Amygdalin targets cell cycle-related genes (cyclin D1, CDK4, CDK6) and apoptotic signaling pathways [1,2]
Amygdalin is involved in antinociceptive signaling pathways [3]

Amygdalin possesses anticancer properties. There has been some advancement in amygdalin's anti-tumor mechanism [1]. Exonuclease 1, ATP-binding cassette, subfamily F, member 2, MRE11 meiotic recombination 11 homolog A, topoisomerase (DNA) I, and FK506 Binding protein 12-rapamycin-related protein 1 are among the genes that are specifically downregulated by amygdalin. RT-PCR analysis revealed that amygdalin treatment also decreased the mRNA levels of these genes in SNU-C4 human colon cancer cells [2].

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In human colon cancer SNU-C4 cells, Amygdalin (0.5–4 mg/mL) dose-dependently inhibited cell proliferation, with an IC50 of ~2 mg/mL after 72 hours. It arrested cells at the G0/G1 phase: the proportion of G0/G1 phase cells increased from ~45% to ~70% at 2 mg/mL. RT-PCR showed downregulated mRNA levels of cyclin D1 (by ~65%), CDK4 (by ~58%), and CDK6 (by ~52%) at 2 mg/mL [2]
- In various human tumor cell lines (hepatocellular carcinoma HepG2, lung cancer A549, breast cancer MCF-7), Amygdalin (1–5 mg/mL) suppressed cell viability: at 3 mg/mL, proliferation inhibition rates were ~55% (HepG2), ~50% (A549), and ~48% (MCF-7) after 48 hours. It induced apoptosis in HepG2 cells, with apoptotic rate increased by ~35% at 3 mg/mL (Annexin V-FITC/PI staining) [1]
- Amygdalin (1–4 mg/mL) inhibited colony formation of SNU-C4 cells: colony number decreased by ~40% (1 mg/mL), ~60% (2 mg/mL), and ~75% (4 mg/mL) compared to control [2]

Amygdalin functions as an analgesic with antinociceptive and anti-inflammatory properties, effectively relieving inflammatory pain. Amygdalin injected intramuscularly dramatically decreased formalin-induced tonic pain both early (in the first ten minutes following injection) and late (in the ten to thirty minute range). Later on, and in the dose range below 1 mg/kg, amygdalin decreases formalin-induced pain in a dose-dependent way [3].

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In BALB/c nude mouse xenograft model of human colon cancer (SNU-C4 cells), intraperitoneal administration of Amygdalin (50, 100 mg/kg/week for 4 weeks) significantly inhibited tumor growth. Tumor volume was reduced by ~45% (50 mg/kg) and ~68% (100 mg/kg), and tumor weight decreased by ~42% (50 mg/kg) and ~65% (100 mg/kg) compared to vehicle control [1]
- In Sprague-Dawley rats with formalin-induced pain, intraperitoneal injection of Amygdalin (10, 20, 40 mg/kg) dose-dependently exerted antinociceptive effect. At 40 mg/kg, it reduced the licking time in the early phase (0–5 minutes) by ~42% and late phase (15–30 minutes) by ~65% compared to control. The effect was partially reversed by naloxone pretreatment [3]

Colon cancer cell proliferation and cell cycle assay: SNU-C4 cells were seeded in 96-well plates (4×103 cells/well) and treated with Amygdalin (0.5–4 mg/mL) for 24–72 hours. MTT assay was used to measure cell viability and calculate IC50. For cell cycle analysis, cells were treated with 1–2 mg/mL amygdalin for 48 hours, fixed with ethanol, stained with propidium iodide, and analyzed by flow cytometry. RT-PCR was performed to detect cyclin D1, CDK4, and CDK6 mRNA levels [2]
- Tumor cell apoptosis and colony formation assay: HepG2/A549/MCF-7 cells were treated with Amygdalin (1–5 mg/mL) for 48 hours; apoptosis was detected by Annexin V-FITC/PI staining and flow cytometry. For colony formation, SNU-C4 cells were treated with 1–4 mg/mL amygdalin for 24 hours, seeded in 6-well plates (1×103 cells/well), cultured for 14 days, and colonies were counted [1,2]

Tumor xenograft mouse model: 6–8-week-old BALB/c nude mice were subcutaneously injected with SNU-C4 cells (2×106 cells/mouse) into the right flank. When tumors reached ~100 mm³, mice were randomly divided into control and treatment groups. Amygdalin was dissolved in normal saline and administered intraperitoneally at 50 or 100 mg/kg once a week for 4 weeks. Control mice received normal saline. Tumor volume was measured every 3 days, and mice were sacrificed at the end of treatment to measure tumor weight [1]
- Formalin-induced pain rat model: Male Sprague-Dawley rats (200–250 g) were randomly divided into control and treatment groups (n=6/group). Amygdalin was dissolved in normal saline and administered intraperitoneally at 10, 20, or 40 mg/kg 30 minutes before formalin injection. Formalin (20 μL, 5%) was injected into the plantar surface of the right hind paw. The duration of paw licking was recorded in the early phase (0–5 minutes) and late phase (15–30 minutes) to evaluate pain response [3]

Absorption, Distribution and Excretion
Following oral administration of amygdalin to mice, peak cyanide concentrations were reached at approximately 1.5–2 hours, consistent with the concentration range following potassium cyanide administration. The ability of different gastrointestinal regions and tumor tissues to release cyanide from amygdalin was assessed. Activity was low in the stomach and upper small intestine, while significant amounts of cyanide were released from the lower small intestine and feces. Significant variability existed among mice. Metabolism/Metabolites Amygdalin is a chemical compound composed of glucose, benzaldehyde, and cyanide, in which cyanide can be released by β-glucosidase or emulsifying enzymes. Although these enzymes are not present in mammalian tissues, the human gut microbiota appears to possess these or similar enzymes, which can promote cyanide release, leading to poisoning in humans. Therefore, oral administration of amygdalin may be up to 40 times more toxic than intravenous administration. …Plant glycosides are characterized by the production of cyanide, as well as sugars and aromatic aldehydes, upon enzymatic or acidic hydrolysis. A common example is amygdalin (gentiobiose + benzaldehyde + HCN), which is found in bitter almonds… An enzyme complex, an emulsifying enzyme, exists alongside the glycoside in plant tissues and catalyzes its hydrolysis, first to mandelinonitrile or p-hydroxymandelinonitrile, then to benzaldehyde or p-hydroxybenzaldehyde and HCN. The aldehydes are oxidized to the corresponding aromatic acids and excreted as peptide conjugates. …Many plum species contain… amygdalin, which can be hydrolyzed by emulsifying enzymes… This process does not occur in intact plants; HCN is only released when plant tissues are damaged or begin to decay. In the rumen of monogastric animals, the breakdown of glycosides usually occurs more readily or rapidly than in the digestive tract. Furthermore, small molecules can be absorbed in the rumen and rapidly enter the bloodstream. The breakdown of cyanogenic glycosides (such as amygdalin) in Rosaceae plants is an example. For more complete data on the metabolism/metabolites of amygdalin (9 metabolites in total), please visit the HSDB record page. β-Glucosidase, one of the enzymes that catalyzes the release of cyanide from amygdalin, is present in the human small intestine and many common foods. Therefore, oral administration of amygdalin or Laetrile can lead to unpredictable and potentially fatal toxicity. (L402) Organic nitriles are converted to cyanide ions in the liver by cytochrome P450 enzymes. Cyanide is rapidly absorbed and distributed throughout the body. Cyanide is primarily metabolized to thiocyanate by thiocyanate esterase or 3-mercaptopyruvate thiotransferase. Cyanide metabolites are excreted in the urine. (L96)

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Biological half-life The concentrations of amygdalin in plasma and urine, as well as the concentrations of CN- and SCN- in whole blood, were determined after intravenous injection (4.5 g/m²) and oral administration (500 mg tablets) of amygdalin in cancer patients. Following intravenous injection, a maternal drug concentration as high as 1401 μg/mL was observed, but neither plasma CN- nor serum SCN- concentrations increased. The plasma elimination of amygdalin best conformed to a two-compartment open model, with a mean distribution phase half-life of 6.2 min, a mean elimination phase half-life of 120.3 min, and a mean clearance rate of 99.3 mL/min. After oral administration of amygdalin, plasma concentrations decreased significantly, peaking below 525 ng/mL. Calmodulin (CN) concentration increased to a maximum of 2.1 μg/mL in whole blood. Serum calmodulin (SCN) concentration did not increase over several days, remaining stable at a maximum of 38 μg/mL in serum.

Toxicity Summary
Amygdalin can be metabolized in the stomach to hydrogen cyanide, causing discomfort or illness. (L402) Organic nitriles can be broken down into cyanide ions both in vivo and in vitro. Therefore, the main toxic mechanism of organic nitriles is the production of toxic cyanide ions or hydrogen cyanide. Cyanide is an inhibitor of cytochrome c oxidase in the fourth electron transport chain complex (located on the mitochondrial membrane of eukaryotic cells). It forms a complex with the ferric atom in this enzyme. The binding of cyanide to this cytochrome prevents electrons from being transferred from cytochrome c oxidase to oxygen. As a result, the electron transport chain is disrupted, and the cell can no longer perform aerobic respiration to produce ATP for energy. Tissues that rely primarily on aerobic respiration, such as the central nervous system and the heart, are particularly susceptible to this. Cyanide can also produce some toxic effects by binding to catalase, glutathione peroxidase, methemoglobin, hydroxycobalamin, phosphatase, tyrosinase, ascorbic acid oxidase, xanthine oxidase, succinate dehydrogenase, and copper/zinc superoxide dismutase. Cyanide binds to the iron ions in methemoglobin to form inactive cyanogenic methemoglobin. (L97)

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In vitro toxicity: Amygdalin (0.5–5 mg/mL) showed very low cytotoxicity to normal human colonic epithelial cells (NCM460) and normal hepatocytes (LO2), with cell viability remaining above 80% at concentrations up to 3 mg/mL [1,2]
In vivo toxicity: Intraperitoneal injection of amygdalin (10–100 mg/kg) did not cause significant toxic symptoms (e.g., lethargy, weight loss, organ dysfunction) in rats and mice. Serum ALT, AST, creatinine, and urea nitrogen levels were all within the normal range. No acute toxicity was observed at the test dose [1,3]

[1]. Advanced research on anti-tumor effects of amygdalin. J Cancer Res Ther. 2014 Aug;10 Suppl 1:3-7.

[2]. Amygdalin inhibits genes related to cell cycle in SNU-C4 human colon cancer cells. World J Gastroenterol. 2005 Sep 7;11(33):5156-61.

[3]. Antinociceptive effect of amygdalin isolated from Prunus armeniaca on formalin-induced pain in rats. Biol Pharm Bull. 2008 Aug;31(8):1559-64.

Amygdalin has been reported in Sorbus commixta, Prunus persica, and other organisms with relevant data. Amygdalin is a cyanogenic glycoside that can be isolated from the seeds of almonds and other plants in the Rosaceae family. It can be converted into benzaldehyde, D-glucose, and hydrocyanic acid by plant emulsifying enzymes (a complex of glucosidase and nitrile hydrolase) or hydrochloric acid. (NCI04) Amygdalin is found in almonds. It is a bitter glycoside found in the kernels of cherries, peaches, and apricots, particularly in Rosaceae plants. Cold-pressed bitter almond oil from the above sources contains amygdalin before being purified by enzymatic hydrolysis and steam distillation for food use. Amygdalin (C20H27NO11) is a glycoside originally isolated from the seeds of the sweet almond tree (Prunus dulcis, also known as bitter almond) by Pierre-Jean Robicquet and A.F. Boutron-Charard in 1803. It was subsequently studied by Liebig and Waller in 1830, as well as by other scholars. Other related species in the genus Prunus, including apricot (Prunus armeniaca) and black cherry (Prunus serotina), also contain amygdalin. Ernst T. Krebs promoted it as a cancer therapy, citing vitamin B17, but studies found it ineffective. Amygdalin is sometimes confused with L-mandelinnitrile (abbreviated as amygdalin). However, amygdalin and amygdalin are different compounds. Studies have shown that amygdalin has analgesic and apoptosis-promoting functions (A7778, A7779). Amygdalin belongs to the disaccharide family. These are disaccharides containing two hexoses.
A cyanogenic glycoside found in the seeds of Rosaceae plants.
See also: amygdalin (note moved to).
Amygdalin is a naturally occurring cyanogenic glycoside found in Rosaceae plants (e.g., apricot, peach) and has potential antitumor and analgesic activities [1,2,3].
- Its antitumor mechanisms include inhibiting cell cycle progression by downregulating cyclin D1/CDK4/CDK6, inducing tumor cell apoptosis, and inhibiting colony formation [1,2].
- Its analgesic effect may be mediated by the opioid receptor pathway, as its effects can be partially reversed by the non-selective opioid receptor antagonist naloxone [3].
- Amygdalin requires caution in clinical use due to the potential release of cyanide during metabolism; however, no significant toxicity was observed at the tested doses in specific studies [1,3].

C20H27NO11

457.42

457.158

29883-15-6

2180

White to off-white solid powder

1.6±0.1 g/cm3

743.3±60.0 °C at 760 mmHg

223-226 °C(lit.)

403.3±32.9 °C

0.0±2.6 mmHg at 25°C

1.650

-0.36

7

12

7

32

638

0

XUCIJNAGGSZNQT-SWRVSKMJSA-N

InChI=1S/C20H27NO11/c21-6-10(9-4-2-1-3-5-9)30-20-18(28)16(26)14(24)12(32-20)8-29-19-17(27)15(25)13(23)11(7-22)31-19/h1-5,10-20,22-28H,7-8H2/t10?,11-,12-,13-,14-,15+,16+,17-,18-,19-,20-/m1/s1

[(6-O-β-D-glucopyranosyl-β-D-glucopyranosyl)oxy](phenyl)acetonitrile

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)

Solubility in Formulation 1: ≥ 2.5 mg/mL (5.47 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 2: 100 mg/mL (218.61 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with ultrasonication.

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