Apricot

Scientific Name(s): Prunus armeniaca L. (Rosaceae) ; P. armeniaca L. var. vulgaris Zabel

Common Name(s): Apricot

Uses

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

There is no clinical evidence to guide dosage of apricots or apricot-containing products.

Contraindications

Contraindications have not been identified.

Pregnancy/Lactation

The apricot fruit is generally recognized as safe. Avoid dosages above those found in food 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.

Interactions

None well documented.

Adverse Reactions

Hypersensitivity has been reported. Adverse reactions similar to cyanide poisoning have been reported.

Toxicology

Cyanide poisoning and death have resulted from laetrile and apricot kernel ingestion.

Botany

Apricots grow on trees that reach 9 m in height. The leaves are oval and finely serrated, with 5-petaled white flowers growing together in clusters. The fruit's color varies from yellow to orange to deep purple and ripens in late summer. The apricot is native to China and Japan but is also cultivated in warmer, temperate regions of the world, including Turkey through Iran, southern Europe, South Africa, Australia, and California. The many varieties and species of apricot differ in flavor, color, and size. 1 , 2 , 3

History

The apricot has been used medicinally for over 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 , referring to the fruit's early ripening. From this, the name apricot evolved. 4

In very small amounts, the toxic hydrogen cyanide present in apricot kernels has been traditionally prescribed in Chinese medicine for treating asthma, cough, and constipation. 4

A decoction of the plant's bark has been used as an astringent to soothe irritated skin. Other uses of apricot in folk medicine include treatment of hemorrhage, infertility, eye inflammation, and spasm. Apricot kernel paste has been used in vaginal infections. The oil has been used in cosmetics and as a pharmaceutical vehicle. 4

Chemistry

The fresh apricot fruit contains carbohydrates, vitamins C and K, betacarotene, thiamine, niacin, and iron. Organic acids, phenols, volatile compounds (eg, benzaldehyde), some esters, norisoprenoids, and terpenoids also have been isolated. 3 , 5

Apricot kernels contain the cyanogenic glycoside amygdalin. 5 Amygdalin 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 the human intestine. 6

Laetrile is often used interchangeably with amygdalin, but they are not the same chemical entity. The term laetrile is an acronym from laevorotatory and mandelonitrile , used to describe a purified form of amygdalin. 7 The US patent for laetrile specifies a semisynthetic derivative of amygdalin that is different from the Mexican laetrile/amygdalin made from crushed apricot seeds. 7

Uses and Pharmacology

Cancer

Despite promising in vitro experiments, the use 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. 8 Interest in the efficacy of laetrile/amygdalin in cancer treatment continues; a Cochrane meta-analysis found no controlled clinical trials from which judgment might be formed. 7 Laetrile is banned from use in cancer therapy by the Food and Drug Administration and the European Union. 7 , 9 An experiment has been reported on the effect of apricot extract on intestinal P-glycoprotein substrates with a view to a potential role in multidrug-resistant cancer. 10

Antimicrobial activity

In an in vitro study, apricot oil failed to demonstrate any antimicrobial activity against common pathogenic organisms. 11

Japanese apricots (a related Prunus spp.) have been studied for their activity against Helicobacter pylori , but there are no reports of studies in the P. armeniaca species. 12

Other

Apricots are consumed as a dietary source of the antioxidants vitamin A and C. 2 , 5 The total antioxidant activity of apricots is lower than that of grapes, raisins, plums, or cherries. 5

Dosage

There is no clinical evidence to guide dosage of apricots or apricot-containing products.

Pregnancy/Lactation

The apricot fruit is generally recognized as safe. Avoid dosages greater than those found in food 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.

Cyanide has not been reported to directly cause human birth defects; however, birth defects, harmful effects on the reproductive system, and skeletal abnormalities have been reported in mice given water containing sodium cyanide and in hamsters given oral laetrile. 13 , 14 Infants born to mothers exposed to cyanide and thiocyanate during pregnancy have exhibited thyroid disease. 14

Interactions

None well documented.

Adverse Reactions

Contact dermatitis has been reported from apricot kernels, and allergy to apricots is common. Cross reactivity to peaches has been displayed in clinical and in vitro experiments. 15 , 16

Toxicology

Cyanide poisoning and death have resulted from laetrile and apricot kernel ingestion. 13 , 17 A minimum lethal dose of cyanide is estimated at 50 mg (or 0.5 mg/kg body weight). 6 Oral amygdalin/laetrile is considered 40 times more toxic than the intravenous form because of its conversion to hydrogen cyanide by enzymes present in the human intestine. 6 , 8

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 by taking high doses of vitamin C. 8

No toxicology data were found in the literature for the flesh or skin of apricot fruits.

Bibliography

1. PLANTS Database . United States Department of Agriculture. Natural Resources Conservation Service. Prunus armeniaca L. apricot. Available at: http://plants.usda.gov/java/profile?symbol=PRAR3. Accessed July, 11 2006.
2. Ruiz D , Egea J , Tomas-Barberan FA , Gil MI . Carotenoids from new apricot ( Prunus armeniaca L.) varieties and their relationship with flesh and skin color . J Agric Food Chem . 2005;53:6368-6374.
3. Riu-Aumatell M , Lopez-Tamames E , Buxadera S . Assessment of the volatile composition of juices of apricot, peach, and pear according to two pectolytic treatments . J Agric Food Chem . 2005;53:7837-7843.
4. Chevallier A . The Encyclopedia of Medicinal Plants . New York, NY: DK Publishing; 1996:254-255.
5. Karakaya S , El SN , Tas AA . Antioxidant activity of some foods containing phenolic compounds . Int J Food Sci Nutr . 2001;52:501-508.
6. Shragg TA , Albetrson TE , Fischer CJ Jr . Cyanide poisoning after bitter almond ingestion . West J Med . 1982;136:65-69.
7. Milazzo S , Ernst E , Lejeune S , Schmidt K . Laetrile treatment for cancer . Cochrane Database Syst Rev . 2006;(2):CD005476.
8. National Cancer Institute. U.S. National Institutes of Health. Latrile/Amygdalin (PDQ¯) . Health Professional Version. 2005. Available at: http://www.cancer.gov/cancertopics/pdq/cam/laetrile/HealthProfessional. Accessed July 11, 2006.
9. Meijer E , Liikan E . Sale over the internet of substances for human consumption which are regarded as harmful in America . OJEC . 2001;44:58-59.
10. Deferme S , Mols R , Van Driessche W , Augustijns P . Apricot extract inhibits the P-gp-mediated efflux of talinolol . J Pharm Sci . 2002;91:2539-2548.
11. Hammer KA , Carson CF , Riley TV . Antimicrobial activity of essential oils and other plant extracts . J Appl Microbiol . 1999;86:985-990.
12. Miyazawa M , Utsunomiya H , Inada K , et al. Inhibition of Helicobacter pylori motility by (+)-Syringaresinol from unripe Japanese apricot . Biol Pharm Bull . 2006;29:172-173.
13. Medline Plus. Bethesda, MD: National Library of Medicine. Natural Starndard: The authority on integrative medicine [Internet]. Cambridge, MA: Natural Standard;©2005. Bitter Almond ( Prunus amygdalus Batch Var. amara (DC.) Focke) and Laetrile. Availabe at: http://www.nlm.nig.gov/medlineplus/druginfo/natural/patient-betteralmond.html. Accessed July, 11 2006.
14. Agency for Toxic Substances and Disease Registry (ATSDR). 2004. ToxFAQs™ for Cyanide (Cianuro). Atlanta, GA: US Department of Health and Human Services, Public Health Service. Available at: http://www.atsdr.cdc.gov/tfacts8.html . Accessed July 11, 2006.
15. Pastorello EA , D'Ambrosio FP , Pravettoni V , et al. Evidence for a lipid transfer protein as the major allergen of apricot . J Allergy Clin Immunol . 2000;105(2 pt 1):371-377.
16. Rodriguez J , Crespo JF , Lopez-Rubio A , et al. Clinical cross-reactivity among foods of the Rosaceae family . J Allergy Clin Immunol . 2000;106(1 pt 1):183-189.
17. Suchard JR , Wallace KL , Gerkin RD . Acute cyanide toxicity caused by apricot kernel ingestion . Ann Emerg Med . 1998;32:742-744.

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