phase protein behavior in patients with SLE.

Immunological and biochemical parameters of patients with metabolic syndrome and the participation of oxidative and nitroactive stress

Metabolic syndrome (MS) is a multifactorial disease involving inflammatory activity and endothelial dysfunction. The aim of the present study was to evaluate the relationship between the changes in lipoperoxidation, in immunological and biochemical parameters and nitric oxide metabolite (NOx) levels in MS patients. Fifty patients with MS (4 males/46 females) and 50 controls (3 males/47 females) were studied. Compared to control (Mann-Whitney test), MS patients presented higher serum levels (P < 0.05) of fibrinogen: 314 (185-489) vs 262 (188-314) mg/dL, C-reactive protein (CRP): 7.80 (1.10-46.50) vs 0.70 (0.16-5.20) mg/dL, interleukin-6: 3.96 (3.04-28.18) vs 3.33 (2.55-9.63) pg/mL, uric acid: 5.45 (3.15-9.65) vs 3.81 (2.70-5.90) mg/dL, and hydroperoxides: 20,689 (19,076-67,182) vs 18,636 (15,926-19,731) cpm. In contrast, they presented lower (P < 0.05) adiponectin: 7.11 (3.19-18.22) vs 12.31 (9.11-27.27) µg/mL, and NOx levels: 5.69 (2.36-8.18) vs 6.72 (5.14-12.43) µM. NOx was inversely associated (Spearman’s rank correlation) with body mass index (r = -0.2858, P = 0.0191), insulin resistance determined by the homeostasis model assessment (r = -0.2530, P = 0.0315), CRP (r = -0.2843, P = 0.0171) and fibrinogen (r = -0.2464, P = 0.0413), and positively correlated with hydroperoxides (r = 0.2506, P = 0.0408). In conclusion, NOx levels are associated with obesity, insulin resistance, oxidative stress, and inflammatory markers. The high uric acid levels together with reactive oxygen species generation may be responsible for the reduced NO levels, which in turn lead to endothelial dysfunction. The elevated plasma chemiluminescence reflecting both increased plasma oxidation and reduced antioxidant capacity may play a role in the MS mechanism.