Inhibitory Mechanism of Advanced Glycation End-Product Formation by Avenanthramides Derived from Oats through Scavenging the Intermediates

Formation of advanced glycation end products in glucose-amino acid models of Maillard reaction under dry- and wet-heating conditions

BACKGROUND

Advanced glycation end products (AGEs) are compounds formed by non-enzymatic processes in the Maillard reaction and can cause various chronic diseases. This study explores the AGE formation process in a glucose-amino acid system under both wet- and dry-heating conditions, and analyzes the effect of cysteine in AGE formation.

RESULTS

Under wet-heating conditions, Nε-carboxymethyllysine (CML) and Nε-carboxyethyllysine (CEL) concentrations rose for the initial 90 min and subsequently declined after 120 min; after 90 min of heating, the maximum yields in the absence of cysteine were 1151.04 ± 14.01 and 3386.90 ± 26.55 ng mL-1, respectively. The concentration of pyrraline (Pyr) increased after 30 min and then decreased after 60 min with a maximum yield of 777.68 ± 23.36 ng mL-1. However, in dry-heating models, the AGE concentrations consistently increased with increasing heating time; the maximum yields for CML, CEL and Pyr were 468.66 ± 10.96, 1993.57 ± 14.81 and 1085.74 ± 58.06 ng mL-1, respectively. The addition of cysteine showed an inhibitory effect on AGE formation, especially for Pyr in the dry-heating model, with inhibition rates ranging from 17.14% to 95.60%.

CONCLUSION

Although wet-heating models produced more CML and CEL, they produced less Pyr than dry-heating models. The AGE formation in wet-heating models positively correlated with the reaction rate; however, the dry-heating reaction demonstrated a more complex relationship between reaction rate and reaction protocol. Moreover, cysteine exhibited a significant inhibitory effect on AGE production, and the degree of inhibition was proportional to the cysteine concentration. This study provides important insights into the mechanisms for AGE formation under various heating conditions, such as those representing baking (dry-heating) and steaming conditions (wet-heating). © 2024 Society of Chemical Industry.

Advances of nanoparticle derived from food in the control of α-dicarbonyl compounds-A review

α-Dicarbonyl compounds (α-DCs) are predominantly generated through the thermal processing of carbohydrate and protein-rich food. They are pivotal precursors to hazard formation, such as advanced glycation end products (AGEs), acrylamide, and furan. Their accumulation within the body will be genotoxicity and neurotoxicity. Recently, significant advancements have been made in nanotechnology, leading to the widespread utilization of nanomaterials as functional components in addressing the detrimental impact of α-DCs. This review focuses on the control of α-DCs through the utilization of nanoparticle-based functional factors, which were prepared by using edible components as resources. Four emerging nanoparticles are introduced including phenolic compounds-derived nanoparticle, plant-derived nanoparticle, active peptides-derived nanoparticle, and functional minerals-derived nanoparticle. The general control mechanisms as well as the recent evidence pertaining to the aforementioned aspects were also discussed, hoping to valuable helpful references for the development of innovative α-DCs scavengers and identifying the further scope of research.

Potential inhibitory effect of Auricularia auricula polysaccharide on advanced glycation end-products (AGEs)

In this study, a novel polysaccharide, AAP-2S, was extracted from Auricularia auricula, and the anti-glycosylation effect of AAP-2S and its underlying mechanisms were investigated using an in vitro BSA-fructose model and a cellular model. The results demonstrated the inhibiting formation of advanced glycation end products (AGEs) in vitro by AAP-2S. Concurrently, it attenuated oxidative damage to proteins in the model, preserved protein sulfhydryl groups from oxidation, reduced protein carbonylation, prevented structural alterations in proteins, and decreased the formation of β-crosslinked structures. Furthermore, AAP-2S demonstrated metal-chelating capabilities. GC-MS/MS-based metabolomics were employed to analyze changes in metabolic profiles induced by AAP-2S in a CML-induced HK-2 cell model. Mechanistic investigations revealed that AAP-2S could mitigate glycosylation and ameliorate cell fibrosis by modulating the RAGE/TGF-β/NOX4 pathway. This study provides a foundational framework for further exploration of Auricularia auricular polysaccharide as a natural anti-AGEs agent, paving the way for its potential development and application as a food additive.

Comparison of the anti-diabetic effects of various grain and legume extracts in high-fat diet and streptozotocin-nicotinamide-induced diabetic rats

The anti-diabetic properties of whole groats and dietary fibers from various grains and legumes are well known. Nevertheless, studies on the anti-diabetic effects of their extracts are limited, and it is difficult to compare their efficacy. This study investigated the anti-diabetic potential of ethanol extracts from oats (OE), sorghum (SE), foxtail millet (FE), proso millet (PE), adzuki bean (AE), and black soybean (BE) in a high-fat diet and streptozotocin-nicotinamide-induced diabetic rat models. The extracts, obtained using 99.9 % ethanol, were orally administered to diabetic rats for four weeks. Various parameters were evaluated, including fasting blood glucose levels, glucose tolerance, insulin sensitivity, serum insulin levels, and pancreas histological analysis. OE and SE effectively reduced fasting blood glucose levels and the area under the curve (AUC) in the oral glucose tolerance test. Only OE significantly decreased the AUC in the insulin tolerance test and increased insulin concentration and homeostatic model assessment of the β-cell function index, indicating improved insulin sensitivity and β-cell function. Histological and immunohistochemical analysis of the pancreas supported these findings, demonstrating that OE protected against pancreatic cell damage. In contrast, FE, PE, AE, and BE did not have a significant effect on diabetes-related parameters. These findings identify OE as the most promising natural intervention for diabetes management.

Potential inhibitory effect of fish, maize, and whey protein hydrolysates on advanced glycation end-products (AGEs)

Advanced glycation end-products (AGEs) are produced in the final stage of the Maillard reaction. AGEs formation may be inhibited by natural hydrolysates derived from plant or animal sources. The present study aimed to investigate the antiglycation potential of fish, maize, and whey protein hydrolysates. It was carried out in four model systems, Bovine serum albumin (BSA)-Glucose, BSA-Fructose, BSA-Sorbitol, and BSA-HFCS (high fructose corn syrup), by evaluation of fluorescent intensity of AGEs after seven days of reaction at 37°C. The results showed that the highest inhibitory effect belonged to 0.16% of FPH (fish protein hydrolysate, percent inhibition ~99.0%), whereas maize protein hydrolysate (MPH) had lower antiglycation activity in comparison with FPH. Among all hydrolysates, whey protein hydrolysate with the lowest degree of hydrolysis showed the weakest inhibitory activity. Overall, our results indicated that the investigated hydrolysates, particularly FPH, have promising antiglycation potential and can be recommended for the production of functional foods.

Magnetically driven nanorobots based on peptides nanodots with tunable photoluminescence for rapid scavenging reactive α-dicarbonyl species and effective blocking of advanced glycation end products

The present work constructed magnetically driven nanorobots by conjugating the photoluminescent β-alanine-histidine (β-AH) nanodots to superparamagnetic nanoparticles (SPNPs) for simultaneously sensitive determination and fast trapping RDS in food processing, achieving efficient regulation of advanced glycation end products (AGEs) risk. Bio-derivative β-AH nanodots with orderly self-assembly nanostructure and tunable photoluminescent properties served as both biorecognition elements to effectively bind and scavenge the reactive α-dicarbonyl species (RDS), as well as the indicator with sensitive fluorescence response in the food matrix. The magnetically driven nanorobots with excellent biosafety of endogenous dipeptides displayed a high binding capacity of 80.12 mg g^-1 with ultrafast equilibrium time. Furthermore, the magnetically driven nanorobots achieved rapid removal of the RDS with the manipulation of the external magnetic field, which enabled intercepting AGEs generation without byproducts residual as well as ease-of-operation. This work provided a promising strategy with biosafety and versatility for both accurate determination and efficient removal of hazards.

Fluorescent Molecularly Imprinted Polymers Loaded with Avenanthramides for Inhibition of Advanced Glycation End Products

Encapsulating bioactive avenanthramides (AVAs) in carriers to respond to the environmental changes of food thermal processing allows the controlled release of AVAs for the effective inhibition of biohazards. In this study, fluorescent molecular imprinted polymers (FMIPs) loaded with AVAs were prepared by reverse microemulsion. The fluorescent signal was generated by carbon dots (CDs), which were derived from oat bran to determine the load of AVAs. The FMIPs were uniformly spherical in appearance and demonstrated favorable properties, such as thermal stability, protection of AVAs against photodegradation, high encapsulation efficiency, and effective scavenging of free radicals. After consideration of the different kinetics models, the release of AVAs from the FMIPs matched the Weibull model and followed a Fickian diffusion mechanism. The FMIPs exhibited good inhibition of pyrraline in a simulated casein-ribose system and in milk samples, indicating the release of AVAs could inhibit the generation of pyrraline.