1. Department of Biochemistry, King Abdul Aziz University, Jeddah 21589, Saudi Arabia.
Background: Diabetic patients with hyperglycaemia show oxidative stress and increased formation of advanced glycation endproducts (AGEs) which increases their susceptibility to chronic complications. Aged garlic extract has antioxidant properties and prevents the formation of AGEs in vitro. This study investigated the effects of dietary intervention with Kyolic® aged garlic extract on glycaemia, lipidaemia and oxidative stress in diabetic patients.
Methods: Blood samples were collected from 48 diabetic patients on recruitment, after one month and then monthly following an intake of 3000 mg of aged garlic extract daily over a period of 3-months. Samples were analysed for glucose, glycated haemoglobin and lipid profile using automated analyses. Low molecular weight AGEs were measured using a fluorometric method. Lipid hydroperoxides and total antioxidant status were determined using colorimetric kit methods.
Results: Intervention with aged garlic extract did not affect blood glucose, glycated haemoglobin or the lipid profile but serum triacylglycerol concentrations declined after 3-months of intervention (P< 0.05). Aged garlic extract intake did reduce levels of serum AGEs although this was not significant. Lipid hydroperoxide, an indicator of oxidative stress, was significantly reduced following intake of aged garlic extract (P<0.05).
Conclusion: Aged garlic extract may therefore protect against the harmful effects of AGEs and oxidative stress thus further investigations are needed to fully evaluate the benefits of long-term consumption of aged garlic extract, in particular its effects on tissue AGEs and oxidative stress.
Keywords: Diabetes mellitus, advanced glycation endproducts, aged garlic extract, antioxidant, lipid peroxidation, hyperglycaemia.