Black garlic has cardioprotective effect
Researchers at the Autonomous University of Madrid have led a study into the cardioprotective properties of aged black garlic. The findings, published in the Journal of Functional Foods, demonstrate that this novel functional food may help mitigate the decline in cardiac contractility following a myocardial infarction in rats.
A team from the Faculty of Medicine at the Autonomous University of Madrid (UAM), in collaboration with Pharmactive Biotech S.L., conducted a study to investigate the cardiovascular effects of aged black garlic. This type of garlic is widely used as a seasoning in Asian cuisine, and its use has spread to North America and Europe in recent years. It is produced from regular garlic through an accelerated ageing process in which temperature and humidity parameters are carefully controlled.
Unlike conventional garlic, the resulting product contains higher levels of polyphenols, polyunsaturated fatty acids such as linolenic acid, and sulphur-containing compounds, particularly S-allylcysteine (SAC), which gives it greater antioxidant capacity.
The study aimed to assess the in vitro effects of black garlic extract on cardiac function in rats following a myocardial infarction. The experiments were conducted using the Langendorff isolated perfused heart technique, which allows cardiac function to be assessed ex vivo and treatments to be administered directly to the heart.
The results showed that black garlic extract has a potent vasodilatory effect on the coronary arteries and that administering the extract before and after an ischaemic event (heart attack) prevents the resulting decline in cardiac contractility.
“The effect on cardiac contractility was found to be dose-dependent, occurring exclusively when a dose of 50 mg/L of the extract was administered, but not at the higher dose of 500 mg/L,” explains Miriam Granado, from the Department of Physiology at the UAM and lead researcher of the study.
GREATER VASODILATION
As part of the study, the scientists administered black garlic extract to sections of the aorta using an organ bath system to assess vascular reactivity. They observed that black garlic extract induced vasodilation at high doses and increased the release of nitric oxide (NO) at both 50 mg/L and 500 mg/L.
These functional studies of the heart and aorta were complemented by an analysis of the expression of inflammatory and oxidative stress markers in arterial and cardiac tissue.
“Contrary to expectations, administering black garlic extract not only failed to reduce the expression of these markers but also slightly increased it in some cases. However, the extract also increased the expression of certain anti-inflammatory and antioxidant markers,” explains Miriam Granado.
“These results,” she continues, “may be explained by hormesis, a phenomenon underlying the pharmacological effects of certain medicinal substances. It is defined as the process whereby exposure to low doses of a particular chemical or environmental agent, which may be harmful at high doses, triggers an adaptive response and a beneficial effect in the cell or organism.
“Therefore,” the researcher adds, “it is possible that inducing a mild inflammatory and oxidative state causes black garlic extract to simultaneously activate anti-inflammatory and antioxidant mechanisms that may partially prevent the changes caused by more severe damage, such as a myocardial infarction.”
CARDIOVASCULAR BENEFITS OF GARLIC
In addition to conventional therapies, certain foods and nutritional compounds have been shown to be effective in the prevention and treatment of cardiovascular diseases, which, according to the World Health Organization (WHO), are the leading cause of death worldwide.
Among these foods, garlic (Allium sativum L.) has had a well-established reputation for centuries across various cultures for its antithrombotic and antihypertensive properties.
The latter are due, at least in part, to the active compound S-allyl-cysteine (SAC), which reduces oxidative stress and inflammation and promotes the release of vasodilatory substances such as nitric oxide (NO) and hydrogen sulphide (H₂S). Both substances are produced by vascular endothelial cells and play an important role in regulating vascular tone.
BIBLIOGRAPHIC REFERENCE
García-Villalón AL, Amor S, Monge L, Fernández N, Prodanov M, Muñoz M, Inarejos-García AM, Granado M. “In vitro studies of an aged black garlic extract enriched in
S-allyl cysteine and polyphenols with cardio protective effects”. Journal of Functional Foods. Volume 27, December 2016, Pages 189–200.