Development of a colorimetric sensor based on nanofiber cellulose film modified with ninhydrin to measure the formalin index of fruit juice.

In this research, a color sensor based on nanofiber cellulose film modified with ninhydrin was designed to measure amino acids and formalin index in fruit juice. For this purpose, three types of cellulose films with porosity of 5, 30 and 125 µm were used. These films were treated with standard solution of ninhydrin. The characteristics of modified films were investigated using Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and X-ray Diffraction (XRD) tests. The color factors of the sensors (a and b) changed in the presence of amino acids and juice with different levels of formalin index. Therefore, the modified films with ninhydrin as a colorimetric sensor were calibrated using 7 types of amino acids and based on the formalin index of 4 types of juice. Then the sensors were used to measure the formalin index in 4 types of juice. The results showed that the sensors have relative selectivity towards methionine amino acid. The formalin index values calculated in the juices by the sensor were compared with the titration method as a reference method. All three types of sensors were able to detect formalin index. The results of the sensor performance verification showed that the sensors can measure formalin index in different juices with 95-98 % accuracy. These sensors showed fast sensitivity and selectivity to the amino acids in juice, also these sensors are safe and the measurement method is fast and simple.

Effect of L-serine on oxidative stress markers in the kidney of streptozotocin-induced diabetic mice.

Oxidative stress is critical in the occurrence and development of diabetes and its related complications. L-serine has recently been shown to reduce oxidative stress, the incidence of autoimmune diabetes and improve glucose homeostasis. The aim of this study was to investigate the effects of daily L-serine administration on blood glucose, renal function and oxidative stress markers in the kidney of streptozotocin-induced diabetic mice. Eighteen C57BL/6 male mice were randomly divided into three groups (n = 6 per group). Streptozotocin was used to induce diabetes and a group of diabetic mice was treated with 280 mg/day of L-serine dissolved in drinking water for 4 weeks. The level of blood glucose, biochemical markers of renal function (total protein, urea, creatinine and albumin) and oxidative stress markers (protein carbonyls, malondialdehyde, glutathione peroxidase, superoxide dismutase and catalase) were measured using spectrophotometry. The results indicated that L-serine significantly decreased the glucose level in diabetic mice (188.6 ± 22.69 mg/dL, P = 0.02). Moreover, treatment of diabetic mice with L-serine reduced protein carbonyls (3.249 ± 0.9165 nmol/mg protein, P < 0.05) and malondialdehyde levels (1.891 ± 0.7696 µM/mg protein, P = 0.051). However, L-serine showed no significant effects on renal function, and a slight reduction in histopathological changes was observed in mice receiving L-serine. This study revealed that L-serine effectively ameliorates oxidative stress in kidney tissue and reduces the blood glucose concentration in diabetic mice.

Total Antioxidant Capacity and Total Oxidant Status and Disease Severity in a Cohort Study of COVID-19 Patients.

BACKGROUND: Previous reports have suggested the role of oxidative stress in progression of COVID-19 infection, but there is limited information regarding the effect of antioxidant capacity and total oxidant status of patients with COVID-19 on disease severity. In the present study, we aimed to investigate the relationship between total antioxidant capacity (TAC), total oxidant status (TOS), TAC/TOS levels, and disease severity in hospitalized patients with COVID-19. METHODS: This cohort study was carried out at Masih Daneshvari Hospital in Tehran, Iran, from September 2020 to October 2020. Clinical data of 331 patients with COVID-19 admitted to the hospital were analyzed and divided into mild, moderate, and severe groups (needed oxygen, intubation, and mechanical ventilation). The patients' TAC, TOS, and TAC/TOS levels were assessed using the serum samples by colorimetric assay kit. RESULTS: We found no significant difference in serum levels of TAC, TOS, and TAC/TOS in terms of the disease severity. CONCLUSIONS: These results indicated that total antioxidant capacity and total oxidant status may not be the determining factor on the disease severity.

A (GCC) repeat in SBF1 reveals a novel biological phenomenon in human and links to late onset neurocognitive disorder.

The human SBF1 (SET binding factor 1) gene, alternatively known as MTMR5, is predominantly expressed in the brain, and its epigenetic dysregulation is linked to late-onset neurocognitive disorders (NCDs), such as Alzheimer's disease. This gene contains a (GCC)-repeat at the interval between + 1 and + 60 of the transcription start site (SBF1-202 ENST00000380817.8). We sequenced the SBF1 (GCC)-repeat in a sample of 542 Iranian individuals, consisting of late-onset NCDs (N = 260) and controls (N = 282). While multiple alleles were detected at this locus, the 8 and 9 repeats were predominantly abundant, forming > 95% of the allele pool across the two groups. Among a number of anomalies, the allele distribution was significantly different in the NCD group versus controls (Fisher's exact p = 0.006), primarily as a result of enrichment of the 8-repeat in the former. The genotype distribution departed from the Hardy-Weinberg principle in both groups (p < 0.001), and was significantly different between the two groups (Fisher's exact p = 0.001). We detected significantly low frequency of the 8/9 genotype in both groups, higher frequency of this genotype in the NCD group, and reverse order of 8/8 versus 9/9 genotypes in the NCD group versus controls. Biased heterozygous/heterozygous ratios were also detected for the 6/8 versus 6/9 genotypes (in favor of 6/8) across the human samples studied (Fisher's exact p = 0.0001). Bioinformatics studies revealed that the number of (GCC)-repeats may change the RNA secondary structure and interaction sites at least across human exon 1. This STR was specifically expanded beyond 2-repeats in primates. In conclusion, we report indication of a novel biological phenomenon, in which there is selection against certain heterozygous genotypes at a STR locus in human. We also report different allele and genotype distribution at this STR locus in late-onset NCD versus controls. In view of the location of this STR in the 5' untranslated region, RNA/RNA or RNA/DNA heterodimer formation of the involved genotypes and alternative RNA processing and/or translation should be considered.

Interplay between oxidative stress and autophagy function and its role in inflammatory cytokine expression induced by palmitate in skeletal muscle cells.

Autophagy is a cellular process activated in response to various stresses such as starvation, hypoxia, and oxidative stress. Autophagy was reported to modulate the inflammatory pathways. However, whether autophagy is involved in regulation of palmitate-induced inflammation of skeletal muscle C2C12 cells is still unknown. The present study aimed to investigate the autophagic pathway in C2C12 cells treated with 0.5 mM palmitate. The results showed that the protein levels of LC3BII and P62 were increased in C2C12 cells after 12 h palmitate treatment. Besides, inhibition of autophagy by chloroquine or 3-methyladenin and its activation by rapamycin were associated with elevated mRNA and protein levels of IL-6 and TNF-α inflammatory cytokines in C2C12 cells. To study the mechanism by which autophagy impairment leads to activation of inflammatory responses, reactive oxygen species (ROS) levels in palmitate-treated cells were measured. The results showed that while palmitate stimulates ROS production, pretreatment of the cells with N-acetyl cysteine (NAC), a ROS scavenger, reduced inflammatory responses and also improved LC3-BII and P62 protein in the C2C12 cells exposed to palmitate. These findings suggest that palmitate-induced defect of autophagic flux leads to elevated inflammatory cytokine expression in the skeletal muscle cells by regulating the oxidative stress process.

Evidence for the link between defective autophagy and inflammation in peripheral blood mononuclear cells of type 2 diabetic patients

Autophagy was shown to modulate inflammation in immune cells. This study was designed to evaluate the association between autophagy and inflammation in peripheral blood mononuclear cells (PBMCs) of type 2 diabetic (T2D) and non-diabetic (ND) subjects. The autophagy markers were measured by real-time PCR and western blot. The gene expression of pro- and anti-inflammatory cytokines was assessed by real-time PCR. Reduced transcription of BECN1 and LAMP2 and unchanged expression of MAP1LC3B and ATG5 were observed in PBMCs of T2D patients. Decreased LC3B-II and increased p62/SQSTM1 levels were found in PBMCs of diabetic patients. The p-mTOR level was higher in PBMCs of diabetic patients. An increase in both IL-1Beta and TNF-alfa gene expression, along with a decrease in the expression of IL-10, was observed in PBMCs of T2D patients. TNF-α mRNA expression was inversely correlated with the mRNA expression of BECN1 and LAMP2. TNF-alfa and IL-1Beta expression were negatively correlated with the protein levels of LC3B-II. TNF-alfa and IL-1Beta expression had also a positive correlation with protein level of p62. IL-10 mRNA expression was positively correlated with the mRNA expression of BECN1 and LAMP2 and protein levels of LC3B-II and negatively correlated with protein level of p62. In addition, p-mTOR level was positively correlated with IL-1Beta and TNF-alfa mRNA expression. The results revealed a reduced autophagy in PBMCs of T2D patients that is liked with an enhanced inflammation. The suppression of autophagy in PBMCs of diabetic patients may be associated with the activation of the mTOR signaling

Evidence for the link between defective autophagy and inflammation in peripheral blood mononuclear cells of type 2 diabetic patients.

Autophagy was shown to modulate inflammation in immune cells. This study was designed to evaluate the association between autophagy and inflammation in peripheral blood mononuclear cells (PBMCs) of type 2 diabetic (T2D) and non-diabetic (ND) subjects. The autophagy markers were measured by real-time PCR and western blot. The gene expression of pro- and anti-inflammatory cytokines was assessed by real-time PCR. Reduced transcription of BECN1 and LAMP2 and unchanged expression of MAP1LC3B and ATG5 were observed in PBMCs of T2D patients. Decreased LC3B-II and increased p62/SQSTM1 levels were found in PBMCs of diabetic patients. The p-mTOR level was higher in PBMCs of diabetic patients. An increase in both IL-1ß and TNF-α gene expression, along with a decrease in the expression of IL-10, was observed in PBMCs of T2D patients. TNF-α mRNA expression was inversely correlated with the mRNA expression of BECN1 and LAMP2. TNF-α and IL-1ß expression were negatively correlated with the protein levels of LC3B-II. TNF-α and IL-1ß expression had also a positive correlation with protein level of p62. IL-10 mRNA expression was positively correlated with the mRNA expression of BECN1 and LAMP2 and protein levels of LC3B-II and negatively correlated with protein level of p62. In addition, p-mTOR level was positively correlated with IL-1ß and TNF-α mRNA expression. The results revealed a reduced autophagy in PBMCs of T2D patients that is liked with an enhanced inflammation. The suppression of autophagy in PBMCs of diabetic patients may be associated with the activation of the mTOR signaling.

Synergistic Effects of Ad-Libitum Low-Dose Fructose Drinking and Low-Dose Streptozotocin Treatment in Wistar Rats: A Mild Model of Type 2 Diabetes.

To develop a convenient animal model of T2D by pretreatment with low-dose 10% w/v fructose (FRC) solution followed by the injection of low doses of streptozotocin (STZ) in Wistar rats. For this 8-week experimental study; rats were first fed a standard chow ad-libitum diet and either tap water (n=40) or 10% w/v FRC solution (n=40) for 4 weeks. Next, rats in each category were randomly allocated to 4 subgroups (n=10 each) of low-dose STZ (25,35, and 45 mg/kg). The final mean fasting blood sugar (FBG) of FRC+STZ45 (197±55.87 mg/dl) were significantly higher than that of the STZ45 (P=0.015) and FRC (P=0.019) groups. FRC+STZ45 showed the highest insulin resistance demonstrated by insulin tolerance test [area under the curve (AUC) of insulin tolerance test; P<0.05]. AUC was not significantly different between the STZ45 and non-STZ groups and between FRC and non-FRC fed groups. Furthermore, FBG levels did not differ between FRC and non-FRC groups. Body weight measurement showed that the FRC+STZ45 group had the lowest body weight compared to all other groups. Our data provide the evidence that FRC and STZ45 synergistically could induce hyperglycemia and insulin resistance in Wistar rats. Here we presented a feasible model for initial forms of T2D by employing pretreatment with low-dose FRC solution and treatment with low-dose STZ.

Decreased expression of microRNA-21 is associated with increased cytokine production in peripheral blood mononuclear cells (PBMCs) of obese type 2 diabetic and non-diabetic subjects.

The aim of this study was to investigate the role of miR-21 in inflammatory responses in peripheral blood mononuclear cells (PBMCs) of type 2 diabetic (T2D) and healthy subjects. 20 healthy and 20 T2D subjects were enrolled in the study. miR-21 expression in PBMCs of the subjects was measured using real-time PCR. IL-6 and TNF-α levels in culture supernatants were quantified using ELISA. miR-21 expression was not significantly different between the diabetic and nondiabetic groups. A downregulation of miR-21 expression was observed in PBMCs of obese subjects in both diabetic and nondiabetic groups. In addition, miR-21 expression was negatively correlated with weight, waist circumference, body mass index, and triglyceride in both the diabetic and nondiabetic groups. Our results also demonstrated that the PBMCs of obese subjects significantly secreted a higher level of IL-6 and TNF-α in comparison with the PBMCs of nonobese subjects. Furthermore, a significant inverse correlation between miR-21 expression and TNF-α and IL-6 production from the PBMCs was observed. These data suggest that miR-21 expression is decreased in PBMCs of obese subjects and reduced expression appears to be associated with increased secreted cytokine level in media of PBMCs of obese subjects.

Downregulated microRNA-155 expression in peripheral blood mononuclear cells of type 2 diabetic patients is not correlated with increased inflammatory cytokine production.

OBJECTIVES: The role of miR-155 in immune responses of PBMCs of type 2 diabetic (T2D) patients has not been studied. DESIGN AND METHODS: 20 Healthy and 20 T2D subjects were participated in the study. miR-155 expression in PBMCs of the subjects was measured using real-time PCR. The levels of secreted IL-6 and TNF-α cytokines were quantified using ELISA. RESULTS: A downregulation of miR-155 expression was observed in untreated and LPS treated PBMCs of diabetic patients compared to controls. There was a significant upregulation of miR-155 after LPS treatment in PBMCs of both control and diabetic groups. In healthy subjects and in both untreated and LPS-treated conditions, miR-155 expression was negatively correlated with weight, waist circumference and body mass index. In diabetic group, there was a negative correlation between miR-155 expression and glucose levels only in LPS treated cells. Furthermore, systolic blood pressure was found to negatively correlate with miR-155 expression in untreated PBMCs of both healthy and diabetic subjects. The results also showed a significant correlation between miR-155 expression and TNF-α and IL-6 levels in LPS treated cells. CONCLUSIONS: Our data demonstrate that miR-155 expression is reduced in PBMCs of diabetic patients and this reduced expression does not seem to be involved in increased cytokine production from PBMCs of these patients.

Protective effect of fish oil supplementation on DNA damage induced by cigarette smoking.

The study examined the influence of fish oil (FO) supplementation on serum 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels as indicated by DNA damage markers and total antioxidant capacity (TAC) among male cigarette smokers. This double-blind, placebo-controlled randomized study was conducted among healthy cigarette smokers (n=40) who were part of a larger prospective cohort study. Twenty smokers were randomly selected to receive FO for 3 months (1 g/day), and another 20 smokers received a placebo for 3 months; 8-OHdG and TAC levels were measured in blood samples before and after the intervention. Serum 8-OHdG significantly decreased (p=0.001) and TAC increased (p<0.001) after 3 months of treatment with FO. Between baseline and endline, the difference in 8-OHdG significantly correlated with the difference in TAC among smokers who received FO (r=-0.540, p=0.014). The study provides evidence that FO supplementation can modify decreased antioxidants and increased oxidative DNA damage in cigarette smokers.

Effect of breastfeeding on serum osteoprotegerin and soluble receptor activator of nuclear factor-kappa B ligand in full term neonates.

BACKGROUND: Human breast milk, the sole source of nutrition during the early neonatal period, is rich in nutrients, hormones, growth factors, and immunoactive molecules, which influence the growth, development, and immune status of the newborn infant. It had long been thought that breast milk is an adequate source of anthracitic activity for the newborns and growing child. OBJECTIVE: Human milk is a complex biologic fluid which contains nutritional and protective factors such as Osteoprotegerin (OPG), at levels 1000-fold higher than normal human serum. Since OPG and Receptor activator of nuclear factor-kappa B ligand (RANKL) system are tightly involved in bone remodeling and immune activity, the study was designated to evaluate the effect of breastfeeding on serum soluble receptor activator of nuclear factor-kappa B ligand (sRANKL) /OPG ratio in full term neonates in comparison with those of formula feeding full term neonates. MATERIALS AND METHODS: In this cross-sectional study serum levels of OPG and sRANKL in 45 breastfed infants were compared to those of 44 formula-fed full term infants. The levels of serum OPG, sRANKL, and Tumor necrosis factor alpha (TNFα) were determined by standard techniques using enzyme-linked immunosorbent assay kits. RESULTS: The serum levels of OPG were significantly higher (P < 0.001), and the concentrations of TNFα was markedly lower (P = 0.024) in breastfed infants than those of formula-fed infants. No marked differences were observed between the serum levels of sRANKL in the two study groups (P = 0.8). CONCLUSIONS: High OPG and low TNFα levels in serum of breastfed infants are important factors involved in remodeling of bone, and immune activity may prove superiority of breastfeeding over formula feeding during infancy.

Effect of fish oil supplements on serum paraoxonase activity in female patients with rheumatoid arthritis: a double-blind randomized controlled trial.

BACKGROUND: This study was conducted to determine the effect of fish oil (FO) supplements on high density lipoprotein cholesterol (HDL-C), apolipoprotein-AI (Apo-AI), malondialdehyde (MDA), arylesterase (Aryl), and paraoxonase-1 (PON1) activity in female patients with rheumatoid arthritis (RA). METHODS: A total of 90 RA patients were randomly allocated into two groups that were treated with one FO pearl (1 gr) daily or placebo for three months in addition to conventional treatment. HDL-C, Apo-AI, and MDA levels as well as PON1 and Aryl activities were measured before and after treatment. Independent t-test was used to match basal parameters of case and control groups. Paired t-test was used to assess significance of the differences. Correlation was evaluated by Pearsons test and the statistical significance was set at P < 0.05. RESULTS: No significant differences were noted between FO and placebo patients with regards to age, disease duration, post-menopausal status, conventional therapy, body mass index (BMI), and numbers of swollen and tender joints at the beginning of the study. There were 83 patients who completed the three-month follow up. Serum levels of HDL-C (P = 0.018), Apo-AI (P = 0.165), Aryl (P = 0.026), and PON1 (P = 0.049) activity increased, whereas MDA levels decreased significantly with FO supplementation (P = 0.077). Significant correlations between increased PON1 activity and both HDL-C (P = 0.007, r = 0.419) and Apo-AI (P < 0.001, r = 0.742) concentrations as well as between HDL-C and Apo AI levels (P = 0.01, r = 0.403) were found. CONCLUSION: According to the results of this study, FO could increase serum HDL-C and PON1 levels and Aryl activity in female patients with RA.

Serum paraoxonase phenotype distribution in exudative age-related macular degeneration and its relationship to homocysteine and oxidized low-density lipoprotein.

PURPOSE: Disequilibrium between oxidative stress and antioxidant levels has been proposed as an important case of exudative age-related macular degeneration (AMD). The aim of the present study was to investigate homocysteine (Hcy) level and antioxidant paraoxonase 1 (PON1) activity within its phenotypes together with oxidized low-density lipoprotein (OX-LDL) levels in the patients with exudative AMD. METHODS: Serum PON1 activity and plasma Hcy and OX-LDL levels were analyzed in 45 exudative AMD patients and compared with 45 healthy controls. Paraoxonase 1 activity was measured in serum using paraoxon and phenylacetate as substrates. The PON1 phenotype was determined using double-substrate method. Homocysteine and OX-LDL levels were determined by enzyme-linked immunosorbent assay method. RESULTS: The distribution of PON1 phenotypes was significantly different between the patients with exudative AMD and control subjects (chi-square = 6.17, P = 0.01). AA phenotype with low activity was significantly more frequent in exudative AMD patients compared with healthy subjects (62.2% vs. 35.6%, respectively). Other phenotype frequencies in the patients compared with controls were as AB phenotype (intermediate activity) 28.9% versus 46.7% and BB phenotype (high activity) 8.9% versus 17.8%, respectively. Except in BB phenotype (P = 0.2), patients with AA and AB phenotypes had higher plasma Hcy levels in comparison to those of controls (P = 0.02 and P = 0.03, respectively). The mean OX-LDL levels, in all 3 phenotypes (P < 0.05), and OX-LDL/high-density lipoprotein ratio, in AA and AB phenotypes (P = 0.001, P = 0.1, respectively) but not in BB (P = 0.1), were significantly higher in the patients than controls. No significant differences in comparison of Hcy and OX-LDL levels between 3 PON1 phenotypes in both control (P = 0.6 for Hcy, P = 0.7 for OX-LDL) and patients (P = 0.8 for Hcy, P = 0.6 for OX-LDL) were found CONCLUSION: Increased plasma OX-LDL levels and ratios of OX-LDL/high-density lipoprotein, as biomarkers of lipoprotein oxidative stress, higher levels of Hcy, as oxidant agent, and more common low or intermediate PON1 activity in patients with exudative AMD, compared with controls, indicate that PON1 activity is insufficient to explain the increased oxidative stress observed in exudative AMD.

Plasma oxidized LDL and thiol-containing molecules in patients with exudative age-related macular degeneration.

PURPOSE: It was proposed that total thiols (tSH) as powerful reducing agents and oxidized low-density lipoprotein (OX-LDL) may be associated with development of choroidal neovascularization in exudative age-related macular degeneration (E-ARMD). METHODS: In a case-control study, 45 patients with E-ARMD were compared with 45 sex- and age-matched healthy controls. The levels of plasma homocysteine (Hcy) and OX-LDL as oxidant agents, and of tSH and glutathione (GSH) as antioxidant markers, were estimated in E-ARMD patients and controls. RESULTS: The levels of Hcy (15.4±7.2 µM versus 10.7±3.7 µM; p=0.001) and OX-LDL (52.2±13.8 U/l versus 37.8±10.8 U/l; p=0.001) were statistically higher, while GSH (1.10±0.97 µM versus 2.09±1.04 µM; p=0.001) and tSH (0.31±0.06 mM versus 0.35±0.05 mM; p=0.001) were statistically lower, in the patients with E-ARMD than in the control group, respectively. The plasma OX-LDL concentration also exhibited a positive and significant correlation with Hcy (r=0.719, p=0.001) in patients with E-ARMD. CONCLUSIONS: Lower GSH and tSH as antioxidant and higher Hcy levels as oxidant agents in E-ARMD patients may have resulted in an oxidative environment that was associated with OX-LDL. Further studies with more cases are required to confirm the hypothesis.

Fish oil supplementation decreases serum soluble receptor activator of nuclear factor-kappa B ligand/osteoprotegerin ratio in female patients with rheumatoid arthritis.

OBJECTIVE: Soluble receptor activator of nuclear factor-kappa B ligand (sRANKL) to osteoprotegerin ratio is designated as a bone metabolism equation in many rheumatologic disorders and would be modified with fish oil (FO) supplementation. DESIGN AND METHODS: Eighty-three females with rheumatoid arthritis were divided randomly to 40 and 43 patients treated with (1 g/day) or without FO for 3 months accompanied with conventional drugs, respectively. Osteoprotegerin, sRANKL, tumor necrosis factor alpha (TNFalpha) serum levels were measured before and after treatment. RESULTS: Serum levels of osteoprotegerin increased, although sRANKL, TNFalpha and sRANKL/osteoprotegerin ratio decreased with FO therapy. A significant positive correlation was observed between sRANKL/osteoprotegerin ratio and TNFalpha levels (r=0.327, p=0.040) in the FO-treated group. CONCLUSIONS: FO could decrease the inflammatory response by lowering of serum TNFalpha levels and sRANKL/osteoprotegerin ratio.