Development of enzyme-inorganic hybrid nanoflower-modified electrodes and a smartphone-controlled electrochemical analyzer for point-of-care testing of salivary amylase in saliva.

Quantitation of salivary alpha-amylase (sAA) plays a significant role in not only theoretical studies but also clinical practice. This study reports a quantitative point-of-care testing (POCT) system for sAA quantitation anywhere, anytime and by anyone, which consists of customized electrodes and a smartphone-controlled electrochemical analyzer. Organic-inorganic hybrid nanoflowers (NFs) encapsulating α-glucosidase (AG) and glucose dehydrogenase (GDH) have been synthesized and modified onto screen-printed electrodes (SPCEs) to fabricate the customized electrodes. The SPCEs integrated with the smartphone-controlled electrochemical analyzer exhibit good analytical performance for sAA with a low detection limit of 5.02 U mL-1 and a wide dynamic range of 100-2000 U mL-1 using chronoamperometry. The reported POCT system has been successfully demonstrated for quantitation of sAA in clinical saliva samples, and the quantitation results correlated well with those of the Bernfeld method which is extensively used in clinics. More importantly, this study reveals the great potential of sAA as an early warning indicator of abnormal glucose metabolism in obese individuals. Considering the non-invasive saliva sampling process as well as the easy-to-use and cost-effectiveness features of this quantitative POCT system, quantitation of salivary sAA at home by laypersons might become an appealing choice for obese individuals to monitor their glucose metabolism status anytime.

Harnessing the Therapeutic Potential of Ginsenoside Rd for Activating SIRT6 in Treating a Mouse Model of Nonalcoholic Fatty Liver Disease.

Nonalcoholic fatty liver disease (NAFLD) is a prevalent global condition and a common precursor to liver cancer, yet there is currently no specific medication available for its treatment. Ginseng, renowned for its medicinal and dietary properties, has been utilized in NAFLD management, although the precise underlying mechanism remains elusive. To investigate the effectiveness of ginsenoside Rd, we employed mouse and cell models to induce NAFLD using high-fat diets, oleic acid, and palmitic acid. We explored and confirmed the specific mechanism of ginsenoside Rd-induced hepatic steatosis through experiments involving mice with a liver-specific knockout of SIRT6, a crucial protein involved in metabolic regulation. Our findings revealed that administration of ginsenoside Rd significantly reduced the inflammatory response, reactive oxygen species (ROS) levels, lipid peroxide levels, and mitochondrial stress induced by oleic acid and palmitic acid in primary hepatocytes, thereby mitigating excessive lipid accumulation. Moreover, ginsenoside Rd administration effectively enhanced the mRNA content of key proteins involved in fatty acid oxidation, with a particular emphasis on SIRT6 and its target proteins. We further validated that ginsenoside Rd directly binds to SIRT6, augmenting its deacetylase activity. Notably, we made a significant observation that the protective effect of ginsenoside Rd against hepatic disorders induced by a fatty diet was almost entirely reversed in mice with a liver-specific SIRT6 knockout. Our findings highlight the potential therapeutic impact of Ginsenoside Rd in NAFLD treatment by activating SIRT6. These results warrant further investigation into the development of Ginsenoside Rd as a promising agent for managing this prevalent liver disease.

Decreased salivary α-amylase activity responding to citric acid stimulation in Myasthenia gravis with malnutrition.

OBJECTIVES: Malnutrition, defined according to Nutritional risk screening (NRS 2002), is commonly observed in patients of Myasthenia gravis (MG), a neuromuscular disorder manifested by varied degrees of skeletal muscle weakness. Because biochemical composition of saliva changes in correspondence to alterations in nutritional status, we tested our hypothesis that a certain saliva component(s) might serve as a biomarker(s) for nutrition status of MG, particularly for those MG patients with high risk of malnutrition. MATERIALS AND METHODS: 60 MG patients and 60 subjects belonging to the healthy control group (HCG) were enrolled in this case-control study. The salivary α-amylase (sAA) activity, salivary flow rate (SFR), pH, total protein density (TPD), and the concentrations of chloride and calcium ions in MG group with or without malnutrition were measured before and after citric acid stimulation. Thereafter, the relationship between sAA activity and BMI was determined in MG and HCG. RESULTS: Compared with HCG, more patients with malnutrition, increased TPD and chloride and calcium concentrations but decreased pH value and SFR both before and after acid stimulation, as well as reduced sAA activity, pH and TPD responses to acid stimulation. MG with malnutrition showed decreased sAA activity and TPD responding to acid stimulation compared with those without malnutrition. Compared with normal BMI, sAA activity response to acid stimulation was reduced in low BMI. There was a significant strong positive correlation between the ratio of sAA activity and BMI in MG. CONCLUSIONS: Salivary biochemical characteristics are abnormally altered in MG with malnutrition. Altered sAA activity responding to acid stimulation was associated with malnutrition. CLINICAL RELEVANCE: Decreased sAA activity responding to acid stimulation can reflect malnutrition state and may be one potential screening marker for MG patients with high risk of malnutrition.

Diurnal pattern of salivary alpha-amylase and cortisol under citric acid stimulation in young adults.

Background: Saliva composition has diurnal variations. Citric acid stimulation plays a major role in the change of salivary flow rate and salivary composition. However, diurnal variations and sex differences in salivary alpha-amylase (sAA), pH, salivary flow rate (SFR), and salivary cortisol before and after citric acid stimulation remain unclear. Methods: We recruited 30 healthy volunteers, including 15 women (24.7 ± 1.0 years old) and 15 men (25.3 ± 1.3 years old). At four time points (T1, 7:00; T2, 10:00; T3, 16:00; and T4, 20:00), saliva was collected from healthy volunteers before and after citric acid stimulation; and sAA, pH, SFR and salivary cortisol were measured and compared between men and women. Results: There were circadian fluctuations in sAA activity, SFR, pH, and cortisol level both before and after citric acid stimulation, and the diurnal fluctuations of these indexes were not affected by citric acid stimulation. There were significant differences in salivary cortisol between men and women before and after acid stimulation in T1. Neither SFR nor pH showed sex-related differences before or after acid stimulation. The variation trend of sAA activity was contrary to that of cortisol, with a significant negative correlation. Conclusions: Our data suggest that sAA and cortisol showed diurnal fluctuation, and the variation characteristics of male and female under resting state and acid stimulation were basically the same. The variation trend of salivary alpha-amylase activity was opposite to that of cortisol, with significant negative correlation. Our findings may enable the selection of the correct sampling time for research and the selection of appropriate sampling strategies in studies investigating chronic psychosocial conditions.

Patchouli alcohol activates PXR and suppresses the NF-κB-mediated intestinal inflammatory.

ETHNOPHARMACOLOGICAL RELEVANCE: The pregnane-X-receptor (PXR) is involved in inflammatory bowel disease (IBD). Patchouli alcohol (PA) has anti-inflammatory effects; however, the effect of PA on IBD pathogenesis remains largely unknown. AIM OF THE STUDY: The aim of the present study was to investigate the anti-inflammatory effect of PA, primarily focused on crosstalk between PA-mediated PXR activation and NF-κB inhibition. MATERIALS AND METHODS: We evaluated the anti-inflammatory effect of PA with respect to PXR/NF-κB signalling using in vitro and in vivo models. In vitro, PA, identified as a PXR agonist, was evaluated by hPXR transactivation assays and through assessing for CYP3A4 expression and activity. NF-κB inhibition was analysed based on NF-κB luciferase assays, NF-κB-mediated pro-inflammatory gene expression, and NF-κB nuclear translocation after activation of PXR by PA. In vivo, colonic mPXR and NF-κB signalling were analysed to assess PA-mediated the protective effect against dextran sulphate sodium (DSS)-induced colitis. Furthermore, pharmacological inhibition of PXR was further evaluated by examining PA protection against DSS-induced colitis. RESULTS: PA induced CYP3A4 expression and activity via an hPXR-dependent mechanism. PA-mediated PXR activation attenuated inflammation by inhibiting NF-κB activity and nuclear translocation. The anti-inflammatory effect of PA on NF-κB was abolished by PXR knockdown. PA prevented DSS-induced inflammation by regulating PXR/NF-κB signalling, whereas pharmacological PXR inhibition abated PA-mediated suppressive effects on NF-κB inflammation signalling. CONCLUSIONS: PA activates PXR signalling and suppresses NF-κB signalling, consequently causing amelioration of inflammation. Our results highlight the importance of PXR-NF-κB crosstalk in colitis and suggest a novel therapeutic reagent.

Abnormalities in acute salivary biochemical characteristic responses to gustatory stimulation with citric acid in chronic non-atrophic gastritis.

BACKGROUND AND AIM: Salivary characteristics are altered in gastrointestinal diseases and related to oral taste disorder. However, specific salivary biochemical characteristics and their relationships with oral taste disturbances in chronic non-atrophy gastritis (CNAG) remain uncertain. METHODS: Seventy patients with CNAG and 70 subjects in healthy control group (HCG) were enrolled in our study. The levels of salivary flow rate (SFR), pH, salivary α-amylase (sAA) activity, total protein density (TPD), chloride concentration, and calcium concentration were determined before and after citric acid stimulation and compared between CNAG with and without oral taste disturbances. RESULTS: Average body mass index (BMI) of CNAG (17.75 ± 2.08) was lower than that of HCG (21.96 ± 1.72, P < 0.01). Compared with HCG, CNAG showed increased TPD and calcium concentration but decreased SFR both before and after acid stimulation (P < 0.01), as well as reduced sAA and salivary chloride responses to acid stimulation (P < 0.01). Compared with CNAG with normal BMI (24.29%, 17/70), sAA activity response to acid stimulation was reduced in those with low BMI (75.71%, 53/70, P < 0.05). Under resting condition, CNAG with dry mouth (55.71%, 39/70) showed increased SFR and decreased TPD (P < 0.05), as compared with CNAG without dry mouth (44.29%, 31/70). Compared with CNAG without bitter taste (57.14%, 40/70), pH was decreased in those with bitter taste (42.86%, 30/70) under both resting and stimulated conditions (P < 0.05). CONCLUSION: Decreased sAA activity may reflect malnutrition state and be one potential marker of poor digestion, decreased salivary pH may contribute to bitter taste perception, and reduced TPD might be a cause of dry mouth in CNAG.

Polysaccharide extracts of Astragalus membranaceus and Atractylodes macrocephala promote intestinal epithelial cell migration by activating the polyamine-mediated K+ channel.

Astragalus membranaceus (Radix Astragali, RA) and Atractylodes macrocephala (Rhizoma Atractylodis Macrocephalae, RAM) are often used to treat gastrointestinal diseases. In the present study, we determined the effects of polysaccharides extracts from these two herbs on IEC-6 cell migration and explored the potential underlying mechanisms. A migration model with IEC-6 cells was induced using a single-edged razor blade along the diameter of cell layers in six-well polystyrene plates. The cells were grown in control media or media containing spermidine (5 µmol·L-1, SPD), alpha-difluoromethylornithine (2.5 mmol·L-1, DFMO), 4-Aminopyridine (40 µmol·L-1, 4-AP), the polysaccharide extracts of RA or RAM (50, 100, or 200 mg·L-1), DFMO plus SPD, or DFMO plus polysaccharide extracts of RA or RAM for 12 or 24 h. Next, cytosolic free Ca2+ ([Ca2+]cyt) was measured using laser confocal microscopy, and cellular polyamine content was quantified with HPLC. Kv1.1 mRNA expression was assessed using RT-qPCR and Kv1.1 and RhoA protein expressions were measured with Western blotting analysis. A cell migration assay was carried out using Image-Pro Plus software. In addition, GC-MS was introduced to analyze the monosaccharide composition of both polysaccharide extracts. The resutls showed that treatment with polysaccharide extracts of RA or RAM significantly increased cellular polyamine content, elevated [Ca2+]cyt and accelerated migration of IEC-6 cells, compared with the controls (P < 0.01). Polysaccharide extracts not only reversed the inhibitory effects of DFMO on cellular polyamine content and [Ca2+]cyt, but also restored IEC-6 cell migration to control level (P < 0.01 or < 0.05). Kv1.1 mRNA and protein expressions were increased (P < 0.05) after polysaccharide extract treatment in polyamine-deficient IEC-6 cells and RhoA protein expression was increased. Molar ratios of D-ribose, D-arabinose, L-rhamnose, D-mannose, D-glucose, and D-galactose was 1.0 : 14.1 : 0.3 : 19.9 : 181.3 : 6.3 in RA and 1.0 : 4.3 : 0.1 : 5.7 : 2.8 : 2.2 in RAM. In conclusion, treatment with RA and RAM polysaccharide extracts stimulated migration of intestinal epithelial cells via a polyamine-Kv1.1 channel activated signaling pathway, which facilitated intestinal injury healing.

[Effect of 3 saliva collection methods on salivary secretion].

PURPOSE: This study compared the effect of 3 saliva collection methods on salivary secretion, in order to select optimum collection method for follow-up studies. METHODS: Fifty-five young healthy volunteers' saliva samples were collected by EP tube collecting emulated with natural flow (ETC), rotating mouth swab slightly (RMS) and chewing mouth swab (CMS) before and after stimulating with acid. The salivary flow rate, salivary alpha-amylase (sAA) activity of each saliva sample and its ratio before and after stimulating with acid were detected to provide the basis for the preferred method of collecting saliva. SPSS 17 software package was used to compare the results before and after acid stimulation. RESULTS: The salivary flow rate ratio (1.73 ± 1.35 and 1.37 ± 0.82, respectively), sAA activity ratio (1.22 ± 0.38 and 1.10 ± 0.30, respectively) and unit time total sAA activity ratio (2.12 ± 1.57 and 1.56 ± 1.18, respectively) of ETC and RMS increased after acid stimulation with the same tendency, and the detection rate of the indexes were closer between ETC and RMS (salivary flow rates: 80%, 78.2%; sAA activity:67.3%, 60.0%; unit time total sAA activity: 83.6%, 76.4%, respectively). Among them, RMS had the advantage of objective and paralleled to collect sufficient amount of saliva. However, the results of CMS were quite different with the first two methods. The detection rate of each index ratio increased in the CMS (salivary flow rate, sAA activity and unit time total sAA activity were 67.3%, 40%, 61.8%, respectively) was significantly lower than the first two, and did not accurately reflect the status of sAA activity in healthy people after acid stimulation. CONCLUSIONS: RMS is recommended when studying on the variation of salivary secretion before and after salivary gland stimulated by acid.

Differential expression of immune-related genes between healthy volunteers and type 2 diabetic patients with spleen-deficiency pattern.

OBJECTIVE: To investigate the clinical differentia tion of spleen-deficiency pattern (SDP), a group of symptoms and signs defined in terms of Traditional Chinese Medicine for its clinical practice. METHODS: Peripheral venous blood (> 3 mL) was collected from each of six type 2 diabetes mellitus (T2DM)-SDP patients and six healthy volunteers. After the isolation of peripheral white blood cells (PWBCs), total RNA was extracted, and quality control was performed on all RNA samples. Microarray experiments were conducted using the Agilent human whole genome gene chip, and genes demonstrating differential expression were screened. Bioinformatics analysis was conducted on these genes using several online databases. RESULTS: We screened a total of 175 differentially expressed genes (DEGs), of which 111 (63%) were down-regulated and 64 (37%) were up-regulated in T2DM-SDP patients compared with healthy controls. Among the 175 genes, 158 had biological function annotations: 46 (29%) were directly related to an individual's immune regulation or response, 25 (16%) were associated with substance and energy metabolism of PWBCs which could also indirectly influence immunity, and the remaining 87 (55%) were involved in a variety of PWBC biological processes that might eventually influence the immune function. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis revealed that the DEGs were predominantly enriched in seven immune-related pathways. Hierarchical cluster analysis identified gene expression patterns that were distinguishable between the two study groups. CONCLUSION: Our results suggest that T2DM-SDP patients experience significant hypoimmunity and/or immune dysfunctions, and possess a specific gene expression profile. These findings offer new insights into SDP and the clinical pattern differentiation of T2DM-SDP.

[Effect and mechanism of reserpine for changing salivary protein secretion in Pi-deficient rats].

OBJECTIVE: To study the effect of reserpine (RSP) for changing salivary protein secretion in Pi-deficient rats and to explore its possible mechanism. METHODS: Twenty rats allocated in the RSP group were given subcutaneous injection of RSP [0.4 mg/(kg x d)] for 9 successive days, while the other 20 rats in the control group were injected with same volume of saline instead. On the 10th day, ten rats randomly selected from each group were subjected for extracting saliva to detect salivary amylase activity (sAA) before and after an acid stimulation; and drawing blood from the orbital vein to measure the contents of vasoactive intestinal peptide (VIP) and cyclic adenosine monophosphate (cAMP). Then they were sacrificed and their parotids were taken out for pathological examination with HE staining, as well as for VIP and cAMP measuring, and zymogen granules counting under a transmission electron microscope. The remainder animals were stopped injecting and normally fed to 40 days, then subjected to be detected as above-mentioned. RESULTS: Food intake and body weight reduction were more significantly in the RSP group than in the control group. On the 10th day, the ratio of sAA before/after stimulation in the RSP group was 0.39 +/- 0.18, significantly lower than that in the control group (0.80 +/- 0.21, P < 0.01), but it was restored rapidly, reaching the normal range on the 25th day, on the 40th day, it became significantly different to the level on the 10th day (P < 0.05) and approached the level in the control group (P > 0.05). No significant pathological change of parotid was found in both groups; but the number of zymogen granules in the RSP group was remarkably more than that in the control group (41.4 +/- 4.9 vs 34.6 +/- 5.2, P < 0.01). Serum level of VIP in the RSP group was significantly less while that of cAMP was higher than that in the control group (22.5 +/- 13.1 mg/L vs 38.5 +/- 14.1 mg/L, and 125.8 +/- 15.5 micromol/L vs 105.3 +/- 16.7 micromol/L, both P < 0.05), but no inter-group difference was found in parotid tissue contents of both VIP and cAMP. All the indices detected became equivalent in the two groups on the 40th day. CONCLUSION: The reduction of salivary protein in Pi-deficient rats induced by RSP may be related to the regulatory pathway of VIP and cAMP.