Biology:Grapefruit seed extract
Grapefruit seed extract (GSE), also known as citrus seed extract, is a liquid extract derived from the seeds, pulp, and white membranes of grapefruit.[1] GSE is prepared by grinding the grapefruit seed and juiceless pulp, then mixing with glycerin.[1] Commercially available GSEs sold to consumers are made from the seed, pulp, and glycerin blended together.[1] GSE is sold as a dietary supplement and is used in cosmetics.[2]
Grapefruit history
The grapefruit is a subtropical citrus tree grown for its fruit which was originally named the "forbidden fruit" of Barbados.[3] The fruit was first documented in 1750 by Rev. Griffith Hughes when describing specimens from Barbados.[4] All parts of the fruit can be used. The fruit is mainly consumed for its tangy juice.[5] The peel can be processed into aromatherapy oils[6] and is also a source of dietary fiber.[7] The seed and pulp, as byproducts of the juice industry, are retrieved for GSE processing[8] or sold as cattle feed.[9]
Efficacy
Despite claims that GSE has antimicrobial effects,[10] there is no scientific evidence that GSE has such properties.[11][8] Some evidence indicates that the suspected antimicrobial activity of GSE was due to the contamination or adulteration of commercial GSE preparations with synthetic antimicrobials or preservatives.[1][2][12] These chemicals were not present in grapefruit seed extracts prepared in the laboratory, and GSE preparations without the contaminants were found to possess no detectable antimicrobial effect.[1] Although citrus seed extract is sold in health food markets,[12] there is no good evidence for any antimicrobial activity.[1]
Phytochemicals
Analysis shows the phytochemicals of the seed extract and pulp are flavonoids,[13][14] ascorbic acid (vitamin C), tocopherols, citric acid, limonoids,[15][16] sterols, and minerals.[17]
Preparations
GSE is prepared by grinding the grapefruit seed and juiceless pulp, then mixing with glycerin.[1] Commercially available GSE is made from the seed, pulp, glycerin, and synthetic preservatives all blended together.[1]
Health claims and safety concerns
Although various health claims for using GSE are marketed in the dietary supplement industry, there is no scientific evidence from high-quality clinical research that it has any health effects, as of 2018.[8][11] Phytochemicals in grapefruit seeds, particularly furanocoumarins and flavonoids, may cause adverse effects on health resulting from grapefruit–drug interactions that influence the intended therapeutic effects of some 85 prescription drugs.[11][18] The main safety concern about GSE is inhibition of the liver enzyme, cytochrome P450, which controls liver metabolism of drugs; consequently, its inhibition by GSE unpredictably increases the blood concentrations of prescribed drugs.[18]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 "Aspects of the antimicrobial efficacy of grapefruit seed extract and its relation to preservative substances contained". Pharmazie 54 (6): 452–6. June 1999. PMID 10399191.
- ↑ 2.0 2.1 "Development and validation of an HPLC/UV/MS method for simultaneous determination of 18 preservatives in grapefruit seed extract". J. Agric. Food Chem. 54 (11): 3768–72. May 2006. doi:10.1021/jf060543d. PMID 16719494.
- ↑ Dowling, Curtis F.; Morton, Julia Frances (1987). Fruits of warm climates. Miami, Fla: J.F. Morton. pp. 152–8. ISBN 978-0-9610184-1-2. http://www.hort.purdue.edu/newcrop/morton/grapefruit.html.
- ↑ Michael Quinion. World Wide Words: Questions & Answers; Grapefruit. 2009.
- ↑ "Nutrient content and nutrition labeling of several processed Florida citrus juice products". J Am Diet Assoc 90 (8): 1079–84. August 1990. doi:10.1016/S0002-8223(21)01704-1. PMID 2380455.
- ↑ Worwood, Valerie Ann (1991). The complete book of essential oils and aromatherapy. Novato, Calif: New World Library. ISBN 978-0-931432-82-8. https://archive.org/details/completebookofes00worw.
- ↑ "The effects of grapefruit pectin on patients at risk for coronary heart disease without altering diet or lifestyle". Clin Cardiol 11 (9): 589–94. September 1988. doi:10.1002/clc.4960110902. PMID 3229016.
- ↑ 8.0 8.1 8.2 "Not natural, not safe: Grapefruit seed extract". Science-based Medicine. 10 March 2016. https://sciencebasedmedicine.org/not-natural-not-safe-grapefruit-seed-extract/. Retrieved 17 November 2018.
- ↑ "Citrus pulp for cattle". Vet. Clin. North Am. Food Anim. Pract. 18 (2): 317–26, vii. July 2002. doi:10.1016/S0749-0720(02)00023-3. PMID 12235663.
- ↑ Cvetnić Z, Vladimir-Knezević S (September 2004). "Antimicrobial activity of grapefruit seed and pulp ethanolic extract". Acta Pharm 54 (3): 243–50. PMID 15610620.
- ↑ 11.0 11.1 11.2 "Grapefruit". Drugs.com. 15 January 2018. https://www.drugs.com/npp/grapefruit.html. Retrieved 17 November 2018.
- ↑ 12.0 12.1 "Identification of benzalkonium chloride in commercial grapefruit seed extracts". J. Agric. Food Chem. 53 (19): 7630–6. September 2005. doi:10.1021/jf0514064. PMID 16159196.
- ↑ "Bitter taste, phytonutrients, and consumer: a review". Am. J. Clin. Nutr. 72 (6): 1424–35. 2000. doi:10.1093/ajcn/72.6.1424. PMID 11101467.
- ↑ Tirillini B (2000). "Grapefruit: the last decade acquisitions". Fitoterapia 71: 29–37. doi:10.1016/S0367-326X(00)00176-3. PMID 10930710.
- ↑ "Glucosides of acidic limonoids in citrus". Phytochemistry 28 (10): 2777–81. 1989. doi:10.1016/S0031-9422(00)98087-7. https://zenodo.org/record/1259689.
- ↑ Ohta H, Fong CH, Berhow M, Hesegawa (1993). "Thin-layer and high-performance liquid chromatographic analyses of limonoids and limonoid glucosides in citrus seeds". J. Chromatogr. 639 (2): 295–302. doi:10.1016/0021-9673(93)80266-B. https://zenodo.org/record/1253912.
- ↑ "Sterols of grapefruit, orange, mandarin pulps (Citrus paradisi, Citrus sinensis, Citrus unshiu)". Chemistry of Natural Compounds 18: 445–7. 1983. doi:10.1007/BF00579640.
- ↑ 18.0 18.1 Bailey, D. G.; Dresser, G.; Arnold, J. M. O. (2012). "Grapefruit-medication interactions: Forbidden fruit or avoidable consequences?". Canadian Medical Association Journal 185 (4): 309–316. doi:10.1503/cmaj.120951. PMID 23184849.
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