Effects of Black Garlic on Cardiovascular System Diseases
1.Black Garlic and Platelet Aggregation.
The activation of blood platelets plays a vital role in many important physiological and pathological processes, including various arterial phenomena, such as myocardial infarction and strokes.
The platelets bind to the exposed collagen, laminin , and von Willebrand factor in the injured vessel wall, referred to as platelet activation. Adenosine-5-diphosphate (ADP) and thrombin can also process the activation. The activated platelets change their shape, remove pseudopodia, release granules, and adhere to other platelets, thus commencing the platelet aggregation process. Platelet-activating factor, a cytokine released by neutrophils, monocytes, and platelets, also promotes aggregate formation.
Several studies have shown that BG has great potential in inhibiting platelet aggregation.
|Products||Subjects/Cell Line/Animal Model||Outcomes|
|Aged garlic||30 participants (12 weeks)||Reduced cardiovascular risk factors|
|Aged black garlic||28 participants (12 weeks)||Reduced atherogenic markers.|
|Aged garlic (AG)||34 participants (44 weeks)||AG exerted selective inhibition on platelet aggregation and adhesion, platelet functions.|
|Fermented garlic||Male Sprague-Dawley rats||Ameliorated, hypercholesterolemia and inhibited platelet activation.|
|Fermented garlic (FG)||Male Sprague-Dawley rats||FG significantly inhibited platelet aggregation and granule secretion in hypercholesterolemic rats.|
Fermented garlic is also effective in the inhibition of hypercholesterolemia and platelet aggregation. It was observed that the oral administration of fermented garlic (300 mg/kg) in male Sprague-Dawley rats once a day, along with a hypercholesterolemia diet for one month, inhibited collagen and ADP-induced platelet aggregation and ATP release. Besides, fermented garlic treatment downregulated the expression of sterol regulatory element-binding protein, acetyltransferase- 2, and 3-hydroxy-3-methylglutaryl coenzyme A.
Several cl inical trials have been conducted in the recent years to investigate the cardioprotective effects of Black garlic extract. Most of the studies have been found to have positive effects. In a study, Seo et al. showed that a 12 week aged garlic extract regimen with regular exercise reduced cardiovascular risk factors in postmenopausal by decreasing the body weight, body mass index, total cholesterol, LDL-C, malondialdehyde, and homocysteine levels. In another study, Jung et al. Investigated whether aged black garlic supplementation could improve blood lipid profile in mild hypercholesterolemia patients. They found that aged black garlic supplement increased the high-density lipoprotein cholesterol levels with the ratio of low-density lipoprotein cholesterol/apolipoprotein B with a decrease in the levels of apolipoprotein B.
2.Black Garlic and Arterial Hypertension
Several risk factors are associated with the development of arterial hypertension. Numerous studies showed the potential effects of Black garlic extract on decreasing arterial hypertension and inhibiting ACE.
Ried et al. carried out a clinical trial on 88 patients with uncontrolled arterial hypertension patients. After 12 weeks of study, the findings indicated that aged garlic extract significantly reduced mean blood pressure along with arterial stiffness, mean arterial pressure, central blood pressure, central pulse pressure, pulse wave velocity, and augmentation pressure. Aged garlic extract administration for 12 weeks in 49 participants with uncontrolled arterial hypertension was also found effective in reducing blood pressure and had the potential to improve inflammation, arterial stiffness, and enhanced gut microbial profile.
Similarly, Yu et al. reported that Black Garlic extract was the most active in ACE inhibition with the lowest IC50 value (0.04 mg/mL) compared to raw garlic extract. Having said that, the authors also identified two Amadori compounds in BG extract, specifically N-(1-deoxy-D-fructos-1-yl)-l-arginine and N-(1-deoxy-D-fructos-1-yl)-l-methionine, which were probably attributed to ACE inhibitory activity. It has also been reported by Jang et al. , in their study, that ACE inhibitory effects of the BG extract were greater (88.8%) than normal garlic extract (52.7%).
However, there is still not enough data to suggest BG for the treatment of hypertensive patients as a standard clinical therapy. More properly designed and analyzed trials are needed for a definite conclusion.
3.Black Garlic and Atherosclerosis
Atherosclerosis occurs as a result of fat, cholesterol, and other substances interacting within the cellular components of the arterial wall. These deposits are called plaques. Over time, these plaques can eventually narrow or totally block the arteries, causing complications throughout the body.
Numerous pre-clinical and clinical investigations have demonstrated and confirmed Black garlic’s efficacy in preventing and treating atherosclerosis.
In a randomized double-blind placebo-controlled trial, aged garlic extract significantly inhibited CAC progression, lowered the levels of IL-6 glucose, and blood pressure in 104 patients at increased risk of cardiovascular events after taking 2400 mg/daily of aged garlic extract for one year.
Another randomized clinical trial showed that a combination of aged garlic extract and co-enzyme Q10 suppressed the CAC progression and significantly decreased carbon reactive protein levels. In 2009, a placebo-controlled, double-blind, randomized study involved 65 intermediate-risk patients and supplied them a capsule containing aged garlic extract with vitamin B6, vitamin B12, folic acid, and L-arginine for 12 months. At the end of the clinical trial, the data suggested that aged garlic extract with supplements decreased TGs, LDL-C, homocysteine, immunoglobulin G, and immunoglobulin M autoantibodies to malondialdehyde-low density lipoprotein and apolipoprotein B-immune complexes while high-density lipoprotein, oxidized phospholipids/apolipoprotein B and lipoprotein were significantly increased.
Furthermore, a study of 60 asymptomatic patients showed that fermented garlic extract with supplements decreased the levels of epicardial adipose tissue, pericardial adipose tissue, periaortic adipose tissue, and subcutaneous adipose tissue after 12 months of treatment. Thus, aged garlic extract with supplements reduced the metabolic risk and the severity of coronary artery calcification by suppressing the progression rate of adipose tissue volume.