Beyond the well-known effects on blood pressure (BP) of the dietary approaches to stop hypertension (DASH) and the Mediterranean diets, a large number of studies has investigated the possible BP lowering effect of different dietary supplements and nutraceuticals, the most part of them being antioxidant agents with a high tolerability and safety profile. In particular relatively large body of evidence support the use of potassium, L-arginine, vitamin C, cocoa flavonoids, beetroot juice, coenzyme Q10, controlled-release melatonin, and aged garlic extract. However there is a need for data about the long-term safety of a large part of the above discussed products. Moreover further clinical research is advisable to identify between the available active nutraceuticals those with the best cost-effectiveness and risk-benefit ratio for a large use in general population with low-added cardiovascular risk related to uncomplicated hypertension.

Garlic (Allium sativum) is used for culinary and medicinal purposes in diverse cultures worldwide. When fresh garlic is soaked in aqueous ethanol under ambient environment over 4 months or longer, the majority of irritating taste and odor is eliminated and the antioxidant profile in the resulting aged garlic extract (AGE) changes significantly. Recently, AGE and its components have been demonstrated to exert neuroprotective effects in neurodegenerative diseases, includingAlzheimer's disease, Parkinson's disease, Huntington's disease, and cerebral ischemia. Because of its health supporting potential, there is increasing interest in understanding the antioxidant and anti-inflammatory properties and the underlying mechanisms for its protective effects in heath and disease. There is evidence for AGE to exert its action on distinct signaling pathways associated with oxidative stress and neuroinflammation, although the primary molecular mechanisms remain unclear. By utilizing quantitative proteomic approaches, we demonstrated that AGE and two of its major ingredients, S-allyl-L-cysteine and N (α)-(1-deoxy-D-fructos-1-yl)-L-arginine, can attenuate neuroinflammatory responses in microglial cells through modulation of Nrf2-mediated signaling as well as other oxidative stress-related pathways. These experimental data provide information for the molecular targetsof AGE and its components to mitigate neurodegeneration and neuroinflammation and show a promising potential of these compounds as dietary supplements for health maintenance.

PURPOSE:Production of reactive oxygen species and reactive nitrogen species is a natural biological event in metabolism. However, the presence of antioxidants can highly reduce the negative effect of free radicals. Thus, the efficiency of antioxidant system in the physiology of exercise is very important.

DESIGN:Considering the known antioxidant capacity of garlic, the purpose of this study was to evaluate the effect on combining 14 days aerobic exercise till exhaustion with garlic extract supplementation on the antioxidant capacity of saliva.

METHODS:Sixteen young men volunteered to participate in this randomized, double blind, placebo-controlled study and were randomly placed into two groups, placebo (Group I) and garlic extract (Group II). The participants performed exhaustive aerobic exercise on a treadmill before and after supplementation. Their unstimulated salivary samples were collected before, immediately after, and 1 h after the activity. The antioxidant activity in terms of peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) was then measured in the collected samples using their specific substrates.

RESULTS:A significant increase in salivary antioxidant activity of SOD, POD, and CAT was observed in saliva of the supplement group compared to the placebo group (P ≤ 0.05).

CONCLUSION:The findings from this study suggest that increased activity of antioxidant enzymes could possibly decrease exercise-induced oxidative damage in male athletes.