Apricot
Scientific Name(s): Prunus armeniaca L.
Common Name(s): Apricot, Apricot kernel oil, Semen Armeniacae, Vitamin B17
Clinical Overview
Use
Apricots are used as a dietary source of vitamins and minerals, and in confectionery. Apricot kernels have been used for cancer treatment; however, there is no clinical evidence to support this use.
Dosing
No clinical evidence is available to provide guidance on dosing of apricots or apricot-containing products.
Contraindications
Contraindications have not been identified. Consumption of the dried ripe seeds of P. armeniaca is not recommended during pregnancy or breast-feeding, or in children.
Pregnancy/Lactation
Apricot fruit is generally recognized as safe (GRAS). Doses greater than those found in food should be avoided because safety and efficacy are unproven. Consumption of apricot kernels or laetrile is not recommended in pregnant or breast-feeding women.
Interactions
None well documented.
Adverse Reactions
Hypersensitivity and adverse reactions similar to cyanide poisoning have been reported.
Toxicology
Cyanide poisoning and death have resulted from laetrile and apricot kernel ingestion.
Botany
Apricot trees grow up to 9 m in height. The plant leaves are oval and finely serrated, and the 5-petaled white flowers grow in clusters. The downy, orange-red drupe (fruit) ripens in late summer and has a fleshy outer layer and inner hard stone containing the seed (kernel). The apricot is native to China and Japan but is also cultivated in warmer, temperate regions of the world, including Turkey, Iran, southern Europe, South Africa, Australia, and California. The many varieties and species of apricot differ in flavor, color, and size, and are related to other members of the plum genus, including the peach. 1, 2, 3 Synonyms include P. armeniaca L. var. vulgaris Zabel, Armeniaca vulgaris Lam., Amygdalus armeniaca (L.) Dumort., and Armeniaca vulgaris Lam.
History
The apricot has been used medicinally for more than 2,000 years in India and China. The Greeks wrongly assumed that the apricot originated in Armenia, hence its botanical name P. armeniaca. The Romans named the fruit "praecocium," meaning "precocious," which refers to the fruit's early ripening. From this word, the name "apricot" evolved3, 4
In Chinese medicine, the amygdalin present in apricot kernels has been traditionally prescribed in very small amounts for treating asthma, cough, and constipation.3, 4 A decoction of the plant's bark has been used as an astringent to soothe irritated skin. In folk medicine, other uses include the treatment of hemorrhage, infertility, eye inflammation, and spasms. Apricot kernel paste has been used in vaginal infections. The oil has been used in cosmetics and as a vehicle in certain pharmaceutical formulations4, 5
Chemistry
The fresh apricot fruit contains carbohydrates, vitamins C and K, beta-carotene, thiamine, niacin, and iron. Organic acids, phenols, volatile compounds (eg, benzaldehyde), some esters, norisoprenoids, and terpenoids have also been isolated.6, 7, 8 When apricot seed essential oil was evaluated under spectroscopy, benzaldehyde was the predominant compound, with lesser amounts of benzoic acid and the cyanogenic glycoside amygdalin identified.7, 8, 9 Oleic acid, sterols (including campesterol, beta-sitosterol, and others), and squalene have also been identified in the seed oil.10, 11
Amygdalin, a cyanogenic glycoside from the kernels of apricots, can be hydrolyzed to form glucose, benzaldehyde, and hydrocyanic acid. Enzymatic release of cyanide occurs in the presence of beta-glucuronidase, an enzyme found in human intestines.12 "Laetrile" is a term often used interchangeably with "amygdalin," but they are not the same chemical entity. The term "laetrile" refers to a purified form of amygdalin.13 The US patent for laetrile specifies a semisynthetic derivative of amygdalin that is different from the Mexican laetrile/amygdalin made from crushed apricot seeds.13 Amygdalin may also be referred to as vitamin B17 or amygdaloside.14
Uses and Pharmacology
Anti-inflammatory
Animal data
Anti-inflammatory effects of the kernel extract and/or oil were demonstrated in rats with induced ulcerative colitis.15 In rats with induced benign prostatic hyperplasia administered an extract of P. armeniaca bark, histological and biochemical parameters were improved, possibly due to reduced inflammation from phytosterol activity.16
Clinical data
Research reveals no clinical studies evaluating the efficacy of apricot extracts on inflammatory diseases.
Cancer
Animal data
Amygdalin demonstrated activity against renal cell carcinoma in vitro17 and inhibited the growth of implanted tumors in rats.18 When fed to rats with induced hepatic carcinogenesis, the fruit demonstrated protective qualities by increasing the resistance of healthy cells.19
One experiment reported a potential effect of apricot extract on intestinal P-glycoprotein substrates, suggesting a possible role in multidrug-resistant cancer.20
Clinical data
Despite promising in vitro experiments, the efficacy of amygdalin to treat cancer has not been validated by any rigorous clinical trials. The National Cancer Institute sponsored phase 1 and 2 clinical trials in the 1980s but found no evidence to support the use of laetrile in cancer treatment.21
Although interest in the efficacy of laetrile/amygdalin in cancer treatment continues, a Cochrane meta-analysis found no controlled clinical trials to form an opinion.13 Laetrile is banned from use in cancer therapy by the US Food and Drug Administration and the European Union, and it remains an unapproved drug product in the United States.13, 14, 22
Hepatic disease
Animal data
Studies evaluating the effect of ground apricot kernel on induced hepatic fibrosis in rats suggest positive effects due to the fatty acid content23; a protective effect of beta-carotene from the apricot fruit was also demonstrated on the liver of ethanol-fed rats.24
Clinical data
Clinical data to support traditional use of apricot seed extract in liver disease are limited; however, a small clinical trial reported improvement, as observed with ultrasound evaluation, in participants with fatty liver disease.25
Other uses
Apricots are consumed as a dietary source of vitamins A and C.7, 26 The total antioxidant activity of apricots is lower than that of grapes, raisins, plums, and cherries.7 Protective antioxidant effects of apricot kernel oil were demonstrated in a reperfusion injury study in rats.27
The carotenoid fraction, especially lutein from apricot fruits, exerted antiamyloidogenic properties in vitro, suggesting a potential application as a food source for the prevention of amyloid-associated diseases such as Alzheimer disease.28
Equivocal findings regarding antimicrobial activity of the essential oil have been reported.9, 29
Apricot seed oil inhibited keratinocyte proliferation and induced apoptosis in vitro in a study evaluating potential application in psoriasis.30 Apricot seed oil possibly had a positive influence on the immune system in a rat model of cyclophosphamide-induced immunosuppression.31
Dosing
No clinical evidence is available to provide guidance on dosing of apricots or apricot-containing products.
A short-term reference dose for cyanide (via consumption of bitter apricot kernels) of 0.005 to 0.075 mg/kg of body weight has been suggested based on studies in healthy adults; adverse effects may occur at these doses.32
Pregnancy / Lactation
The apricot fruit is GRAS. Doses greater than those found in food should be avoided because safety and efficacy are unproven.
Consumption of apricot kernels or laetrile is not recommended in pregnant or breast-feeding women because of insufficient data and a potential risk of birth defects.3
Cyanide has not been reported to directly cause human birth defects; however, birth defects occurred in rats that ate cassava root diets, harmful effects on the reproductive system occurred in rats and mice given water containing sodium cyanide, and skeletal abnormalities occurred in the offspring of pregnant hamsters administered oral laetrile.33 Infants born to mothers exposed to cyanide and thiocyanate during pregnancy have exhibited thyroid disease.34
Interactions
None well documented.
Adverse Reactions
Contact dermatitis from apricot kernels has been reported, and allergy to apricots is common. Cross-reactivity to peaches has been demonstrated in clinical and in vitro experiments.35, 36
Adverse effects of amygdalin consumption (eg, nausea, vomiting, headache, dizziness) are similar to those of neurotoxic cyanide.3
Toxicology
Cyanide poisoning due to laetrile and apricot kernel ingestion continues to be reported, but not all cases result in death.37, 38, 39, 40, 41, 42 A minimum lethal dose of cyanide is estimated at 50 mg (ranging from 0.5 to 1.5 mg/kg of body weight in the literature).38, 39, 42 Oral amygdalin/laetrile is considered 40 times more toxic than the intravenous form because of its conversion to hydrogen cyanide by enzymes in the human intestine.12, 23
Symptoms of cyanide poisoning (eg, coma, cyanosis, dizziness, headache, hypotension, nausea, neuropathies, ptosis, vomiting) may be potentiated by eating foods containing beta-glucosidase (eg, bean sprouts, carrots, celery, peaches) or high doses of vitamin C.3, 23
There are no toxicology data regarding the flesh or skin of apricot fruits.
References
Disclaimer
This information relates to an herbal, vitamin, mineral or other dietary supplement. This product has not been reviewed by the FDA to determine whether it is safe or effective and is not subject to the quality standards and safety information collection standards that are applicable to most prescription drugs. This information should not be used to decide whether or not to take this product. This information does not endorse this product as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this product. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this product. This information is not specific medical advice and does not replace information you receive from your health care provider. You should talk with your health care provider for complete information about the risks and benefits of using this product.
This product may adversely interact with certain health and medical conditions, other prescription and over-the-counter drugs, foods, or other dietary supplements. This product may be unsafe when used before surgery or other medical procedures. It is important to fully inform your doctor about the herbal, vitamins, mineral or any other supplements you are taking before any kind of surgery or medical procedure. With the exception of certain products that are generally recognized as safe in normal quantities, including use of folic acid and prenatal vitamins during pregnancy, this product has not been sufficiently studied to determine whether it is safe to use during pregnancy or nursing or by persons younger than 2 years of age.
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