Ambient particulate air pollution from vehicles promotes lipid peroxidation and inflammatory responses in rat lung

Oxidative stress plays a major role in the pathogenesis of particle-dependent lung injury. Ambient particle levels from vehicles have not been previously shown to cause oxidative stress to the lungs. The present study was conducted to a) determine whether short-term exposure to ambient levels of particulate air pollution from vehicles elicits inflammatory responses and lipid peroxidation in rat lungs, and b) determine if intermittent short-term exposures (every 4 days) induce some degree of tolerance. Three-month-old male Wistar rats were exposed to ambient particulate matter (PM) from vehicles (N = 30) for 6 or 20 continuous hours, or for intermittent (5 h) periods during 20 h for 4 consecutive days or to filtered air (PM <10 µm; N = 30). Rats continuously breathing polluted air for 20 h (P-20) showed a significant increase in the total number of leukocytes in bronchoalveolar lavage compared to control (C-20: 2.61 x 105 ± 0.51;P-20: 5.01 x 105 ± 0.81; P < 0.05) and in lipid peroxidation ([MDA] nmol/mg protein: C-20: 0.148 ± 0.01; P-20: 0.226 ± 0.02; P < 0.05). Shorter exposure (6 h) and intermittent 5-h exposures over a period of 4 days did not cause significant changes in leukocytes. Lipid damage resulting from 20-h exposure to particulate air pollution did not cause a significant increase in lung water content. These data suggest oxidative stress as one of the mechanisms responsible for the acute adverse respiratory effects of particles, and suggest that short-term inhalation of ambient particulate air pollution from street with high automobile traffic represents a biological hazard.

Protection against cephalosporin-induced lipid peroxidation and nephrotoxicity by (+)-cyanidanol-3 and vitamin E

The ability of the clinically used cephalosporins: cephalothin, cefotaxime and cefotiam to induce lipid peroxidation (LPO) and renal damage was compared to that of nephrotoxic cephaloridine under in vivo conditions. Glutathione was measured in rat liver or in renal cortex as non-protein sulfhydryls. LPO was measured in plasma, renal cortex and liver by the generation of malondialdehyde or as the increase in renal cortical concentration of conjugated dienes. Impairment of renal function was measured as the decrease in renal cortical accumulation of the organic anion p-aminohippurate (PAH). Administration of cephalosporins to rats as a single dose (2000 mg/kg, ip) induced a significant glutathione-depletion in the renal cortex with cephaloridine, and in the liver with cephaloridine, cephalothin and cefotiam. Treatment of rats with cephaloridine, cephalothin and cefotiam (200, 500, or 1000 mg kg-1 day-1, ip) for 5 days resulted in a dose-dependent increase of LPO in the renal cortex. While cephaloridine induced the highest concentration of conjugated diene, cefotaxime had no effect. Measurements of PAH accumulation in renal cortical slices from cephalosporin-treated rats showed a dose-dependent decrease in the renal cortical accumulation of PAH. Pretreatment with the antioxidants vitamin E or cyanidanol (400 mg kg-1 day-1, ip) 1 h before treatment with cephaloridine, cephalothin or cefotiam (1000 mg kg-1 day-1, ip) for 3 days inhibited cephalosporin-induced LPO and significantly reduced the impairment of renal cortical accumulation of PAH. The potential of different cephalosporins for inducing LPO and reducing PAH accumulation was ranked as follows: cephaloridine > cephalothin > cefotiam > cefotaxime.

Correlation of serum leptin and insulin levels of pregnant protein-restricted rats with predictive obesity variables

During pregnancy and protein restriction, changes in serum insulin and leptin levels, food intake and several metabolic parameters normally result in enhanced adiposity. We evaluated serum leptin and insulin levels and their correlations with some predictive obesity variables in Wistar rats (90 days), up to the 14th day of pregnancy: control non-pregnant (N = 5) and pregnant (N = 7) groups (control diet: 17% protein), and low-protein non-pregnant (N = 5) and pregnant (N = 6) groups (low-protein diet: 6%). Independent of the protein content of the diet, pregnancy increased total (F1,19 = 22.28, P < 0.001) and relative (F1,19 = 5.57, P < 0.03) food intake, the variation of weight (F1,19 = 49.79, P < 0.000) and final body weight (F1,19 = 19.52, P < 0.001), but glycemia (F1,19 = 9.02, P = 0.01) and the relative weight of gonadal adipose tissue (F1,19 = 17.11, P < 0.001) were decreased. Pregnancy (F1,19 = 18.13, P < 0.001) and low-protein diet (F1,19 = 20.35, P < 0.001) increased the absolute weight of brown adipose tissue. However, the relative weight of this tissue was increased only by protein restriction (F1,19 = 15.20, P < 0.001) and the relative lipid in carcass was decreased in low-protein groups (F1,19 = 4.34, P = 0.05). Serum insulin and leptin levels were similar among groups and did not correlate with food intake. However, there was a positive relationship between serum insulin levels and carcass fat depots in low-protein groups (r = 0.37, P < 0.05), while in pregnancy serum leptin correlated with weight of gonadal (r = 0.39, P < 0.02) and retroperitoneal (r = 0.41, P < 0.01) adipose tissues. Unexpectedly, protein restriction during 14 days of pregnancy did not alter the serum profile of adiposity signals and their effects on food intake and adiposity, probably due to the short term of exposure to low-protein diet.

Association between dental-oral health in young adults and salivary glutathione, lipid peroxidation and sialic acid levels and carbonic anhydrase activity

The aim of the present study was to evaluate the relationship between salivary oxidative stress and dental-oral health. Healthy young adults, matched for gender and age, with (N = 21, 10 men, mean age: 20.3 ± 1 years) and without (N = 16, 8 men, mean age: 21.2 ± 1.8 years) caries were included in this study. The World Health Organization (WHO) caries diagnostic criteria were used for determining the decayed, missing, filled teeth (DMFT) index. The oral hygiene and gingival status were assessed using the simplified oral hygiene index and gingival index, respectively. Unstimulated salivary total protein, glutathione (GSH), lipid peroxidation and total sialic acid levels, carbonic anhydrase activity, and salivary buffering capacity were determined by standard methods. Furthermore, salivary pH was measured with pH paper and salivary flow rate was calculated. Simplified oral hygiene index and gingival index were not significantly different between groups but DMFT scores were significant (P < 0.01). Only, GSH values were significantly different (P < 0.05) between groups (2.2 and 1.6 mg/g protein in young adults without caries and with caries, respectively). There was a significant negative correlation between DMFT and GSH (r = -0.391; P < 0.05; Pearson's correlation coefficient). Our results suggest that there is an association between caries history and salivary GSH levels.

Liver lipid peroxidation and antioxidant capacity in cerulein-induced acute pancreatitis

The aim of this study was to evaluate the role of oxidative damage in pancreatitis-induced hepatic injury. Thirty-five rats were divided into five groups (each of 7 rats): control, cerulein (100 µg/kg body weight), cerulein and pentoxifylline (12 mg/kg body weight), cerulein plus L-NAME (10 mg/kg body weight) and cerulein plus L-arginine (160 mg/kg body weight). The degree of hepatic cell degeneration differed significantly between groups. Mean malondialdehyde levels were 7.00 ± 2.29, 20.89 ± 10.13, 11.52 ± 4.60, 18.69 ± 8.56, and 8.58 ± 3.68 nmol/mg protein for the control, cerulein, pentoxifylline, L-NAME, and L-arginine groups, respectively. Mean catalase activity was 3.20 ± 0.83, 1.09 ± 0.35, 2.05 ± 0.91, 1.70 ± 0.60, and 2.85 ± 0.47 U/mg protein for the control, cerulein, pentoxifylline, L-NAME, and L-arginine groups, respectively, and mean glutathione peroxidase activity was 0.72 ± 0.25, 0.33 ± 0.09, 0.37 ± 0.04, 0.34 ± 0.07 and 0.42 ± 0.1 U/mg protein for the control, cerulein, pentoxifylline, L-NAME, and L-arginine groups, respectively. Cerulein-induced liver damage was accompanied by a significant increase in tissue malondialdehyde levels (P < 0.05) and a significant decrease in catalase (P < 0.05) and GPx activities (P < 0.05). L-arginine and pentoxifylline, but not L-NAME, protected against this damage. Oxidative injury plays an important role not only in the pathogenesis of AP but also in pancreatitis-induced hepatic damage.

Plasma cytokine response, lipid peroxidation and NF-κB activation in skeletal muscle following maximum progressive swimming

Our objective was to determine lipid peroxidation and nuclear factor-κB (NF-κB) activation in skeletal muscle and the plasma cytokine profile following maximum progressive swimming. Adult male Swiss mice (N = 15) adapted to the aquatic environment were randomly divided into three groups: immediately after exercise (EX1), 3 h after exercise (EX2) and control. Animals from the exercising groups swam until exhaustion, with an initial workload of 2% of body mass attached to the tail. Control mice did not perform any exercise but were kept immersed in water for 20 min. Maximum swimming led to reactive oxygen species (ROS) generation in skeletal muscle, as indicated by increased thiobarbituric acid reactive species (TBARS) levels (4062.67 ±1487.10 vs 19,072.48 ± 8738.16 nmol malondialdehyde (MDA)/mg protein, control vs EX1). Exercise also promoted NF-κB activation in soleus muscle. Cytokine secretion following exercise was marked by increased plasma interleukin-6 (IL-6) levels 3 h post-exercise (P < 0.05). Interleukin-10 (IL-10) levels were reduced following exercise and remained reduced 3 h post-exercise (P < 0.05). Plasma levels of other cytokines investigated, monocyte chemotactic protein-1 (MCP-1), tumor necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ) and interleukin-12 (IL-12), were not altered by exercise. The present findings showed that maximum swimming, as well as other exercise models, led to lipid peroxidation and NF-κB activation in skeletal muscle and increased plasma IL-6 levels. The plasma cytokine response was also marked by reduced IL-10 levels. These results were attributed to exercise type and intensity.

Gene transfer of Chlorella vulgaris n-3 fatty acid desaturase optimizes the fatty acid composition of human breast cancer cells

Chlorella vulgaris has the gene of n-3 fatty acid desaturase (CvFad3), which can synthesize the precursor of n-3 polyunsaturated fatty acids (PUFAs) or convert n-6 to n-3 PUFAs. The objective of the present study was to examine whether the CvFad3 gene from C. vulgaris can be functionally and efficiently expressed in human breast cancer cells and whether its expression can exert a significant effect on cell fatty acid composition. We inserted the CvFad3 gene into the plasmid pEGFP-C3 to construct the eukaryotic expression vector pEGFP-C3-n-3 and to express the n-3 Fad gene in human breast cancer cells (MCF-7 cells). Transfection of MCF-7 cells with the recombinant vector resulted in a high expression of n-3 fatty acid desaturase. Lipid analysis indicated that the ratio of n-6/n-3 PUFAs was decreased from 6:1 in the control cells to about 1:1 in the cells expressing the n-3 fatty acid desaturase. Accordingly, the CvFad3 gene significantly decreased the ratio of n-6/n-3 PUFAs of the MCF-7 cell membrane. The expression of the CvFad3 gene can decrease cell proliferation and promote cell apoptosis. This study demonstrates that the CvFad3 gene can dramatically balance the ratio of n-6/n-3 PUFAs and may provide an effective approach to the modification of the fatty acid composition of mammalian cells, also providing a basis for potential applications of its transfer in experimental and clinical settings.

Cardiorespiratory fitness, pulmonary function and C-reactive protein levels in nonsmoking individuals with diabetes

The objective of this study was to evaluate cardiorespiratory fitness and pulmonary function and the relationship with metabolic variables and C-reactive protein (CRP) plasma levels in individuals with diabetes mellitus (DM). Nineteen men with diabetes and 19 age- and gender-matched control subjects were studied. All individuals were given incremental cardiopulmonary exercise and pulmonary function tests. In the exercise test, maximal workload (158.3±22.3vs 135.1±25.2, P=0.005), peak heart rate (HRpeak: 149±12 vs 139±10, P=0.009), peak oxygen uptake (VO2peak: 24.2±3.2 vs18.9±2.8, P<0.001), and anaerobic threshold (VO2VT: 14.1±3.4 vs 12.2±2.2, P=0.04) were significantly lower in individuals with diabetes than in control subjects. Pulmonary function test parameters, blood pressure, lipid profile (triglycerides, HDL, LDL, and total cholesterol), and CRP plasma levels were not different in control subjects and individuals with DM. No correlations were observed between hemoglobin A1C (HbA1c), CRP and pulmonary function test and cardiopulmonary exercise test performance. In conclusion, the results demonstrate that nonsmoking individuals with DM have decreased cardiorespiratory fitness that is not correlated with resting pulmonary function parameters, HbA1c, and CRP plasma levels.

PPARγ induces growth inhibition and apoptosis through upregulation of insulin-like growth factor-binding protein-3 in gastric cancer cells

Peroxisome proliferator activator receptor-gamma (PPARγ) is a ligand-activated transcriptional factor involved in the carcinogenesis of various cancers. Insulin-like growth factor-binding protein-3 (IGFBP-3) is a tumor suppressor gene that has anti-apoptotic activity. The purpose of this study was to investigate the anticancer mechanism of PPARγ with respect to IGFBP-3. PPARγ was overexpressed in SNU-668 gastric cancer cells using an adenovirus gene transfer system. The cells in which PPARγ was overexpressed exhibited growth inhibition, induction of apoptosis, and a significant increase in IGFBP-3 expression. We investigated the underlying molecular mechanisms of PPARγ in SNU-668 cells using an IGFBP-3 promoter/luciferase reporter system. Luciferase activity was increased up to 15-fold in PPARγ transfected cells, suggesting that PPARγ may directly interact with IGFBP-3 promoter to induce its expression. Deletion analysis of the IGFBP-3 promoter showed that luciferase activity was markedly reduced in cells without putative p53-binding sites (-Δ1755, -Δ1795). This suggests that the critical PPARγ-response region is located within the p53-binding region of the IGFBP-3 promoter. We further demonstrated an increase in PPARγ-induced luciferase activity even in cells treated with siRNA to silence p53 expression. Taken together, these data suggest that PPARγ exhibits its anticancer effect by increasing IGFBP-3 expression, and that IGFBP-3 is a significant tumor suppressor.

Influence of food components on lipid metabolism: scenarios and perspective on the control and prevention of dyslipidemias

Cardiovascular diseases (CVD) are the main causes of death in the Western world. Among the risk factors that are modifiable by diet, for reducing cardiovascular disease risks, the total plasma concentrations of cholesterol, triglycerides, LDL-C, and HDL-C are the most important. Dietary measures can balance these components of the lipid profile thus reducing the risk of cardiovascular diseases. The main food components that affect the lipid profile and can be modified by diet are the saturated and trans fats, unsaturated fats, cholesterol, phytosterols, plant protein, and soluble fiber. A wealth of evidence suggests that saturated and trans fats and cholesterol in the diet raise the total plasma cholesterol and LDL-C. Trans fats also reduce HDL-C, an important lipoprotein for mediating the reverse cholesterol transport. On the other hand, phytosterols, plant proteins, isoflavones, and soluble fiber are protective diet factors against cardiovascular diseases by modulating plasma lipoprotein levels. These food components at certain concentrations are able to reduce the total cholesterol, TG, and LDL-C and raise the plasma levels of HDL-C. Therefore, diet is an important tool for the prevention and control of cardiovascular diseases, and should be taken into account as a whole, i.e., not only the food components that modulate plasma concentrations of lipoproteins, but also the diet content of macro nutrients and micronutrients should be considered.

Study of the proteins in the defatted flour and protein concentrate of baru nuts (Dipteryx alata Vog)

Baru (Dipteryx alata Vog.) is an abundant legume in the Brazilian Savanna. Its nuts can be exploited sustainably using its protein and lipid fractions. This study aimed to analyze the proteins of the nuts present in the defatted flour and protein concentrate in terms of their functional properties, the profile of their fractions, and the in vitro digestibility. The flour was defatted with hexane and extracted at the pH of higher protein solubility to obtain the protein concentrate. The electrophoretic profile of the protein fractions was evaluated in SDS-PAGE gel. The functional properties of the proteins indicate the possibility of their use in various foods, like soybeans providing water absorption capacity, oil absorption capacity, emulsifying properties, and foamability. Globulins, followed by the albumins, are the major fractions of the flour and protein concentrate, respectively. Digestibility was greater for the concentrate than for the defatted flour.

Replacement of mechanically deboned chicken meat with its protein hydrolysate in mortadella-type sausages

Mortadella-type sausage manufactured using mechanically deboned chicken meat were reformulated replacing MDCM with increasing amounts of MDCM protein hydrolysates (10%, 20%, and 30%), and their physicochemical, microbiological, and sensorial characteristics were evaluated for 60 days of storage at 4 °C. The higher substitutions resulted in sausages more susceptible to lipid oxidation with higher TBARS values during storage; however, these values were lower than the organoleptic perception threshold. The sausages were darker and less red, with lower lightness (L*) and redness (a*) values than those of the control treatment. They had soft texture, which was evidenced by both the instrumental and sensory analysis. Therefore, the formulation containing 10% of MDCM protein hydrolysates proved to be the most suitable for mortadella-type sausage elaboration.

Effect of different stress conditions on the stability of quercetin-loaded lipid microparticles produced with babacu ( Orbignya speciosa ) oil: evaluation of their potential use in food applications

Lipid micro and nanoparticles have been extensively investigated as carriers for hydrophobic bioactives in food systems because they can simultaneously increase the dispersibility of these lipophilic substances and help improve their bioavailability. In this study, lipid microparticles of babacu oil and denatured whey protein isolate were produced, and their ability to protect quercetin against degradation was evaluated over 30 days of storage. Additionally, the lipid microparticles were subjected to the typical stress conditions of food processing (presence of sucrose, salt, and thermal stresses), and their physico-chemical stability was monitored. The data show that the babacu microparticles efficiently avoided the oxidation of quercetin because 85% of the initial amount of the flavonoid was preserved after 30 days. The particles were notably stable up to a temperature of 70 °C for 10 minutes at relatively high concentrations of salt and sucrose. The type of stirring (mechanical or magnetic) also strongly affected the stability of the dispersions.