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Laetrile (Amygdalin or Vitamin B 17 )

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  • GITAM (Deemed to be University)

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Laetrile is the name for a semi-synthetic compound which is chemically related to amygdalin, a cyanogenic glycoside from the kernels of apricots and various other species of the genus Prunus.-Laetrile and amygdalin are promoted under various names for the treatment of cancer although there is no evidence for its efficacy. Due to possible cyanide poisoning, laetrile can be dangerous.-Laetrile is a word created from the first letters of laevorotatory and mandelonitrile and describes a semi-synthetic form of amygdalin.-There are 3 names which are interchangeable being Vitamin B 17 , Laetrile and Amygdalin. Vitamin B 17 was extracted from the kernels of apricots by a biochemist named Ernst T Krebs Jr. He also called it Laetrile which is simply short for Laevo-mandelonitrile and was awarded its vitamin status officially in 1952.-Amygdalus communis Linnaeus, now known as Prunus amygdalus Batsch, of the rose family Rosaceae.-Amygdalin Chemically, it is cyanogenic diglucoside, with a condensed formula C 20 H 27 NO 11 , with a molecular weight of 457,42g molL-1 , a chemical name of D (1) Mandelonetrile-betaglucoside-6 beta-D-glucoside.-Foods that contain vitamin B17 are as follows: o Kernels or seeds of fruit: The highest concentration of vitamin B17 to be found in nature, aside from bitter almonds,
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Laetrile (Amygdalin or Vitamin B17)
Lecturer Notes_Dr. Sumanta Mondal_GITAM (Deemed To Be University) Page 1 of 6
Email: logonchemistry@gmail.com; Mobile: 9703615761
- Laetrile is the name for a semi-synthetic compound which is chemically related to amygdalin, a cyanogenic
glycoside from the kernels of apricots and various other species of the genus Prunus.
- Laetrile and amygdalin are promoted under various names for the treatment of cancer although there is no
evidence for its efficacy. Due to possible cyanide poisoning, laetrile can be dangerous.
- Laetrile is a word created from the first letters of laevorotatory and mandelonitrile and describes a semi-
synthetic form of amygdalin.
- There are 3 names which are interchangeable being Vitamin B17, Laetrile and Amygdalin. Vitamin B17 was
extracted from the kernels of apricots by a biochemist named Ernst T Krebs Jr. He also called it Laetrile which is
simply short for Laevo-mandelonitrile and was awarded its vitamin status officially in 1952.
- Amygdalus communis Linnaeus, now known as Prunus amygdalus Batsch, of the rose family Rosaceae.
- Amygdalin Chemically, it is cyanogenic diglucoside, with a condensed formula C20H27NO11, with a molecular
weight of 457,42g molL-1, a chemical name of D (1) Mandelonetrile-betaglucoside-6 beta-D-glucoside.
- Foods that contain vitamin B17 are as follows:
o Kernels or seeds of fruit: The highest concentration of vitamin B17 to be found in nature, aside from bitter
almonds, apricot, apple, cherry, nectarine, peach, pear, plum etc;
o Beans: broad (Vicia faba), burma, lentils (sprouted), lima, mung (spruted), rangoon;
o Nuts: bitter almond, macadamia, cashew;
o Berries: almost all wild berries-blackberry, chokeberry, christmas berry, cranberry, elderberry, raspberry,
strawberry;
o Seeds: chia, flax, sesame;
o Grasses: acacia, alfalfa (spruted), wheat grass, white dover.
o Grains: oat groats, barley, brown rice, buckwheat groats, millet, sorghum, rye, wheat berries
- Preparation of Amygdalin:
o The cyanogenetic glycoside amygdalin is usually obtained from either the cake of bitter almond or other
prunaceous seeds after expression of the fixed oil.
o The cake is subjected to extraction with ethanol (95% v/v) and the resulting alcoholic extract is concentrated
to a small volume preferably under vacuum and mixed with a large volume of ether, when the desired
glycoside will separate out as a crystalline product.
o Amygdalin upon enzymatic hydrolysis gives rise to one mole each of benzaldehyde and hydrocyanic acid plus
two moles of glucose.
o It is, however, assumed that the enzyme emulsin, isolated from the kernels of bitter almonds, comprises of
several enzymes, such as: amygdalase, prumase, hydroxynitrilase etc.
Laetrile (Amygdalin or Vitamin B17)
Lecturer Notes_Dr. Sumanta Mondal_GITAM (Deemed To Be University) Page 2 of 6
Email: logonchemistry@gmail.com; Mobile: 9703615761
o The enzymatic hydrolysis of amygdalin takes place in three steps as follows:
(i) The enzyme amygdalase helps to cleave the glycoside amygdalin first into one mole of each Glucose and
Prunasin (Mandelonitrile glucoside).
(ii) Then the enzyme prunasin helps to liberate the second molecule of glucose with the formation of the
aglycone Mandelonitrile (Benzaldehyde Cyanohydrin).
(iii) The enzyme hydroxynitrilase helps to break down the Mandelonitrile into one mole each of Benzaldehyde
and Hydrocyanic Acid.
- Cyanogenetic Glycosides Chemical Tests:
(i) Ferriferrocyanide Test: Macerate 1 g of the powdered drug with 5 ml of alcoholic KOH (5% w/v) for five
minutes. Transfer it to an aqueous solution containing FeSO4 (2.5 %w/v) and FeCl3 (1% w/v), and maintain
at 60-70°C for 10 minutes. Now, transfer the contents to HCl (20%) when the appearance of a distinct
Prussian blue colour confirms the presence of HCN.
(ii) Precipitation of Hg from HgNO3: The reduction of aqueous mercurous nitrate solution (3% w/v) to
metallic Hg by HCN being observed by an instant formation of black metallic Hg in the cells.
APRICOT
Prunus armeniaca
Family: Rosaceae
ALMOND
Prunus dulcis Mill.
Family: Rosaceae
CASHEW
Anacardium occidentale L.
Family: Anacardiaceae
SESAME
Sesamum indicum L.
Family: Pedaliaceae
ALFALFA
Medicago sativa L.
Family: Fabaceae
BROWN RICE
Oryza longistaminata A. Chev. & Roehrich
Family: Poaceae
Laetrile (Amygdalin or Vitamin B17)
Lecturer Notes_Dr. Sumanta Mondal_GITAM (Deemed To Be University) Page 3 of 6
Email: logonchemistry@gmail.com; Mobile: 9703615761
Note By:
Mandelonitrile: Mandelonitrile is the nitrile of mandelic acid, or the cyanohydrin derivative of benzaldehyde.
Mandelonitrile
A Cyanohydrin is a functional group found in organic compounds in which a cyano and a hydroxy group are
attached to the same carbon atom. The general formula is R2C(OH)CN, where R is H, alkyl, or aryl.
Cyanohydrin
Nitrile is any organic compound that has a −C≡N functional group.
nitrile
Mandelic acid is an aromatic alpha hydroxy acid with the molecular formula C6H5CH(OH)CO2H. It is a white
crystalline solid that is soluble in water and polar organic solvents. It is a useful precursor to various drugs. The
molecule is chiral. The racemic mixture is known as paramandelic acid.
Mandelic acid
Benzaldehyde (C6H5CHO) is an organic compound consisting of a benzene ring with a formyl substituent. It is the
simplest aromatic aldehyde and it is a colorless liquid with a characteristic almond-like odor. The primary component
of bitter almond oil.
Benzaldehyde
Laevorotatory having the property of rotating the plane of a polarized light ray to the left, i.e. anticlockwise facing
the oncoming radiation.
Brown Rice is whole grain rice, with the inedible outer hull removed; white rice is the same grain with the hull, bran
layer and cereal germ removed. Red rice, gold rice, and black rice (sometimes known as purple rice) are all whole
rices, but with a differently-pigmented outer layer.
- Laetrile is prepared for oral as well as for intravenous or intramuscular application. The results of an analysis conducted
by the National Cancer Institute (NCI) in order to assess the purity of both oral and injectable amygdalin products
indicated that they were substandard by US criteria for pharmaceutical products.
- Other studies also showed the presence of contaminants in both injectable and oral supplements of laetrile and the FDA
deemed that laetrile products were toxic and ineffective and laetrile was consequently banned from US-interstate
transportation.
- However, in 1980 the Associated Press reported that 23 US States had legalized the use of the laetrile within their
boundaries and for the treatment of terminal cancer patients. During the 1970s at least 70,000 Americans had used
laetrile.
- Laetrile's proponents consider it to be a "natural cancer cure"; whereas opponents consider "the slickest, most
sophisticated, and certainly the most remunerative cancer quack promotion in medical history".
BERRY
Laetrile (Amygdalin or Vitamin B17)
Lecturer Notes_Dr. Sumanta Mondal_GITAM (Deemed To Be University) Page 4 of 6
Email: logonchemistry@gmail.com; Mobile: 9703615761
- Mechanism of Action of Laetrile:
o Cyanide released from enzymatic degradation of laetrile or amygdalin is believed to be the ingredient
responsible for the alleged anti-cancer action.
o Proponents claim that malignant cells are specifically vulnerable to cyanogenic glycosides because of two
characteristics: a higher level of beta-glucosidases and beta-glucuronidase compared to normal cells, which
would lead to a more rapid intracellular release of cyanide from laetrile or amygdalin and a deficiency in
rhodanese, an enzyme that converts cyanide into the harmless compound thiocyanate.
o Another theory claims that cancer develops due to the deficiency of a vitamin, named "vitamin B17", which was
the name that the chemist E.T. Krebs gave to laetrile.
- How Laetrile works:
o Vitamin B-17/ Laetrile are a molecule made up of four parts: 2 parts Glucose, 1 part Benzaldahyde, 1 part
Hydrogen Cyanide (which is also found in vitamin B-12).
o It is important to note that the body has the proper compounds to either neutralize the B17 molecules or to
unlock to them at the site of cancer. This is because the enzyme rhodanese is found in normal healthy cells and
it automatically neutralize the Benzaldahyde and Hydrogen Cyanide, converting them into harmless compounds
which the body will then excrete.
o Rhodanese is found everywhere in the body except for in (or around) cancer cells or tumors.
o In contrast, Beta-Glucosidase is found only at the site of cancer and is referred to as the “unlocking enzyme”
since it will unlock the cyanide and benzaldahyde at the site of cancerous cells and tumors.
o When glucose delivers the Vitamin B-17 molecules to the cancerous cells, they are unable to neutralize the
cyanide since they lack the rhodanese enzyme. Instead, the cyanide and benzaldahyde are released at the site of
cancer allowing them to target the cancer cells directly.
Note By: A BERRY is a small, pulpy, and often edible fruit. Berries belong to the Rosaceae family which are
typically juicy, rounded, brightly colored, sweet or sour, and do not have a stone or pit, although many pips or seeds
may be present. Common examples are strawberries (Fragaria ananassa Duchesne), Raspberries (Rubus
crataegifolius), Blueberries (Vaccinium sect. Cyanococcus Rydb.), Red Currants (Ribes rubrum; Family:
Grossulariaceae), and Black Currants (Ribes nigrum L.; Family: Grossulariaceae).
Note By: Rhodanese, also known as rhodanase, thiosulfate sulfurtransferase, thiosulfate cyanide transsulfurase, and
thiosulfate thiotransferaseis a mitochondrial enzyme that detoxifies cyanide (CN) by converting it to thiocyanate (SCN).
Laetrile (Amygdalin or Vitamin B17)
Lecturer Notes_Dr. Sumanta Mondal_GITAM (Deemed To Be University) Page 5 of 6
Email: logonchemistry@gmail.com; Mobile: 9703615761
- Summary of mechanism of Laetrile:
o When the laetrile compound molecule comes across a cancer cell, it is broken down into 2 molecules of
glucose, 1 molecule of hydrogen cyanide and 1 molecule of benzaldehyde.
o In the early days of laetrile research it was assumed that the hydrogen cyanide molecule was the major cancer
cell killing molecule, but now it is known that it is the benzaldehyde molecule that is by far the major reason
the cancer cell is killed.
o The reason laetrile therapy takes so long to work, in spite of the marvelous design of the laetrile molecule, is
because if the laetrile molecule must chemically react with the enzyme of a non-cancerous cell (i.e.
rhodanese), before it reacts with the enzyme of a cancerous cell (beta-glucosidase); the rhodanese will break
apart the laetrile molecule in such a way that it can no longer kill a cancer cell.
o Thus laetrile molecules, over a long enough time, that enough laetrile molecule coincidently (as far as we
know) hit all of the cancer cells first.
- Laetrile Dosage:
o Vitamin B-17 or laetrile is not a stand-alone cancer cure but something that can be used in addition to other
protocols.
o For a person with an active cancer: most experts in the field would recommend 24 to 40 apricot kernels per
day and spreading them throughout the day. Start by eating 3-4 per day and then gradually build yourself to
taking the higher amounts.
o For a person in remission: 12- 16 apricot kernels a day, or 1 kernel per 10 pounds of body weight, once again,
starting with 2-4 per day and building up to taking more. Kernels should be taken with food. They can be
chewed whole or run through a coffee grinder and then sprinkled into foods such as smoothies, as an addition to
oatmeal, salads, the Budwig cottage cheese/flax oil mixture, organic yogurt, etc.
o Vitamin B-17 Tablets are taken with water 1/2 hour before eating a meal. Start with one tablet per day and then
build yourself up to taking 4 per day (or 2,000 mg). [Start with a low dosage and then build up slowly to an
optimal dosage].
- The following supplements are recommended in order for laetrile to work properly:
o Zinc, which is considered to be the transport mechanism for laetrile
o DMG benefits the immune system and has anti-cancer properties. 1 pill is taken 3 times per day with food.
o Pancreatic enzymes are good for digestion and assimilation of nutrients, and they have the ability to break
down tumor proteins.
Note By: DMG is an abbreviation for dimethylglycine, an amino acid with the chemical formula (CH3)2NCH2COOH.
It is derived from glycine, which is one of the 20 amino acids commonly used to synthesize proteins in humans.
- Testimonials:
o Carl O Helvie used Vitamin B17 to treat his terminal lung cancer
o Sandi Rog credits Vitamin B17 with curing her stage 4 Non-Hodgkin’s Lymphoma
o Felicity Corbin-Wheeler used Laetrile as part of her protocol to heal from pancreatic cancer
o Allan Taylor used apricot kernels as part of his healing plan for colon cancer
o John Curry used apricot kernels as part of his healing plan for prostate cancer
- Pharmacological Activity of Amygdalin:
1. Anti-asthmatic effect
o Amygdalin can promote synthesis of pulmonary surfactant. Amygdalin is decomposed into benzaldehyde and
hydrocyanic acid after oral administration which prevent respiratory center to reach certain level and slow down
respiratory movement and produce antitussive and antiasthmatic effect.
o Amygdalin or laetrile used for prevention of asthma in Korean traditional medicine.
o However, proper antiasthmatic action of amygdalin still not completely understood. Amygdalin does not engulf
or kill the type 1 helper T cell response, but it kills the type 2 helper T cell.
Laetrile (Amygdalin or Vitamin B17)
Lecturer Notes_Dr. Sumanta Mondal_GITAM (Deemed To Be University) Page 6 of 6
Email: logonchemistry@gmail.com; Mobile: 9703615761
2. Enhanced caspase-mediated cell death of human renal fibroblast
o Laetrile can promote action of type 1 collagenase released by human kidney fibroblast in definite action of time
and concentration which inhibit certain expression of type 1 collagenase and human kidney fibroblast production,
which encourage apoptosis of human renal fibroblast.
3. Role in immune system
o Laetrile can promote polyhydroxyalkanoates induced human T lymphocytes proliferation and increase blood
lymphocytes motivated by polyhydroxyalkanoates which secret IL-2 and Interferon and prevent TGF-β1 thus
enhancing immune response.
4. Pain relieving effect
o The mechanism of antinociceptive activity of amygdalin is reported by some research reports.
o Benzaldehyde unit of amygdalin chemical structure play important part in antinociceptive action.
o Anti-inflammatory and analgesic characteristics of amygdalin, through inhibition of pro-inflammatory cytokines
release, as well as TNF-, IL-1 or IL-6, or other mediators like the c-Fos protein, cyclooxygenase or nitric
oxide synthase.
5. Effect on digestive system
o Amygdalin inhibits the level of AST, ALT and rise hydroxyproline content, inhibits extension of euglobulins
lysis time.
6. Inhibit hyperglycemia
o Amygdalin prevents the alloxan induced hyperglycemia which depends on effective concentration of drug in
blood.
o Research has shown therapeutic effect of amygdalin for gastric ulcer. It also induces angiogenesis in the diabetic
rats.
7. Toxicity of amygdalin
o The toxicity of amygdalin through intravenous route is less good than the toxicity of oral administration.
o In rats the fatal dose (LD50) of oral administration of amygdalin is described as 880 mg/kg body weight in rats.
o In case of intravenous injection in rats the lethal dose (LD50) of amygdalin are 25 g/kg.
o In case of intraperitoneal injection, in rats the LD50 or fatal doses of amygdalin are 8 g/kg.
o Human lethal dose of intravenous injection is 5 g. After oral administration amygdalin is produce more
hydrocyanic acid as it is hydrolyzed or decomposed by intestinal microbes. Toxicity in human when amygdalin is
orally administrated is 4 g per day for 15 days is shown and intravenous injection for month. If dose is reduced to
daily oral doses, then it can avoid toxicity.
References
1. Holzbecher MD, Moss MA, Ellenberger HA (1984) The cyanide content of laetrile preparations, apricot, peach and apple
seeds. J Toxicol Clin Toxico 22: 341-347.
2. Shim SM, Kwon H (2010) Metabolites of amygdalin under simulated human digestive fluids. Int J Food Sci Nutr 61: 770-
779.
3. Milazzo S, Lejeune S, Ernst E (2007) Laetrile for cancer: A systematic review of the clinical evidence. Support Care Cancer
15: 583-595.
4. O'brien B, Quigg C, Leong T (2005) Severe cyanide toxicity from„vitamin supplements‟. Eur J Emerg Med 12: 257 -258.
5. Muhammad Qadir, Kiran Fatima (2017) Review on Pharmacological Activity of Amygdalin. Archives in Cancer Research
5(4): 1-3.
ResearchGate has not been able to resolve any citations for this publication.
Article
Full-text available
Many cancer patients treated with conventional therapies also try 'alternative' cancer treatments. Laetrile is one such 'alternative' that is claimed to be effective by many alternative therapists. Laetrile is also sometimes referred to as amygdalin, although the two are not the same. The aim of this review is to summarize all types of clinical data related to the effectiveness or safety of laetrile interventions as a treatment of any type of cancer. All types of clinical studies containing original clinical data of laetrile interventions were included. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (from 1951), EMBASE (from 1980), Allied and Complementary Medicine (AMED), Scirus, CancerLit, Cumulative Index to Nursing and Allied Health (CINAHL; all from 1982), CAMbase (from 1998), the MetaRegister, the National Research Register, and our own files. For reports on the safety of laetrile, we also searched the Uppsala database. No language restrictions were imposed. Thirty six reports met our inclusion criteria. No controlled clinical trials were found. Three articles were nonconsecutive case series, 2 were consecutive case series, 6 were best case series, and 25 were case reports. None of these publications proved the effectiveness of laetrile. Therefore, the claim that laetrile has beneficial effects for cancer patients is not supported by sound clinical data.
Article
In the present study, degradation of amygdalin in the human digestive fluids and absorption of its metabolites by the human small intestine were evaluated by simulating a gastrointestinal digestion model combined with a human intestinal cell culture. Orally administered amygdalin was degraded into prunasin by digestive enzymes after passing through the salivary and gastrointestinal phases. Prunasin, the major metabolite of amygdalin in the digestive fluids, was incubated in a caco-2 cell culture system. Prunasin was degraded into the mandelonitrile by β-glucosidase and then hydroxylated across the small intestinal wall, producing hydroxymandelonitrile (149 Da). Results from this study suggest that risk assessment of amygdalin from food consumption can be done in a more accurate way by determining a pathway of amygdalin metabolism in the simulating human upper gastrointestinal tract.
Article
Laetrile preparations obtained from a cyanide intoxicated patient were analyzed for their cyanide content by a microdiffusion colorimetric procedure. Cyanide was also determined in apricot, peach and apple seeds. The results were compared to those reported in the literature for cyanogenic glycoside containing seeds.
Article
The use of alternative medicines is increasing and poorly regulated. We describe a case of severe cyanide poisoning arising from amygdalin, a putative vitamin supplement. A 32-year-old woman arrived in the emergency department by ambulance unresponsive, shocked and with fixed dilated pupils. She was hypothermic and tachycardic but was breathing spontaneously. Despite her age, she had documented breast cancer with hepatic metastases. Conventional treatment having failed, she only took 'vitamin supplements' bought on the Internet, her father said. Over the next 6 h she required mechanical ventilation and increasing doses of inotropes. Diabetes insipidus developed. As the appropriateness of further treatment was considered, a relative arrived with her medications including 'vitamin B 17' or amygdalin. An Internet search identified this as a debunked cancer remedy and cyanogen. Serum thiocyanate level was markedly elevated. She recovered fully over 8 h. While various antidotes to cyanide exist, in this case supportive therapy alone proved effective.
  • Muhammad Qadir
  • Kiran Fatima
Muhammad Qadir, Kiran Fatima (2017) Review on Pharmacological Activity of Amygdalin. Archives in Cancer Research 5(4): 1-3.