The study demonstrates that alliin modulates MAPK (ERK1/2, JNK, p38) phosphorylation, PPARγ activation, and downstream NF-κB/AP-1/STAT-1 signaling pathways. [2]

In LPS-stimulated RAW264.7 macrophages, alliin (10, 25, 50, 100 μg/mL, 4 h pretreatment) dose-dependently inhibited the mRNA expression of iNOS, TNF-α, IL-1β, and IL-6. The inhibitory effect was also time-dependent (2, 4, 6, 12 h pretreatment with 100 μg/mL alliin followed by 12 h LPS stimulation). [2]
Alliin (10, 25, 50, 100 μg/mL) dose-dependently inhibited NO production in LPS-stimulated RAW264.7 cells, with a time-dependent effect observed at 100 μg/mL. [2]
Alliin (100 μg/mL, 6 h pretreatment) significantly reduced the protein expression of iNOS, TNF-α, IL-1β, and IL-6 in LPS-stimulated RAW264.7 cells. [2]
Alliin (10, 25, 50, 100 μg/mL, 6 h pretreatment) suppressed LPS-induced phosphorylation of ERK1/2, JNK, and p38 MAPK in a dose-dependent manner. [2]
Using MAPK inhibitors (SP600125 for JNK, SB203580 for p38, U0126 for ERK1/2), the study demonstrated that alliin blocked JNK/ERK1/2-mediated PPARγ phosphorylation and activation, and suppressed NF-κB/AP-1/STAT-1 nuclear translocation through inhibition of MAPK pathways. [2]

In DSS-induced colitis mice, oral administration of alliin (500 mg/kg, intragastric, daily for 17 days) significantly ameliorated disease symptoms: prevented body weight loss (from 45.82 ± 1.24 g to 44.51 ± 1.88 g on day 10, p < 0.01 vs. DSS group), reduced disease activity index (DAI) score (from 4.7 ± 0.80 to 3.88 ± 0.70, p < 0.01), decreased hematochezia (from 70% to 50%) and diarrhea (from 90% to 50%) incidence. [2]
Alliin significantly increased colon length (from 9.00 ± 1.16 cm to 10.44 ± 0.65 cm, p < 0.01) and decreased spleen weight (from 0.31 ± 0.07 g to 0.17 ± 0.03 g, p < 0.01) compared to DSS-treated mice. [2]
Histological analysis showed that alliin significantly reduced colonic epithelial erosion, crypt damage, and inflammatory cell infiltration. [2]
Alliin significantly reduced colonic MPO activity (from 17.67 ± 2.52 to 11.17 ± 1.68 nmol/mg protein, p < 0.01), MDA level (from 8.77 ± 1.29 to 6.02 ± 0.96 nmol/mg, p < 0.01), and NO content (from 51.07 ± 8.10 to 42.68 ± 5.40 mU/mg protein, p < 0.05) compared to DSS-treated mice. [2]
Alliin suppressed the mRNA and protein expression of iNOS, TNF-α, IL-1β, and IL-6 in colonic tissues, and inhibited the phosphorylation of ERK1/2, JNK, p38 MAPK, and PPARγ (Ser112). [2]

MPO activity assay: Colon tissues (50 mg) were homogenized in 500 μL PBS (80 mM, pH 5.4) with 0.5% cetrimonium bromide, centrifuged at 12,000 rpm for 20 min at 4°C. Supernatant (100 μL) was mixed with 150 μL TMB, 50 μL H₂O₂ (300 mM), and 250 μL PBS, incubated for 30 min at 25°C. Reaction was terminated with 2.5 mL H₂SO₄ (200 mM) and absorbance read at 450 nm. [2]
MDA assay: Colon tissues (100 mg) were homogenized in 1 mL cold PBS (80 mM, pH 5.4). After protein quantification by BCA, the suspension was mixed with 1 mL 0.67% thiobarbituric acid and 1.0 mL 25% trichloroacetic acid, heated to 95°C for 45 min, centrifuged at 12,000 rpm for 20 min at 4°C, and supernatant absorbance read at 535 nm. [2]
NO assay: Colon tissues (50 mg) were homogenized in 200 μL PBS. After mixing with methanol and centrifugation (3,000 rpm, 10 min, 4°C), 100 μL supernatant was mixed with 100 μL vanadium trichloride, 50 μL sulfa, and 50 μL N-(1-naphthyl)ethylenediamine dihydrochloride, incubated for 30 min at 37°C, and absorbance read at 540 nm. For cell culture, 100 μL supernatant was mixed with 100 μL Griess reagent and incubated for 10 min, with absorbance read at 550 nm. [2]

MTS cell viability assay: RAW264.7 cells were seeded in 96-well plates (6-8 × 10⁴ cells/well), treated with alliin for 4 h, then with LPS (1 μg/mL) for 12 h. MTS (20 μL) was added and incubated for 2 h, with absorbance measured at 490 nm. [2]
qRT-PCR: Total RNA was extracted using Trizol Up, reverse transcribed to cDNA, and mRNA expression of iNOS, TNF-α, IL-1β, and IL-6 was measured using SYBR Green real-time PCR with β-actin as internal control. Relative expression was calculated using the 2⁻ΔΔCt method. [2]
Western blotting: Cells were lysed in RIPA buffer with protease and phosphatase inhibitors. Protein lysates (50 μg) were separated by SDS-PAGE, transferred to PVDF membranes, blocked with 5% BSA, and probed with primary antibodies overnight at 4°C, followed by HRP-conjugated secondary antibodies. Chemiluminescence was used for detection. [2]
Nuclear/cytoplasmic fractionation: Cells were processed using a nuclear and cytoplasmic protein extraction kit according to manufacturer’s instructions to analyze NF-κB p65, AP-1 (c-Jun), and STAT-1 nuclear translocation. [2]

Animals: Male ICR mice (10-week-old) were used. Mice were housed under standard conditions (21 ± 2°C, 12/12 h light/dark cycle) with ad libitum access to food and water. [2]
DSS colitis model: Mice were randomly divided into 4 groups (n = 18/group): control, alliin only (500 mg/kg), DSS-treated, and DSS + alliin (500 mg/kg). Alliin was administered intragastrically daily for 7 days before DSS treatment and continued throughout the experiment. Colitis was induced by oral administration of 2% DSS in drinking water for 7 days, repeated twice over a 17-day total experimental period. Control groups received 0.5 mL normal saline per mouse. [2]
Tissue collection: After 12 h fasting, mice were sacrificed; colons and spleens were removed, measured, and stored at -80°C or fixed in 4% paraformaldehyde for histology. [2]
Histopathology: Colon tissues were fixed in 4% paraformaldehyde, embedded in paraffin, sectioned at 5 μM, and stained with hematoxylin and eosin (H&E) for microscopic examination. [2]
Disease activity index (DAI) was assessed based on stool consistency and hematochezia scoring. [2]

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Animals: Male ICR mice (10-week-old) were used. Mice were housed under standard conditions (21 ± 2°C, 12/12 h light/dark cycle) with ad libitum access to food and water. [2]
DSS colitis model: Mice were randomly divided into 4 groups (n = 18/group): control, alliin only (500 mg/kg), DSS-treated, and DSS + alliin (500 mg/kg). Alliin was administered intragastrically daily for 7 days before DSS treatment and continued throughout the experiment. Colitis was induced by oral administration of 2% DSS in drinking water for 7 days, repeated twice over a 17-day total experimental period. Control groups received 0.5 mL normal saline per mouse. [2]
Tissue collection: After 12 h fasting, mice were sacrificed; colons and spleens were removed, measured, and stored at -80°C or fixed in 4% paraformaldehyde for histology. [2]
Histopathology: Colon tissues were fixed in 4% paraformaldehyde, embedded in paraffin, sectioned at 5 μM, and stained with hematoxylin and eosin (H&E) for microscopic examination. [2]
Disease activity index (DAI) was assessed based on stool consistency and hematochezia scoring. [2]

Alliin at concentrations of 0 to 160 μmol/L showed no cytotoxicity in HepG2 cells. At concentrations of 320 μmol/L and above, cell viability was significantly decreased (p < 0.01). [1]

[1]. Alliin attenuates 1, 3-dichloro-2-propanol-induced lipogenesis in HepG2 cells through activation of the AMP-activated protein kinase-dependent pathway. Life Sci. 2018 Feb 15;195:19-24.

[2]. Alliin, a garlic organosulfur compound, ameliorates gut inflammation through MAPK-NF-κB/AP-1/STAT-1 inactivation and PPAR-γ activation. Mol Nutr Food Res. 2017 Sep;61(9).

(R)C(S)S-alliin is an α-amino acid. 2-Z-3-prop-2-enylsulfinylpropionate has been reported in garlic (Allium sativum), and relevant data are available. See also: 3-(allylsulfinyl)-L-alanine (note moved to).

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Alliin ((+)-S-allyl-L-cysteine sulfoxide) is an organosulfur compound naturally occurring in garlic (Allium sativum) and other Allium species. It is the most original and important sulfur compound in garlic, with content of 7.23 ± 0.01 mg/g in garlic. Alliin is stable with no specific odor, unlike its enzymatic conversion product allicin. This study demonstrates that alliin exerts anti-inflammatory effects in DSS-induced colitis mice and LPS-stimulated RAW264.7 macrophages by inhibiting the phosphorylation of ERK1/2, JNK, and p38 MAPK, thereby suppressing PPARγ activation and downstream NF-κB/AP-1/STAT-1 signaling pathways, leading to reduced expression of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, iNOS) and NO production. These findings suggest alliin as a potential candidate for adjuvant therapy of inflammatory bowel disease. [2]

C6H11NO3S

177.218

177.045

556-27-4

121922

White to off-white solid powder

1.4±0.1 g/cm3

416.1±45.0 °C at 760 mmHg

165ºC

205.5±28.7 °C

0.0±2.1 mmHg at 25°C

1.579

-0.48

2

5

5

11

181

0

S(C([H])([H])C([H])=C([H])[H])(C([H])([H])C([H])(C(=O)O[H])N([H])[H])=O

XUHLIQGRKRUKPH-UHFFFAOYSA-N

InChI=1S/C6H11NO3S/c1-2-3-11(10)4-5(7)6(8)9/h2,5H,1,3-4,7H2,(H,8,9)

2-amino-3-prop-2-enylsulfinylpropanoic acid

EINECS 209-118-9 Alliin S-Allyl-L-cysteine-S-oxide

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: This product requires protection from light (avoid light exposure) during transportation and storage.

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

H2O : ~250 mg/mL (~1410.68 mM)
DMSO :< 1 mg/mL

Solubility in Formulation 1: 100 mg/mL (564.27 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with sonication.

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