S-Allylcysteine — SAC (Organosulfur Cysteine Derivative · Aged Garlic · Neuroprotective)
| Compound | S-Allylcysteine (SAC) |
| Chemical class | Organosulfur — Cysteine Derivative (S-Allyl-L-cysteine) |
| CAS | 37921-38-3 |
| Primary source | Allium sativum (aged garlic bulb) — primary bioactive of aged garlic extract (AGE) |
| Key applications | Neuroprotective, cardiovascular, antioxidant, anti-inflammatory, hepatoprotective |
| Claim strength | Moderate |
| Typical form | Aged garlic extract (AGE); SAC isolate; Kyolic® type preparations |
| Buy from Herbuno | Request availability and bulk pricing → |
Name origin: S-allyl (the allyl group attached to the sulfur) + cysteine (the amino acid). SAC is formed from alliin during the prolonged aging of garlic in aqueous ethanol — alliinase converts alliin to allicin which then undergoes further reactions including conversion to SAC and S-allylmercaptocysteine (SAMC) under mild conditions over months. SAC is the primary and most pharmacologically studied bioactive in aged garlic extract (AGE, best known commercially as Kyolic®). Traditional use: Aged garlic preparations have been used in Japanese traditional medicine and food culture for centuries. The specific health benefits associated with long-aged garlic (improved cardiovascular health, enhanced immune function, longevity) are consistent with the SAC-enriched profile of AGE compared to fresh garlic. Research trajectory: SAC has an extensive research database covering: cardiovascular (blood pressure, cholesterol, atherosclerosis), neuroprotective (Alzheimer’s disease models, cognitive function), antioxidant, anti-inflammatory, hepatoprotective, and anticancer mechanisms. Multiple human RCTs specifically with AGE (Kyolic-type preparations) have been conducted — with SAC as the primary standardisation marker. Unlike allicin, SAC is stable, odourless, and has excellent oral bioavailability (~98% absorption in animal studies). Commercial source: SAC from aged garlic is not currently available as a standalone extract at commercial supplement scale from Herbuno. Contact Herbuno for availability assessment.
Evidence for SAC Applications
Cardiovascular — blood pressure and atherosclerosis: Multiple human RCTs with AGE preparations (Kyolic-type, 1,200–2,400 mg/day) demonstrate significant blood pressure reduction (comparable to allicin-based garlic preparations, approximately 5 mmHg systolic) and significant slowing of coronary artery calcium score progression (a measure of atherosclerosis). The Budoff et al. 2016 RCT (n=55, statin-treated patients) showed significant reduction in CAC progression with AGE + CoQ10 + vitamins B1/B6/B12/C/E. Claim strength: Moderate (multiple AGE RCTs; SAC as marker).
Neuroprotective — Alzheimer’s disease models: SAC reduces amyloid-beta toxicity, inhibits beta-secretase (BACE1 — the enzyme producing amyloid-beta), and reduces neuroinflammation in AD animal models. SAC increases glutathione in brain tissue and protects dopaminergic neurons in Parkinson’s models. Relevant for cognitive health and neuroprotective supplement positioning. Claim strength: Moderate (convergent preclinical; human data from AGE studies).
Antioxidant: SAC directly scavenges reactive oxygen species and induces Nrf2-mediated antioxidant enzyme upregulation. It increases intracellular glutathione (GSH) levels — the primary endogenous antioxidant. Human studies with AGE show increased plasma antioxidant capacity and reduced lipid peroxidation markers. Claim strength: Moderate.
Hepatoprotective: SAC protects against alcohol-induced liver damage, CCl4-induced liver injury, and NAFLD in animal models via antioxidant mechanisms and reduction of hepatic lipid peroxidation. Relevant for liver health supplement formulations. Claim strength: Moderate.
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Dosage & Formulator Specification
AGE human RCT doses: 1,200–2,400 mg/day Kyolic®-type AGE, standardised to SAC content. SAC content in commercial AGE: typically 0.1–0.5 mg SAC per 100 mg extract (1–5 mg SAC per 1,200 mg AGE daily dose). For isolated SAC applications, 5–20 mg/day SAC is a working extrapolation from AGE clinical doses. SAC has excellent oral bioavailability and stability — unlike allicin, it does not require special formulation for absorption. No pungency, no garlic breath (odourless) — palatability advantage for long-term supplementation. Contact Herbuno for SAC extract availability and specification.
Frequently Asked Questions — S-Allylcysteine
What is the difference between allicin and SAC as garlic bioactives?
Allicin (diallyl thiosulfinate) and SAC (S-allylcysteine) represent two completely different garlic pharmacological profiles: Fresh garlic / allicin — potent, immediate, volatile, pungent, unstable, antimicrobial-dominant, short-lived. Aged garlic / SAC — mild, stable, odourless, excellent bioavailability, antioxidant and neuroprotective-dominant, sustained. Fresh garlic preparations are preferred for antimicrobial applications; aged garlic (SAC-enriched) is preferred for long-term cardiovascular, neuroprotective, and antioxidant supplementation where palatability and stability are priorities.
Is SAC the reason aged garlic doesn’t have garlic smell?
Yes — the aging process converts allicin (the primary odour compound, along with its degradation products diallyl disulfide and diallyl trisulfide) to odourless water-soluble organosulfur compounds including SAC, SAMC, and allixin. The prolonged aqueous ethanol aging environment (typically 20 months for Kyolic®) allows enzymatic and chemical conversion of volatile allicin-derived compounds to stable, non-volatile SAC. This is why AGE can be taken as an odourless supplement without social concerns about garlic breath.
Can SAC cross the blood-brain barrier?
Yes — SAC has documented blood-brain barrier penetration in animal pharmacokinetic studies. After oral SAC administration, SAC is detected in brain tissue including hippocampus, cortex, and cerebellum. This CNS penetration is the basis for SAC’s documented neuroprotective activity in AD and PD animal models and positions SAC as a genuine neuroactive compound, not just a peripheral antioxidant. The amino acid structure of SAC (cysteine derivative) may facilitate brain uptake via amino acid transporters.
Can SAC be combined with CoQ10 for cardiovascular protection?
Yes — this combination is supported by a human RCT. The Budoff et al. 2016 trial used aged garlic extract (2,400 mg/day, SAC-standardised) + CoQ10 (100 mg/day) + B vitamins and antioxidants, demonstrating significant reduction in coronary artery calcium score progression in statin-treated patients. SAC and CoQ10 address complementary cardiovascular mechanisms: SAC for endothelial antioxidant protection and anti-atherosclerotic activity; CoQ10 for mitochondrial energy production in cardiac muscle and statin-induced CoQ10 depletion compensation. The combination is mechanistically rational and clinically supported.
Related compounds: Allicin, Alliin, Diindolylmethane, Sulforaphane
Claim-strength scale – High = multiple human RCTs; Moderate = limited trials or strong preclinical convergence; Emerging = early-stage lab or animal data.
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