Antioxidant capacity and biomarkers of oxidative stress in saliva of khat-chewing patients: a case-control study

Gingival Enlargement Associated with Orthodontics Appliance Increases Protein Carbonylation and Alters Phosphorylation of Salivary Proteome

Gingival enlargement is a common clinical sign in the gingival diseases associated with orthodontic treatment. Its biological mechanisms are not completely understood; nevertheless, the biochemical changes associated with these inflammatory and overgrowth processes could alter the post-translational protein modifications occurring in various locations within the mouth. Here, changes in the profiles of the carbonylated and phosphorylated proteins in saliva were examined in donors with gingival enlargement (seven men and seven women) and healthy donors (six men and eight women). The sociodemographic characteristics of both groups did not present significant differences. Carbonylation was measured by a quantitative immunoassay (Dot Blot), whereas the profiles of the phosphorylated proteins were visualized by SDS-PAGE with quercetin staining. Some phosphopeptides were also identified using a typical LC-MS-MS approach. Our results showed that gingival enlargement induced a significant increase in oxidative damage in salivary proteins. While a significant reduction in phosphorylation was observed at the stain level in SDS-PAGE, there was a slight increase in the number of phosphorylated proteins identified by MS in samples with gingival enlargement.

Distinguishable short-term effects of tea and water drinking on human saliva redox

Food consumption can alter the biochemistry and redox status of human saliva, and the serving temperature of food may also play a role. The study aimed to explore the immediate (3 min) and delayed (30 min) effects of hot tea (57 ± 0.5 °C) ingestion and cold tea (8 ± 0.5 °C) ingestion on the salivary flow rate and salivary redox-relevant attributes. The saliva was collected from 20 healthy adults before, 3-min after and 30-min after the tea ingestion. The hot or cold deionised water at the same temperatures were used as control. The salivary flow rate and redox markers in hot tea (HBT), cold tea (CBT), hot water (HW) and cold water (CW) group were analysed and compared. The results demonstrated that neither the black tea nor the water altered the salivary flow rate; the black tea immediately increased the salivary thiol (SH) and malondialdehyde (MDA) content while reduced salivary uric acid (UA) significantly. The tea ingestion showed a tendency to elevate the ferric reducing antioxidant power (FRAP) in saliva, although not significantly. The water ingestion decreased the MDA content immediately and increased the UA level significantly. Cold water was found to induce a greater delayed increase in total salivary total protein (TPC) than the hot water. In conclusion, the black tea ingestion affects the redox attributes of human saliva acutely and significantly, while the temperature of drink makes the secondary contribution.

Risks of khat chewing on the cardiovascular, nervous, gastrointestinal, and genitourinary systems: A narrative review

Khat is an evergreen plant and its fresh green leaves and buds are chewed for several hours a day for its psychostimulant response. This study aimed to review the effects of khat chewing on the body. PubMed was searched for literature on the different aspects of khat chewing to summarize its effects on different body systems. The major effects of khat chewing are those on the cardiovascular system including increased blood pressure, increased heart rate, and increased risk of myocardial infarction. It causes insomnia, stress, depression, hallucination, and increased risk of brain stroke. It causes dental caries, bad oral hygiene, periodontitis, increased oral mucosal ulcers, and increased gingival bleeding and recession. Khat chewing causes loss of appetite, gastritis, constipation, and hemorrhoids, and increased risk of hepatotoxicity and liver cirrhosis. Ultimately, it causes weak micturition, decreased sperm motility and count, and low birth-weight offspring in khat chewing mothers. The published articles about khat chewing in journals indexed in the PubMed was reviewed. Inclusion criteria involved each article available with English language and have a reported new effect of khat chewing.

Metabolomics to Diagnose Oxidative Stress in Perinatal Asphyxia: Towards a Non-Invasive Approach

There is a need for feasible and non-invasive diagnostics in perinatal asphyxia. Metabolomics is the study of small molecular weight products of cellular metabolism that may, directly and indirectly, reflect the level of oxidative stress. Saliva analysis is a novel approach that has a yet unexplored potential in metabolomics in perinatal asphyxia. The aim of this review was to give an overview of metabolomics studies of oxidative stress in perinatal asphyxia, particularly searching for studies analyzing non-invasively collected biofluids including saliva. We searched the databases PubMed/Medline and included 11 original human and 4 animal studies. In perinatal asphyxia, whole blood, plasma, and urine are the most frequently used biofluids used for metabolomics analyses. Although changes in oxidative stress-related salivary metabolites have been reported in adults, the utility of this approach in perinatal asphyxia has not yet been explored. Human and animal studies indicate that, in addition to antioxidant enzymes, succinate and hypoxanthine, as well acylcarnitines may have discriminatory diagnostic and prognostic properties in perinatal asphyxia. Researchers may utilize the accumulating evidence of discriminatory metabolic patterns in perinatal asphyxia to develop bedside methods to measure oxidative stress metabolites in perinatal asphyxia. Although only supported by indirect evidence, saliva might be a candidate biofluid for such point-of-care diagnostics.