Hexagonosides A-F: Pregnane glycosides isolated from Caralluma hexagona.

Chemical investigation of Caralluma hexagona Lavranos, a wild plant growing in Yemen, led to the isolation of four previously undescribed acylated pregnane glycosides, hexagonosides A-D (1-4), together with two sets of mixtures (hexagonosides E and F), each set consists of three interconvertible pregnane glycoside isomers, hexagonosides E (5a-c) and F (6a-c). The chemical structures of the isolated pregnane glycosides were elucidated by extensive 1D/2D NMR and HRESI-MS analysis, featuring 6'-O-benzoyl-1'-O-ß-glucosyl residue at aglycone C-20; while aglycone C-3 was substituted with disaccharide sugar chain (1, 2, 5a-c) or a trisaccharide sugar chain (3, 4, 6a-c). Metabolites E and F included an extra benzoyl substitution in C-20 glucosyl residue which is migrating between the OH groups of C-2', C-3' and C-4' resulting in equilibrating conformations (5a-c and 6a-c) when incubated in HPLC solvent, which we confirmed by the analytical study.

Sialendoscopy enhances saliva production of parotid glands in primary Sjögren syndrome patients.

OBJECTIVE: Primary Sjögren syndrome (pSS) is a chronic systemic autoimmune disorder that harms exocrine glands located mainly in the oral and ocular regions. pSS patients often complain about pain and mouth dryness. The aim of this retrospective study was to evaluate the influence of parotid glands' sialendoscopy on salivary flow in pSS patients and to assess the tissue characteristics of the parotid glands during the sialendoscopy procedure. METHOD AND MATERIALS: Twenty-six pSS patients (52 glands) treated with sialendoscopy for their parotid glands between the years 2017 and 2019 were included. The unstimulated whole saliva (UWS) flow rate was obtained 2 weeks before intervention (T1) and 3 months post intervention (T2). For 20 patients, UWS was measured 6 months post intervention (T3); and for 11 patients, UWS was measured 12 months post intervention (T4). Patients were asked about their oral quality of life before and after sialendoscopy. RESULTS: UWS was significantly higher at T2, T3, and T4 compared to T1 (P = .002, P = .01, and P = .04 respectively). In total, 22 patients (84.6%) reported substantial improvement of their oral quality of life at T2. Of the 52 glands, 33 (63.5%) exhibited avascularity in the walls of the Stensen duct, 33 (63.5%) had strictures, and in 8 (15.4%) mucus plugs were present. No major complications were observed in this study except for one patient who suffered from duct perforation, which during follow-up was spontaneously healed. CONCLUSION: This study indicates a positive effect of sialendoscopy on salivary flow rate and oral quality of life in pSS patients. Sialendoscopy should be considered as a vital tool in treating pSS patients. (Quintessence Int 2023;54:234-240; doi: 10.3290/j.qi.b3609681).

Anticholinesterase and anti-inflammatory constituents from Caralluma awdeliana, a medicinal plant from Yemen.

From the dichloromethane (DCM) fraction of the crude ethanolic extract of Caralluma awdeliana, four pregnane glycosides and a flavone glycoside were isolated using a bio-guided isolation approach. The different extracts of C. awdeliana were subjected to in vitro enzyme inhibitory assays of anticholinesterases (AChE and BChE) and anti-inflammatory (COXs and 5-LOX). The highest inhibitory activity was exhibited by DCM fraction against COX-1, COX-2, and 5-LOX with IC50 of 4.8 ± 0.5 µg/mL, 0.68 ± 0.2 µg/mL, and 39.5 ± 3.0 µg/mL, respectively. The DCM showed also a moderate activity against AChE (IC50 384.72 ± 3.6 µg/mL), and BChE (IC50 384.72 ± 3.6 µg/mL). The repeated chromatography of DCM fraction resulted in the isolation of two new pregnane glycosides, namely awdeliosides A (1) and B (4), two known ones, namely caratuberosides B and D, along with the known flavone glycoside identified as luteolin 4 -O-neohesperidoside. All the isolated compounds were tested for their in vitro enzyme inhibitory assays. Among the isolated compounds, awdelioside B (4) showed the most potent effect against COX-1 with IC50 value of 10.99 ± 0.35 µM, compared to standard celecoxib (IC50 230.74 ± 2.62 µM). All the isolated compounds showed weak anticholinesterase, except a moderate activity observed for awdelioside B (4) against BChE with IC50 value of 15.63 ± 3.5 µM, compared to standard donepezil (IC50 0.77 ± 0.0088 µM).

Phenolics from Chrozophora oblongifolia Aerial Parts as Inhibitors of α-Glucosidases and Advanced Glycation End Products: In-Vitro Assessment, Molecular Docking and Dynamics Studies.

Modern life is associated with low physical activity that leads to the accumulation of fats, gaining more weight, and obesity. Accumulation of fat in the abdomen region contributes to diabetes via insulin resistance and hyperglycemia. Polyphenols are major plant constituents that exert antidiabetic activity through different mechanisms, including radicle scavenging activity, regulation of glucose uptake, and inhibition of fat and polysaccharide hydrolysis in addition to their inhibitory role regarding the formation of advanced glycation end products (AGEs). Chemical investigation of C. oblongifolia aerial parts resulted in the isolation of five major compounds: apeginin-7-O-ß-D-glucoside (1), quercetin-3-O-ß-D-glucuronic acid (2), quercetin-3-O-ß-D-galacturonic acid (3), rutin (4), and 1,3,6-trigalloyl glucose (5). The isolated compounds were tested for their antioxidant and AGEs formation, α-glucosidase, and lipase inhibitory activities. Compound 5 revealed the highest antioxidant and AGEs inhibitory activity in bovine serum albumin (BSA)-methylglyoxal, BSA-fructose, and arginine-methylglyoxal models. Moreover, it exhibited a potent inhibitory profile on Saccharomyces cerevisiae α-glucosidases compared to the positive control, acarbose. Compound (5) further depicted promising binding affinity and stability towards the human intestinal maltase-glucoamylase α-glucosidases, which is a diabetes-related therapeutic target, through coupled molecular docking and dynamics studies. The obtained results encourage the usage of 1,3,6-trigalloyl glucose in the management of diabetes and its complications. However, detailed in-vivo studies for this compound should be performed.

New Pregnane Glycosides Isolated from Caralluma hexagona Lavranos as Inhibitors of α-Glucosidase, Pancreatic Lipase, and Advanced Glycation End Products Formation.

Caralluma hexagona Lavranos (Family Asclepiadaceae) is an endemic herb in Yemen and Saudi Arabia, traditionally used to treat diabetes, abdominal pain, and stomach ulcers. Different extracts, fractions, and main constituents of C. hexagona were evaluated for their inhibitory activity against key enzymes in diabetes and hyperlipidemia, i.e., α-glucosidase and pancreatic lipase. In addition, the antioxidative effect and inhibition of advanced glycation end products (AGEs) were also assayed. Using a bioguided approach, the crude aqueous, methanolic extracts, methylene chloride (CH2Cl2), Diaion HP20 50% MeOH (DCF-1), and 100% MeOH (DCF-2) fractions of C. hexagona were evaluated for their possible α-glucosidase and pancreatic lipase inhibition and antioxidant activity. In addition, inhibition of AGE generation using bovine serum albumin (BSA)-fructose, BSA-methylglyoxal, and arginine-methylglyoxal models was carried out. Moreover, the main constituents of the most active fraction were isolated and identified using different chromatographic and sprectroscopic methods. From the most active CH2Cl2 fraction, four new pregnane glycosides were isolated and identified as 12ß-O-benzoyl 3ß,8ß,12ß,14ß,20-pentahydroxy-(20S)-pregn-5-ene-3-O-ß-d-glucopyranosyl-(1 → 4)-O-ß-d-digitaloside (1), 3ß,8ß,14ß,20-tetrahydroxy-(20S)-pregn-5-ene-3-O-ß-d-glucopyranosyl-(1 → 4)-O-ß-d-digitaloside-20-O-3-isoval-ß-d-glucopyranoside (2), 3ß,8ß,14ß,20-tetrahydroxy-(20R)-pregn-5-ene-3-O-ß-d-glucopyranosyl-(1 → 4)-O-ß-d-digitaloside-20-O-3-isoval-4-benzoyl-ß-d-glucopyranoside (3A), and 3ß,8ß,14ß,20-tetrahydroxy-(20R)-pregn-5-ene-3-O-ß-d-glucopyranosyl-(1 → 4)-O-ß-d-digitaloside-20-O-3,4 di-benzoyl-ß-d-glucopyranoside (3B). Among the tested samples, the highest trolox equivalent (TE) antioxidant capacity (TEAC) was observed for DCF-1 with values of 128.53 ± 5.07, 378.58 ± 5.19, and 106.71 ± 5.66 µM TE/mg using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and ferric reducing antioxidant potential (FRAP) assays, respectively. The isolated apigenin-8-C-neohesperoside showed the highest antioxidant capacity (168.80 ± 1.80 and 278.21 ± 13.26 µM TE/mM) in DPPH and FRAP, respectively, while luteolin 4'-O-ß-d-neohesperidoside had the highest TEAC (599.19 ± 9.57 µM TE/mM) in ABTS assay. Compounds 1, 2, and the mixture 3A and 3B inhibited α-glucosidase with IC50 values of 0.92 ± 0.02, 0.67 ± 0.01, and 0.74 ± 0.02 mM, respectively. In the AGE assays, DCF-1 showed the highest inhibitory effect in BSA-fructose and arginine-methylglyoxal models with IC50 values of 0.39 ± 0.02 and 0.77 ± 0.10 mg/mL, respectively. Among the isolated compounds, flavonoid compounds showed the highest antiglycation effect, while pregnanes revealed higher α-glucosidase inhibition. In conclusion, the current study revealed that C. hexagona is a promising Yemeni natural remedy, of which the major content of pregnane glycosides and flavonoids could be considered as a new therapeutic candidate targeting the metabolic syndrome.

Severe chronic nonlichenoid oral mucositis in pembrolizumab-treated patients: new cases and a review of the literature.

Aim: To report of severe chronic oral mucositis (OM) in two pembrolizumab-treated cancer patients. Materials & methods: A retrospective chart review was performed. Inclusion/exclusion criteria detected patients that developed OM during pembrolizumab immunotherapy. In addition, we searched the literature for nonlichenoid OM in immunotherapy-treated cancer patients. Results: Two male patients treated for anaplastic astrocytoma and lung adenocarcinoma were included. Extensive painful OM (grade 4) developed in both patients during the course of immunotherapy and the ulcerations remained >30 weeks (>16 weeks after stopping immunotherapy). Superficial mucocele appeared in one patient. In one patient, pain relief was achieved with photobiomodulation (low-level laser) therapy. Conclusion: OM induced by immunotherapy may be a major cause of suffering and eating difficulties. In most cases, the OM lasted for months even after the drug was stopped. There is a controversy regarding the beneficial effect of corticosteroids on OM in these patients.

Bayesian clinical classification from high-dimensional data: Signatures versus variability.

When data exhibit imbalance between a large number d of covariates and a small number n of samples, clinical outcome prediction is impaired by overfitting and prohibitive computation demands. Here we study two simple Bayesian prediction protocols that can be applied to data of any dimension and any number of outcome classes. Calculating Bayesian integrals and optimal hyperparameters analytically leaves only a small number of numerical integrations, and CPU demands scale as O(nd). We compare their performance on synthetic and genomic data to the mclustDA method of Fraley and Raftery. For small d they perform as well as mclustDA or better. For d = 10,000 or more mclustDA breaks down computationally, while the Bayesian methods remain efficient. This allows us to explore phenomena typical of classification in high-dimensional spaces, such as overfitting and the reduced discriminative effectiveness of signatures compared to intra-class variability.