Inhibitors of advanced glycation end products from coffee bean roasting by-product

Simultaneous analysis of advanced glycation end products using dansyl derivatization

Herein, new pre-column derivatization based on dansylation is present to resolve analytical difficulties, such as chromatographic separation difficulty, in identifying and quantifying advanced glycation end products (AGEs) owing to their high hydrophilicity, wide variety, and structural similarity. The proposed analytical method facilitated the separation of 14 AGEs, including structural isomers. Limits of detection of 1.0-43.3 ng/mL and linear ranges of the double- or triple-digit were achieved. Intra- and inter-day precisions of 1.1-3.0% and 1.3-3.1%, respectively, were achieved for standard solutions, while those for food specimens were 1.4-11.2% and 1.7-15.7%, respectively. The matrix effect was insignificant with regard to the percent recoveries and differences between slopes for both the standard solutions and food specimens. Furthermore, the quantitation results of AGEs in foods (coffee, beer, and sausage) and glycated proteins revealed the potential applicability of the developed method in various fields of food chemistry and biochemistry.

Mechanisms of action of coffee bioactive compounds - a key to unveil the coffee paradox

The knowledge of the relationship between the chemical structure of food components with their mechanisms of action is crucial for the understanding of diet health benefits. This review relates the chemical variability present in coffee beverages with the mechanisms involved in key physiological events, supporting coffee as a polyvalent functional food. Coffee intake has been related with several health-promoting properties such as neuroprotective (caffeine, chlorogenic acids and melanoidins), anti-inflammatory (caffeine, chlorogenic acids, melanoidins, diterpenes), microbiota modulation (polysaccharides, melanoidins, chlorogenic acids), immunostimulatory (polysaccharides), antidiabetic (trigonelline, chlorogenic acids), antihypertensive (chlorogenic acids) and hypocholesterolemic (polysaccharides, chlorogenic acids, lipids). Nevertheless, caffeine and diterpenes are coffee components with ambivalent effects on health. Additionally, a large range of potentially harmful compounds, including acrylamide, hydroxymethylfurfural, furan, and advanced glycation end products, are formed during the roasting of coffee and are present in the beverages. However, coffee beverages are part of the daily human dietary healthy habits, configuring a coffee paradox.

Antiglycoxidative Properties of Extracts and Fractions from Reynoutria Rhizomes

Hyperglycemia, when sustained over a long time in diabetes mellitus (DM), leads to biochemical and cellular abnormalities, primarily through the formation of advanced glycation end-products (AGEs). In the treatment of diabetes, beside blood-sugar-lowering medications, a consumption of herbal products that can inhibit the AGEs’ formation is recommended. This study investigated the in vitro antiglycoxidative potential of extracts and fractions from the rhizomes of Japanese, Giant, and Bohemian knotweeds (Reynoutria japonica (Houtt.), R. sachalinensis (F. Schmidt) Nakai, and R.× bohemica Chrtek et Chrtkova). Their effects on glycooxidation of bovine and human serum albumin were evaluated by incubation of the proteins with a mixture of glucose and fructose (0.5 M) and 150 µg/mL of extract for 28 days at 37 °C, followed by measuring early and late glycation products, albumin oxidation (carbonyl and free thiol groups), and amyloid-β aggregation (thioflavin T and Congo red assays). The highest antiglycoxidative activity, comparable or stronger than the reference drug (aminoguanidine), was observed for ethyl acetate and diethyl ether fractions, enriched in polyphenols (stilbenes, phenylpropanoid disaccharide esters, and free and oligomeric flavan-3-ols). In conclusion, the antiglycoxidative compounds from these three species should be further studied for potential use in the prevention and complementary treatment of DM.

Polyphenols and AGEs/RAGE axis. Trends and challenges

The formation of advanced glycation end-products (AGEs) is a key pathophysiological event linked not only to the onset and progression of diabetic complications, but also to neurodegeneration, cardiovascular diseases, cancer, and others important human diseases. AGEs contributions to pathophysiology are mainly through the formation of cross-links and by engaging the receptor for advanced glycation end-products (RAGE). Polyphenols are secondary metabolites found largely in fruits, vegetables, cereals, and beverages, and during many years, important efforts have been made to elucidate their beneficial effects on human health, mainly ascribed to their antioxidant activities. In the present review, we highlighted the beneficial actions of polyphenols aimed to diminish the harmful consequences of advanced glycation, mainly by the inhibition of ROS formation during glycation, the inhibition of Schiff base, Amadori products, and subsequent dicarbonyls group formation, the activation of the glyoxalase system, as well as by blocking either AGEs-RAGE interaction or cell signaling.

Advanced Glycation Endproducts (AGEs) in Food: Health Implications and Mitigation Strategies

Controversy remains over the impact of advanced glycation endproducts (AGEs), not only in their formation, but also whether they actually come directly from food products or are generated by the body in response to ingestion of certain foods. This final chapter will take a different approach to food contaminants and look at the health impact of AGEs, regardless of whether they are directly ingested from food, autogenerated by the body as a consequence of underlying disease conditions or contribute to the aetiology of disease. AGEs are formed from food components or as a consequence of some disease states, such as type II diabetes or cardiovascular disease (CVD). As such these compounds are inextricably linked to the Maillard reaction and cooking conditions. Furthermore, processing-derived chemical contaminants in cooked foods are of concern to consumers. This chapter examines new research into naturally derived plant extracts as inhibitory agents on new dietary AGE (dAGE) formation and introduces practical approaches for the reduction of dAGE consumption in the daily diet. Understanding the pathogenic mechanisms of AGEs is paramount to developing strategies against diabetic and cardiovascular complications.

Inhibition of the Maillard Reaction by Phytochemicals Composing an Aqueous Coffee Silverskin Extract via a Mixed Mechanism of Action

This work aimed to evaluate the contribution of isoflavones and melatonin to the aqueous extract obtained from the coffee silverskin (CSE) antiglycative properties, which has not been previously studied. To achieve this goal, two model systems constituted by bovine serum albumin (BSA) and reactive carbonyls (glucose or methylglyoxal) in the presence or absence of pure phytochemicals (chlorogenic acid (CGA), genistein, and melatonin) and CSE were employed. Glucose was used to evaluate the effect on the formation of glycation products formed mainly in the early stage of the reaction, while methylglyoxal was employed for looking at the formation of advanced products of the reaction, also called methylglyoxal-derivative advanced glycation end products (AGE) or glycoxidation products. CGA inhibited the formation of fructosamine, while genistein and melatonin inhibited the formation of advanced glycation end products and protein glycoxidation. It was also observed that phenolic compounds from CSE inhibited protein glycation and glycoxidation by forming BSA-phytochemical complexes. CSE showed a significant antiglycative effect (p < 0.05). Variations in the UV-Vis spectrum and the antioxidant capacity of protein fractions suggested the formation of protein-phytochemical complexes. Fluorescence quenching and in silico analysis supported the formation of antioxidant-protein complexes. For the first time, we illustrate that isoflavones and melatonin may contribute to the antiglycative/antiglycoxidative properties associated with CSE. CGA, isoflavones, and melatonin composing CSE seem to act simultaneously by different mechanisms of action.

Diet and Alzheimer's dementia - Nutritional approach to modulate inflammation

BACKGROUND

Alzheimer's disease (AD) is the most common neurodegenerative disease causing dementia in the elderly population. Due to the fact that there is still no cure for Alzheimer's dementia and available treatment strategies bring only symptomatic benefits, there is a pressing demand for other effective strategies such as diet. Since the inflammation hypothesis gained considerable significance in the AD pathogenesis, elucidating the modulatory role of dietary factors on inflammation may help to prevent, delay the onset and slow the progression of AD. Current evidence clearly shows that synergistic action of combined supplementation and complex dietary patterns provides stronger benefits than any single component considered separately. Recent studies reveal the growing importance of novel factors such as dietary advanced glycation end products (d-AGE), gut microbiota, butyrate and vitamin D₃ on inflammatory processes in AD.

CONCLUSION

This paper summarizes the available evidence of pro- and anti-inflammatory activity of some dietary components including fatty acids, vitamins, flavonoids, polyphenols, probiotics and d-AGE, and their potential for AD prevention and treatment.