S-Allyl-L-Cysteine(SAC)

What is S-Allyl-L-cysteine?
S-Allyl L-cysteine (SAC), according to Wikipedia, is a sulfur containing amino acid that is a natural constituent of fresh garlic. It is a derivative of the amino acid cysteine in which an allyl group has been added to the sulfur atom. However, there are far more S-Allyl-L-cysteine in fermented black garlic than fresh garlic.

Source of S-Allyl-L-cysteine
S-Allyl L-cysteine is found to be in fresh white garlic and aged black garlic. Researchers have found that black garlic has twice the antioxidants of fresh garlic, which appears to also be a result of the curing process. You may not able to find S-Allyl-L-cysteine in other sources except fresh white garlic and aged black garlic. However, Black garlic has a higher concentration of s-allycycteine (SAC), which is thought to play a major role in its overall health benefits. S-Allylmercaptocysteine (SAMC) also has the same effects, while S-Allyl-L-cysteine is more stable, safer and better enteric solubility. Allyl cysteine is currently being investigated as a potential cholesterol lowering agent and as a chemopreventive. Studies have shown numerous healthful properties of SAC including helping to lower cholesterol and decrease the risk of cancer.

Mechanism of action of S-Allyl-L-cysteine
How does S-Allyl-L-cysteine work? There is no so much information out there for reference. We will update the latest information for S-Allyl-L-cysteine ingredient. The data for S-Allyl-L-cysteine available is as follow: during aging process, unstable compounds of fresh garlic including alliin are converted into stable compounds including s-allyl cysteine (SAC), the water-soluble compound with potent antioxidant effect. It was reported that aged black garlic showed stronger antioxidant activity in vitro than garlic. In the previous study, we reported that consumption of diet containing 5% aged black garlic improved insulin resistance, decreased serum total cholesterol and triglyceride, and increased HDL-cholesterol levels in db/db mice. Therefore, aged black garlic could be more useful than garlic in prevention of diabetic complications.

S-Allyl-L-cysteine works as an antioxidant agent: Inhibits reperfusion-induced HIF-1α, VEGF, and MMP-9 upregulation. Shows selective neuroprotective effects against amyloid β-protein-induced cell death. Shows anti-ischemic effects in vivo. Orally active.

Health Benefits of S-allyl cysteine (SAC)
S-allyl-L-cysteine is exclusively found in fermented black garlic extract and fresh garlic with antioxidant, anti-cancer, anti-hepatotoxic, neuro-protective and neurotrophic activity. S-allyl-L-cysteine has potent activity in several animal models of ischemic injury and Alzhemer′s disease.

S-allyl-L-cysteine (SAC) on blood glucose
Strong evidence found that fresh garlic lowers blood glucose. In the study to evaluate the possible protective effects of S-allyl cysteine (SAC) on the antioxidant defense system of pancreas in streptozotocin(STZ) induced diabetes in rats by Bharathiyar University, Coimbatore, Tamilnadu, indicated that tlevels of glucose, TBARS and enzymatic antioxidants were altered in diabetic rats. These alterations were reverted back to near control levels after the treatment of SAC. The antidiabetic and antioxidant effect of SAC was compared with glyclazide, a well-known hypoglycemic drug

S-allyl-L-cysteine as a garlic-derived antioxidant
In the study to evaluate the effect of a garlic-derived compound and well-characterized free radical scavenger, S-allylcysteine, on quinolinic acid-induced striatal neurotoxicity and oxidative damage, by Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, showed that administration of 300 mg/kg of this compound to rats decreased effectively the quinolinic acid-induced oxidative injury measured as striatal reactive oxygen species formation (P < 0.01) and lipid peroxidation (P < 0.05). S-Allylcysteine (300 mg/kg) also prevented the striatal decrease of copper/zinc-superoxide dismutase activity (P < 0.05) produced by quinolinate. In addition, S-allylcysteine, at the same dose tested, was able to reduce the quinolinic acid-induced neurotoxicity evaluated as circling behavior (P < 0.01) and striatal morphologic alterations. In summary, S-allylcysteine ameliorates the in vivo quinolinate striatal toxicity by a mechanism related to its ability to: (a) scavenge free radicals; (b) decrease oxidative stress; and (c) preserve the striatal activity of Cu,Zn-superoxide dismutase (Cu,Zn-SOD)

S-allyl-L-cysteine and diabetes
Iron may play a role in the pathogenesis of diabetes. In the study to investigate the effects of S-allylcysteine (SAC), a sulphur containing amino acid derived from garlic on the changes in iron metabolism induced by oxidative stress in tissues, as well as on serum biochemical parameters of streptozotocin (STZ)-induced diabetic rats by the Centre for Biological Science, K.S. Rangasamy College of Arts and Science, found that S-allylcysteine could have a protective effect against alterations in oxidative stress induced iron metabolism in the diabetic state which was evidenced by the capacity of this natural antioxidant to modulate parameters of iron metabolism.
S-allyl-L-cysteine (SAC) inhibits Oral tumour progression
Studies have indicated that an increase in the osteopontin (OPN) plasma level is correlated with the progression of oral cancer. According to the study by the Taipei Medical University, the SAC-mediated suppression of cyclin D1 protein was associated with an augmented expression of the cell-cycle inhibitor p16(Ink4). Furthermore, SAC inhibited the expression of cyclo-oxygenase-2, vimentin and NF-κB p65 (RelA).

S-Allylcysteine (SAC) antihypertensive and cardioprotective effects
In the study to investigate the role of fresh garlic homogenate (FGH) and its bioactive sulphur compound S-allyl cysteine sulphoxide (SACS) in potentiating antihypertensive and cardioprotective activities of captopril in rats, showed that combined therapy of garlic (250 mg/kg) with captopril(CAP) demonstrated higher synergistic action than combination of SACS (0.222 mg/kg) with CAP suggesting the role of additional bioactive constituents apart from SACS, responsible for therapeutic efficacy of garlic. Moreover, combination of SACS and CAP exerted super-additive (synergistic) interaction with respect to fall in blood pressure and ACE inhibition.