Establishment and application of a screening method for α-glucosidase inhibitors based on dual sensing and affinity chromatography

α-Glucosidase plays a direct role in the metabolic pathways of starch and glycogen, any dysfunction in its activity could result in metabolic disease. Concurrently, this enzyme serves as a target for diverse drugs and inhibitors, contributing to the regulation of glucose metabolism in the human body. Here, an integrated analytical method was established to screen inhibitors of α-glucosidase. This step-by-step screening model was accomplished through the biosensing and affinity chromatography techniques. The newly proposed sensing program had a good linear relationship within the enzyme activity range of 0.25 U mL-1 to 1.25 U mL-1, which can quickly identify active ingredients in complex samples. Then the potential active ingredients can be captured, separated, and identified by an affinity chromatography model. The combination of the two parts was achieved by an immobilized enzyme technology and a microdevice for reaction, and the combination not only ensured efficiency and accuracy for inhibitor screening but also eliminated the occurrence of false positive results in the past. The emodin, with a notable inhibitory effect on α-glucosidase, was successfully screened from five traditional Chinese medicines using this method. The molecular docking results also demonstrated that emodin was well embedded into the active pocket of α-glucosidase. In summary, the strategy provided an efficient method for developing new enzyme inhibitors from natural products.

A comparative UHPLC-QTOF-MS/MS-based metabolomics approach reveals the metabolite profiling of wolfberry sourced from different geographical origins

Wolfberry, known as Goji berry, is the fruit of Lycium barbarum L. (LB). As a famous functional food and TCM, the cost and efficacy of LB are closely linked to its geographical origin. The present study aimed to establish an effective method for distinguishing LB from different geographical origins. By employing UHPLC-QTOF-MS/MS combined with multivariate analysis, the metabolite profiling of LB (199 batches) obtained from Ningxia, Gansu, Qinghai, and Xinjiang, was evaluated. The results demonstrated that the method effectively distinguished LB from the four regions, with a total of 148 different metabolites being detected. Subsequent assessment using heat maps, Venn analysis, receiver operating characteristics curves and dot plots revealed 21 of these metabolites exhibited exceptional sensitivity and specificity, with under-curve values approaching 1, thus indicating their potential as biomarkers for LB. These findings strongly support the suitability of UHPLC-QTOF-MS/MS-based metabolomics as an effective approach to identify the source of LB.

[Advances in the application of dynamic virtual patients in prosthodontics]

With the development and application of technologies such as facial scanning, intraoral scanning, virtual facebow and mandibular movement tracking in prosthodontics, dynamic virtual patients are gradually applied to preoperative analysis, esthetic diagnosis, treatment planning, and restorative implementation, becoming a research hotspot in recent years. This review focuses on data acquisition, construction of dynamic virtual patients and their application advantages, aiming to provide a reference for the clinical application of related digital technologies.

Exploring the therapeutic potential of natural compounds modulating the endocannabinoid system in various diseases and disorders: review

Cannabinoid receptors, endogenous cannabinoids (endocannabinoids), and the enzymes involved in the biosynthesis and degradation of the endocannabinoids make up the endocannabinoid system (ECS). The components of the ECS are proven to modulate a vast bulk of various physiological and pathological processes due to their abundance throughout the human body. Such discoveries have attracted the researchers' attention and emerged as a potential therapeutical target for the treatment of various diseases. In the present article, we reviewed the discoveries of natural compounds, herbs, herbs formula, and their therapeutic properties in various diseases and disorders by modulating the ECS. We also summarize the molecular mechanisms through which these compounds elicit their properties by interacting with the ECS based on the existing findings. Our study provides the insight into the use of natural compounds that modulate ECS in various diseases and disorders, which in turn may facilitate future studies exploiting natural lead compounds as novel frameworks for designing more effective and safer therapeutics.

Rubus chingii Hu relieved the polycystic ovary syndrome with enhanced insulin sensitivity through inhibiting TXNIP/NLRP3 inflammasome signaling

BACKGROUND

Polycystic ovary syndrome (PCOS) is one of the most prevalent endocrine disorders in gynecology with severe metabolic abnormalities. Therefore, identifying effective treatments and drugs for PCOS is important. We aimed to investigate effect of the traditional Chinese medicine (TCM) Rubus chingii Hu (R. chingii) on ovarian function and insulin resistance (IR) of PCOS rat models, and to explore the underlying mechanisms.

METHODS

A PCOS rat model was established by subcutaneous injection of dehydroepiandrosterone (DHEA) solution for 20 days. PCOS rats were randomly divided into a control group (CON), model group (MOD), metformin group (MET), TCM R. chingii group (RCG), and RCG + Ad-TXNIP groups. After 28 days of treatment, the samples were collected for subsequent experiments.

RESULTS

R. chingii treatment alleviated hormone imbalance and IR while improving ovarian pathology in the PCOS model. R. chingi inhibited the activation of the thioredoxin-interacting protein (TXNIP)/NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome in the ovarian tissue of PCOS rats. Furthermore, TXNIP overexpression hindered the protective effect of R. chingii intervention in PCOS rats, as evidenced by the increase of homeostasis model assessment of insulin resistance (HOMA-IR), luteinizing hormone (LH), testosterone (T), C-reactive protein (CRP) levels, and atretic follicles.

CONCLUSION

R. chingii intervention improved ovarian polycystic development by suppressing the TXNIP/NLRP3 inflammasome, which may be an effective treatment for PCOS.

Hydrogen Peroxide Might Bleach Natural Dentin by Oxidizing Phosphoprotein

Recent studies suggested that bleaching agents may whiten teeth by oxidizing the fluorescent materials, which are the proteins located in the organic-inorganic interface. Therefore, we postulated that fluorescence of dentin came from dentin phosphoprotein (DPP) and that bleaching agents might bleach dentin by oxidizing DPP. Fifty-six specimens were randomly divided into 4 groups and exposed to distilled water, hydrogen peroxide (HP), ethylenediamine tetraacetic acid disodium salt (EDTA), and acetic acid for 24 h. After measuring the organic and inorganic components, fluorescence, and color characteristics of dentin before and after exposure, we found that when DPP was removed from dentin by EDTA, fluorescent intensity declined proportionally with the reduction in Raman relative intensity, and dentin was whitened considerably, with an Δ E value 6 times higher than that of the distilled water group. On the contrary, due to the incapability of acetic acid to dissolve DPP during decalcification, fluorescent intensity values and tooth color remained nearly unchanged after exposure to acetic acid. Dentin exposed to neutral HP showed no obvious morphologic and organic/inorganic component changes except for the destruction of DPP. Similarly, dramatically decreased fluorescent intensity and lightened color were found in the HP group. Moreover, DPP solution of the HP group exhibited decreased ultraviolet absorbance, especially between 250 and 300 nm, which arose from aromatic amino acids. The results indicated that DPP was responsible for the fluorescent properties of dentin and that HP might bleach dentin by the oxidization of aromatic amino acids in DPP. These findings are of great significance in promoting our further understanding of the mechanism of tooth bleaching and the fluorescent property of normal dentin.

New Insights into Effects of Aromatic Amino Acids on Hydroxyapatite

Biomimetics inspired by superstructures and extraordinary properties of teeth have resulted in tooth repair and the generation of novel materials. However, little attention has been paid to tooth color, whose origin remains unknown. Based on recent studies, fluorophores-mainly aromatic amino acids (AAAs) in proteins-might be responsible for tooth color. We synthesized carbonated hydroxyapatite (HA; the mineral phase of teeth) in the presence of different amino acids (AAs; the basic units of protein matrix of teeth) as a simplified model of teeth to explore the color source at the AA level. After measuring the fluorescence and color characteristics of HA-AAs before and after bleaching treatment, we found that only HA, synthesized in the presence of AAAs, exhibited remarkable fluorescence and color property. Furthermore, linearly increased fluorescence intensity and deeper color were observed with an increase in AAA content in HA-AAAs. Similarly, significantly decreased absorbance of HA-AAAs between 250 and 300 nm in ultraviolet spectra, declined fluorescence intensity, and decolored performance of HA-AAAs were observed after bleaching treatment. The results showed that AAAs contributed to the fluorescence and color properties of HA and that hydrogen peroxide might whiten HA-AAAs by oxidizing the benzene ring in AAAs. These findings are of great significance in promoting the synthesis of advanced tooth-colored materials and furthering our understanding of the possible mechanisms of hydrogen peroxide. Moreover, our study shed light on the importance of AAAs and might provide new ideas for investigations of biomineralization and biomimetics.

Minimally invasive treatment for esthetic management of severe dental fluorosis: a case report

Dental fluorosis is a developmental disturbance of enamel caused by excessive fluoride on ameloblasts during enamel formation. Patients often present to the dentist with a main goal of improving their esthetic appearance. This case report describes a minimally invasive technique for treating a severe case of enamel fluorosis with brown surface aspect and small defects. A selective mega-abrasion and microabrasion were used to recreate macro- and micro- surface morphology, followed by power bleaching, home bleaching, and resin infiltration to improve the esthetic appearance.

Effects of two in-office bleaching agents with different pH on the structure of human enamel: an in situ and in vitro study

This study evaluated the effects of two in-office bleaching agents (Beyond and Opalescence Boost) with different pH on the structure and mechanical properties of human enamel in vitro and in situ. One hundred and eight enamel slabs were obtained from freshly extracted premolars. The specimens were randomly distributed into nine groups (n=12), and the human saliva (HS) in the volunteers' oral cavities was used to simulate the in situ condition: Beyond + HS, Opalescence Boost (O-Boost) + HS, Control + HS, Beyond + artificial saliva (AS), O-Boost + AS, Control + AS, Beyond + distilled water (DW), O-Boost + DW, and Control + DW. The bleaching treatments were performed on the first and eighth day, and the total bleaching time was 90 minutes. Baseline and final surface roughness (RMS), surface morphology, microhardness, and fracture toughness (FT) were measured before the treatment and on the fifteenth day, respectively. Compared with control groups, surface alterations on enamel were found in the Beyond + AS and Beyond + DW groups under atomic force microscopy evaluation. Two-way analysis of variance and Tukey test revealed that the RMS showed significant intergroup differences for both storage condition and bleaching agent, whereas microhardness and FT revealed no significant alteration. The results indicated that in-office bleaching agents with low pH values could induce enamel morphology alterations under in vitro conditions. The presence of natural HS could eliminate the demineralization effect caused by low pH.

WE-C-217BCD-05: A Novel Interpolation Method for the 3D Reconstruction of Cell Structures

PURPOSE

To develop a new interpolation method for accurate 3D reconstruction of cell morphology from laser scanning confocal microscope (LSCM) image data.

METHODS

Current techniques are based on the assumption that pixel intensity or contour shapes of images change linearly in the interpolation direction. Gray-value and position of the pixel in interpolated image slice are obtained through weighted average calculation with gray-values and distances of corresponding pixels in two adjacent original image slices, only information from adjacent image slices is considered, often fail to meet the need of 3D reconstruction for cells because of the complex cell morphology. The new method interpolates cellular organelle contours in polar coordinate system. Coordinate system origin is chosen to be the mass center weighted by pixel intensity instead of conventional geometric center, contour points of the organelle is sampled by their angles first and fitted with uniform cubic B-spline to perform interpolation. For complex organelle structures such as branched nuclei, a special method combining morphological information and corner detection technique based on curvature scale space has been developed to solve the contour division and related problems. New method was applied to confocal images of 130 different cells acquired with an LSCM system (LSM510, Zeiss), sampling step was set as 0.5 μm in longitudinal direction, pixel size in horizontal plane was 0.07 μm and the resolution was 512×512. Marching cubes algorithm was used for 3D reconstruction.

RESULTS

Experiments showed that reconstructed 3D images with new method have much smoother and more valid organelle surfaces for both cytoplasm and nucleus than those from conventional methods.

CONCLUSIONS

The new interpolation method can significantly improve the quality of 3D reconstruction and serve as a valid and effective tool for quantitative study of 3D cell morphology in radiation biology and other areas of life science.*support by NSFC- 81171342. Supported by the National Science Foundation of China (NSFC- 81171342).

[Enhanced continent mechanism of the tapered ileum in continent urinary reservoir]

OBJECTIVE

To construct a reliable continent tube that is easy to catheterize and is surgically simple.

METHODS

From October 1999 through March 2001, 20 patients underwent a procedure in which ileal segment was tapered as an efferent tube and the partial efferent tube was placed between the back surface of the rectus muscle and the wall of the ileal pouch. The internal orifice of the tapered ileum was anastomosed to the ileal pouch and its external orifice of the tapered ileum was anastomosed to the umbilicus. Urodynamic study of the efferent tubes and pouch was done 1.5 to 3 months and 6 to 17 months after operation.

RESULTS

The stoma was easily catheterized with a 16 F catheter in all patients. One patient died of heart disease 55 days after the operation, while 18 of the remaining 19 were completely continent day and night. At 1.5 to 3 months, the urodynamic study of the efferent tubes showed the maximum close pressure with a full pouch of 46-124 cmH2O(91.53 +/- 17.21), and when the pouch was empty it was 34-84 cmH2O(66.68 +/- 11.60). The difference in the mean maximum closure pressure in full and empty pouches was statistically significant (t = 10.59, P < 0.01). At 6 to 17 months, urodynamic study was performed in 12 patients, the maximum closure pressure in the efferent tube was 77 to 154 cmH2O (100.92 +/- 20.88) when the pouch was filled with saline. When the pouch was empty, it was 56 to 115 cmH2O (74.08 +/- 14.59). The difference in the mean maximum closure pressure in full and empty pouches was statistically significant (t = 8.54, P < 0.01). Reservoir capacity was 360 to 750 ml (455 +/- 110.74). When it was filled to the maximum, the reservoir pressure was 16 to 35 cmH2O (23.17 +/- 5.82). There was no contractive wave in filling in any patient.

CONCLUSIONS

This study indicates that the continent mechanism of the tapered ileum can be greatly enhanced by fixing it between the abdominal and pouch walls. This maneuver also provides easy catheterization and surgical simplicity.