Salivary and Urinary Total Antioxidant Capacity as Biomarkers of Oxidative Stress in Humans

Effects of stannous fluoride dentifrice on gingival health and oxidative stress markers: a prospective clinical trial

BACKGROUND

Periodontal disease results in oral dysbiosis, increasing plaque virulence and oxidative stress. Stannous fluoride (SnF2) binds lipopolysaccharides to reduce plaque virulence. This study prospectively assessed SnF2 effects on oxidative stress in adults with gingivitis.

METHODS

This was a 2-month, single-center, single-treatment clinical trial. Twenty "disease" (> 20 bleeding sites with ≥ 3 pockets 3 mm-4 mm deep) and 20 "healthy" (≤ 3 bleeding sites with pockets ≤ 2 mm deep) adults were enrolled. All participants were instructed to use SnF2 dentifrice twice daily for 2 months. An oral examination, Modified Gingival Index (MGI) examination and Gingival Bleeding Index (GBI) examination were conducted at baseline, 1 month and 2 months. Gingival crevicular fluid (GCF), saliva, oral lavage and supragingival plaque were collected at each visit to evaluate: Endotoxins, Protein Carbonyls, L-lactate dehydrogenase (LDH), Ferric reducing antioxidant power (FRAP), Oxidized low density lipoproteins (oxi-LDL), IL-6 and C-reactive protein (CRP). A subset-analysis examined participants considered at higher risk of cardiovascular disease. Change-from-baseline analyses within each group were of primary interest.

RESULTS

The disease group showed statistically significant reductions in GBI at Month 1 (67%) and Month 2 (85%) and in MGI at Month 1 (36%) and Month 2 (51%) versus baseline (p < 0.001). At baseline, the disease group showed greater LDH in GCF and oxi-LDL levels in saliva versus the healthy group (p ≤ 0.01). Total antioxidant capacity (FRAP) in saliva increased versus baseline for the disease group at Months 1 and 2 (p < 0.05), and levels for the disease group were greater than the healthy group at both timepoints (p < 0.05). SnF2 treatment reduced endotoxins (lavage) for both disease and healthy groups at Month 2 (p ≤ 0.021) versus baseline. There was a reduction in oxidative stress markers, namely protein carbonyl in saliva, at Months 1 and 2 (p < 0.001) for both groups and a reduction in cytokine IL-6 (lavage) in the disease group at Month 2 (p = 0.005). A subset analysis of participants at higher coronary disease risk showed reductions in endotoxins in lavage, oxi-LDL, and CRP in saliva at Month 2 (p ≤ 0.04).

CONCLUSION

SnF2 dentifrice use reversed gingival inflammation, suppressed endotoxins and reduced some harmful oxidant products in saliva and gingiva.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov NCT05326373, registered on 13/04/2022.

Concentrations of Glypican-4, Irisin and Total Antioxidant Status in Women with Metabolic Syndrome: Influence of Physical Activity

Glypican-4 belongs to a group of poorly understood adipokines, with potential importance in people with metabolic syndrome, especially in groups of patients with glucose metabolism disorder. This study aimed to assess the effect of physical activity on serum glypican-4 and irisin levels and total antioxidant status (TAS) in plasma and saliva in women with metabolic syndrome (MetS). Seventy-two Caucasian women aged 25-60 were included in the study (36 women with MetS and 36 women without MetS (control group, CONTR)). The glypican-4 and irisin concentrations, total antioxidant status, glycemia, lipid profile, anthropometric parameters, and blood pressure were analyzed before and after 28 days of controlled physical activity. Serum glypican-4 and plasma TAS levels were higher (p = 0.006 and p = 0.043, respectively) on the 28th day than on the first day of the study only in the CONTR group. In the MetS group, 28 days of physical activity caused a reduction in body fat mass (p = 0.049) without changes in glypican-4, irisin, or TAS levels. In both groups, glypican-4 levels correlated positively with irisin levels and negatively with Waist-Hip Ratio (WHR), while irisin levels correlated positively with High-Density Lipoprotein Cholesterol (HDL-C) levels and negatively with waist circumference (WC) and WHR values on the 28th day of the study. To summarize, a 28-day moderate training, accompanied by a reduction in body fat mass, stabilized glypican-4 levels and TAS in female patients with MetS.

Platelet-rich plasma attenuates the UPEC-induced cystitis via inhibiting MMP-2,9 activities and downregulation of NGF and VEGF in Canis Lupus Familiaris model

One of the most prevalent disorders of the urinary system is urinary tract infection, which is mostly brought on by uropathogenic Escherichia coli (UPEC). The objective of this study was to evaluate the regenerative therapeutic and antibacterial efficacy of PRP for induced bacterial cystitis in dogs in comparison to conventional antibiotics. 25 healthy male mongrel dogs were divided into 5 groups (n = 5). Control negative group that received neither induced infection nor treatments. 20 dogs were randomized into 4 groups after two weeks of induction of UPEC cystitis into; Group 1 (control positive; G1) received weekly intravesicular instillation of sodium chloride 0.9%. Group 2 (syst/PRP; G2), treated with both systemic intramuscular antibiotic and weekly intravesicular instillation of PRP; Group 3 (PRP; G3), treated with weekly intravesicular instillation of PRP, and Group 4 (syst; G4) treated with an intramuscular systemic antibiotic. Animals were subjected to weekly clinical, ultrasonographic evaluation, urinary microbiological analysis, and redox status biomarkers estimation. Urinary matrix metalloproteinases (MMP-2, MMP-9) and urinary gene expression for platelet-derived growth factor -B (PDGF-B), nerve growth factor (NGF), and vascular endothelial growth factor (VEGF) were measured. At the end of the study, dogs were euthanized, and the bladder tissues were examined macroscopically, histologically, and immunohistochemically for NF-κB P65 and Cox-2. The PRP-treated group showed significant improvement for all the clinical, Doppler parameters, and the urinary redox status (p < 0.05). The urinary MMPs activity was significantly decreased in the PRP-treated group and the expression level of urinary NGF and VEGF were downregulated while PDGFB was significantly upregulated (p < 0.05). Meanwhile, the urinary viable cell count was significantly reduced in all treatments (P < 0.05). Gross examination of bladder tissue showed marked improvement for the PRP-treated group, expressed in the histopathological findings. Immunohistochemical analysis revealed a marked increase in Cox-2 and NF-κB P65 in the PRP-treated group (P < 0.05). autologous CaCl2-activated PRP was able to overcome the bacterial infection, generating an inflammatory environment to overcome the old one and initiate tissue healing. Hence, PRP is a promising alternative therapeutic for UPEC cystitis instead of conventional antibiotics.

Urine biomarker could be a useful tool for differential diagnosis of a lower urinary tract dysfunction

A precision diagnosis of lower urinary tract dysfunctions (LUTD) such as bladder outlet obstruction, detrusor overactivity (DO), interstitial cystitis/bladder pain syndrome (IC/BPS), dysfunctional voiding (DV), or detrusor underactivity (DU) needs invasive videourodynamic study. Exploring non-invasive tools to help screening LUTD is necessary for clinicians in their daily practice. This article reviews recently clinical studies of using urinary inflammatory proteins and oxidative stress biomarkers in the identification of specific LUTD among men and women with lower urinary tract symptoms (LUTS). Some important findings have been reported: (1) Using urine chemokines CXCL-1 and interleukin-8 (IL-8), we may discriminate overactive bladder (OAB) symptoms in women between DO and urinary tract infection. (2) Urinary levels of oxidative stress biomarkers such as 8-hydroxydeoxyguanosine (8-OHdG) and 8-isoprostane have a potential being used as a tool to identify women with mixed DO and stress urinary incontinence. (3) Urine levels of total antioxidant capacity (TAC), and prostaglandin E2 (PGE2) are positively correlated with voiding detrusor pressure in patients with DU. (4) Urine levels of brain-derived neurotrophic factor (BDNF) and PGE2 were significantly higher in the DU patients with detrusor function recovery. (5) Women with DV had higher urinary levels of tumor necrosis factor-alpha (TNF-α) and 8-OHdG, and urinary IL-2 level was significantly lower. (6) Urine level of 8-isoprostane was higher in the patients with idiopathic DO and neurogenic DO. (7) Higher urine cytokine levels of monocyte chemoattractant protein-1 (MCP-1), regulated on activation, normal T-cell expressed and secreted (RANTES), CXCL-10, IL-7, and eotaxin-1 in patients with IC/BPS than controls. (8) The urine levels of IL-8, CXCL-10, BDNF, IL-6, and RANTES were significantly higher in patients with Hunner's IC than non-Hunner's IC. (9) Male patients with IC/BPS had a significantly higher level of eotaxin, MCP-1, TNF-α, 8-OHdG, and TAC. Combining a higher eotaxin and a higher TNF-α can provide a satisfactory diagnostic value in discriminating IC/BPS from other LUTD in men. These studies provide evidence that measurement of cluster of urine biomarkers could be used as a diagnostic tool to differentiate different LUTD in patients with similar LUTS.

Circulating biomarkers of oxidative stress in people with acne vulgaris: a systematic review and meta-analysis

The relationship between acne vulgaris and oxidative stress biomarkers lacks a clear consensus. This study aimed to explore the potential correlation between acne vulgaris and circulating oxidative stress biomarkers (superoxide dismutase [SOD], malondialdehyde [MDA], and total antioxidant capacity [TAC]). We searched the PubMed, Embase, and Cochrane Library databases for articles published before June 26, 2023. The literature search combined free words and the medical subject headings terms related to acne vulgaris, SOD, MDA, and TAC. Data were analyzed using Stata 15 software. Additionally, we conducted a subgroup analysis stratified by the severity of acne vulgaris. A total of 14 trials involving 1191 participants were included. Overall results revealed that acne vulgaris was associated with MDA concentrations (SMD = 1.73; 95% CI 1.05, 2.4; P < 0.001). Subgroup analyses indicated that the severity of acne vulgaris was correlated with levels of circulating biomarkers of oxidative stress. TAC concentrations were significantly lower in patients with moderate acne vulgaris compared to controls (SMD =  - 1.37; 95% CI =  - 2.15, - 0.58, P = 0.001). SOD concentrations were significantly lower (SMD =  - 2.92; 95% CI =  - 5.39, - 0.46, P = 0.02) and MDA concentrations were significantly higher (SMD = 2.26; 95% CI = 0.95, 3.57, P = 0.001) in patients with severe acne vulgaris compared to controls. Our results implied that oxidative stress may exist in acne vulgaris. Furthermore, the severity of acne vulgaris was also correlated with oxidative stress.

Electrochemical platform produced by 3D printing for analysis of small volumes using different electrode materials

Fused deposition modeling (FDM) 3D printing is a promising additive manufacturing technique to produce low-cost disposable electrochemical devices. However, the print of devices like well-known screen-printed electrodes (all electrodes on the same device) is difficult using the available technology (few materials available for production of working electrodes). In this paper we present a procedure to produce disposable and robust electrochemical devices by FDM 3D printing that allows reproducible analysis of small volumes (50-2000 μL). The device consists of just two printed parts that allow easy coupling of different conductive materials for using as disposable or non-disposable working electrodes with reproducible geometric area. Printed counter and pseudo-reference electrodes can also be easily fitted into the microcell. Moreover, conventional counter (platinum wire) and mini reference electrodes can also be used. As a proof of concept, paracetamol, cocaine and uric acid were used as model analytes using different materials as working electrodes. Linear calibration curves (r > 0.99) with similar slopes (0.29 ± 0.01 μA μmol L-1; RSD = 3.4%) were obtained by square wave voltammetry (SWV) using a complete printed system and different volumes of standard solutions of paracetamol (50, 100, and 200 μL). For uric acid, a linear range of 10-125 μmol L-1 (r > 0.99), was obtained using differential pulse voltammetry as the electrochemical technique and a disposable laser-induced graphene base as the working electrode. With the coupling of boron-doped diamond working electrode, screening tests were successfully performed in seized cocaine samples with selective detection of cocaine in the presence of its most common adulterants. The production cost per unit of a complete electrochemical system is around US 5.00. In large-scale production, only the working electrode needs to be replaced while the microcell and counter/pseudo reference electrodes do not need to be discarded.

Effect of In Ovo Administration of a Multi-Strain Probiotic and Zinc Glycine Chelate on Antioxidant Capacity and Selected Immune Parameters in Newly Hatched Chicks

The aim of this study was to determine the effect of in ovo co-supplementation of chicken embryos with a multi-strain probiotic containing effective microorganisms and zinc glycine chelate on total antioxidant capacity; concentrations of sulfhydryl groups, bityrosine bridges, formylkynurenines, hydroperoxides, proteins, corticosterone, pro- and anti-inflammatory cytokines and heat shock proteins; and the activity of catalase and superoxide dismutase in the serum, yolk sac and tissues of broiler chickens at 12 h and at 7 days after hatching. The results indicate high SOD activity in the small and large intestines of chicks at 12 h post-hatch in the groups receiving the multi-strain probiotic and in the small intestine and yolk sac of birds receiving the multi-strain probiotic and Zn-Gly chelate. High concentrations of TNF-α and IFN-γ in the yolk sac and serum after in ovo administration of Zn-Gly chelate were observed 12 h after hatching. The use of a probiotic and a probiotic with Zn-Gly chelate increased the total antioxidant capacity in the tissues of chickens. It can be concluded that in ovo administration of a multi-strain probiotic and Zn-Gly chelate can maintain the oxidant/antioxidant balance in chickens and increase the defense capacity against oxidative stress.

Maternal oxidative stress during pregnancy associated with emotional and behavioural problems in early childhood: implications for foetal programming

Childhood mental disorders, including emotional and behavioural problems (EBP) are increasingly prevalent. Higher maternal oxidative stress (OS) during pregnancy (matOSpreg) is linked to offspring mental disorders. Environmental factors contribute to matOSpreg. However, the role of matOSpreg in childhood EBP is unclear. We investigated the associations between (i) matOSpreg and offspring EBP; (ii) social and prenatal environmental factors and matOSpreg; and (iii) social and prenatal factors and childhood EBP and evaluated whether matOSpreg mediated these associations. Maternal urinary OS biomarkers, 8-hydroxyguanosine (8-OHGua; an oxidative RNA damage marker) and 8-hydroxy-2'-deoxyguanosine (8-OHdG; an oxidative DNA damage marker), at 36 weeks of pregnancy were quantified by liquid chromatography-mass spectrometry in a population-derived birth cohort, Barwon Infant Study (n = 1074 mother-infant pairs). Social and prenatal environmental factors were collected by mother-reported questionnaires. Offspring total EBP was measured by Child Behavior Checklist Total Problems T-scores at age two (n = 675) and Strengths and Difficulties Questionnaire Total Difficulties score at age four (n = 791). Prospective associations were examined by multivariable regression analyses adjusted for covariates. Mediation effects were evaluated using counterfactual-based mediation analysis. Higher maternal urinary 8-OHGua at 36 weeks (mat8-OHGua36w) was associated with greater offspring total EBP at age four (β = 0.38, 95% CI (0.07, 0.69), P = 0.02) and age two (β = 0.62, 95% CI (-0.06, 1.30), P = 0.07). Weaker evidence of association was detected for 8-OHdG. Five early-life factors were associated with both mat8-OHGua36w and childhood EBP (P-range < 0.001-0.05), including lower maternal education, socioeconomic disadvantage and prenatal tobacco smoking. These risk factor-childhood EBP associations were partly mediated by higher mat8-OHGua36w (P-range = 0.01-0.05). Higher matOSpreg, particularly oxidant RNA damage, is associated with later offspring EBP. Effects of some social and prenatal lifestyle factors on childhood EBP were partly mediated by matOSpreg. Future studies are warranted to further elucidate the role of early-life oxidant damage in childhood EBP.

Salivary stimulatory effect of novel low level transcutaneous electro neurostimulator in geriatric patients with xerostomia

BACKGROUND

Xerostomia (dryness of the mouth) is one of the most common long-term consequences of ageing, and it causes a tremendous impact on the function and morphology of the salivary ductal system. As a consequence, it leads to a decrease in the amount of salivary output and also affects the overall quality of life. The purpose of this study was to determine whether electrostimulation using a custom designed transcutaneous electrical nerve stimulation (TENS) device will help to improve the quality of secreted saliva following electrostimulation.

METHODS

One hundred thirty-five participants underwent the intervention for three months, twice daily (80 Hz). Pre-intervention and post-intervention unstimulated saliva were collected. Parameters such as salivary pH, cortisol level, salivary antioxidants, total protein, the viscosity of saliva, and microbial carriage were analysed.

RESULTS

Salivary pH, cortisol, microbial cultures, viscosity, and antioxidants showed a significant difference at the end of the 3rd month (p < 0.05). Irrespective of the patient's age, gender, and common underlying systemic illnesses (diabetes and hypertension), a significant change in the quality of the salivary analytes was observed.

CONCLUSION

The study emphasises the use of a custom designed TENS device in improving the quality of secreted saliva among old patients with oral dryness.

A Pilot Study on Oxidative Stress during the Recovery Phase in Critical COVID-19 Patients in a Rehabilitation Facility: Potential Utility of the PAOT® Technology for Assessing Total Anti-Oxidative Capacity

BACKGROUND

Oxidative stress (OS) could cause various COVID-19 complications. Recently, we have developed the Pouvoir AntiOxydant Total (PAOT®) technology for reflecting the total antioxidant capacity (TAC) of biological samples. We aimed to investigate systemic oxidative stress status (OSS) and to evaluate the utility of PAOT® for assessing TAC during the recovery phase in critical COVID-19 patients in a rehabilitation facility.

MATERIALS AND METHODS

In a total of 12 critical COVID-19 patients in rehabilitation, 19 plasma OSS biomarkers were measured: antioxidants, TAC, trace elements, oxidative damage to lipids, and inflammatory biomarkers. TAC level was measured in plasma, saliva, skin, and urine, using PAOT and expressed as PAOT-Plasma, -Saliva, -Skin, and -Urine scores, respectively. Plasma OSS biomarker levels were compared with levels from previous studies on hospitalized COVID-19 patients and with the reference population. Correlations between four PAOT scores and plasma OSS biomarker levels were analyzed.

RESULTS

During the recovery phase, plasma levels in antioxidants (γ-tocopherol, β-carotene, total glutathione, vitamin C and thiol proteins) were significantly lower than reference intervals, whereas total hydroperoxides and myeloperoxidase (a marker of inflammation) were significantly higher. Copper negatively correlated with total hydroperoxides (r = 0.95, p = 0.001). A similar, deeply modified OSS was already observed in COVID-19 patients hospitalized in an intensive care unit. TAC evaluated in saliva, urine, and skin correlated negatively with copper and with plasma total hydroperoxides. To conclude, the systemic OSS, determined using a large number of biomarkers, was always significantly increased in cured COVID-19 patients during their recovery phase. The less costly evaluation of TAC using an electrochemical method could potentially represent a good alternative to the individual analysis of biomarkers linked to pro-oxidants.

Enhanced Peroxidase-Mimic Catalytic Activity via Cerium Doping of Strontium-Based Metal-Organic Frameworks with Design of a Smartphone-Based Sensor for On-Site Salivary Total Antioxidant Capacity Detection in Lung Cancer Patients

The development of artificial nanozymes with superior catalytic performance and excellent stability has been a long-standing objective for chemists. The total antioxidant capacity (TAC) is one of the most important bioanalytical measures of oxidative stress in the body. The present work aims to develop a smartphone-assisted visual detection sensor using cerium-doped strontium-based metal-organic frameworks (Ce-SrMOFs) as peroxidase-like nanozymes for the rapid, low-cost, on-site detection of TAC. The pristine SrMOF functioned as a peroxidase nanozyme, and its enzymatic activity was enhanced after doping it with Ce(IV) ions because of the multivalent nature and synergistic impact of the heteroatoms. The Ce-SrMOFs were sensitive to the single electron transfer and hydrogen atom transfer processes, which implies that the Ce-SrMOFs can serve as an ideal nanozyme candidate for TAC analysis. The investigated mechanism revealed that •OH is the most active oxygen species for the peroxidase-like activity. The Ce-SrMOFs exhibited a strong affinity for 3,3',5,5'-tetramethylbenzidine (TMB) and H₂O₂, with K_m values of 0.082 and 0.427 mM, which are 5.29- and 8.67-fold lower than those of horseradish peroxidase (HRP), respectively. The Ce-SrMOFs were used for the detection of ascorbic acid, cysteine, and glutathione, with limits of detection of 44, 53, and 512 nM, respectively. The proposed method proved effective in measuring the TAC in saliva samples from lung cancer patients, thereby yielding results with satisfactory precision and accuracy.

Semiconducting Polymer Nanoparticles-Manganese Based Chemiluminescent Platform for Determining Total Antioxidant Capacity in Diabetic Mice

The total antioxidant capacity (TAC) is a key indicator of the body's resistance to oxidative stress injury in diabetic patients. The measurement of TAC is important for effectively evaluating the redox state to prevent and control the occurrence of diabetes complications. However, there is a lack of a simple, convenient, and reliable method to detect the total antioxidant capacity in diabetes. Herein, we design a novel chemiluminescent platform based on semiconducting polymer nanoparticles-manganese (SPNs-Mn^VII) to detect the total antioxidant capacity of urine in diabetic mice. We synthesize semiconducting polymer nanoparticles with four different structures and discover the ability of Mn^VII to produce singlet oxygen (¹O₂) that is employed to excite thiophene-based SPNs (PFODBT) to emit near-infrared chemiluminescence. Notably, the chemiluminescent intensity has a good linear relationship with the concentration of Mn^VII (detection limit: 2.8 μM). Because antioxidants (e.g., glutathione or ascorbic acid) can react with Mn^VII, such a chemiluminescent tool of SPNs (PFODBT)-Mn^VII can detect the glutathione or ascorbic acid with a larger responsive range. Furthermore, the total antioxidant capacity of urine from mice is evaluated via SPNs (PFODBT)-Mn^VII, and there are statistically significant differences between diabetic and healthy mice. Thus, this new chemiluminescent platform of SPNs (PFODBT)-Mn^VII is convenient, efficient, and sensitive, which is promising for monitoring antioxidant therapy of diabetes.

Salivary Antioxidant Capacity and Magnesium in Generalized Anxiety Disorder

Generalized anxiety disorder (GAD) is a prevalent disorder. The search for biomarkers may contribute to new knowledge about molecular pathogenesis and treatment. Since oxidative stress and micronutrient imbalance play a key role in the development of mental disorders, we aimed to study salivary antioxidant capacity and magnesium in patients with GAD in an anxiety model of solving problems with increasing complexity. The study subgroup consisted of 15 patients with GAD, and 17 healthy volunteers of the same age made up the control subgroup. Participants took a test with six levels of difficulty, which included false feedback. In this test, the participants were asked to remember the colors of balloons and react when the color changed. The reaction time, the number of correct answers, as well as biochemical parameters such as the antioxidant capacity of saliva and salivary magnesium, were assessed. There was no difference in the results of the quest between the subgroups; however, anxious participants spent more time at the moment of experimental frustration due to incorrect feedback and additional negative psycho-emotional load. Antioxidant capacity did not differ between the subgroups both before and after the experimental session. Average antioxidant capacity also did not change significantly at the endpoint of the experiment. However, the endpoint antioxidant capacity correlated negatively with the reaction time in anxious patients in the second block (where the false feedback as a frustrating factor appeared). Magnesium was initially significantly higher in the group of anxious participants and decreased at the experiment endpoint; in healthy patients, there were no changes in salivary magnesium at the endpoint. In conclusion, the compensatory potential of oxidative metabolism and magnesium in patients with GAD was spent with additional psycho-emotional stress, in contrast to healthy individuals, but it was sufficient to avoid exhaustion during experimental frustrating exposure.

Evaluation of salivary parameters and Streptococcus' Mutans count in children with cerebral palsy in Egypt: a case control study

BACKGROUND

Children with cerebral palsy (CP) are at high risk for dental caries. Alteration of some salivary properties encountered among them compared to healthy children, could play a role in this elevated risk.

OBJECTIVES

The aim of the present study was to assess salivary physicochemical properties; including total antioxidant (TAC), flow rate, viscosity, pH and buffering capacity, as well as Streptococcus mutans level among children with CP, also to correlate these variables to their caries experience.

MATERIALS AND METHODS

This case control study included 80 children with CP, study group (SG) and matched number of healthy children for control group (CG). Interview-based questionnaire, clinical examination, salivary biochemical and microbiological investigations using MALDI-TOF were done.

RESULTS

In SG, the caries experience in primary teeth dmft and S. mutans log value were significantly higher than CG (P = 0.039, P = 0.002) while unstimulated salivary flow rate, buffering capacity and salivary TAC were significantly lower (P < 0.0001). Multivariate linear regression showed that the presence of CP was significantly associated with the greatest variation in caries experience in the primary teeth and permanent teeth. Higher unstimulated salivary flow rate, or an increase in buffering capacity by 1 ml of acid/ml of saliva were associated with lower number of the affected primary and permanent teeth. On the other hand, One-unit increase in S. mutans log count and higher salivary TAC were associated with higher caries experience.

CONCLUSION

Children with CP have higher caries experience (dmf) due to lower salivary protective factors and higher S. mutans counts.

Comparison of Salivary Interleukin-6, Interleukin-8, C - reactive protein levels and Total Antioxidants Capacity of Obese Individuals with Normal Weight Ones

Objective: Obesity is a worldwide concern that may lead in type 2 diabetes, cardiovascular diseases, etc. Several serum biomarkers have been identified in the saliva of obese individuals, including inflammatory cytokines, adipokines, insulin, and cortisol. The present study aimed to compare salivary interleukin-6(IL-6), interleukin-8(IL-8), C-reactive protein (CRP) levels and total antioxidants capacity (TAC) of obese individuals with normal-weighted ones.

Methods: In this case–control study, 92 participants matched in terms of age and gender were placed into two groups according to the body mass index (BMI); case group: BMI>30 and control group: 18.5<BMI<24.99. Unstimulated saliva was collected. ELISA and FRAP method were used to determine IL-6, IL-8, CRP and TAC. Data was analyzed using SPSS 24, at the significant level of 0.05.

Results: Mean salivary levels of IL-6 and IL-8 in the normal individuals were 53.36 and 421.25ng/mL, with 86.09ng/mL and 510.19ng/mL in obese individuals, respectively. There were significant differences in the mean salivary levels of IL-6 and IL-8 between two experimental groups.

The mean salivary levels of CRP of control and case group was 2.84 and2.63 ng/mL and the total salivary antioxidant levels in the normal and obese individuals were 0.29 and 0.36, respectively which had no significant different.

Conclusion: According to the results of the present study, salivary levels IL-8 and IL-6 was significantly higher in obese individuals than in those with normal weight. However, the mean salivary CRP and TAC were not significantly different between the obese individuals and normal-weighted ones.

Effects of Calorie Restricted Diet on Oxidative/Antioxidative Status Biomarkers and Serum Fibroblast Growth Factor 21 Levels in Nonalcoholic Fatty Liver Disease Patients: A Randomized, Controlled Clinical Trial

Oxidative stress plays a fundamental role in the development and progression of nonalcoholic fatty liver disease (NAFLD). This study aimed to investigate the effects of a calorie-restricted (CR) diet on oxidative/anti-oxidative status in patients with NAFLD and the potential mediating role of fibroblast growth factor 21 (FGF-21) in this regard. This randomized, controlled clinical trial was carried out on sixty patients with NAFLD aged 20 to 60 years with body mass index (BMI) ranging from 25 to 35 kg/m2. Participants were randomly assigned to either the CR diet group (received a prescribed low-calorie diet for twelve weeks, n = 30) or the control group (n = 30). Fasting blood samples, anthropometric measurements, dietary intake, and physical activity data were collected for all participants at baseline and at the end of the trial. Significant reductions in weight, BMI, waist circumference, and serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were observed in the CR diet group compared to the control group (all p < 0.05). Liver steatosis grade, serum levels of malondialdehyde (MDA), total antioxidant capacity (TAC), and FGF-21, as well as erythrocyte superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities did not show significant changes in the CR group when compared to the controls at the end of the study (p > 0.05). CR diet with moderate weight loss has some favorable effects on NAFLD but was not able to modify oxidative/anti-oxidative status in these patients. Future studies are warranted to target the effects of long-term interventions with a greater weight loss in this patient population.

Diagnostic and prognostic value of urine biomarkers among women with dysfunctional voiding

The current study aimed to investigate the diagnostic and prognostic value of urine biomarkers among female patients with dysfunctional voiding (DV). Urine samples were collected from 43 female patients with DV and 25 controls. Oxidative stress biomarkers (8-hydroxy-2-deoxyguanosine [8-OHdG], 8-isoprostane, and total antioxidant capacity [TAC]) and inflammatory markers (interleukin-1 beta [IL-1β], IL-2, IL-6, IL-8, tumor necrosis factor alpha, nerve growth factor, and brain-derived neurotrophic factor) levels were analyzed. In total, 26 patients with DV received further treatment with biofeedback pelvic floor muscle exercise or external urethral sphincter botulinum toxin A injections. Patients with DV had significantly higher urine 8-OHdG, IL-1β, IL-8, and brain-derived neurotrophic factor levels than controls. Both urine 8-OHdG and IL-1β levels were positively correlated with clinical symptoms. Patients with DV who had successful treatment outcomes had significantly lower pretreatment urine 8-isoprostane and TAC levels than those with unsuccessful outcomes. The pretreatment urine TAC level was the only independent predictor of successful treatment outcomes (odds ratio: 0.995). Compared with controls, female patients with DV had distinct urine oxidative stress biomarker and inflammatory marker profiles, which also mapped their clinical characteristics and treatment outcomes. These urine analytes might have diagnostic and prognostic values among female patients with DV.

Effect of Normobaric Hypoxia on Alterations in Redox Homeostasis, Nitrosative Stress, Inflammation, and Lysosomal Function following Acute Physical Exercise

Hypoxia is a recognized inducer of oxidative stress during prolonged physical activity. Nevertheless, previous studies have not systematically examined the effects of normoxia and hypoxia during acute physical exercise. The study is aimed at evaluating the relationship between enzymatic and nonenzymatic antioxidant barrier, total antioxidant/oxidant status, oxidative and nitrosative damage, inflammation, and lysosomal function in different acute exercise protocols under normoxia and hypoxia. Fifteen competitive athletes were recruited for the study. They were subjected to two types of acute cycling exercise with different intensities and durations: graded exercise until exhaustion (GE) and simulated 30 km individual time trial (TT). Both exercise protocols were performed under normoxic and hypoxic ( $\text{Fi}{\text{O}}_2=16.5\%$ ) conditions. The number of subjects was determined based on our previous experiment, assuming the test $\text{power}=0.8$ and $\alpha =0.05$ . We demonstrated enhanced enzymatic antioxidant systems during hypoxic exercise (GE: ↑ catalase (CAT), ↑ superoxide dismutase; TT: ↑ CAT) with a concomitant decrease in plasma reduced glutathione. In athletes exercising in hypoxia, redox status was shifted in favor of oxidation reactions (GE: ↑ total oxidant status, ↓ redox ratio), leading to increased oxidation/nitration of proteins (GE: ↑ advanced oxidation protein products (AOPP), ↑ ischemia-modified albumin, ↑ 3-nitrotyrosine, ↑ S-nitrosothiols; TT: ↑ AOPP) and lipids (GE: ↑ malondialdehyde). Concentrations of nitric oxide and its metabolites (peroxynitrite) were significantly higher in the plasma of hypoxic exercisers with an associated increase in inflammatory mediators (GE: ↑ myeloperoxidase, ↑ tumor necrosis factor-alpha) and lysosomal exoglycosidase activity (GE: ↑ N-acetyl-β-hexosaminidase, ↑ β-glucuronidase). Our study indicates that even a single intensive exercise session disrupts the antioxidant barrier and leads to increased oxidative and nitrosative damage at the systemic level. High-intensity exercise until exhaustion (GE) alters redox homeostasis more than the less intense exercise (TT, near the anaerobic threshold) of longer duration ( $20.2\pm 1.9$  min vs. $61.1\pm 5.4$  min—normoxia; $18.0\pm 1.9$  min vs. $63.7\pm 3.0$  min—hypoxia), while hypoxia significantly exacerbates oxidative stress, inflammation, and lysosomal dysfunction in athletic subjects.

Redefining the Cut-Off Ranges for TSH Based on the Clinical Picture, Results of Neuroimaging and Laboratory Tests in Unsupervised Cluster Analysis as Individualized Diagnosis of Early Schizophrenia

Thyroid abnormalities, including mild forms of hypothyroidism and hyperthyroidism, are reported as risk factors for the development of a number of neuropsychiatric disorders, including schizophrenia. The diagnostic process still takes into account the extreme ranges of the accepted reference values for serum TSH since the concentration of free thyroxine in the serum does not change by definition. TSH mU/L cut-off values in psychiatric patients are currently clinically considered in the case of extremely high serum TSH levels (>4.0 mU/L). The results obtained in this study suggest that the clinically significant value has a lower TSH cut-off point with an upper limit of 2–2.5 mU/L. The criteria for the differential diagnosis of patients with schizophrenia, however, mainly take into account statutory reference ranges without a background related to the history of thyroid diseases in the family. The results indicate the need to lower the upper cut-off values for TSH among patients with early psychosis, which is related to the potential clinical significance of the obtained values both in the field of clinical evaluation and neuroimaging and laboratory evaluation parameters. The cut-off points obtained with the prior available knowledge coincided with the values established in the unsupervised clustering method, which further confirms the legitimacy of their use in the individualized diagnosis strategy of schizophrenia.

An investigation of different intracellular parameters for Inborn Errors of Metabolism: Cellular stress, antioxidant response and autophagy

Oxidative stress is associated with various disease pathologies including Inborn Errors of Metabolism (IEMs), among the most important causes of childhood morbidity and mortality. At least as much as oxidative stress in cells, reductive stress poses a danger to the disruption of cell homeostasis. p62/SQSTM1, protects cells from stress by activation of Nrf2/Keap1 and autophagy pathways. In this study, we tested the role of cellular stress, mitochondrial dysfunction and autophagy via Nrf2/Keap1/p62 pathway in the pathophysiology of three main groups of IEMs. Our results showed that antioxidant and oxidant capacity alone would not be sufficient to reflect the true clinical picture of these diseases. ATP, ROS and mitochondrial membrane potantial (MMP) measurements demonstrated increased cellular stress and bioenergetic imbalance in methylmalonic acidemia (MMA), indicating mild mitochondrial dysfunction. In isovaleric acidemia (IVA), no major change was detected in ATP, ROS and MMP values. Propionic acidemia (PA), mitochondrial diseases (MIT) and mucopolysaccharidosis IV (MPS IV) might point out mitohormesis to cope with chronic reductive stress. Induction of Nrf2/Keap1/p62 pathway and increased expression of HMOX1 were detected in all IEMs. LC3B-II and p62 expression results indicated an impaired autophagic flux in MIT and MPS IV and an induction of autophagic flux in MMA, PA and IVA, but also partial expression of Beclin1, enables autophagy activation, was detected in all IEMs. We conclude that individual diagnosis and treatments are of great importance in IEMs. In addition, we assume that the application of therapeutic antioxidant or preventive treatments without determining the cellular stress status in IEMs may disrupt the sensitive oxidant-antioxidant balance in the cell, leading to the potential to further disrupt the clinical picture, especially in patients with reductive stress. To the best of our knowledge, this is the first study to simultaneously relate IEMs with cellular stress, mitochondrial dysfunction, and autophagy.

New conductive filament ready-to-use for 3D-printing electrochemical (bio)sensors: Towards the detection of SARS-CoV-2

The 3D printing technology has gained ground due to its wide range of applicability. The development of new conductive filaments contributes significantly to the production of improved electrochemical devices. In this context, we report a simple method to producing an efficient conductive filament, containing graphite within the polymer matrix of PLA, and applied in conjunction with 3D printing technology to generate (bio)sensors without the need for surface activation. The proposed method for producing the conductive filament consists of four steps: (i) mixing graphite and PLA in a heated reflux system; (ii) recrystallization of the composite; (iii) drying and; (iv) extrusion. The produced filament was used for the manufacture of electrochemical 3D printed sensors. The filament and sensor were characterized by physicochemical techniques, such as SEM, TGA, Raman, FTIR as well as electrochemical techniques (EIS and CV). Finally, as a proof-of-concept, the fabricated 3D-printed sensor was applied for the determination of uric acid and dopamine in synthetic urine and used as a platform for the development of a biosensor for the detection of SARS-CoV-2. The developed sensors, without pre-treatment, provided linear ranges of 0.5-150.0 and 5.0-50.0 μmol L^-1, with low LOD values (0.07 and 0.11 μmol L^-1), for uric acid and dopamine, respectively. The developed biosensor successfully detected SARS-CoV-2 S protein, with a linear range from 5.0 to 75.0 nmol L^-1 (0.38 μg mL^-1 to 5.74 μg mL^-1) and LOD of 1.36 nmol L^-1 (0.10 μg mL^-1) and sensitivity of 0.17 μA nmol^-1 L (0.01 μA μg^-1 mL). Therefore, the lab-made produced and the ready-to-use conductive filament is promising and can become an alternative route for the production of different 3D electrochemical (bio)sensors and other types of conductive devices by 3D printing.

Systematic Review and Meta-Analysis of Oxidative Stress and Antioxidant Markers in Oral Lichen Planus

Background

Oral lichen planus (OLP) is a relatively common chronic inflammatory disease of unknown etiology, which might be caused by oxidative stress and impaired antioxidant defense.

Objective

To systematically investigate the markers of oxidative stress and antioxidant systems in the saliva and blood from OLP patients and healthy controls.

Methods

The PubMed, Cochrane Library, and Embase were systematically queried to collect data from studies in which oxidative stress/antioxidant markers from OLP and healthy subjects had been evaluated until March 10, 2021.

Results

A total of 28 studies fulfilled inclusion criteria, and 25 of them, having 849 OLP patients and 1,052 control subjects and analyzing 12 oxidative stress and antioxidant state marker levels, were subjected to meta-analysis. We found a significant decrease in total antioxidant capacity (TAC) and uric acid (UA) and a significant increase in malondialdehyde (MDA) and nitric oxide (NO) levels in the saliva and serum/plasma of OLP patients. Moreover, a significant elevation of 8-hydroxy-deoxyguanosine (8-OHdG) and advanced oxidation protein product (AOOP) level and a decrease in vitamin C were also observed in the saliva of the OLP group. In contrast, salivary vitamin A, zinc, glutathione peroxidase (GPx), vitamin E, and nitrite were not significantly different between the two groups. In single studies, markers of oxidative stresses such as superoxide dismutase (SOD) and 8-isoprostanelevels were elevated in OLP, and antioxidant parameters such as glutathione (GSH) and total protein (TP) levels were dysregulated.

Conclusion

This meta-analysis helps to clarify the profile of oxidative stress and antioxidant state markers in OLP patients although existing evidence is rather heterogeneous and many studies are affected by several limitations. Larger and more standardized studies are warranted to ascertain whether these markers are potential causes or effects of OLP and whether antioxidant therapy improving oxidative stress will be useful.

Selenium, oxidative stress and inflammatory markers in handicraft workers occupationally exposed to lead

Occupational Lead (Pb) exposure increases reactive oxygen species and has been reported to impact inflammatory response by modulating intracellular signaling pathways. Selenium (Se) a vital component of the antioxidant system that plays an important role in modulating cytokines. The present study evaluated Se, malondialdehyde (MDA), total antioxidant capacity (TAC) and cytokines (IL-6, TNF-α, IL-10, IL-17a) in 81 Pb exposed male workers. The median (range) of blood lead level (BLL) and Se were 5 (0.50-31.76) µg/dL and 104 (46.9-189.6) µg/L respectively. The Se, TAC levels were decreased, and MDA, IL-6 levels were increased in the high Pb group (>5μg/dL). Blood lead level independently predicted oxidative stress and antioxidant status. Selenium, TAC levels negatively and MDA, IL-6 levels positively correlated with BLL. Association of Se with IL-6 and TAC suggests some probable role of Se in the underlined mechanism of Pb toxicity.

Lactobacillus plantarum Exhibits Antioxidant and Cytoprotective Activities in Porcine Intestinal Epithelial Cells Exposed to Hydrogen Peroxide

Probiotics are widely used for protection against stress-induced intestinal dysfunction. Oxidative stress plays a critical role in gastrointestinal disorders. It is established that probiotics alleviate oxidative stress; however, the mechanism of action has not been elucidated. We developed an in vitro intestinal porcine epithelial cells (IPEC-J2) model of oxidative stress to explore the antioxidant effect and potential mode of action of Lactobacillus plantarum ZLP001. The IPEC-J2 cells were preincubated with and without L. plantarum ZLP001 for 3 h and then exposed to hydrogen peroxide (H₂O₂) for 4 h. Pretreatment with L. plantarum ZLP001 protected IPEC-J2 cells against H₂O₂-induced oxidative damage as indicated by cell viability assays and significantly alleviated apoptosis elicited by H₂O₂. L. plantarum ZLP001 pretreatment decreased reactive oxygen species production and the cellular malondialdehyde concentration and increased the mitochondrial membrane potential compared with H₂O₂ treatment alone, suggesting that L. plantarum ZLP001 promotes the maintenance of redox homeostasis in the cells. Furthermore, L. plantarum ZLP001 regulated the expression and generation of some antioxidant enzymes, thereby activating the antioxidant defense system. Treatment with L. plantarum ZLP001 led to nuclear erythroid 2-related factor 2 (Nrf2) enrichment in the nucleus compared with H₂O₂ treatment alone. Knockdown of Nrf2 significantly weakened the alleviating effect of L. plantarum ZLP001 on antioxidant stress in IPEC-J2 cells, suggesting that Nrf2 is involved in the antioxidative effect of L. plantarum ZLP001. Collectively, these results indicate that L. plantarum ZLP001 is a promising probiotic bacterium that can potentially alleviate oxidative stress.

Influence of SGLT2 Inhibitor Treatment on Urine Antioxidant Status in Type 2 Diabetic Patients: A Pilot Study

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) have been recognized as potent antioxidant agents. Since SGLT2i are nephroprotective drugs, we aimed to examine the urine antioxidant status in patients with type 2 diabetes mellitus (T2DM). One hundred and one subjects participated in this study, including 37 T2DM patients treated with SGLT2i, 31 T2DM patients not using SGLT2i, and 33 healthy individuals serving as a control group. Total antioxidant capacity (TAC), superoxide dismutase (SOD), manganese superoxide dismutase (MnSOD), free thiol groups (R-SH, sulfhydryl groups), and catalase (CAT) activity, as well as glucose concentration, were assessed in the urine of all participants. Urine SOD and MnSOD activity were significantly higher among T2DM patients treated with SGLT2i than T2DM patients without SGLT2i treatment (p = 0.009 and p = 0.003, respectively) and to the healthy controls (p = 0.002 and p = 0.001, respectively). TAC was significantly lower in patients with T2DM treated with SGLT2i when compared to those not treated and healthy subjects (p = 0.036 and p = 0.019, respectively). It could be hypothesized that the mechanism by which SGLT2i provides nephroprotective effects involves improvement of the SOD antioxidant activity. However, lower TAC might impose higher OS (oxidative stress), and elevation of SOD activity might be a compensatory mechanism.

The Implication of Reactive Oxygen Species and Antioxidants in Knee Osteoarthritis

Knee osteoarthritis (KOA) is a chronic multifactorial pathology and a current and essential challenge for public health, with a negative impact on the geriatric patient's quality of life. The pathophysiology is not fully known; therefore, no specific treatment has been found to date. The increase in the number of newly diagnosed cases of KOA is worrying, and it is essential to reduce the risk factors and detect those with a protective role in this context. The destructive effects of free radicals consist of the acceleration of chondrosenescence and apoptosis. Among other risk factors, the influence of redox imbalance on the homeostasis of the osteoarticular system is highlighted. The evolution of KOA can be correlated with oxidative stress markers or antioxidant status. These factors reveal the importance of maintaining a redox balance for the joints and the whole body's health, emphasizing the importance of an individualized therapeutic approach based on antioxidant effects. This paper aims to present an updated picture of the implications of reactive oxygen species (ROS) in KOA from pathophysiological and biochemical perspectives, focusing on antioxidant systems that could establish the premises for appropriate treatment to restore the redox balance and improve the condition of patients with KOA.

Salivary Biomarkers of Oxidative Stress and Inflammation in Stroke Patients: From Basic Research to Clinical Practice

Cerebral stroke is a serious worldwide health problem, as can be seen by the global epidemic of the disease. In this disorder, when the blood flow is compromised by ruptures or blocked arteries, sudden death of neurons is observed as a result of a lack of oxygen and nutrients. Numerous severe problems and frequent complications also exist in stroke patients; therefore, there is an urgent need to develop new therapeutic, diagnostic, and prognostic methods for the disease. At present, the diagnosis of stroke is based on a neurological examination, medical history, and neuroimaging, due to the fact that rapid and noninvasive diagnostic tests are unavailable. Nevertheless, oxidative stress and inflammation are considered key factors in stroke pathogenesis. Oxygen free radicals are responsible for oxidation of lipids, proteins, and DNA/RNA, which in turn contributes to oxidative damage of the brain. Toxic products of the oxidation reactions act cytostatically on the cell by damaging cell membranes and leading to neuronal death by apoptosis or necrosis. Thus, it seems that redox/inflammatory biomarkers might be used in the diagnosis of the disease. Nowadays, saliva is of increasing interest in clinical laboratory medicine. Redox biomarkers could be obtained easily, noninvasively, cheaply, and stress-free from saliva. This minireview is aimed at presenting the current knowledge concerning the use of salivary biomarkers of oxidative stress and inflammation in the diagnosis and prognosis of stroke.

Antioxidant and reduced skin-ageing effects of a polyphenol-enriched dietary supplement in response to air pollution: a randomized, double-blind, placebo-controlled study

Background

Air pollution exposure is one of the major threats to skin health and accelerates skin ageing mainly through oxidative stress mechanisms. Since it is difficult to minimize skin exposure to air pollutants, especially in urban areas, strategies to protect the skin are needed. Plant phenolic compounds have been found to be effective in attenuating cellular oxidative stress and inflammation induced by different air pollutants and a dietary approach based on these compounds could provide an efficient protection measure.

Objective

Here we investigated the efficacy of a commercially available polyphenol-enriched dietary supplement (Zeropollution^®) in reducing pollution-induced oxidative stress and in improving different skin parameters related to skin ageing of Caucasian and Asian subjects exposed to air pollution. Zeropollution is composed of four standardized herbal extracts: Olea europaea leaf, Lippia citriodora, Rosmarinus officinalis, and Sophora japonica.

Design

A double-blind randomized, parallel group study was carried out on 100 outdoor workers living in a polluted urban European area (Milan) to assess the efficacy of the dietary supplement. The total antioxidant capacity on saliva (FRAP), the oxidative damage on skin (lipoperoxides content), skin moisturization (corneometer), transepidermal water loss (tewameter), skin radiance and colour (spectrophotometer), skin elasticity (cutometer), skin sebum content (sebumeter), and the skin roughness (image analysis) were measured.

Results

Both inter-group and intra-group analysis proved that the dietary supplement improved all clinical and biochemical-monitored parameters, in both Caucasian and Asian individuals. Some of the positive effects such as decreased wrinkle depth, increased elasticity and firmness, improved skin moisturization and transepidermal water loss, and reduced dark spots pigmentation were statistically significant as early as 2 weeks of product consumption.

Conclusions

The results of the study indicate reduced oxidative stress-induced skin damage in both Asian and Caucasian women living in a polluted urban area. Therefore, the oral intake of this four-plant based supplement could be considered a complementary nutrition strategy to avoid the negative effects of environmental pollution exposure.

Common and Novel Markers for Measuring Inflammation and Oxidative Stress Ex Vivo in Research and Clinical Practice-Which to Use Regarding Disease Outcomes?

Many chronic conditions such as cancer, chronic obstructive pulmonary disease, type-2 diabetes, obesity, peripheral/coronary artery disease and auto-immune diseases are associated with low-grade inflammation. Closely related to inflammation is oxidative stress (OS), which can be either causal or secondary to inflammation. While a low level of OS is physiological, chronically increased OS is deleterious. Therefore, valid biomarkers of these signalling pathways may enable detection and following progression of OS/inflammation as well as to evaluate treatment efficacy. Such biomarkers should be stable and obtainable through non-invasive methods and their determination should be affordable and easy. The most frequently used inflammatory markers include acute-phase proteins, essentially CRP, serum amyloid A, fibrinogen and procalcitonin, and cytokines, predominantly TNFα, interleukins 1β, 6, 8, 10 and 12 and their receptors and IFNγ. Some cytokines appear to be disease-specific. Conversely, OS-being ubiquitous-and its biomarkers appear less disease or tissue-specific. These include lipid peroxidation products, e.g., F2-isoprostanes and malondialdehyde, DNA breakdown products (e.g., 8-OH-dG), protein adducts (e.g., carbonylated proteins), or antioxidant status. More novel markers include also -omics related ones, as well as non-invasive, questionnaire-based measures, such as the dietary inflammatory-index (DII), but their link to biological responses may be variable. Nevertheless, many of these markers have been clearly related to a number of diseases. However, their use in clinical practice is often limited, due to lacking analytical or clinical validation, or technical challenges. In this review, we strive to highlight frequently employed and useful markers of inflammation-related OS, including novel promising markers.

Label-free analysis of gingival crevicular fluid (GCF) by surface enhanced Raman scattering (SERS)

Gingival crevicular fluid (GCF) is an interesting biofluid reflecting the physiological and pathological states of a single dental element. Due to this unique feature, in recent years, metabolomic analysis of GCF has gained attention as a biometric tool for the diagnosis and therapy of periodontal disease. Traditional methods are, however, too slow, cumbersome and expensive for a health-care routine. Surface enhanced Raman scattering (SERS) can offer rapid and label-free detailed molecular fingerprints that can be used for biofluid analysis. Here we report the first SERS characterization of GCF using an easy and quick sample preparation. The dominant features in the SERS spectrum of GCF are ascribed to very few metabolites, in particular to uric acid, hypoxanthine, glutathione and ergothioneine. Additionally, we succeeded in differentiating between the SERS signal of GCF collected from healthy volunteers and the one collected from patients with periodontal disease.

Effect of chronic exposure to microplastic fibre ingestion in the sea cucumber Apostichopus japonicus

Microplastics (MPs) in the form of microfibres (MFs) are of great concern because of their size and increasing abundance, which increase their potential to interact with or be ingested by aquatic organisms. Although MFs are the dominant shape of MPs ingested by sea cucumbers in habitats, their effect on sea cucumbers remains unclear. This study examined the effect of dietary exposure to MFs on the growth and physiological status of both juvenile and adult Apostichopus japonicus sea cucumbers. MFs were mixed into the diet of sea cucumbers for 60 d at environmentally relevant concentrations of 0.6 MFs g^-1, 1.2 MFs g^-1 and 10 MFs g^-1. Dietary exposure to MFs, with concentrations at or above those commonly found in the habitats, did not significantly affect the growth and faecal production rate of either juvenile or adult sea cucumbers. However, a disruption in immunity indices (acid phosphatase and alkaline phosphatase activity) and oxidative stress indices (total antioxidant capacity and malondialdehyde content) was observed in juvenile and adult sea cucumbers, indicating that these indices might be useful as potential biomarkers of the exposure to MF ingestion in sea cucumbers. This study provides insights into the toxicity mechanism of MF ingestion in a commercially and ecologically important species.

Mediterranean Diet for the Prevention of Gestational Diabetes in the Covid-19 Era: Implications of Il-6 In Diabesity

The aim of this review is to highlight the influence of the Mediterranean Diet (MedDiet) on Gestational Diabetes Mellitus (GDM) and Gestational Weight Gain (GWG) during the COVID-19 pandemic era and the specific role of interleukin (IL)-6 in diabesity. It is known that diabetes, high body mass index, high glycated hemoglobin and raised serum IL-6 levels are predictive of poor outcomes in coronavirus disease 2019 (COVID-19). The immunopathological mechanisms of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection include rising levels of several cytokines and in particular IL-6. The latter is associated with hyperglycemia and insulin resistance and could be useful for predicting the development of GDM. Rich in omega-3 polyunsaturated fatty acids, vitamins, and minerals, MedDiet improves the immune system and could modulate IL-6, C reactive protein and Nuclear Factor (NF)-κB. Moreover, polyphenols could modulate microbiota composition, inhibit the NF-κB pathway, lower IL-6, and upregulate antioxidant enzymes. Finally, adhering to the MedDiet prior to and during pregnancy could have a protective effect, reducing GWG and the risk of GDM, as well as improving the immune response to viral infections such as COVID-19.

The effect of tropisetron on oxidative stress, SIRT1, FOXO3a, and claudin-1 in the renal tissue of STZ-induced diabetic rats

Tropisetron is a 5-HT3 receptor antagonist that exerts protective effect against DN. The aim of this study was to investigate the possible molecular mechanisms associated with the renoprotective effects of tropisetron in STZ-induced diabetic rats. Animals were subdivided into 5 equal groups; control, tropisetron, diabetes, tropisetron + diabetes, and glibenclamide + diabetes (n = 7). For induction of type 1 diabetes, a single injection of STZ (55 mg/kg, i.p.) was administered to the animals. Diabetic rats were treated with tropisetron (3 mg/kg) and glibenclamide (1 mg/kg) for 2 weeks. According to the conducted analysis, diabetes led to renal dysfunction (reduction in glomerular filtration rate and urine urea and creatinine as well as elevation in plasma urea and creatinine) and abnormalities in antioxidant defense system (reduction in TAC and elevation in MDA), compared with the control group, which was prevented by tropisetron treatment. Reverse transcription-quantitative polymerase chain reaction and western blotting analysis demonstrated that SIRT1 gene expression decreased while FOXO3a and NF-κB gene expression as well as phosphorylated FOXO3a/total FOXO3a protein ratios and claudin-1 protein level increased in the kidney of diabetic rats compared with the control group. Herein, the results of this research showed that tropisetron treatment reversed these changes. Besides, all these changes were comparable with those produced by glibenclamide as a positive control. Hence, tropisetron ameliorated renal damage due to diabetic nephropathy possibly by suppressing oxidative stress and alteration of SIRT1, FOXO3a, and claudin-1 levels.

Salivary Stress/Immunological Markers in Crohn's Disease and Ulcerative Colitis

There is continuous and growing interest in research into new alternatives to standard biomarkers to detect and follow-up disease, reducing physical and psychological stress in patients needing regular and invasive medical examinations for the evaluation of pathologies, including inflammatory bowel diseases (IBD). Saliva is one of the most promising body fluids in the research of new biomarkers, thanks to the large number of molecules it contains. Many molecules present in saliva are often directly correlated to their concentration in the blood but may be affected by the condition of the oral cavity. This means that a careful selection of a specific biomarker is required for each pathology, especially pathologies such as IBD, which may induce inflammation in the oral cavity. Here, we analyze the currently used and the proposed new salivary biomarkers (i.e., calprotectin, cytokines, IgA, cortisol, and oxidative stress markers) for the detection and follow-up of the main subtypes of IBD, known as ulcerative colitis and Crohn's disease.

Diagnostic and Prognostic Value of Salivary Biochemical Markers in Oral Squamous Cell Carcinoma

The purpose of the work is a comprehensive assessment of biochemical saliva markers for the diagnosis and prognosis of oral cancer. The group of patients included 68 patients with oral squamous cell carcinoma, 50 with non-cancerous diseases of the oral cavity, and 114 healthy volunteers. Before the start of treatment, 23 biochemical parameters of saliva were determined. Participants were monitored for six years to assess survival rates. The statistical analysis was performed by means of Statistica 10.0 and R package. A complex of metabolic changes occurring in saliva in oral cancer is described. It was shown that none of the studied parameters could be used to diagnose oral cancer in an independent variant; the use of combinations of parameters is more informative. The high prognostic value of the content of malondialdehyde (MDA) and the Na/K-ratio in saliva before treatment was established. Thus, the content of MDA ˂ 7.34 nmol/mL and the Na/K-ratio > 1.09 c.u. is a prognostically unfavorable factor (HR = 7.88, 95% CI 1.10-54.62, p = 0.01876), which may be useful for optimizing the treatment of patients with oral cancer. It has been shown that saliva has great potential for the development of diagnostic and prognostic tests for oral cancer.

Myogenous temporomandibular disorders and salivary markers of oxidative stress-A cross-sectional study

BACKGROUND

The clinical care of chronic pain requires personalised understanding of the mechanisms involved. Temporomandibular disorders (TMD) are the most common chronic orofacial pain conditions, and oxidative stress has been proposed to be implicated in their pathophysiology, especially in arthrogenous TMD. However, few studies have explored oxidative stress in myogenous TMD (TMDM).

OBJECTIVE

The aims of this study were to compare the salivary oxidative stress profiles between individuals with TMDM and healthy controls, and to explore associations of these markers with clinical characteristics.

METHODOLOGY

Saliva samples were collected from 39 individuals with TMDM and 37 age and sex-matched healthy volunteers. Psychological stress levels and clinical characteristics were assessed in all participants. The samples were analysed for total oxidant status (TOS), total antioxidative capacity (TAC) and superoxide dismutase activity (SODa). Comparisons between groups were performed using parametric and non-parametric tests depending on data distribution.

RESULTS

Psychological stress was higher in TMDM compared to controls (P < .001). TAC levels were significantly higher (P < .05) whereas TOS levels were significantly lower (P < .05) in TMDM compared to controls. There were no differences in SODa levels between groups and no correlations were found between clinical characteristics and oxidative stress markers.

CONCLUSION

Individuals with TMDM showed higher levels of antioxidative markers, but lower levels of oxidative markers. These results can be explained in part by chronicity and adaptation to the disease and other factors, such as psychological stress. Longitudinal studies must be conducted to clarify the role of oxidative stress in TMDM.

Effect of Occupational Exposure to Herbicides on Oxidative Stress in Sprayers

Background

Herbicides such as glyphosate, paraquat, and 2,4-dichlorophenoxyacetic acid have been reported to cause adverse side effects through production of reactive oxygen species. However, there were no data representing the adverse effects of a mixture herbicide usage in farmers, especially the changes in oxidative marker and antioxidant defense. This study aimed to determine the urinary malondialdehyde (MDA) and glutathione (GSH) level in farmers using mixed herbicides.

Methods

Ninety-three farmers were recruited, and two spot urine samples (before and after work) were collected. The urinary MDA level was evaluated by thiobarbituric acid reactive substance assay, and the urinary GSH level was determined using the enzymatic recycling method.

Results

Sixty-two percent of the participants were men, and 59% of the participants worked in a farm for 20–40 years. The common combinations of herbicide usage were glyphosate with 2,4-dichlorophenoxyacetic acid (36.5%). There was no significant difference between pre- and post-work urinary MDA and GSH levels among the 3 groups of herbicides. However, the urinary MDA levels in farmers using the combination of glyphosate and paraquat were significantly higher than those found in farmers using glyphosate alone. The associated factors with changes in MDA levels found that the exposure intensity index (B = 0.154), the cumulative exposure intensity index (B = 0.023), and wearing gloves while working (B = −2.347) were found to be significantly associated with MDA level.

Conclusion

The results suggest that the combined use of glyphosate and paraquat caused a significant increase in urinary MDA levels. Moreover, intensity of exposure to herbicide and wearing gloves were associated with the level of MDA.

Effect of levetiracetam drug on antioxidant and liver enzymes in epileptic patients: case-control study

BACKGROUND

There is a limited amount of data regarding levetiracetam (LEV), an antiepileptic drug.

OBJECTIVE

This study was conducted to assess the effect of LEV on antioxidant status and liver enzymes.

METHODS

In this case-control study, 33 epileptic patients under treatment with LEV for at least 6 months were compared with 35 healthy subjects. We measured serum total antioxidant capacity (TAC), salivary superoxide dismutase (SOD), alanine aminoteransferase (ALT), and aspartate aminoteransferase (AST) levels in both groups. Dietary intakes were collected using a Food Frequency Questionnaire (FFQ).

RESULT

The level of TAC in the healthy subjects was significantly higher than it was in the patients (P=0.02), but the mean of ALT (P=0.02) and AST (P=0.03) was significantly higher in the patients in comparison with the controls. Mean salivary SOD showed no difference between the two groups. In the patients, the duration of drug use was inversely correlated with serum TAC (p=0.04) and had a direct correlation with ALT (p=0.01) and AST (p=0.03.).

CONCLUSION

The results of our study indicated that LEV increased liver enzymes Also, treatment with this drug did not improve oxidative stress, but this could be due to the different in the dietary antioxidant intake. Routine screening of the liver and antioxidant enzymes in patients with chronic use of LEV is recommended.

Total Oxidant and Antioxidant Capacity of Gingival Crevicular Fluid and Saliva in Patients with Periodontitis: Review and Clinical Study

Periodontitis is inextricably linked to oxidative-reductive (redox) imbalance. However, little is still known about the resultant ability to scavenge oxygen free radicals in saliva and gingival crevicular fluid in patients with periodontitis. The multitude of enzymatic and non-enzymatic antioxidants and their synergistic effects cause an interest in the evaluation of the total antioxidative capacity. Thus, our study aimed to evaluate the total oxidative and antioxidative activity of gingival crevicular fluid and saliva in the periodontitis, as well as to relate these biomarkers to clinical indices of periodontopathy. Additionally, by calculating the oxidative stress index (OSI), the intensity of redox disturbances was also evaluated. Fifty-eight periodontitis patients were included in the study and divided into two subgroups depending on the severity of the disease. In the non-stimulated/stimulated saliva as well as a gingival crevicular fluid of the study group, we found significantly higher OSI and total oxidant status (TOS) as well as lower total antioxidant capacity (TAC). However, the ability to reduce iron ions (FRAP) was significantly lower only in stimulated and non-stimulated saliva of patients with periodontitis. The examined parameters correlated with the periodontium’s clinical condition, which indicates the exacerbation of the inflammatory process. However, TAC, TOS, OSI, and FRAP did not differentiate individual stages of periodontitis.

Impact of Weight Loss on the Total Antioxidant/Oxidant Potential in Patients with Morbid Obesity-A Longitudinal Study

The assessment of total antioxidant activity seems to have a higher diagnostic value than the evaluation of individual antioxidants separately. Therefore, this is the first study to assess the total antioxidant/oxidant status in morbidly obese patients undergoing bariatric surgery. The study involved 60 patients with Class 3 obesity (BMI > 40 kg/m²) divided into two equal subgroups: morbidly obese patients without and with metabolic syndrome. The analyses were performed in plasma samples collected before surgery as well as 1, 3, 6, and 12 months after a laparoscopic sleeve gastrectomy. Total antioxidant capacity (TAC), ferric-reducing antioxidant power (FRAP), DPPH (2,2′-diphenyl-1-picrylhydrazyl) radical assay, and total oxidant status (TOS) were significantly higher before surgery (as compared to the healthy controls, n = 60) and generally decreased after bariatric treatment. Interestingly, all assessed biomarkers correlated positively with uric acid content. However, the total antioxidant/oxidant potential did not differ between obese patients without metabolic syndrome and those with both obesity and metabolic syndrome. Only DPPH differentiated the two subgroups (p < 0.0001; AUC 0.8) with 73% sensitivity and 77% specificity. Plasma TAC correlated positively with body mass index, waist–hip ratio, serum insulin, and uric acid. Therefore, TAC seems to be the best biomarker to assess the antioxidant status of obese patients.

Salivary Oxidative Stress Increases With the Progression of Chronic Heart Failure

The aim of the study was to evaluate the rate of reactive oxygen species (ROS) production, antioxidant barrier, and oxidative damage in non-stimulated (NWS) and stimulated (SWS) saliva as well as plasma/erythrocytes of 50 patients with chronic heart failure (HF) divided into the two subgroups: NYHA II (33 patients) and NYHA III (17 patients). The activity of superoxide dismutase and catalase was statistically increased in NWS of HF patients as compared to healthy controls. The free radical formation, total oxidant status, level of uric acid, advanced glycation end products (AGE), advanced oxidation protein products and malondialdehyde was significantly elevated in NWS, SWS, and plasma of NYHA III patients as compared to NYHA II and controls. We were the first to demonstrate that with the progression of HF, disturbances of enzymatic and non-enzymatic antioxidant defense, and oxidative damage to proteins and lipids occur at both central (plasma/erythrocytes) and local (saliva) levels. In the study group, we also observed a decrease in saliva secretion, total salivary protein and salivary amylase activity compared to age- and gender-matched control group, which indicates secretory dysfunction of salivary glands in patients with HF. Salivary AGE may be a potential biomarker in differential diagnosis of HF.

Oxidative-Antioxidant Imbalance and Impaired Glucose Metabolism in Schizophrenia

Schizophrenia is a neurodevelopmental disorder featuring chronic, complex neuropsychiatric features. The etiology and pathogenesis of schizophrenia are not fully understood. Oxidative-antioxidant imbalance is a potential determinant of schizophrenia. Oxidative, nitrosative, or sulfuric damage to enzymes of glycolysis and tricarboxylic acid cycle, as well as calcium transport and ATP biosynthesis might cause impaired bioenergetics function in the brain. This could explain the initial symptoms, such as the first psychotic episode and mild cognitive impairment. Another concept of the etiopathogenesis of schizophrenia is associated with impaired glucose metabolism and insulin resistance with the activation of the mTOR mitochondrial pathway, which may contribute to impaired neuronal development. Consequently, cognitive processes requiring ATP are compromised and dysfunctions in synaptic transmission lead to neuronal death, preceding changes in key brain areas. This review summarizes the role and mutual interactions of oxidative damage and impaired glucose metabolism as key factors affecting metabolic complications in schizophrenia. These observations may be a premise for novel potential therapeutic targets that will delay not only the onset of first symptoms but also the progression of schizophrenia and its complications.

Bladder cancer: total antioxidant capacity and pharmacotherapy with vitamin-E

PURPOSE

Free radicals play an important role in the different complex course of carcinogenesis. Higher concentrations of reactive oxygen species are highly associated with the presence of tumors. The urinary bladder organ is also a target for many carcinogens. The major objective of this investigation was to measure the role of redox state or total antioxidant capacity (T-AOC) and antioxidant functions of vitamin E in patients with low-grade papillary cancer of the bladder (BC).

METHODS

The blood sample was used for measurement of the T-AOC by the Trolox-TAC assay kit. Thirty-five patients with BC and thirty-five healthy subjects that matched for age were entered in this study. The obtained data were analyzed using the Statistical Package (SPSS Inc, Chicago, IL, USA). The significance level was set at p ≤ 0.05.

RESULTS

In healthy controls, the mean ± SD for T-AOC was 91.8 ± 16.6 (U/ml), that was significantly higher when compared to the mean value of 24.5 ± 28.9 (U/ml) in patients with BC (p = 0.00). The difference in concentration of T-AOC before and after prescription of vitamin E was encountered with a p value of 0.16.

CONCLUSIONS

By reference to the significant difference between T-AOC in patients and healthy controls, our results strongly suggest a low level of T-AOC in patients with BC. The obtained changes in T-AOC before and after management with vitamin E recommended additional consideration associates with different stages and grade of tumor in patients with BC.

Salivary 8-hydroxyguanine as a lifestyle-related oxidative stress biomarker in workers

Oxidative stress is a risk factor for lifestyle-related diseases, such as cancer. Investigations of the factors that increase or decrease oxidative stress contribute to disease prevention. In the present study, we focused on the 8-hydroxyguanine (8-OHGua) in saliva, as a new oxidative stress biomarker. The relationship between lifestyles and salivary 8-OHGua levels in 541 Japanese subjects was analyzed. The salivary 8-OHGua levels were significantly elevated in older persons, as well as those who smoke, have hypertension, or excess visceral fat. By contrast, statistically significant lower levels of 8-OHGua were observed in persons who moderately exercised or recently drank green tea or coffee. The direct collection of saliva, without any special collecting device, was suitable for the 8-OHGua analysis. The present results suggest that oxidative stress can be measured in a non-invasive manner with easily collectable saliva, and the salivary 8-OHGua may be a useful biomarker for lifestyle-related disease prevention.

Immobilization of Allantoinase for the Development of an Optical Biosensor of Oxidative Stress States

Allantoin, the natural end product of purine catabolism in mammals, is non-enzymatically produced from the scavenging of reactive oxygen species through the degradation of uric acid. Levels of allantoin in biological fluids are sensitively influenced by the presence of free radicals, making this molecule a candidate marker of acute oxidative stress in clinical analyses. With this aim, we exploited allantoinase—the enzyme responsible for allantoin hydrolization in plants and lower organisms—for the development of a biosensor exploiting a fast enzymatic-chemical assay for allantoin quantification. Recombinant allantoinase was entrapped in a wet nanoporous silica gel matrix and its structural properties, function, and stability were characterized through fluorescence spectroscopy and circular dichroism measurements, and compared to the soluble enzyme. Physical immobilization in silica gel minimally influences the structure and the catalytic efficiency of entrapped allantoinase, which can be reused several times and stored for several months with good activity retention. These results, together with the relative ease of the sol-gel preparation and handling, make the encapsulated allantoinase a good candidate for the development of an allantoin biosensor.

Effect of Storage Time and Temperature on Salivary Total Antioxidant Capacity, Total Oxidant Status, and Oxidant Stress Index

Objective

The aim of this study was to compare the effects of short-term storage in two different temperatures on stability of salivary total antioxidant capacity (TAC), total oxidant status (TOS) and oxidant stress index (OSI).

Materials and methods

Saliva samples were collected from twenty healthy volunteers for the study. An aliquot was selected for immediate analysis and the rest was stored at -20°C and -80°C for a period of 120 days, and analyzes were performed at 15, 30, 45, 60, 90 and 120 days. The determination of the TOS and the TAC were performed by colorimetric methods.

Results

The results show that the two storage temperatures were able to preserve oxidants and antioxidants up to 60 days with similar levels when compared with fresh samples. When comparing the different storage temperatures at each time point, no significant differences were observed. Finally, the OSI remains constant over time of storage at both temperatures without statistically significant differences between them. The results were expressed as mean ± standard error of mean. Statistical analysis was performed using the repeated-measures analysis of variance (ANOVA), the Bonferroni and t-test. A p-value <0.05 was accepted to be statistically significant.

Conclusion

The two temperatures were able to keep salivary TOS and TAC levels similar to fresh saliva samples. Therefore they are reliable for assessing oxidative stress up to 60 days.

Salivary Redox Biomarkers in Different Stages of Dementia Severity

This study is the first to evaluate oxidative stress biomarkers in saliva/blood of patients with varying degrees of dementia progression. The study included 50 healthy controls and 50 dementia patients divided into two groups: those with mild and moderate dementia (MMSE 11–23) and patients suffering from severe dementia (MMSE 0–10). Cognitive functions of the subjects were assessed using the Mini Mental State Examination (MMSE). Enzymatic and non-enzymatic antioxidants, oxidative damage products and protein glycoxidative modifications were determined in non-stimulated (NWS) and stimulated (SWS) saliva as well as erythrocyte/plasma samples. Generally, in dementia patients, we observed the depletion of antioxidant defences leading to oxidative and glycoxidative damage in NWS, SWS and blood samples. Both salivary and blood oxidative stress increased with the severity of the disease, and correlated with a decrease of cognitive functions. Interestingly, in dementia patients, reduced glutathione (GSH) in NWS correlated not only with the severity of dementia, but also with GSH concentration in the plasma. In receiver operating characteristic (ROC) analysis, we have demonstrated that salivary GSH clearly distinguishes patients with severe dementia from those suffering from mild or moderate dementia (area under the curve (AUC) = 1). Therefore, salivary GSH can be used as a non-invasive biomarker of cognitive impairment.