Development and validation of a simple and noninvasive method for salivary uric acid: potential applications for monitoring the salivary uric acid level in healthy volunteers and gout patients

Abstract Serum uric acid (UA) is a traditional biomarker in the clinical diagnosis of gout and hyperuricemia. However, serum treatment and storage are cumbersome, and wounds are susceptible to infection. Therefore, in this study, a simple and noninvasive method was developed to detect the UA in human saliva to monitor the gout. An Inertsil ODS-3 column was used for the analysis under the condition of isocratic elution with the mixed solution phosphate buffer (74 mM, pH=2.2): Methanol=98:2 (v:v) and the UV detection at 284 nm. Using salivary UA data from healthy volunteers (HVs) (n=68) and gout patients (GPs) (n=14), we examined the salivary UA difference in their content. The intra-and inter-day accuracy and precision (RSD %) were less than 2.56%, the limit of detection (LOD) of UA was 5.0 ng/mL, the mean recoveries of the corresponding compounds were 102.48%. Saliva levels of UA in HVs and GPs were 35.26±14.06 µg/mL and 91.96±23.90 µg/mL, respectively. The concentrations of salivary UA in GPs were significantly higher than those in HVs ( p < 0.001). This method was also expected to monitor the hyperuricemia and other metabolic disorders in the future

Potential use of a dried saliva spot(DSS)in therapeutic drug monitoring and disease diagnosis / 药物分析学报

In recent years,scientific researchers have increasingly become interested in noninvasive sampling methods for therapeutic drug monitoring and disease diagnosis.As a result,dried saliva spot(DSS),which is a sampling technique for collecting dried saliva samples,has been widely used as an alternative matrix to serum for the detection of target molecules.Coupling the DSS method with a highly sensitive detection instrument improves the efficiency of the preparation and analysis of biological samples.Furthermore,dried blood spots,dried plasma spots,and dried matrix spots,which are similar to those of the DSS method,are discussed.Compared with alternative biological fluids used in dried spot methods,including serum,tears,urine,and plasma,saliva has the advantage of convenience in terms of sample collection from children or persons with disabilities.This review aims to provide integral strategies and guidelines for dried spot methods to analyze biological samples by illustrating several dried spot methods.Herein,we summarize recent advancements in DSS methods from June 2014 to March 2021 and discuss the advantages and disadvantages of the key aspects of this method,including sample preparation and method validation.Finally,we outline the challenges and prospects of such methods in practical applications.

Differential molecular signature of human saliva using atr-ftir spectroscopy for chronic kidney disease diagnosis

Abstract The symptoms of chronic kidney disease (CKD) are often not specific or absent in the early stages of this illness. Therefore, there is a demand for developing low cost, non-invasive and highly accurate platforms for CKD diagnostics. We hypothesized that the level of specifics salivary components changes when CKD is emplace, which could be clinically used to discriminate CKD patients from healthy subjects. The present study aimed to compare salivary components between CKD patients and matched control subjects by using attenuated total reflection-Fourier Transform Infrared (ATR-FTIR) spectroscopy. The predictive power of salivary components was evaluated by receiver operating characteristic (ROC) curves. Several components were identified, and 4 of them showed different expression (p<0.05) between CKD and control subjects. Thiocyanate (SCN-, 2052 cm-1) and phospholipids/carbohydrates (924 cm-1) vibrational modes using original and second-derivative spectra by ATR-FTIR could potentially be used as salivary biomarkers to differentiate CKD than control subjects. The combination of original and second-derivative spectra by ATR-FTIR of 924 cm-1 vibrational modes could reach 92.8% sensitivity and 85.7% specificity for CKD detection. Despite, the limitation of our investigation, the acquired data indicates that salivary vibrational modes by ATR-FTIR platform should be further explored as an auxiliary diagnostic tool for CKD.

Resumo Os sintomas da doença renal crônica (DRC) são frequentemente inespecíficos ou ausentes nos estágios iniciais desta doença. Desta forma, existe uma demanda para o desenvolvimento de plataformas com baixo custo, não-invasivas e com alta acurácia para o diagnóstico da DRC. Nós hipotetizamos que o nível dos componentes salivares se alteram pela DRC, o que pode ser clinicamente utilizado para discriminar pacientes portadores de DRC de indivíduos controles. O objetivo deste estudo foi comparar componentes salivares entre pacientes portadores de DRC e sujeitos controles utilizando um sistema de reflectância total atenuada com espectroscopia infravermelho com transformada em Fourier (ATR-FTIR). O poder preditivo dos componentes salivares foi avaliado pela curva característica de operação do receptor (ROC). Diversos componentes salivares foram identificados e 4 destes apresentaram diferença na expressão (p<0,05) entre DRC e sujeitos controles. O modos vibracionais do tiocianato (2052 cm-1) e de fosfolipídeos/carbohidratos (924 cm-1) utilizando espectros originais e da segunda-derivada pelo ATR-FTIR podem potencialmente ser utilizados como biomarcadores salivares para discriminar a DRC de sujeitos controles. A combinação dos espectros originais e da segunda-derivada pelo ATR-FTIR do modo vibracional 924 cm-1 pode apresentar sensibilidade de 92.8% e especificidade de 85.7% para a detecção da DRC. Este estudo indicou que modos vibracionais da saliva pela plataforma ATR-FTIR podem ser uma ferramenta auxiliar no diagnóstico da DRC.

Effect of snack eating on sensitive salivary stress markers cortisol and chromogranin A

<p><b>OBJECTIVES</b>To investigate the effect of snack eating on salivary cortisol and chromogranin A (CgA).</p><p><b>METHODS</b>From 14∶00 to 18∶00, starting two hours after consumption of a midday meal, saliva samples were collected every 30 minutes from 15 healthy males, 7 of whom (snack group) ate a snack immediately after the sampling at 15∶00. Salivary cortisol and CgA levels were determined by ELISA. Samples were controlled according to salivary flow rates.</p><p><b>RESULTS</b>For the snack group, after snack consumption, salivary cortisol increased to exceed significance (p<0.05) at 15∶30 and rose even higher at 16∶00. In the control group, there was no such change. There was no significant change in salivary CgA in either the snack group or the control groups during the sampling period.</p><p><b>CONCLUSIONS</b>These findings suggest that no food should be consumed for at least 90 mins before saliva sampling for cortisol determination and that salivary CgA is probably not affected by snack eating.</p>

Effect of Snack Eating on Sensitive Salivary Stress Markers Cortisol and Chromogranin A

Objectives: To investigate the effect of snack eating on salivary cortisol and chromogranin A (CgA). Methods: From 14:00 to 18:00, starting two hours after consumption of a midday meal, saliva samples were collected every 30 minutes from 15 healthy males, 7 of whom (snack group) ate a snack immediately after the sampling at 15:00. Salivary cortisol and CgA levels were determined by ELISA. Samples were controlled according to salivary flow rates. Results: For the snack group, after snack consumption, salivary cortisol increased to exceed significance (p<0.05) at 15:30 and rose even higher at 16:00. In the control group, there was no such change. There was no significant change in salivary CgA in either the snack group or the control groups during the sampling period. Conclusions: These findings suggest that no food should be consumed for at least 90 mins before saliva sampling for cortisol determination and that salivary CgA is probably not affected by snack eating.

Beneficial effect of tomato juice drinking on anti-mutagenicity of saliva

<p><b>OBJECTIVES</b>The purpose of this study was to investigate the effect of tomato juice drinking on the antimutagenicity of saliva.</p><p><b>METHODS</b>Subjects were 22 healthy male university students. They were divided into tomato group and control group. The tomato group drank tomato juice for 10 days. The anti-mutagenicity of saliva was measured using the umu test.</p><p><b>RESULTS</b>In the tomato group, there was a significant increase in the inhibiting capacity of saliva on the mutagenicity of AF-2 after tomato juice drinking for 10 days. This increase was, however, temporary. In the control group, there was no such change in the inhibiting capacity of saliva.</p><p><b>CONCLUSIONS</b>These findings suggest the significant effect of tomato juice drinking on the anti-mutagenicity of saliva. In addition, lycopene may have played an important role in its mechanism.</p>

Beneficial Effect of Tomato Juice Drinking on Anti-Mutagenicity of Saliva

Objectives: The purpose of this study was to investigate the effect of tomato juice drinking on the anti-mutagenicity of saliva. Methods: Subjects were 22 healthy male university students. They were divided into tomato group and control group. The tomato group drank tomato juice for 10 days. The anti-mutagenicity of saliva was measured using the umu test. Results: In the tomato group, there was a significant increase in the inhibiting capacity of saliva on the mutagenicity of AF-2 after tomato juice drinking for 10 days. This increase was, however, temporary. In the control group, there was no such change in the inhibiting capacity of saliva. Conclusions: These findings suggest the significant effect of tomato juice drinking on the anti-mutagenicity of saliva. In addition, lycopene may have played an important role in its mechanism.

A Further Note on the Sampling Device for the Anti-Mutagenicity of Saliva

Objectives: The purpose of this study was to compare the anti-mutagenicity of Salivette and test-tube sampling saliva. In addition, the relation between the inhibiting and pH-buffering capacities of saliva was investigated. Methods: Subjects were 52 healthy female university students. The collection of saliva samples was carried out using 2 sampling devices; test-tube and Salivette. The anti-mutagenicity of the saliva was measured using the umu test. Results: The inhibiting capacity of Salivette-saliva was significantly lower compared with that of test-tube-saliva (p<0.01, t test). However, there was a significant correlation between them (r=0.35; p<0.05). In addition, there was a significant correlation between the inhibiting and pH-buffering capacities of saliva (r=−0.36; p<0.05). Conclusions: These findings suggest that both the Salivette and the test-tube may be appropriate as saliva-sampling devices. In addition, they suggest that the bicarbonates might inhibit the anti-mutagenicity of saliva, or that the activity of substances related to the anti-mutagenicity of saliva might be dependent on pH.

Daily Lifestyles and Anti-Mutagenicity of Saliva

Objectives: The purpose of this study was to investigate the relation between lifestyle and the anti-mutagenicity of saliva. Methods: Subjects were 52 healthy female university students. The collection of the saliva samples and the lifestyle measurements were carried out for them. The anti-mutagenicity of the saliva was measured using the umu test. Results: With regard to the lifestyle items, only “nutrient balance” tended to contribute positively to the inhibiting capacity of the saliva on the mutagenicity of AF-2. In addition, there was a significant inverse correlation between the score of 7 other items and the inhibiting capacity of the saliva (r=−0.32; p<0.05). We also found a significant relation between their tea and/or coffee consumption and the inhibiting capacity of the saliva. Conclusions: These findings suggest that the inhibiting capacity of saliva worked to decrease mutagen levels that were enhanced by poor lifestyle. In addition, “nutrient balance” may contribute to the inhibiting capacity of the saliva independent of 7 other items. With regard to the tea and/or coffee consumption, further studies should be carried out.

Daily lifestyles and anti-mutagenicity of saliva

<p><b>OBJECTIVES</b>The purpose of this study was to investigate the relation between lifestyle and the antimutagenicity of saliva.</p><p><b>METHODS</b>Subjects were 52 healthy female university students. The collection of the saliva samples and the lifestyle measurements were carried out for them. The anti-mutagenicity of the saliva was measured using the umu test.</p><p><b>RESULTS</b>With regard to the lifestyle items, only "nutrient balance" tended to contribute positively to the inhibiting capacity of the saliva on the mutagenicity of AF-2. In addition, there was a significant inverse correlation between the score of 7 other items and the inhibiting capacity of the saliva (r=-0.32; p<0.05). We also found a significant relation between their tea and/or coffee consumption and the inhibiting capacity of the saliva.</p><p><b>CONCLUSIONS</b>These findings suggest that the inhibiting capacity of saliva worked to decrease mutagen levels that were enhanced by poor lifestyle. In addition, "nutrient balance" may contribute to the inhibiting capacity of the saliva independent of 7 other items. With regard to the tea and/or coffee consumption. further studies should be carried out.</p>

A further note on the sampling device for the anti-mutagenicity of saliva

<p><b>OBJECTIVES</b>The purpose of this study was to compare the anti-mutagenicity of Salivette and test-tube sampling saliva. In addition, the relation between the inhibiting and pH-buffering capacities of saliva was investigated.</p><p><b>METHODS</b>Subjects were 52 healthy female university students. The collection of saliva samples was carried out using 2 sampling devices; test-tube and Salivette. The anti-mutegenicity of the saliva was measured using the umu test.</p><p><b>RESULTS</b>The inhibiting capacity of Salivette-saliva was significantly lower compared with that of testube-saliva (p<0.01,t test). However, there was a significant correlation between them (r=0.35; p<0.05). In addition, there was a significant correlation between the inhibiting and pH-buffering capacities of saliva (r=-0.36; p<0.05).</p><p><b>CONCLUSIONS</b>These findings suggest that both the Salivette and the test-tube may be appropriate as saliva-sampling devices. In addition, they suggest that the bicarbonates might inhibit the anti-mutagenicity of saliva, or that the activity of substances related to the anti-mutagenicity of saliva might be dependent on pH.</p>

The Unique Correlation between Anti-Mutagenicity of Human Saliva and Change in Body Weight

The purpose of this study was to investigate the effect of weight reduction on the anti-mutagenicity of human saliva. Subjects were 16 male college judo players. The anti-mutagenicity of the saliva was measured using the umu test. There was an inhibiting effect of the saliva on the mutagenicity of AF-2. However, a modifying effect of the saliva on Trp-P-1 was not observed. On the day before a competition and 7 days after the competition, the inhibiting capacity of the saliva for the mutagenicity of AF-2 decreased and increased in two non-weight reduction and two weight reduction groups, respectively. However, on the day before the competition, the changed body weights (r=−0.77, p<0.01) and BMI (r=−0.77, p<0.01) were significantly correlated with that of the inhibiting capacity of the saliva for the mutagenicity of AF-2. In addition, the BMI at 20 days before the competition was not significantly but markedly correlated with it (r=0.50, p=0.057). At 7 days after the competition, however, these correlations were not found. These findings suggest a unique correlation between the anti-mutagenicity of human saliva and body weight or BMI.