Effect of Kyolic® aged garlic extract on glycaemia, lipidaemia and oxidative stress in patients with type 2 diabetes mellitus

Abstract

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.

Antioxidant effect of garlic (Allium sativum) and black seeds (Nigella sativa) in healthy postmenopausal women

“…The subjects consumed garlic at a dose of two garlic soft gels per day (equivalent to 2000 mg of fresh garlic bulb) 47 and crude black seed grounded to powder in a dose of 3 g/day for a period of 8 weeks. 48 …”

New Pathogenic Concepts and Therapeutic Approaches to Oxidative Stress in Chronic Kidney Disease

“…Although experimental studies described antidiabetic effects of garlic, human studies are inconclusive but showed a compelling antioxidant effect. Aged garlic extract intake (3 g/day) did not affect blood glucose, HbA 1C , or the lipid profile but did reduce levels of serum advanced glycation end products (AGEs) and lipid hydroperoxide in patients [ 219 ]. In contrast, other studies describe that garlic extract improves blood lipid profile, strengthens TAL, and decreased lipid peroxidation, BP, RAGE, and secretion of IL-1 and TNF in patients [ 220 , 221 ].…”

Protective Effect of Aged Garlic Extract Against the Oxidative Stress Induced by Acute Ionizing Irradiation on Hepatic Antioxidant Enzymes in Rats

“…The increase was more important in "Irradiation+25 mg/kg AGE" group than in "Irradiation+50 mg/kg AGE" group or "Irradiation + Vitamin E and Lipoïc Acid". AGE and SAC were shown to scavenge ROS [10] and to inhibit lipid peroxide formation in several studies [14,46]. These antioxidant effects can be due to allixin, SAC, SMAC and diallyl polysulfides, whose radical-scavenging action increased with the number of sulfur atoms [47].…”

“…The extract is then filtered and concentrated under reduced pressure according to the guidelines of Good Manufacturing practices established by the World Health Organization. The garlic is grown under strictly controlled organic conditions (without herbicides or pesticides of any kind), harvested at full maturity, cleaned, sliced and stored in stainless steel tanks under carefully controlled conditions without the use of a heating process [12][13][14]. The content of water-soluble compounds is relatively high whereas that of oil-soluble compounds is relatively low [14].…”

“…The garlic is grown under strictly controlled organic conditions (without herbicides or pesticides of any kind), harvested at full maturity, cleaned, sliced and stored in stainless steel tanks under carefully controlled conditions without the use of a heating process [12][13][14]. The content of water-soluble compounds is relatively high whereas that of oil-soluble compounds is relatively low [14]. The AGE used in this study is standardized with S-Allyl Cysteine and contained 30% extracted solids (300 mg/ml), and S-allyl cysteine present at 1.47 mg/ml.…”