Unravelling the Potential of Salivary Volatile Metabolites in Oral Diseases. A Review.

Fostered by the advances in the instrumental and analytical fields, in recent years the analysis of volatile organic compounds (VOCs) has emerged as a new frontier in medical diagnostics. VOCs analysis is a non-invasive, rapid and inexpensive strategy with promising potential in clinical diagnostic procedures. Since cellular metabolism is altered by diseases, the resulting metabolic effects on VOCs may serve as biomarkers for any given pathophysiologic condition. Human VOCs are released from biomatrices such as saliva, urine, skin emanations and exhaled breath and are derived from many metabolic pathways. In this review, the potential of VOCs present in saliva will be explored as a monitoring tool for several oral diseases, including gingivitis and periodontal disease, dental caries, and oral cancer. Moreover, the analytical state-of-the-art for salivary volatomics, e.g., the most common extraction techniques along with the current challenges and future perspectives will be addressed unequivocally.

Screening of salivary volatiles for putative breast cancer discrimination: an exploratory study involving geographically distant populations.

Saliva is possibly the easiest biofluid to analyse and, despite its simple composition, contains relevant metabolic information. In this work, we explored the potential of the volatile composition of saliva samples as biosignatures for breast cancer (BC) non-invasive diagnosis. To achieve this, 106 saliva samples of BC patients and controls in two distinct geographic regions in Portugal and India were extracted and analysed using optimised headspace solid-phase microextraction gas chromatography mass spectrometry (HS-SPME/GC-MS, 2 mL acidified saliva containing 10% NaCl, stirred (800 rpm) for 45 min at 38 °C and using the CAR/PDMS SPME fibre) followed by multivariate statistical analysis (MVSA). Over 120 volatiles from distinct chemical classes, with significant variations among the groups, were identified. MVSA retrieved a limited number of volatiles, viz. 3-methyl-pentanoic acid, 4-methyl-pentanoic acid, phenol and p-tert-butyl-phenol (Portuguese samples) and acetic, propanoic, benzoic acids, 1,2-decanediol, 2-decanone, and decanal (Indian samples), statistically relevant for the discrimination of BC patients in the populations analysed. This work defines an experimental layout, HS-SPME/GC-MS followed by MVSA, suitable to characterise volatile fingerprints for saliva as putative biosignatures for BC non-invasive diagnosis. Here, it was applied to BC samples from geographically distant populations and good disease separation was obtained. Further studies using larger cohorts are therefore very pertinent to challenge and strengthen this proof-of-concept study. Graphical abstract ᅟ.

Polystyrene microplastic particles in the food chain: Characteristics and toxicity - A review.

Polystyrene (PS) is a crucial material for modern plastic manufacturers, but its widespread use and direct discard in the environment severely affect the food chain. This review provides a detailed study on the impact of PS microplastics (PS-MPs) on the food chain and the environment, including information on their mechanism, degradation process, and toxicity. The accumulation of PS-MPs in organisms' different organs leads to various adverse reactions, such as reduced body weight, premature deaths, pulmonary diseases, neurotoxicity, transgenerational issues, oxidative stress, metabolic alterations, ecotoxicity, immunotoxicity, and other dysfunctions. These consequences affect diverse elements in the food chain, spanning from aquatic species to mammals and humans. The review also addresses the need for sustainable plastic waste management policies and technological developments to prevent the adverse impacts of PS-MPs on the food chain. Additionally, it emphasizes the importance of developing a precise, flexible, and effective methodology for extracting and quantifying PS-MPs in food, considering their characteristics like particle size, polymer types, and forms. While several studies have focused on the toxicity of polystyrene microplastics (PS-MPs) in aquatic species, further investigation is required to understand the mechanisms by which they are transferred across multiple trophic levels. Therefore, this article serves as the first comprehensive review, examining the mechanism, degradation process, and toxicity of PS-MPs. It presents an analysis of the current research landscape of PS-MPs in the global food chain, providing insights for future researchers and governing organizations to adopt better approaches to managing PS-MPs and preventing their adverse impacts on the food chain. As far as we know this is the first article on this specific and impactant topic.

Volatilomic insight of head and neck cancer via the effects observed on saliva metabolites.

Head and neck cancer (HNC) is a heterogeneous malignant disease with distinct global distribution. Metabolic adaptations of HNC are significantly gaining clinical interests nowadays. Here, we investigated effects of HNC on differential expression of volatile metabolites in human saliva. We applied headspace solid phase microextraction coupled with gas chromatography-mass spectrometry analysis of saliva samples collected from 59 human subjects (HNC - 32, Control - 27). We identified and quantified 48 volatile organic metabolites (VOMs) and observed profound effects of HNC on these metabolites. These effects were VOM specific and significantly differed in the biologically comparable healthy controls. HNC induced changes in salivary VOM composition were well attributed to in vivo metabolic effects. A panel of 15 VOMs with variable importance in projection (VIP) score >1, false discovery rate (FDR) corrected p-value < 0.05 and log2 fold change (log2 FC) value of ≥0.58/≤-0.58 were regarded as discriminatory metabolites of pathophysiological importance. Afterwards, receiver operator characteristic curve (ROC) projected certain VOMs viz., 1,4-dichlorobenzene, 1,2-decanediol, 2,5-bis1,1-dimethylethylphenol and E-3-decen-2-ol with profound metabolic effects of HNC and highest class segregation potential. Moreover, metabolic pathways analysis portrayed several dysregulated pathways in HNC, which enhanced our basic understanding on salivary VOM changes. Our observations could redefine several known/already investigated systemic phenomenons (e.g. biochemical pathways). These findings will inspire further research in this direction and may open unconventional avenues for non-invasive monitoring of HNC and its therapy in the future.