Inhibition of Advanced Glycation End Product Formation by Medicinal Plant Extracts Correlates with Phenolic Metabolites and Antioxidant Activity

Abstract

Nonenzymatic formation of advanced glycation end products (AGEs) is accelerated under hyperglycemic conditions characteristic of type 2 diabetes mellitus and contributes to the development of vascular complications. As such, inhibition of AGE formation represents a potential therapeutic target for the prevention and treatment of diabetic complications. In the present study, ethanolic extracts of 17 medicinal plants were assessed for inhibitory effects on in vitro AGE formation through fluorometric and immunochemical detection of fluorescent AGEs and N(ε)-(carboxymethyl)lysine adducts of albumin (CML-BSA), respectively. Most extracts inhibited fluorescent AGE formation with IC (50) values ranging from 0.4 to 38.6 µg/mL and all extracts reduced CML-BSA formation but to differing degrees. Results obtained through both methods were highly correlated. Antiglycation activities were positively correlated with total phenolic content, free radical scavenging activity and reduction in malonyldiadehyde levels following oxidation of low-density lipoprotein, but negatively correlated with lag time to formation of conjugated dienes. Together, these results provide evidence that antioxidant phenolic metabolites mediate the antiglycation activity of our medicinal plant collection, a relationship that likely extends to other medicinal and food plants.

Evaluation of the In Vitro Inhibitory Activity of Rye-Buckwheat Ginger Cakes with Rutin on the Formation of Advanced Glycation End-Products (AGEs)

“…These findings confirmed the theory that the antiglycation activity is strongly correlated with the scavenging ability of polyphenolic compounds in reducing oxidation of Amadori compounds [Harris et al, 2011]. The high positive correlation between antiglycation and antioxidative activities of spices in BSA-glucose model system was confirmed (TPC/BSA-glucose, r=0.9; DPPH/BSA-glucose, r=0.6) by Ramkissoon et al [2013].…”

“…On the other hand, consumption of foods with natural AGEs inhibitors was proposed [Peng et al, 2011]. According to the latest research conducted by Harris et al [2011] and Peng et al [2011], plant extracts, which are good sources of antioxidant polyphenols, could contribute to the reduction of AGEs formation by preventing oxidative damage of proteins. Green tea and tea infused with selected herbs [Ho et al, 2010], tomato paste [Kiho et al, 2004] or spices [Tosun & Khan, 2015] was highlighted as a potential inhibitor of AGEs formation.…”

Assay of Antioxidant Capacity and Phenolic Compounds in some Romanian and Cypriot Wine

“…All other chemicals used were of analytical grade. "moderate correlation"; 0.60-0.79 "strong correlation"; 0.80-1.0 "very strong correlation", as mentioned in other research studies (Fenercioglu et al, 2010;Floegela et al, 2011;Harris et al, 2011).…”

Serum paraoxonase 1 status and its association with atherogenic indexes in gentamicin-induced nephrotoxicity in rats treated with coenzyme Q10

“…35 Also, the mechanism of hypolipidemic and antiatherogenic action of natural antioxidant may be due to the inhibition of glycation lipoproteins, enzymes and proteins that involve lipid and lipoprotein metabolism. 36 Effect of coenzyme Q10 on serum PON 1 activity and correlation of PON 1 activity with HDL and atherogenic index Serum PON 1 activity significantly was decreased in the untreated nephrotoxic animals in comparison with the control group. Treatment of the nephrotoxic animals with coenzyme Q10 could significantly elevate decreasing of serum PON 1 activity in comparison with the untreated nephrotoxic animals.…”