Alexandra Totan

Salivary biomarkers: Relationship between oxidative stress and alveolar bone loss in chronic periodontitis

Abstract Objectives. Oxidative stress is implicated in the pathogenesis of many systemic and oral diseases such as periodontal disease. The main aim of this study is to explore a possible association between salivary markers of OS and alveolar bone loss. Materials and methods. The study included 20 patients with chronic periodontitis and 20 controls. Salivary OS biomarkers 8-hidroxy-desoxguanosine (8-HOdG), malondialdehyde (MDA), uric acid, total antioxidant capacity (TAC) and glutathione peroxidase (GPx) were evaluated. Bone loss markers such as C-terminal telopeptide of type I collagen (CTX I), matrix metalloproteinases-8 (MMP-8), osteocalcin and 25-hydroxy vitamin D3 (25- OH D) were detected in this study. The methods included general biochemical tests and ELISA. Results. Salivary 8-OHdG, MDA levels were significantly higher in the chronic periodontitis group compared with controls (p < 0.05). Salivary activities for uric acid, TAC and GPx were significantly decreased in patients with chronic periodontitis vs controls (p < 0.05). Salivary levels for CTX I, MMP-8, 25-OH D and Osteocalcin were significantly higher in the chronic periodontitis group compared to the controls (p < 0.05). A significant positive correlation was observed between salivary levels of MDA and CTX I. Significant negative correlations between uric acid and CTX I and between MMP-8 and uric acid have been found. Significant positive correlations were observed between CTX I, MMP-8, 25-OH D, osteocalcin and clinical parameters of periodontal disease. Conclusions. Important oxidative stress associated with alveolar bone loss biomarkers can be detected in saliva of patients with periodontal disease.

Salivary aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase : possible markers in periodontal diseases?

Abstract Background: Saliva can be used as a diagnostic fluid in medicine. Components of saliva proposed as disease markers include enzymes (alkaline phosphatase, esterase, glucuronidase, aminopeptidase), immunoglobulins (IgA, IgG), and hormones (steroid hormones). Many of these salivary components appeared to be useful biochemical markers of the evolution of periodontal disease, for which salivary analysis can offer a cost-effective approach for monitoring the disease. The salivary components proposed as markers for periodontal disease activity are aspartate aminotransferase (AST), alkaline phosphatase (ALP), aminopeptidases, and glucuronidases. The purpose of our study was to illustrate the influence of periodontal disease on the level of salivary AST, alanine aminotransferase (ALT) and ALP. Methods: All clinical periodontal examinations were performed by the same periodontist. All patients included in the study presented a probing depth >5mm, bleeding on probing and alveolar bone loss >40%. Salivary AST, ALT and ALP activities were measured using DiaSys analysis kits from Diagnostic Systems. The methods were adapted for saliva. Results: Salivary AST activity in patients with periodontal disease was significantly increased (p<0.01) (median 81.75±23U/L) compared with controls (15.25±10.5U/L). Salivary ALT activity was not significantly modified in saliva from patients with periodontal disease compared with the control group. Our results showed a significant (p<0.01) increase in salivary ALP activity (34.38±1.5U/L) in patients with periodontal disease compared with controls (6.6±4.2U/L). Conclusions: Our results revealed that periodontal destruction such as periodontal pockets, gingival bleeding and suppuration are related to higher ALP and AST levels in saliva. Salivary AST could be used as a useful marker for monitoring periodontal disease. The increase in salivary ALP activity in periodontitis demonstrated could be associated with alveolar bone loss, a key feature of periodontal disease. More studies are necessary to evaluate which specific clinical, microbiological and histological characteristics of periodontal disease are associated with elevated levels of AST and ALP in saliva.

Hydrogen Sulfide, Oxidative Stress and Periodontal Diseases: A Concise Review

In the past years, biomedical research has recognized hydrogen sulfide (H2S) not only as an environmental pollutant but also, along with nitric oxide and carbon monoxide, as an important biological gastransmitter with paramount roles in health and disease. Current research focuses on several aspects of H2S biology such as the biochemical pathways that generate the compound and its functions in human pathology or drug synthesis that block or stimulate its biosynthesis. The present work addresses the knowledge we have to date on H2S production and its biological roles in the general human environment with a special focus on the oral cavity and its involvement in the initiation and development of periodontal diseases.

Current Uses of Poly(lactic-co-glycolic acid) in the Dental Field: A Comprehensive Review

Poly(lactic-co-glycolic acid) or PLGA is a biodegradable polymer used in a wide range of medical applications. Specifically PLGA materials are also developed for the dental field in the form of scaffolds, films, membranes, microparticles, or nanoparticles. PLGA membranes have been studied with promising results, either alone or combined with other materials in bone healing procedures. PLGA scaffolds have been used to regenerate damaged tissues together with stem cell-based therapy. There is solid evidence that the development of PLGA microparticles and nanoparticles may be beneficial to a wide range of dental fields such as endodontic therapy, dental caries, dental surgery, dental implants, or periodontology. The aim of the current paper was to review the recent advances in PLGA materials and their potential uses in the dental field.

Organic Nanomaterials and Their Applications in the Treatment of Oral Diseases

There is a growing interest in the development of organic nanomaterials for biomedical applications. An increasing number of studies focus on the uses of nanomaterials with organic structure for regeneration of bone, cartilage, skin or dental tissues. Solid evidence has been found for several advantages of using natural or synthetic organic nanostructures in a wide variety of dental fields, from implantology, endodontics, and periodontics, to regenerative dentistry and wound healing. Most of the research is concentrated on nanoforms of chitosan, silk fibroin, synthetic polymers or their combinations, but new nanocomposites are constantly being developed. The present work reviews in detail current research on organic nanoparticles and their potential applications in the dental field.

Trans-resveratrol enriched maternal diet protects the immature hippocampus from perinatal asphyxia in rats

Trans-resveratrol (tRESV), a polyphenol with antioxidant properties, is common in many food sources, hence easily accessible for study as a maternal dietary supplement in perinatal asphyxia (PA). Hypoxic-ischemic encephalopathy secondary to PA affects especially vulnerable brain areas such as hippocampus and is a leading cause of neonatal morbidity. The purpose of this study is to identify new epigenetic mechanisms of brain inflammation and injury related to PA and to explore the benefit of tRESV enriched maternal diet. The hippocampal interleukin 1 beta (IL-1b), tumour necrosis factor alpha (TNFα) and S-100B protein, at 24-48h after 90min of asphyxia were assessed in postnatal day 6 rats whose mothers received either standard or tRESV enriched diet. The expression of non-coding microRNAs miR124, miR132, miR134, miR146 and miR15a as epigenetic markers of hippocampus response to PA was determined 24h post-asphyxia. Our results indicate that neural response to PA could be epigenetically controlled and that tRESV reduces asphyxia-related neuroinflammation and neural injury. Moreover, tRESV could increase, through epigenetic mechanisms, the tolerance to asphyxia, with possible impact on the neuronal maturation. Our data support the neuroprotective quality of tRESV when used as a supplement in the maternal diet on the offsprings outcome in PA.

Salivary antioxidant biomarkers in non-ferrous metals mine workers--a pilot study.

OBJECTIVE The purpose of the present study is to evaluate the relationships between occupational exposure to mine dust, salivary antioxidants and their possible implications in the pathogenicity of different exposure diseases. MATERIAL AND METHODS We studied 30 individuals with long-term occupational exposure to non-ferrous metal mine conditions and a control group consisted of 30 healthy volunteers. Salivary uric acid, gammaglutamyltransferase (GGT), albumin and the total antioxidant capacity (TAC) were measured. RESULTS Statistically significant differences in salivary GGT (P = 0.004), TAC (P < 0.001) and uric acid (P = 0.02) were noted between the two groups. A strong positive correlation between TAC and uric acid was recorded in controls (r = 0.76, P = 0.0002). CONCLUSIONS Saliva may provide an important line of antioxidant defense in humans exposed to oxidant threats. These components may also serve as convenient biomarkers to monitor oxidant exposure.

Maternal High-Fat Diet Modifies the Immature Hippocampus Vulnerability to Perinatal Asphyxia in Rats

Background: High-fat diet (HFD) is a detrimental habit with harmful systemic consequences, including low-grade, long-lasting inflammation. During pregnancy, HFD can induce developmental changes. Moreover, HFD-related maternal obesity might enhance the risk of peripartum complications including hypoxic-ischemic encephalopathy secondary to perinatal asphyxia (PA). Objectives: Following our previous results showing that PA increases neuroinflammation and neuronal injury in the immature hippocampus and modifies hippocampal epigenetic programming, we further aimed to establish the impact of maternal HFD on offspring hippocampus response to PA. Methods: We assessed hippocampal tumor necrosis factor alpha (TNFα), interleukin 1 beta (IL-1b) and S-100B protein (S-100B), 24–48 h after PA exposure in postnatal day 6 Wistar rats, whose mothers received either the standard diet or HFD. The expression of small non-coding microRNA species miR124, miR132, miR134, miR146, and miR15a, as epigenetic markers for the maternal dietary influence on immature hippocampus response after PA, was determined 24 h after asphyxia exposure. Metabolic activity was measured using resazurin test in hippocampal cell suspension obtained 24 h after PA. Results: Our results indicate that maternal HFD additionally increases hippocampal TNFα, IL-1b, and S-100B after PA. Also, PA associated with maternal HFD induces miR124 upregulation and miR132 downregulation relative to PA only. Metabolic activity was increased in hippocampal cells from pups whose mothers received HFD. Conclusion: HFD increases the PA-induced neuroinflammation and neuronal injury, and epigenetically influences homeostatic synaptic plasticity and neuronal tolerance to asphyxia, processes associated with a higher hippocampal cellular metabolism.

Salivary oxidative stress, inflammation and invasivity parameters: future candidates as oral cancer biomarkers in saliva

Introduction Head and neck squamous cell carcinomas (SCC) are the sixth most common malignancies worldwide. Saliva qualifies as one of the most suitable diagnostic fluids due to the non-invasivity nature, simple handling procedures, easy collection and storage. The aim of the present study is to assess the presence in saliva of several parameters, possible future candidats as oral cancer biomarkers, such as: oxidative stress - total antioxidant capacity (TAC) and uric acid (most important saliva antioxidant), inflammation - IL-6, collagen matrix degradation - Metallo-proteinase-9 (MMP-9). Material and methods Our study included: - 30 patients, diagnosed with oral SCC - 14 controls (healthy volunteers). Uric acid was analysed using an automatic biochemistry analyser. ELISA assay was used for quantitative detection of MMP-9. IL-6 detection used a immuno-fluorescence kit from Siemens – Germany. For TAC we used the TEAC method (Trolox equivalent antioxidant capacity). Results Both uric acid and total antioxidant capacity showed decreased levels in the saliva of oral cancer patients. IL-6 and MMP-9 showed increased levels in the saliva of oral patients compared to the control group. Conclusion We can conclude that salivary diagnosis has the potential of becoming a powerful tool in detecting and monitoring oral cancer patients.

Biomarkers of Oxidative Stress, Proliferation, Inflammation and Invasivity in Saliva from Oral Cancer Patients

Cancer represents the main cause of death in the economically developed countries and the second cause of death in developing ones. Head and neck squamous cell carcinomas are the sixth most common malignancies worldwide with oral cavity and pharynx cancers being the most common. Saliva qualifies as one of the most suitable diagnostic fluids due to the non-invasivity nature, simple handling procedures, easy collection and storage and good cooperation with patient groups such as children or persons with disabilities. The aim of the present study is to assess the presence in saliva of several cancer biomarkers such as: tumor cells proliferation - Ki-67 Antigen and Squamous Cell Carcinoma Antigen (SCCA), inflammation - Interleukin-6 (IL-6), extracellular matrix collagen degradation - Matrix Metallo-proteinase-9 (MMP-9) and Tissue Inhibitor of Metalloproteinases 2 (TIMP-2), oxidative stress - total antioxidant capacity and uric acid. Both uric acid and total antioxidant capacity showed decreased levelsin the saliva of oral cancer patients. IL-6, Ki-67, SCCA and MMP-9 showed increased levels in the saliva of oral patients compared to the control group. Salivary TIMP-2 levels were also decreased in the patients group. We can conclude that salivary diagnosis has the potential of becoming a powerful tool in detecting and monitoring oral cancer patients.