Inhibition of advanced glycation end product formation by medicinal plant extracts correlates with phenolic metabolites and antioxidant activity.
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.
Harris
Cory S
CS
Centre for Research in Biopharmaceuticals and Biotechnology, Department of Biology, University of Ottawa, Ottawa, ON, Canada.
Beaulieu
Louis-Philippe
LP
Fraser
Marie-Hélène
MH
McIntyre
Kristina L
KL
Owen
Patrick L
PL
Martineau
Louis C
LC
Cuerrier
Alain
A
Johns
Timothy
T
Haddad
Pierre S
PS
Bennett
Steffany A L
SA
Arnason
John T
JT
D000975:Antioxidants / Q000494:pharmacology*; D002170:Canada; D016166:Free Radical Scavengers / Q000737:chemistry; D017127:Glycation End Products, Advanced / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D008239:Lysine / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000737:chemistry; D008315:Malondialdehyde / Q000737:chemistry; D010084:Oxidation-Reduction; D010636:Phenols / Q000494:pharmacology*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D010946:Plants, Medicinal / Q000737:chemistry*; D013997:Time Factors
D000975:Antioxidants; D016166:Free Radical Scavengers; D017127:Glycation End Products, Advanced; D010636:Phenols; D010936:Plant Extracts; D008315:Malondialdehyde; C048496:N(6)-carboxymethyllysine; D008239:Lysine