title: Moringa oleifera aqueous leaf extract inhibits reducing monosaccharide-induced protein glycation and oxidation of bovine serum albumin.
abstract: Advanced glycation end products (AGEs) play an important factor for pathophysiology of diabetes and its complications. Moringa oleifera is one of the medicinal plants that have anti-hyperglycemic activity. However, anti-glycation property of Moringa oleifera leaf extract on the different types of reducing monosaccharides-induced protein glycation has not been investigated. Therefore, the aim of this study was to examine the protective effect of Moringa oleifera aqueous leaf extract (MOE) on reducing sugars-induced protein glycation and protein oxidation. Total phenolic content of MOE was measured using the Folin-Ciocalteu method. Bovine serum albumin was incubated with 0.5 M of reducing sugars (glucose or fructose) with or without MOE (0.5-2.0 mg/mL) for 1, 2, 3 and 4 weeks. The results found that total phenolic content was 38.56 ± 1.50 mg gallic acid equivalents/g dry extract. The formation of fluorescent and non-fluorescent AGEs [N (ε)-(carboxymethyl) lysine (CML)] and the level of fructosamine were determined to indicate protein glycation, whereas the level of protein carbonyl content and thiol group were examined for protein oxidation. MOE (0.5-2.0 mg/mL) significantly inhibited the formation of fluorescent, N (ε)-CML and markedly decreased fructosamine level (P < 0.05). Moreover, MOE significantly prevented protein oxidation manifested by reducing protein carbonyl and the depletion of protein thiol in a dose-dependent manner (P < 0.05). Thus, the findings indicated that polyphenols containing in MOE have high potential for decreasing protein glycation and protein oxidation that may delay or prevent AGE-related diabetic complications.
authors.affiliation: Graduate Program in Food and Nutrition, Department of Nutrition and Dietetics, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, 10330 Thailand.
authors.forename: Pornpimon
authors.initials: P
authors.lastname: Nunthanawanich
authors.affiliation: Department of Nutrition and Dietetics, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, 10330 Thailand.
authors.forename: Weerachat
authors.initials: W
authors.lastname: Sompong
authors.affiliation: Department of Nutrition and Dietetics, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, 10330 Thailand ; The Halal Science Center, Chulalongkorn University, Bangkok, 10330 Thailand.
authors.forename: Sukrit
authors.initials: S
authors.lastname: Sirikwanpong
authors.affiliation: Department of Nutrition and Dietetics, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, 10330 Thailand ; Research Group of Herbal Medicine for Prevention and Therapeutic of Metabolic Diseases, Chulalongkorn University, Bangkok, 10330 Thailand.
authors.forename: Kittana
authors.initials: K
authors.lastname: Mäkynen
authors.affiliation: Department of Nutrition and Dietetics, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, 10330 Thailand ; Research Group of Herbal Medicine for Prevention and Therapeutic of Metabolic Diseases, Chulalongkorn University, Bangkok, 10330 Thailand.
authors.forename: Sirichai
authors.initials: S
authors.lastname: Adisakwattana
authors.affiliation: The Halal Science Center, Chulalongkorn University, Bangkok, 10330 Thailand.
authors.forename: Winai
authors.initials: W
authors.lastname: Dahlan
authors.affiliation: Department of Nutrition and Dietetics, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, 10330 Thailand ; Research Group of Herbal Medicine for Prevention and Therapeutic of Metabolic Diseases, Chulalongkorn University, Bangkok, 10330 Thailand ; The Halal Science Center, Chulalongkorn University, Bangkok, 10330 Thailand.
authors.forename: Sathaporn
authors.initials: S
authors.lastname: Ngamukote
keywords: Fructose; Glucose; Glycation; Moringa oleifera; Polyphenol