title: Aged garlic has more potent antiglycation and antioxidant properties compared to fresh garlic extract in vitro.
abstract: Protein glycation involves formation of early (Amadori) and late advanced glycation endproducts (AGEs) together with free radicals via autoxidation of glucose and Amadori products. Glycation and increased free radical activity underlie the pathogenesis of diabetic complications. This study investigated whether aged garlic has more potent antiglycation and antioxidant properties compared to fresh garlic extract in vitro in a cell-free system. Proteins were glycated by incubation with sugars (glucose, methylglyoxal or ribose) ±5-15 mg/mL of aged and fresh garlic extracts. Advanced glycation endproducts were measured using SDS-PAGE gels and by ELISA whereas Amadori products were assessed by the fructosamine method. Colorimetric methods were used to assess antioxidant activity, free radical scavenging capacity, protein-bound carbonyl groups, thiol groups and metal chelation activities in addition to phenolic, total flavonoid and flavonol content of aged and fresh garlic extracts. Aged garlic inhibited AGEs by 56.4% compared to 33.5% for an equivalent concentration of fresh garlic extract. Similarly, aged garlic had a higher total phenolic content (129 ± 1.8 mg/g) compared to fresh garlic extract (56 ± 1.2 mg/g). Aged garlic has more potent antiglycation and antioxidant properties compared to fresh garlic extract and is more suitable for use in future in vivo studies.
authors.affiliation: School of Healthcare Science, Manchester Metropolitan University, Manchester M1 5GD, United Kingdom.
authors.forename: Abdulhakim
authors.initials: A
authors.lastname: Elosta
authors.affiliation: School of Healthcare Science, Manchester Metropolitan University, Manchester M1 5GD, United Kingdom.
authors.forename: Mark
authors.initials: M
authors.lastname: Slevin
authors.affiliation: School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool L3 3AF, United Kingdom.
authors.forename: Khalid
authors.initials: K
authors.lastname: Rahman
authors.affiliation: School of Healthcare Science, Manchester Metropolitan University, Manchester M1 5GD, United Kingdom.
authors.forename: Nessar
authors.initials: N
authors.lastname: Ahmed
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D002614:Chelating Agents / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000494:pharmacology; D005737:Garlic / Q000737:chemistry*; D017127:Glycation End Products, Advanced / Q000037:antagonists & inhibitors* / Q000378:metabolism; D066298:In Vitro Techniques; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D002614:Chelating Agents; D016166:Free Radical Scavengers; D017127:Glycation End Products, Advanced; D010936:Plant Extracts