Black Garlic and Its Bioactive Compounds on Human Health Diseases

Black Garlic and Its Bioactive Compounds on Human Health Diseases

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Black garlic extract

Black Garlic and Its Bioactive Compounds on Human Health Diseases


Black Garlic Extract (BGE) and its derivatives have been documented to have multiple biological impacts on health promotion and treatment of various diseases. The transformation of fresh garlic to BG results in modifications in the biological activity of bioactive compounds caused by fermentation. In the past few decades, extensive pre-clinical investigations have shown the therapeutical potential of BG against a wide variety of human diseases. Furthermore, it has been demonstrated that BG interacts directly with a number of signaling molecules. These pre-clinical investigations have established a good foundation for clinical trials investigating BG’s efficacy.


1.Effects of Black Garlic on Metabolic Disorders

1.1Black Garlic and Diabetes

Diabetes mellitus is a heterogeneous form of metabolic disorder characterized by chronic hyperglycemia.

Clinical and experimental studies have demonstrated that chronic hyperglycemia is a major source of oxidative stress and that elevated free radicals play a key role in diabetes mellitus pathogenesis and complications. Several studies have investigated the anti-diabetic potential of black garlic extract and these studies described variable effects of BG on conventional diabetes mellitus markers. For example, aged black garlic extract exhibited ameliorative action on glyco-metabolic biomarkers in streptozotocin-induced diabetic rats by significantly decreasing blood glucose, glycated hemoglobin, and markedly increased serum insulin. Another study examined the anti-diabetic effects of BG powder in male Wister rats and found that BG powder lowered blood glucose, prevented glycogen in the liver, and improved lipid metabolism by increasing the activity of glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, and γ-GTP . The results obtained by Si et al. demonstrated that 40 weeks of supplementation of BG lowered the levels of plasma malondialdehyde, SOD, GSH-Px, and total antioxidant capacity in pregnant women. They also mentioned that Lactobacillus bulgaricus improved the antioxidant capacity of BG in the prevention of gestational diabetes mellitus. On the other hand, Kim et al. [89] used SAC-enriched BG juice and treated streptozotocin 239-induced insulin-deficient mice. The authors found that BG juice improved the glutathione antioxidant system, increased leptin, and adiponectin secretion, inhibited hepatic gluconeogenesis, and suppressed nuclear factor-kappa β (NF-κβ)-mediated inflammatory signaling.

Products Subjects/Cell Line/Animal Model Outcomes
Black garlic juice Male C57BL/6J mice SAC-enriched BGJ counteracted STZ239-induced diabetes and β-cell failure in mice.
Aged garlic Male Sprague-Dawley rats Ameliorated oxidative stress and other complications of diabetes.
Aged black garlic C57BL/KsJ-db/db mice ABG improved insulin sensitivity and dyslipidemia in db/db mice.
Black garlic powder Male Wister rats BGP lowered blood glucose, prevented glycogen in the liver, and improved lipid metabolism.
Aged black garlic C57BL/KsL-db/db mice ABG prevented diabetic complications through antioxidant activity.
Aged garlic BSA or lysozyme AG + SAC prevented the formation of advanced glycation end products.
S-allyl cysteine (SAC)
Aged garlic (AG) Sprague-Dawley rats AG exhibited ameliorative action on indicators of diabetes.


1.2. Black Garlic and Obesity

Obesity has become a major public health problem. Obesity-related problems are linked to a variety of metabolic syndrome symptoms including high blood pressure, dyslipidemia, insulin resistance, and glucose intolerance. Various approaches might be employed in human obesity prevention and control. Since a perfect cure or prevention of obesity still remains to be established and the majority of the anti-obesity drugs could have adverse effects, an exploration into the identification of new materials has shown a growing interest. BG extracts have been reported for their activity in reducing body weight, adipose tissue mass, serum triglyceride, total cholesterol, low-density lipoprotein, and plasma malondialdehyde in mice with high-fat-diet-induced obesity.

Moreover, Chen et al. revealed that methanolic extract of Black Garlic ameliorated diet-induced obesity in male Wister rats via upregulate AMP-activated protein kinase, Forkhead box O1, sirtuin 1, adipose triglyceride lipase, hormone-sensitive lipase (HSL), perilipin, acyl-coenzyme A oxidase, carnitine palmitoyl transferase 1, uncoupling protein 1, and downregulated CD36 in the adipose tissue. Aged black garlic extract has also been reported to show anti-lipogenic and lipolytic effects in mature 3T3-L1 adipocytes by reducing protein expression of PPARγ, HSL, and serum-phosphorylated HSL levels.

Products Subjects/Cell Line/Animal Model Outcomes
Black garlic juice Male C57BL/6J mice SAC-enriched BGJ counteracted STZ239-induced diabetes and β-cell failure in mice.
Aged garlic 51 healthy adults with obesity
Study period: 6 weeks
AG prevented the development of chronic diseases associated with low-grade inflammation.
Fermented garlic by lactic acid bacteria (FBLA) Male C57BL/6J mice FBLA ameliorated diet-induced obesity by inhibiting adipose tissue hypertrophy by suppressing adipogenesis.
Aged garlic Male Sprague-Dawley rats Modified the adipose weight and improved the oxidative stress.
Black garlic Male Wister rats Ameliorated diet-induced obesity via regulating adipogenesis, adipokine biosynthesis, and lipolysis.
Aged garlic Sprague Dawley rats Exhibited anti-obesity, cholesterol-lowering, and anti-inflammatory effects.
Aged black garlic Male Sprague-Dawley rats Improved the body weight gain and dyslipidemia through the suppression of body fat and alteration in lipid profiles and antioxidant defense system.
Black garlic (BG) Male Wister rats BG ameliorated obesity induced by a HFD in rats.
Aged black garlic 3T3-L1 preadipocytes Exhibited anti-lipogenic and lipolytic effects.  


2.Effects of Black Garlic on Genitourinary Tract Diseases

BG has also demonstrated an intriguing capacity to alleviate symptoms associated with a variety of genitourinary diseases. Only a few research have examined the role of aged garlic extract in the treatment of kidney disorders, more precisely those caused by glomerular, tubulo-interstitial, or infectious pathologies. Albrakati et al. studied the effect of the aged black extract on chronic kidney disease and found that aged garlic extract rescued ethephon-induced kidney damage through the activation of nuclear factor erythroid 2–related factor 2 and inhibition of inflammation and apoptotic response. Another study performed by Lee et al. on acute kidney injury in rats, showed very promising results when treated with aged black garlic extract. Treatment with aged black garlic extract prevented deterioration of renal function monitored by standardized biomarkers such as the serum levels of creatinine and blood urea nitrogen. Levels of oxidative stress markers such as 8-hydroxydeoxyguanosine, malondialdehyde, NF-κβ, inducible nitric oxide (NO) synthase, cyclooxygenase-2 (COX-2), and transforming growth factor-beta 1 (TGF-β1) were lower in the aged black garlic.


3.Effects of Black Garlic on Liver Diseases

Numerous substances, including dietary components, drugs, alcohols, and pollutants, can cause acute and/or chronic liver diseases, such as liver fibrosis, non-alcoholic liver disease, non-alcoholic steatohepatitis, and even cirrhosis. Black Garlic has been widely investigated for its hepatoprotective properties (Table 5). In Wister rats with CCl4-induced liver injury, the administration of Black garlic extract was found to show a hepatoprotective effect based on the protection against oxidative damage. The levels of SOD, GSH-Px were decreased with an increase in the levels of alanine transaminase (ALT), aspartate transaminase (AST), lactate dehydrogenase, and alkaline phosphatase (ALP). In another study, Tsai et al. demonstrated that the administration of SAC and polysaccharides enriched-Black garlic extract into ICR mice inhibited CCl4-induced hepatic injury by inhibiting lipid peroxidation and inflammation

Products Subjects/Cell Line/Animal Model Outcomes
Aged garlic C57BL/6 mice Modulation of glycometabolism, lipometabolism,oxidative stress, and inflammation.
Black garlic (BG) Wister rats BG protected against oxidative damage caused by CCl4 -induced liver injury.
Lactic acid-fermented garlic Wister rats Protected against, oxidative liver injury.
Fermented black garlic C57BL/6J mice Improved the effects on fatty liver.
Black garlic ICR mice Inhibited CCl4-induced hepatic injury by inhibiting lipid peroxidation and inflammation.
Aged black garlic Sprague-Dawley rats Exhibited protective effects against chronic alcohol-induced liver damage.
Aged black garlic Sprague-Dawley rats Showed hepatoprotective effects against liver injury.


4.Effects of Black Garlic on Cardiovascular System Diseases. (click for more information)