Long-term and low dose oral malathion exposure causes morphophysiological changes in the colon of rats.

BACKGROUND: Malathion (MAL) is an organophosphate insecticide that inhibits cholinesterases, used to control pests in agriculture and to combat mosquitoes that transmit various arboviruses. As acetylcholine is one of the major neurotransmitters of the enteric nervous system (ENS), humans exposed to MAL by ingestion of contaminated food and water can develop symptoms due disfunction of the gastrointestinal tract. Although the deleterious effects after exposure to high doses are recognized, little is known about the long-term and low-dose effects of this pesticide on the structure and motility of the colon. AIMS: to evaluate the effects of prolonged oral exposure to low levels of MAL on the wall structure and colonic motility parameters of young rats. MAIN METHODS: The animals were divided into three groups: control, and groups that received 10 or 50 mg/kg of MAL via gavage for 40 days. The colon was collected for histological analysis and analysis of the ENS through the evaluation of total neurons and subpopulations of the myenteric and submucosal plexuses. Cholinesterase activity and functional analyzes of the colon were evaluated. KEY FINDINGS: MAL treatments (10 and 50 mg/Kg) reduced the butyrylcholinesterase activity, and caused enlargement of faecal pellets, atrophy of muscle layers and several changes in neurons of both myenteric and submucosal plexi. Considering colonic contraction, MAL (50 mg/Kg) increased the number of retrograde colonic migratory motor complexes. SIGNIFICANCE: The long-term exposure to low doses of MAL affects colonic morphophysiology, which highlights the need to intensify control and care in the use of this pesticide.

Proinflammatory circulating markers: new players for evaluating asymptomatic acute cardiovascular toxicity in breast cancer treatment.

PURPOSE: This study aimed to evaluate markers of cardiac damage (total CK, CKMB and CRP), inflammatory markers (free iron, homocysteine and TNF-α) as well as lipidogram in breast cancer patients undergoing acute cycles of doxorubicin (DOX), paclitaxel (PTX) or trastuzumab (TZ) and to verify if there is an association between these markers and the toxicity of the chemotherapeutic treatment. Methods: Included in the study were 120 breast cancer patients and 50 healthy controls. All analyzes were performed on automated systems. For the statistical analysis, each group was compared with the controls according to their normality by Student's t-test and Mann-Whitney test. Results: Our results showed that DOX treatment led to increased hsCRP (4.80 ± 1.23 mg/dL, p = 0.0005), triglycerides (187.6 ± 25.06, p = 0.0231), TNF-α (42.31 ± 17.96 pg/mL, p = 0.01) and Fe levels (138.8 ± 18.6 µg/dL, p = 0.0193). In the meantime, PTX induced changes in CK-MB (8.78 ± 4.2 U/L, p = 0.0361), hsCRP (7.12 ± 1.87 mg/dL, p = 0.0006), cholesterol (201.7 ± 19.54, p = 0.05), triglycerides (201.7 ± 19.54, p = 0.0277), TNF-α (38.27 ± 9.12 pg/mL, p = 0.023), homocysteine (10.95 ± 0, 86 µmol/L, p = 0.005), and free iron (113 ± 18 6 µg/dL, p = 0.045) while TZ augmented CK-MB (6.9 ± 1.97 U/L, p < 0.00), hsPCR (3.12 ± 0.68 mg/dL, p = 0.095), cholesterol (218.3 ± 16.79, p = 0.0317), triglycerides (218.3 ± 16.79, p = 0.0127), TNF-α (89.6 ± 12.11, p = 0.032), homocysteine (9.95 ± 1.15 µmol/L, p = 0.0396), free iron (120.5 ± 4.64 µg/dl, p = 0.0058) as well. Conclusions: Our data demonstrated the existence of a proinflammatory net triggered by breast cancer chemotherapy that could increase cardiomyocytes permeability and allow the leakage of circulating proteins as CK-MB and induce the production of hsCRP.

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.

Reduction of nitric oxide and DNA/RNA oxidation products are associated with active disease in systemic lupus erythematosus patients.

The aims of the present study were to evaluate biomarkers of oxidative and nitrosative stress in systemic lupus erythematosus (SLE) patients, in particular products of DNA/RNA oxidative damage and their correlation with disease activity. This study included 188 controls and 203 patients; 153 with inactive SLE (SLEDAI < 6) and 50 with active SLE (SLEDAI ≥ 6) without renal impairment. Oxidative stress was assessed by tert-butyl hydroperoxide-initiated by chemiluminescence, advanced oxidation protein products (AOPP), total radical-trapping antioxidant parameter (TRAP), nitric oxide metabolites (NOx), and DNA/RNA oxidation products. Patients with SLE showed increased oxidative stress, as demonstrated by the augmentation of lipid hydroperoxides ( p < 0.0001) and AOPP ( p < 0.001) and reduced total antioxidant capacity ( p < 0.0001), without differences between patients with active disease and in remission. NOx levels and DNA/RNA oxidation products were inversely and independently associated with disease activity ( p < 0.0001 and p = 0.021, respectively), regardless of BMI and prednisone use. The linear regression analysis showed that about 5% of the SLEDAI score can be explained by the levels of DNA/RNA oxidation products ( r2:0.051; p = 0.002) and about 9% of this score by the levels of NOx ( r2:0.091; p < 0.0001). This study provides evidence for an inverse association between serum NOx levels and DNA/RNA oxidation products and SLE disease activity, suggesting that oxidative/nitrosative stress markers may be useful in evaluating SLE disease activity and progression of the 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.

Tumor necrosis factor beta (TNF-ß) NcoI polymorphism is associated with multiple sclerosis in Caucasian patients from Southern Brazil independently from HLA-DRB1.

This study evaluated the association of tumor necrosis factor beta (TNF-ß) NcoI polymorphism with the presence of multiple sclerosis (MS), disability, and HLA-DRB1 alleles in 208 Brazilian MS patients. As controls, 147 healthy individuals were included. The disability was evaluated at baseline and 5-year follow-up using the Expanded Disability Status Scale (EDSS). The TNF-ß genotypes were determined using PCR and restriction fragment length polymorphism and serum TNF-α level was determined using enzyme-linked immunosorbent assay. Among the MS patients, 166 (79.8 %) were white, 39 (18.7 %) were brown, and three (1.4 %) were Asian descents (those were excluded from the further analysis). Among the 205 MS patients, 149 (72.6 %) presented remitting-relapsing MS. The baseline and 5-year follow-up EDSS ranged from 0.0 to 3.0 and from 1.0 to 5.7, respectively. The TNFB2/B2 genotype was associated with the presence of MS among the white patients (p = 0.0443). Brown patients presented higher disability (p = 0.0234) and higher TNF-α levels (p = 0.0463) than white patients. White and brown patients carrying TNFB2/B2 genotype exhibited higher TNF-α levels (p = 0.0354 and p = 0.0309, respectively) than those with other geotypes. Association between TNF-ß NcoI genotypes and HLA-DRB1 alleles was not observed among the MS patients (p > 0.05). Taken together, TNFB2 allele was associated with the presence of MS independently of HLA-DRB1 in white patients and the TNFB2/B2 genotype was associated with increased TNF-α levels in white and brown patients, which could be an important genetic factor candidate for the susceptibility and pathogenesis of MS.

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.

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.

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.

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.

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.

Free radical-mediated pre-hemolytic injury in human red blood cells subjected to lead acetate as evaluated by chemiluminescence.

The mechanisms by which Pb(2+) induces hemolysis are not completely understood. For this reason, the involvement of oxidative stress in the mechanism of Pb(2+)-induced pre-hemolytic lesion was investigated by exposing RBC to Pb(2+) in vitro and then separating the intact non-hemolysed RBC. Oxidative stress was investigated on human RBCs by tert-butyl hydroperoxide-initiated chemiluminescence method (CL). Our results revealed that lead-induced time and concentration-dependent hemolysis and CL time curves showed a very narrow correlation each other. GSH oxidation to GSSG and the stress index also increased significantly. Treatment of lead-exposed RBC with desferrioxamine, an iron-chelating agent or the chain-breaking antioxidant, Trolox, quenched light emission and inhibited hemolysis dramatically. Mannitol and sodium formate, (*)OH scavengers, on the contrary, did not inhibit CL or hemolysis, significantly. These data indicate that lead-induced lipid peroxide formation is mediated by a metal-driven Fenton reaction but do not support the direct involvement of hydroxyl radicals in this process. By contrast, our results revealed a decrease in light emission and decreased hemolysis in the presence of histidine, a singlet oxygen scavenger. Our results suggest that membrane damage and hemolysis of RBC are mediated by Pb(2+) through free radical reactions and that singlet oxygen plays a significant role in this process.