UHPLC-ESI-QTOF-MS/MS Metabolite Profiling of the Antioxidant and Antidiabetic Activities of Red Cabbage and Broccoli Seeds and Sprouts

The antioxidant and antidiabetic properties and metabolite profiling of ethanol extracts of red cabbage (RC) and broccoli (BR) seeds and sprouts were investigated in this study. The total phenolic, flavonoid, and saponin contents were in the ranges of 385.4–480.4 mg FAE/100 g, 206.9–215.6 mg CE/100 g, and 17.8–27.0 mg soysaponin BE/100 g, respectively. BR seed had the highest total phenolic (480.4 mg FAE/100 g) and flavonoid (216.9 mg CE/100 g) contents, whereas BR sprout had the highest saponin content (27.0 soysaponin BE/100g). RC sprout demonstrated the highest antioxidant capacity, with DPPH and ABTS radical scavenging activity levels of 71.5% and 88.5%, respectively. Furthermore, BR and RC sprouts showed the most potent inhibition against α-glucosidase (91.32% and 93.11%, respectively) and pancreatic lipase (60.19% and 61.66%, respectively). BR seed (60.37%) demonstrated the lowest AGE inhibition. A total of 24 metabolites, predominantly amino acids and phenolic compounds, were characterized using UHPLC-QTOF-MS/MS. Germination not only improved the levels of metabolites but also resulted in the synthesis of new compounds. Therefore, these findings show that germination effectively enhanced the functional properties and metabolite profiles of broccoli and red cabbage seeds, making their sprouts more applicable as functional ingredients.

Advanced Glycation End Product Inhibitor Pyridoxamine Attenuates IVD Degeneration in Type 2 Diabetic Rats

Type 2 diabetes mellitus (T2DM) is associated with advanced glycation end product (AGE) enrichment and considered a risk factor for intervertebral disc (IVD) degeneration. We hypothesized that systemic AGE inhibition, achieved using pyridoxamine (PM), attenuates IVD degeneration in T2DM rats. To induce IVD degeneration, lumbar disc injury or sham surgery was performed on Zucker Diabetic Sprague Dawley (ZDSD) or control Sprague Dawley (SD) rats. Post-surgery, IVD-injured ZDSD rats received daily PM dissolved in drinking water or water only. The resulting groups were SD uninjured, SD injured, ZDSD uninjured, ZDSD injured, and ZDSD injured + PM. Levels of blood glycation and disc degeneration were investigated. At week 8 post-surgery, glycated serum protein (GSP) levels were increased in ZDSDs compared to SDs. PM treatment attenuated this increase. Micro-MRI analysis demonstrated IVD dehydration in injured versus uninjured SDs and ZDSDs. In the ZDSD injured + PM group, IVD dehydration was diminished compared to ZDSD injured. AGE levels were decreased and aggrecan levels increased in ZDSD injured + PM versus ZDSD injured rats. Histological and immunohistochemical analyses further supported the beneficial effect of PM. In summary, PM attenuated GSP levels and IVD degeneration processes in ZDSD rats, demonstrating its potential to attenuate IVD degeneration in addition to managing glycemia in T2DM.

Chemical Reactivity Theory and Empirical Bioactivity Scores as Computational Peptidology Alternative Tools for the Study of Two Anticancer Peptides of Marine Origin

This work presents an account of the reactivity behavior of the anticancer marine drugs, Soblidotin and Tasidotin, based on the calculation of the global and local descriptors resulting from Chemical Reactivity Theory (CRT), also known as Conceptual DFT, for their consideration as a useful complement to approximations based on Molecular Docking. The information on the global and local reactivity descriptors of the Soblidotin and Tasidotin molecules, obtained through our proposed methodology, may be used for the design of new pharmaceutical analogs by relying on the chemical interactions between these peptides and their protein-type biological receptors. It can be concluded that the CRT approximation to the global and local chemical reactivity, based on the descriptors, can provide interesting information for the consideration of both molecules as potential therapeutic drugs. This is complemented by a study on Advanced Glycation Endproduct (AGE) inhibition, by comparison with the usual molecular systems considered for the task, as a re-purposing study. Finally, the bioactivity scores for Soblidotin and Tasidotin are predicted through an empirical procedure, based on comparison with molecular structures with well-known pharmacological properties.

INHIBITION OF ADVANCED GLYCATION END-PRODUCT FORMATION BY QUERCETIN AND CATECHIN: AN ALTERNATIVE THERAPY FOR TREATING DIABETIC COMPLICATIONS

Objective: The objective of this research was to determine early advanced glycation end-product (AGE) inhibition by natural aldose reductase inhibitors (ARIs), quercetin and catechin.Methods: The assay mixture (4 ml) consisted of 2 ml of 50 mM phosphate-buffered saline (pH 7.4), 50 μg/μl bovine serum albumin (BSA), and 2 mM glucose with or without the inhibitor. The test samples were treated with three different concentrations (10 mM, 20 mM, and 40 mM) of quercetin and catechin. High-throughput screening-based assay was adapted to perform the BSA-glucose test to determine the induction of AGE formation and its inhibition by quercetin, and catechin, using the fluorescence of the AGE-BSA sample at excitation and emission wavelengths of 350 and 450 nm.Result: The ARIs, quercetin and catechin inhibited early glycation with an inhibitory concentration value of 15.58 mM and 35.01 mM, respectively.Conclusion: The suppression of AGEs formation by natural inhibitors of aldose reductase would provide an alternative approach to the control of diabetic complications.

Antiglycation activity of Vaccinium spp. (Ericaceae) from the Sam Vander Kloet collection for the treatment of type II diabetes1This article is part of a Special Issue entitled “A tribute to Sam Vander Kloet FLS: Pure and applied research from blueberries to heathland ecology”.

In this report, the inhibition of advanced glycation endproducts (AGEs) by extracts of leaves from a collection of six, mainly tropical, Vaccinium L. spp. (Ericaceae) was examined. Indigenous Peoples have used Vaccinium species to treat symptoms of type I and II diabetes. Sustained hyperglycaemia, often associated with diabetes, facilitates crosslinking of sugars with proteins, producing AGEs. AGEs are a therapeutic target since they are responsible for many diabetes symptoms and contribute to ageing and the development of atherosclerosis, kidney, vascular, and neurological diseases. Vaccinium barandanum S. Vidal, Vaccinium consanguineum Klotzsch, Vaccinium gaultheriifolium (Griff.) Hook. f. ex C.B. Clarke, Vaccinium poasanum Donn. Sm., Vaccinium tonkinense Dop, and Disterigma rimbachii (A.C. Sm.) Luteyn (outgroup) were collected from Sam Vander Kloet’s common garden collection. Ethanolic extracts of leaves of these Vaccinium spp. were potent inhibitors of AGEs. Vaccinium and outgroup species extracts tested in an AGE inhibition assay demonstrated concentration dependent inhibition, with a half maximal inhibitory concentration (IC50) ranging from 4.2 to 16.2 µg·mL–1. Phenolic content ranged from 258 to 626 (µg quercetin equivalents·mg extract–1). Activity and phenolic content show that these tropical accessions have a higher phenolic content (p < 0.001, t test) and AGE inhibition (p < 0.03, t test) than six temperate species from our collections in eastern North America. Significant relationships were found between IC50 and latitude of geographic origin.

Ellagic acid, a new antiglycating agent: its inhibition of Nϵ-(carboxymethyl)lysine

Non-enzymatic glycation is a complex series of reactions between reducing sugars and amino groups of proteins. Accumulation of AGEs (advanced glycation end-products) due to non-enzymatic glycation has been related to several diseases associated with aging and diabetes. The formation of AGEs is accelerated in hyperglycaemic conditions, which alters the structure and function of long-lived proteins, thereby contributing to long-term diabetic complications. The present study describes AGE inhibition and the mechanism of action of a new antiglycating agent, EA (ellagic acid), a flavonoid present in many dietary sources. Inhibition of AGE formation by EA was demonstrated with different proteins, namely eye lens TSP (total soluble protein), Hb (haemoglobin), lysozyme and BSA, using different glycating agents such as fructose, ribose and methylglyoxal by a set of complementary methods. These results suggest that the antiglycating action of EA seems to involve, apart from inhibition of a few fluorescent AGEs, predominantly inhibition of CEL [Nϵ-(carboxyethyl)lysine] through scavenging of the dicarbonyl compounds. Furthermore, MALDI–TOF-MS (matrix-assisted laser-desorption ionisation–time-of-flight MS) analysis confirms inhibition of the formation of CEL on lysozyme on in vitro glycation by EA. Prevention of glycation-mediated β-sheet formation in Hb and lysozyme by EA confirm its antiglycating ability. Inhibition of glycosylated Hb formation in human blood under ex vivo high-glucose conditions signifies the physiological antiglycating potential of EA. We have also determined the effectiveness of EA against loss of eye lens transparency through inhibition of AGEs in the lens organ culture system. These findings establish the antiglycating potential of EA and its in vivo utility in controlling AGE-mediated diabetic pathologies.