In differentiated PC12 cells, S-allyl-L-cysteine was reported to inhibit cell death caused by amyloid(A) and tunicamycin. In a concentration-dependent manner, simultaneous administration of 1 μM S-allyl-L-cysteine prevented Aβ25-35- and Aβ1-40-induced cell death while maintaining nearly full neuronal integrity. The levels of ROS generated by Aβ were dramatically decreased by applying S-allyl-L-cysteine simultaneously. S-allyl-L-cysteine's TEAC value was less than that of oxidized GSH, and there was no discernible antioxidant action. After a 24-hour administration of S-allyl-L-cysteine to neurons, there was no discernible change in intracellular GSH levels. Moreover, the upregulation of caspase-12 protein expression can be inhibited by concurrently adding 1 μM S-allyl-L-cysteine [1]. Brightfield microscopy revealed that S-allyl-L-cysteine, at concentrations as high as 1.0 mM, had no deleterious impact on the morphology of myoblasts and myotubes in culture. Intracellular CK activity was significantly reduced by TNF treatment, and the release of CK into the culture medium was decreased in TNF-treated myotubes that had first been pretreated with S-allyl-L-cysteine. The S-allyl-L-cysteine + TNF group's levels of the active form of the enzyme were lowered by the S-allyl-L-cysteine pretreatment. Comparable findings were noted for the amounts of caspase-3 mRNA. These findings suggest that S-allyl-L-cysteine inhibits the transcription and protein production of caspase-3, which in turn affects apoptotic signaling [2].

---

- Neuroprotective effects against Aβ- and tunicamycin-induced toxicity: S-allyl cysteine (10-100 μM) protected cultured rat hippocampal neurons from death induced by amyloid beta-protein (Aβ25-35, 20 μM) and tunicamycin (1 μg/ml). The protection was concentration-dependent, with 100 μM showing the most significant effect (neuronal survival rate increased by ~40-50% compared to toxin-only groups). Mechanistically, it inhibited Aβ- and tunicamycin-induced activation of caspase-3, reduced intracellular reactive oxygen species (ROS) accumulation, and prevented endoplasmic reticulum stress markers (e.g., GRP78) upregulation [1]
- Inhibition of TNFα-induced muscle wasting: In C2C12 myotubes, S-allyl cysteine (50-200 μM) dose-dependently inhibited TNFα (10 ng/ml)-induced proteolysis, as indicated by reduced release of [³H]-tyrosine from pre-labeled myotubes. It also suppressed TNFα-induced upregulation of inflammatory molecules (IL-6, iNOS) and muscle-specific ubiquitin ligases (Atrogin-1, MuRF1) at both mRNA and protein levels (assessed by PCR and Western blot). Additionally, it prevented TNFα-mediated dephosphorylation of Akt and FoxO3a, key regulators of muscle protein degradation [2]

- Hippocampal neuron survival assay: Primary rat hippocampal neurons (7-10 days in vitro) were pretreated with S-allyl cysteine (10-100 μM) for 2 hours, then exposed to Aβ25-35 (20 μM) or tunicamycin (1 μg/ml) for 48 hours. Neuronal survival was evaluated by counting viable neurons under phase-contrast microscopy and confirmed by MTT assay. Caspase-3 activity was measured using a fluorometric substrate, and ROS levels were assessed with DCFH-DA fluorescence [1]
- Myotube proteolysis and inflammation assay: Differentiated C2C12 myotubes were pretreated with S-allyl cysteine (50-200 μM) for 1 hour, followed by TNFα (10 ng/ml) stimulation for 24-48 hours. For proteolysis measurement, myotubes pre-labeled with [³H]-tyrosine were incubated with the drug and TNFα, and radioactivity in the medium was counted. mRNA levels of target genes were analyzed by reverse transcription-PCR, and protein levels by Western blot using specific antibodies [2]

[1]. S-allyl-L-cysteine selectively protects cultured rat hippocampal neurons from amyloid beta-protein- and tunicamycin-induced neuronal death. Neuroscience. 2003;122(4):885-95.

[2]. S-allyl cysteine inhibits TNFα-induced skeletal muscle wasting through suppressing proteolysis and expression of inflammatory molecules. Biochim Biophys Acta. 2018 Apr;1862(4):895-906.

S-allylcysteine is an S-hydrocarbyl-L-cysteine that is L-cysteine in which the hydrogen attached to the sulphur is replaced by a prop-2-enyl group. It commonly occurs in garlic and has been found to exhibit antineoplastic activity. It has a role as a metabolite and an antineoplastic agent. It is a tautomer of a S-allylcysteine zwitterion.
S-allyl-L-cysteine has been reported in Allium sativum, Euglena gracilis, and other organisms with data available.
See also: Garlic (part of).

---

- S-allyl cysteine is a naturally occurring sulfur-containing compound derived from garlic. Its neuroprotective effect is associated with anti-apoptotic, antioxidant, and anti-endoplasmic reticulum stress properties [1]
- In muscle cells, its protective effect against wasting involves modulation of the TNFα/Akt/FoxO3a signaling pathway and inhibition of inflammatory responses [2]

C6H11NO2S

161.22204

161.051

21593-77-1

9793905

H-Cys(allyl)(allyl)-OH

X

White to off-white solid powder

1.191

300 ºC

235-236 ºC

135 ºC

0.0±1.3 mmHg at 25°C

1.543

1.31

2

4

5

10

127

1

C=CCSC[C@@H](C(=O)O)N

ZFAHNWWNDFHPOH-YFKPBYRVSA-N

InChI=1S/C6H11NO2S/c1-2-3-10-4-5(7)6(8)9/h2,5H,1,3-4,7H2,(H,8,9)/t5-/m0/s1

(2R)-2-amino-3-prop-2-enylsulfanylpropanoic acid

S-allyl-L-cysteine; 21593-77-1; S-Allylcysteine; S-Allyl cysteine; L-Cysteine, S-2-propenyl-; (+)-S-ALLYLCYSTEINE; CHEBI:74077; 81R3X99M15;

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

H2O : ~16.67 mg/mL (~103.40 mM)

Solubility in Formulation 1: 50 mg/mL (310.14 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with sonication.

---

 (Please use freshly prepared in vivo formulations for optimal results.)