Effective profile and therapeutic evidence of black garlic extract

July 01, 2025from Patrick Linder

Black garlic extract is obtained from fresh garlic (Allium sativum) through a long fermentation process at controlled temperature and humidity. During this process, the transformation of components creates special bioactive compounds that differ in composition and effect from those of regular garlic.

Production and chemical transformation

Fresh garlic is aged fermentatively for 3–6 weeks at 60–90 °C and 70–90% humidity. During this process, Maillard reactions occur, which lower the pH value and turn the white cloves deep black. Allicin almost completely decomposes during this process; at the same time, stable, water-soluble sulfur compounds such as S-allyl-cysteine (SAC) are formed. as well as phenolic antioxidants and melanoidins.

Key active ingredients

Connection	Structure/Source	Main functions	Special features
Alliin (S-allyl-L-cysteine sulfoxide)	of course in whole garlic	stable, odorless pro-molecule	Substrate of alliinase; starting point for allicin
Allicin (Diallyl thiosulfinates)	alliin is produced after cell injury	Strongly antimicrobial, short-lived radical scavenger	unstable, irritating; &<0.1% in black garlic
S-allyl-cysteine (SAC)	allicin is formed during the “aging” process	antioxidant, anti-inflammatory, H₂S and NO modulator	high oral bioavailabilityüfeasibility (≈ 98%)

Therapeutic applications – clinical evidence

cardiovascular system

A triple-blind RCT with 81 patients with stage I hypertension investigated 250 mg of a standardized black garlic extract (ABG10).⁺, 0.25 mg SAC) üover 12 weeks. Systolic and diastolic blood pressure decreased by 1.8 mmHg and 1.5 mmHg respectively compared to placebo; at the same time, plasma NO and total antioxidant capacity increased, while ACE activity and uric acid decreased.The tolerability was excellent.

Lipid metabolism

In a double-blind RCT with 60 subjects with mild hypercholesterolemia, a 12-week supplementation of 6 g aged black garlic/day increased HDL cholesterol was significantly reduced, and apolipoprotein B as well as the LDL-C/ApoB ratio were lowered., without relevant side effects. Animal studies confirm the lipid-lowering effect through down-regulation of SREBP-1c, ACC and HMG-CoA reductase.

Glycemic control

Preclinical studies on diabetic Wistar rats showed that 25 days of black garlic extract reduces fasting blood sugar by ≈ 90% and LDL-C by &80% reducedHuman studies on glucose control are still pending.

Neuroprotection

SAC behaved In vitro, as an H₂S donor, it stimulated eNOS phosphorylation and reduced ROS load in endothelial cells.In rat models, black garlic extract prevented both acrylamide-induced neuronal apoptosis and MSG-related working memory deficits.

Anti-inflammatory properties and antioxidant cell protection

Several in-vitro- and animal studies confirm a Inhibition of NF-κB, COX-2, iNOS, TNF-α and IL-6 by SAC-rich fractions; simultaneously, endogenous antioxidants (SOD, GSH-Px) increase. These effects underpin the cardioprotective and potentially chemopreventive properties.

Overview of human studies on black garlic extract

Indication/Subjects	Preparation (SAC content)	Length of time	Main result
Stage I hypertension (n = 81)	250 mg ABG10⁺ (0.25 mg SAC)	12 weeks	SBP − 1.8 mmHg; DBP − 1.5 mmHg; ↑NO; ↓ACE
Mild hypercholesterolemia (n = 55)	2 × 3 g aged BG (SAC ≙ ≈1 mg)	12 weeks	↑HDL-C (+5%), ↓ApoB (−7%)

SBP = systolic, DBP = diastolic blood pressure; all changes vs. placebo.

Pharmacological mechanisms

Antioxidant potential: SAC, polyphenols and melanoidins neutralize free radicals and reactivate endogenous defense systems (SOD, CAT).
Gasotransmitter modulation (d.h. Regulation of the activity of gasotransmitters – these are small, gaseous molecules involved in cell communication): SAC releases H₂S, increases eNOS activity and boosts NO bioavailability – which explains the positive vasodilatory effects (widening of blood vessels).
Renin-angiotensin system: Inhibition of ACE activity contributes to lowering blood pressure.
Lipid metabolism: Inhibition of SREBP-1c-dependent lipogenesis steps and HMG-CoA reductase reduces TG and cholesterol.
NF-κB blockade: Sulfur-containing compounds dampen pro-inflammatory signaling pathways.

Dosage, safety and tolerability

Clinical trials used daily doses between 250 mg and 600 mg standardized extract (≈ 0.25-0.6 mg SAC) and 6 g of non-standardized aged black garlicOdor and stomach irritation effects do not occur due to the breakdown of allicin; interactions with anticoagulants have not been reported to date.

Conclusion

Black garlic extract offers benefits due to its high concentration of the stable active ingredient. S-allyl-cysteine as well as other organic sulfur metabolites Clinically proven potential for blood pressure and lipid controlPreclinical data suggest additional neuroprotective and antidiabetic benefits.

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Effective profile and therapeutic evidence of black garlic extract

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