There are still missing non-invasive biomarkers of chronic kidney disease (CKD) in children. Therefore, the aim of the study was to evaluate oxidative stress indicators in the non-stimulated (NWS) and stimulated saliva (SWS) of CKD children (n = 25) and healthy controls (n = 25). Salivary antioxidants (catalase (CAT), peroxidase (Px), superoxide dismutase (SOD), uric acid (UA), reduced glutathione (GSH), albumin), redox status (total antioxidant capacity (TAC), total oxidant status (TOS), oxidative stress index (OSI)), and oxidative damage products (advanced glycation end products (AGE), advanced oxidation protein products (AOPP), malondialdehyde (MDA)) were evaluated. We have demonstrated the significantly higher activity of SWS GPx and SOD, as well as elevated concentrations of UA and albumin in NWS and SWS of CKD children vs. the control group. TAC, TOS and OSI were significantly higher only in SWS, while oxidative damage products (AGE, AOPP and MDA) were significantly higher in both NWS and SWS of CKD children. ROC analysis showed a considerably high diagnostic value of AOPP in both NWS and SWS of CKD children compared to controls (AUC = 0.92; 0.98). CKD is responsible for disturbances in salivary antioxidant systems and oxidative damage to proteins and lipids. Salivary AOPP can be a potential biomarker of CKD in children.

The aim of our research was to evaluate redox balance parameters and biomarkers of oxidative stress (OS) in nonstimulated and stimulated saliva as well as the blood of patients with plaque psoriasis compared to healthy controls. The study involved 40 patients with plaque psoriasis and 40 generally healthy subjects matched by age and gender to the study group patients. We assayed the concentration/activity of antioxidant enzymes: salivary peroxidase (Px), catalase (CAT), and superoxide dismutase (SOD) measured in unstimulated saliva (NWS), stimulated saliva (SWS), and erythrocytes. In plasma as well as NWS and SWS, we measured the concentration/activity of reduced glutathione (GSH), total antioxidant potential (TAC), total oxidative status (TOS), oxidative stress index (OSI), and markers of oxidative modification of proteins: advanced glycation end products (AGE), advanced oxidation protein products (AOPP), and lipid oxidation products: malondialdehyde (MDA) and total lipid hydroperoxide (LOOH). In NWS and SWS, we also evaluated the rate of reactive oxygen species (ROS) production. The concentration of Px, CAT, and SOD was significantly higher in NWS of patients with plaque psoriasis vs. healthy subjects. In SWS of psoriatic patients, we observed considerably higher concentration of Px and CAT, and in erythrocytes of patients with plaque psoriasis, the concentration of GPx and CAT was significantly higher compared to that in the controls. The levels of AOPP, AGE, MDA, and LOOH were considerably higher in NWS, SWS, and plasma of the study group compared to the controls. The concentration of total protein and salivary amylase was significantly lower in NWS and SWS of psoriatic patients compared to the healthy control. In the course of plaque psoriasis, we observed redox imbalances with prevalence of oxidation reactions. Mechanisms involved in the synthesis/secretion of proteins and activity of amylase were depressed in both glands of psoriatic patients; however, they were more inhibited in the parotid gland compared to the submandibular gland. TOS concentration and OSI value in NWS and SWS may serve as diagnostic biomarkers of plaque psoriasis.

Psoriasis is the most common inflammatory skin disease, characterized by the release of proinflammatory cytokines from lymphocytes, keratinocytes, and dendritic cells. Although psoriasis is considered an immune-mediated inflammatory disease, its effect on secretory activity of salivary glands and quantitative composition of saliva is still unknown. The aim of this study was to evaluate the secretion of saliva as well as several selected inflammation and nitrosative stress biomarkers in unstimulated and stimulated saliva as well as plasma of psoriasis patients. We demonstrated that, with progressing severity and duration of the disease, the secretory function of the parotid and submandibular salivary glands is lost, which is manifested as decreased unstimulated and stimulated saliva secretion and reduced salivary amylase activity and total protein concentration. The levels of tumor necrosis factor-alpha (TNF-α), interleukin-2 (IL-2), and interferon-gamma (INF-γ) were significantly higher, whereas interleukin-10 (IL-10) content was considerably lower in unstimulated and stimulated saliva of patients with psoriasis compared to the controls, and the changes increased with the disease duration. Similarly, we observed that the intensity of nitrosative stress in the salivary glands of psoriasis patients depended on the duration of the disease. By means of receiver operating characteristic (ROC) analysis, we showed that the evaluation of nitric oxide (NO), nitrotyrosine, and IL-2 concentration in non-stimulated saliva with high sensitivity and specificity differentiated psoriasis patients on the basis of the rate of saliva secretion (normal salivation vs. hyposalivation). In summary, the dysfunction of salivary glands in psoriasis patients is caused by inflammation and nitrosative stress.

Caries are a pathological process of extracorporeal nature, characterized by demineralization of inorganic substances as well as proteolysis triggered by acids produced by bacteria present in dental plaque, as a result of metabolism of sugars of both external and internal origin. Periodontal disease, on the other hand, is a multifactorial degenerative disease associated with inflammation, involving a group of tissues that surround the dental cervix and root of the tooth. It is believed that one of the mechanisms in the etiopathogenesis of caries and periodontitis are disorders of local and/or general oxidative stress (OS) parameters. Numerous clinical studies have confirmed the relationship between oxidative stress markers and oral diseases. In most analyzed studies, technical and biological variability was so high that none of the markers so far has proven suitable for routine clinical use. The aim of systematic reviews of the literature is to present the existing studies on OS parameters, mainly concerning the activity of antioxidant enzymes in saliva of patients with caries and periodontitis.

Objectives: Sjögren’s syndrome (SjS) is a chronic autoimmune disease primarily affecting the salivary and lacrimal glands. Conventional diagnosis depends on invasive procedures, underscoring the need for non-invasive biomarkers. This systematic review summarizes evidence from 2014 to 2024 on the diagnostic and monitoring potential of salivary biomarkers in SjS. Methods: A systematic search of PubMed, Scopus, and Web of Science was performed according to PRISMA guidelines. Eligible human studies investigating salivary biomarkers in SjS were included. Data extraction and quality assessment were conducted independently by two reviewers. The protocol was registered in the OSF Registries. Results: Thirty-one studies were analyzed, identifying diverse metabolomic, proteomic, and molecular biomarkers. Consistent findings included increased levels of lactate, alanine, taurine, NGAL, β₂-microglobulin, annexin A2, and regulatory RNAs (let-7i-5p, miR-17-5p), along with H19 ICR hypomethylation. Several extracellular vesicle (EV)-derived biomarkers demonstrated improved diagnostic stability and specificity. Conclusions: Saliva represents a promising, non-invasive diagnostic medium for Sjögren’s syndrome. Integrating multi-omics approaches-particularly EV-based analyses may enhance early diagnosis and personalized monitoring. Large, multicenter studies using standardized protocols are needed to validate these findings.

The biological compatibility of endodontic sealers is a key determinant of periapical tissue healing. This in vitro study investigated the cytotoxic, pro-inflammatory, and redox-related effects of eight endodontic sealers on human periodontal ligament fibroblasts (HPdLFs): Biopulp (Chema-Elektromet), AH Plus (Dentsply Sirona), MTA Fillapex (Angelus), EndoSeal MTA (Maruchi), GuttaFlow (Coltène), AH Plus Bioceramic (Dentsply Sirona), TotalFill BC (FKG Dentaire SA), and BioRoot TM (Septodont). Cells were exposed for 24 h to 10-fold-diluted sealer extracts prepared in accordance with the manufacturers’ instructions, while control samples underwent identical procedures without sealer contact. Oxidative stress biomarkers, antioxidant defense parameters, protein oxidation indices, apoptotic activity (caspase-3), pro-inflammatory cytokines (IL-1, IL-6), and cell viability (MTT assay) were assessed. Under the applied conditions, all materials induced only limited global oxidative stress, with most alterations reflecting selective protein and glycoxidative modifications. Nevertheless, AH Plus, MTA Fillapex, and the calcium hydroxide-based Biopulp exhibited a less favorable redox profile and greater protein oxidation compared with calcium silicate-based sealers. AH Plus and EndoSeal MTA were associated with increased IL-6 release, whereas EndoSeal MTA moderately elevated IL-1 levels. BioRoot TM demonstrated the lowest cytokine expression, and TotalFill BC preserved high cell viability. Caspase-3 activity remained comparable across all experimental groups, indicating minimal induction of apoptosis.