Grapefruit seed extract
Encyclopedia
Grapefruit seed extract (GSE), also known as citrus seed extract, is a liquid derived from the seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...

s, pulp, and white membranes
Juice vesicles
The juice vesicles of a citrus fruit are the membranous content of the fruit’s endocarp. The vesicles contain the juice of the fruit. The pulp is usually removed from the juice by filtering it out...

 of grapefruit
Grapefruit
The grapefruit , is a subtropical citrus tree known for its sour fruit, an 18th-century hybrid first bred in Barbados. When found, it was named the "forbidden fruit"; it has also been misidentified with the pomelo or shaddock , one of the parents of this hybrid, the other being sweet orange The...

. Self-made natural GSE processed in the laboratory without solvents or synthetic agents is prepared by grinding the grapefruit seed and juiceless pulp, then mixing with glycerin. Commercially available GSE sold to consumers are made from the seed, pulp, glycerin, and synthetic preservatives all blended together. Grapefruit seed extract is sold as a food supplement
Dietary supplement
A dietary supplement, also known as food supplement or nutritional supplement, is a preparation intended to supplement the diet and provide nutrients, such as vitamins, minerals, fiber, fatty acids, or amino acids, that may be missing or may not be consumed in sufficient quantities in a person's diet...

 and used in cosmetics
Cosmetics
Cosmetics are substances used to enhance the appearance or odor of the human body. Cosmetics include skin-care creams, lotions, powders, perfumes, lipsticks, fingernail and toe nail polish, eye and facial makeup, towelettes, permanent waves, colored contact lenses, hair colors, hair sprays and...

 because it is a claimed natural antimicrobial
Antimicrobial
An anti-microbial is a substance that kills or inhibits the growth of microorganisms such as bacteria, fungi, or protozoans. Antimicrobial drugs either kill microbes or prevent the growth of microbes...

.

An early proponent was Dr. Jacob Harich (1919–1996). A long time promoter of GSE was Aubrey Hampton, the founder of Aubrey Organics. Some marketers of GSE affirm this extract to be a safe, natural, and an effective preservative. This extract
Herbal extract
Tincture is a liquid solution of herbs and a fluid menstruum, usually ethanol. The dried or fresh herbs are combined with alcohol, then the solid matter is removed leaving only the oils of the herbs mixed with the alcohol...

 has been stated by some practitioners of alternative medicine
Alternative medicine
Alternative medicine is any healing practice, "that does not fall within the realm of conventional medicine." It is based on historical or cultural traditions, rather than on scientific evidence....

 to possess antibacterial
Antiseptic
Antiseptics are antimicrobial substances that are applied to living tissue/skin to reduce the possibility of infection, sepsis, or putrefaction...

, antiviral
Antiviral drug
Antiviral drugs are a class of medication used specifically for treating viral infections. Like antibiotics for bacteria, specific antivirals are used for specific viruses...

, and antifungal
Antifungal drug
An antifungal medication is a medication used to treat fungal infections such as athlete's foot, ringworm, candidiasis , serious systemic infections such as cryptococcal meningitis, and others...

 properties. It has been recommended by some nutritionist
Nutritionist
A nutritionist is a person who advises on matters of food and nutrition impacts on health. Different professional terms are used in different countries, employment settings and contexts — some examples include: nutrition scientist, public health nutritionist, dietitian-nutritionist, clinical...

s for the treatment of candidiasis
Candidiasis
Thrush redirects here. For the hoof infection see Thrush .Candidiasis or thrush is a fungal infection of any of the Candida species , of which Candida albicans is the most common...

, earache
Otalgia
Otalgia or an earache is ear pain. Primary otalgia is ear pain that originates inside the ear. Referred otalgia is ear pain that originates from outside the ear.Otalgia is not always associated with ear disease...

, throat infections, and diarrhea
Diarrhea
Diarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...

. GSE is promoted at health food shops
Health food store
A health food store is a type of grocery store that primarily sells health food, organic foods, local produce, and often nutritional supplements...

 and on the internet
Internet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...

.

There are conflicting scientific demonstrations of the efficacy of GSE. Suspicions about the true nature of the active compounds in GSEs arose when synthetic additives were found in commercial products. Suspected counterfeit grapefruit seed extracts were adulterated with synthetic
Chemical synthesis
In chemistry, chemical synthesis is purposeful execution of chemical reactions to get a product, or several products. This happens by physical and chemical manipulations usually involving one or more reactions...

 preservative
Preservative
A preservative is a naturally occurring or synthetically produced substance that is added to products such as foods, pharmaceuticals, paints, biological samples, wood, etc. to prevent decomposition by microbial growth or by undesirable chemical changes....

s. When preservatives were not present in some of the extracts, laboratory tests found the natural extracts had no natural antimicrobial attributes of their own. Some manufacturers of GSE have stated that their extract has compounds nearly identical to benzethonium chloride, but a 2001 study supervised by chemist
Chemist
A chemist is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties such as density and acidity. Chemists carefully describe the properties they study in terms of quantities, with detail on the level of molecules and their component atoms...

 G. Takeoka has documented that commercial GSE preparations contain the synthetic compound benzethonium chloride
Benzethonium chloride
Benzethonium chloride is a synthetic quaternary ammonium salt. This compound is an odorless white solid; soluble in water. It has surfactant, antiseptic, and anti-infective properties, and it is used as a topical antimicrobial agent in first aid antiseptics. It is also found in cosmetics and...

 that could not have been made from GSE.

History

The grapefruit is a subtropical citrus
Citrus
Citrus is a common term and genus of flowering plants in the rue family, Rutaceae. Citrus is believed to have originated in the part of Southeast Asia bordered by Northeastern India, Myanmar and the Yunnan province of China...

 tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...

 grown for its fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...

 which was originally named the "forbidden fruit
Forbidden fruit
Forbidden fruit is any object of desire whose appeal is a direct result of knowledge that cannot or should not be obtained or something that someone may want but is forbidden to have....

" of Barbados
Barbados
Barbados is an island country in the Lesser Antilles. It is in length and as much as in width, amounting to . It is situated in the western area of the North Atlantic and 100 kilometres east of the Windward Islands and the Caribbean Sea; therein, it is about east of the islands of Saint...

. The fruit was first documented in 1750 by Rev. Griffith Hughes
Griffith Hughes
The Reverend Griffith Hughes , FRS, was a naturalist and author. Hughes wrote The Natural History of Barbados, which included the first description of the grapefruit...

 describing specimens from Barbados. All parts of the fruit have uses. The fruit is mainly consumed for a tangy juice
Juice
Juice is the liquid that is naturally contained in fruit or vegetable tissue.Juice is prepared by mechanically squeezing or macerating fruit or vegetable flesh without the application of heat or solvents. For example, orange juice is the liquid extract of the fruit of the orange tree...

. The peel is expressed into an aromatherapy
Aromatherapy
Aromatherapy is a form of alternative medicine that uses volatile plant materials, known as essential oils, and other aromatic compounds for the purpose of altering a person's mind, mood, cognitive function or health....

 oil
Essential oil
An essential oil is a concentrated hydrophobic liquid containing volatile aroma compounds from plants. Essential oils are also known as volatile oils, ethereal oils or aetherolea, or simply as the "oil of" the plant from which they were extracted, such as oil of clove...

 and is also a source of dietary fiber
Dietary fiber
Dietary fiber, dietary fibre, or sometimes roughage is the indigestible portion of plant foods having two main components:* soluble fiber that is readily fermented in the colon into gases and physiologically active byproducts, and* insoluble fiber that is metabolically inert, absorbing water as it...

. The seed and pulp as a by-product of the juice industry is sold as cattle feed and is manufactured for use to make an extract. GSE was originally developed by Dr. Jacob Harich, a nuclear physicist. In 1963, he journeyed to Florida, the heart
Heart (symbol)
The heart has long been used as a symbol to refer to the spiritual, emotional, moral, and in the past, also intellectual core of a human being...

 of grapefruit country in the U.S., and began researching and later marketing
Marketing
Marketing is the process used to determine what products or services may be of interest to customers, and the strategy to use in sales, communications and business development. It generates the strategy that underlies sales techniques, business communication, and business developments...

 of GSE. Aubrey Hampton, founder of Aubrey Organics, has promoted citrus seed extract, a component in "Aubrey’s Preservative", for more than 25 years. Today, GSE is mostly promoted at health food shops
Health food store
A health food store is a type of grocery store that primarily sells health food, organic foods, local produce, and often nutritional supplements...

 and on the internet
Internet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...

.

Efficacy

Anecdotal claims for an antimicrobial effect are based on a few abstract scientific experiments which show some antimicrobial activity for commercial grapefruit seed extracts and an ethanol grapefruit seed extract but not a natural GSE. The preliminary studies for the antimicrobial effect state that the Citricidal commercial brand of GSE was used for testing. There is considerable scientific evidence that the anti-microbial activity associated with grapefruit seed extract is attributable to the contamination or adulteration of commercial GSE preparations with synthetic antimicrobials or preservatives. According to the 2001 GSE study, branded commercial GSE preparations were contaminated with synthetic benzethonium chloride
Benzethonium chloride
Benzethonium chloride is a synthetic quaternary ammonium salt. This compound is an odorless white solid; soluble in water. It has surfactant, antiseptic, and anti-infective properties, and it is used as a topical antimicrobial agent in first aid antiseptics. It is also found in cosmetics and...

 that was implausible to be made from grapefruit seeds. Some of the marketers claimed that their product does not contain benzethonium chloride and the error was due to the similarity in molecular weight of the quaternary ammonium compound which was formed through a proprietary manufacturing process. It is inconceivable that the preservative benzethonium chloride is formed during any extraction and/or processing of grapefruit seeds and pulp. Researchers conclusively demonstrated the presence of benzethonium chloride in commercial GSE using various analytical methods including HPLC, one- and two-dimensional NMR, PIXE analysis, and electrospray ionization MS. Another in vitro study claimed GSE had antibacterial properties. As with the branded in vitro test this extract was contaminated. The ethanolic grapefruit seed and pulp extract tested was prepared or contaminated with ethanol, a chemical solvent used in the extraction process. Ethanol
Ethanol
Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. It is a psychoactive drug and one of the oldest recreational drugs. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a...

, also known as ethyl alcohol, is effective in inhibiting bacteria. Nevertheless, as a result of marketing by manufacturers in the health food arena and a few misinterpreted studies conducted in vitro that tested contaminated extracts which were not pure GSE processed without solvents or brands which are known to contain preservatives, the controversy
Controversy
Controversy is a state of prolonged public dispute or debate, usually concerning a matter of opinion. The word was coined from the Latin controversia, as a composite of controversus – "turned in an opposite direction," from contra – "against" – and vertere – to turn, or versus , hence, "to turn...

 over the effectiveness of GSE continues even when studies concluded self-made pure GSE has no natural antimicrobial properties and commercial GSE has been identified with contamination from synthetic preservatives.

Independent studies have shown that commercial preparations contain the compound benzalkonium chloride
Benzalkonium chloride
Benzalkonium chloride, also known as alkyldimethylbenzylammonium chloride and ADBAC, is a mixture of alkylbenzyldimethylammonium chlorides of various even-numbered alkyl chain lengths. This product is a nitrogenous cationic surface-acting agent belonging to the quaternary ammonium group...

, which is a synthetic antimicrobial commonly used in disinfectants and cleaning products, the related compound benzethonium chloride
Benzethonium chloride
Benzethonium chloride is a synthetic quaternary ammonium salt. This compound is an odorless white solid; soluble in water. It has surfactant, antiseptic, and anti-infective properties, and it is used as a topical antimicrobial agent in first aid antiseptics. It is also found in cosmetics and...

, the antibiotic triclosan
Triclosan
Triclosan is an antibacterial and antifungal agent. It is a polychloro phenoxy phenol. Despite being used in many consumer products, beyond its use in toothpaste to prevent gingivitis, there is no evidence according to the American Food and Drug Administration that triclosan provides an extra...

, or the preservative methylparaben. Some samples were shown to contain up to 22% benzalkonium chloride by weight, despite the known allergenicity
Allergy
An Allergy is a hypersensitivity disorder of the immune system. Allergic reactions occur when a person's immune system reacts to normally harmless substances in the environment. A substance that causes a reaction is called an allergen. These reactions are acquired, predictable, and rapid...

 and toxicity
Toxicity
Toxicity is the degree to which a substance can damage a living or non-living organisms. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a substructure of the organism, such as a cell or an organ , such as the liver...

 of the compound at higher doses. These chemicals were not present in grapefruit seed extracts prepared in the laboratory
Laboratory
A laboratory is a facility that provides controlled conditions in which scientific research, experiments, and measurement may be performed. The title of laboratory is also used for certain other facilities where the processes or equipment used are similar to those in scientific laboratories...

, and GSE preparations without the contaminants were found to possess no detectable antimicrobial effect. Although citrus seed extract is sold in health food markets, there is no good evidence for any natural antimicrobial activity.

A study that examined the antiviral properties of GSE found that GSE had no efficacy as a disinfectant for feline calicivirus
Feline calicivirus
Feline calicivirus is a virus of the family Caliciviridae that causes disease in cats. It is one of the two important viral causes of respiratory infection in cats, the other being feline herpesvirus. FCV can be isolated from about 50 percent of cats with upper respiratory infection...

 and feline parvovirus
Feline panleukopenia
Feline panleukopenia virus , also known as Feline infectious enteritis, Feline distemper, feline ataxia, or cat plague, is a viral infection affecting cats, both domesticated and wild feline species. It is caused by feline parvovirus, a close relative of both type 2 canine parvovirus and mink...

.
Grapefruit seed extract has been advocated to be a powerful antimicrobial
Antimicrobial
An anti-microbial is a substance that kills or inhibits the growth of microorganisms such as bacteria, fungi, or protozoans. Antimicrobial drugs either kill microbes or prevent the growth of microbes...

 with proven activity against bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

 and fungi
Fungus
A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds , as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, and bacteria...

. However, independent studies have shown the efficacy of grapefruit seed extract as an antimicrobial is not demonstrated. Although citrus seed extract is claimed to be a highly effective plant-based preservative by some natural personal care
Natural skin care
Natural skin care is the care of the skin using naturally-derived ingredients combined with naturally occurring carrier agents, preservatives, surfactants, humectants and emulsifiers...

 manufacturers, studies asserted that the universal antimicrobial benefits associated with GSE are merely from the presence of synthetic preservative
Preservative
A preservative is a naturally occurring or synthetically produced substance that is added to products such as foods, pharmaceuticals, paints, biological samples, wood, etc. to prevent decomposition by microbial growth or by undesirable chemical changes....

s. Natural
Nature
Nature, in the broadest sense, is equivalent to the natural world, physical world, or material world. "Nature" refers to the phenomena of the physical world, and also to life in general...

 GSE has no antimicrobial properties. Newer studies found many commercial grapefruit seed extracts contaminated with synthetic preservatives. In a 2007 study the main synthetic antimicrobial agent identified in commercial GSE samples was benzethonium chloride. In a 2008 study synthetic disinfectants such as benzethonium or benzalkonium chloride were identified in most of the commercial GSE products. In a 2008 study suspected counterfeit products were determined to contain benzethonium chloride in grapefruit seed extract samples.

Methodology

Grapefruit seed extracts are added to cosmetics
Cosmetics
Cosmetics are substances used to enhance the appearance or odor of the human body. Cosmetics include skin-care creams, lotions, powders, perfumes, lipsticks, fingernail and toe nail polish, eye and facial makeup, towelettes, permanent waves, colored contact lenses, hair colors, hair sprays and...

, food supplements
Dietary supplement
A dietary supplement, also known as food supplement or nutritional supplement, is a preparation intended to supplement the diet and provide nutrients, such as vitamins, minerals, fiber, fatty acids, or amino acids, that may be missing or may not be consumed in sufficient quantities in a person's diet...

, and pesticides for their antimicrobial effect, but suspicions about the true nature of the active compounds in GSEs arose when synthetic additives were found in commercial products. Various analytical methods
Analytical chemistry
Analytical chemistry is the study of the separation, identification, and quantification of the chemical components of natural and artificial materials. Qualitative analysis gives an indication of the identity of the chemical species in the sample and quantitative analysis determines the amount of...

 were developed to determine the constituents or compounds in GSE samples which include particle-induced x-ray emission (PIXE), electrospray ionization mass spectrometry
Electrospray ionization
Electrospray ionization is a technique used in mass spectrometry to produce ions. It is especially useful in producing ions from macromolecules because it overcomes the propensity of these molecules to fragment when ionized...

 (ESI-MS), high performance liquid chromatography
High performance liquid chromatography
High-performance liquid chromatography , HPLC, is a chromatographic technique that can separate a mixture of compounds and is used in biochemistry and analytical chemistry to identify, quantify and purify the individual components of the mixture.HPLC typically utilizes different types of stationary...

 (HPLC), liquid chromatography-mass spectrometry
Liquid chromatography-mass spectrometry
Liquid chromatography–mass spectrometry is an analytical chemistry technique that combines the physical separation capabilities of liquid chromatography with the mass analysis capabilities of mass spectrometry. LC-MS is a powerful technique used for many applications which has very high...

 (LC-MS), and nuclear magnetic resonance
Nuclear magnetic resonance
Nuclear magnetic resonance is a physical phenomenon in which magnetic nuclei in a magnetic field absorb and re-emit electromagnetic radiation...

 (NMR) analysis.

Properties

There is evidence that the extract of citrus grapefruit seed has antioxidant
Antioxidant
An antioxidant is a molecule capable of inhibiting the oxidation of other molecules. Oxidation is a chemical reaction that transfers electrons or hydrogen from a substance to an oxidizing agent. Oxidation reactions can produce free radicals. In turn, these radicals can start chain reactions. When...

 properties. Analysis shows the constituents of the seed extract and pulp are flavonoids, ascorbic acid
Ascorbic acid
Ascorbic acid is a naturally occurring organic compound with antioxidant properties. It is a white solid, but impure samples can appear yellowish. It dissolves well in water to give mildly acidic solutions. Ascorbic acid is one form of vitamin C. The name is derived from a- and scorbutus , the...

 (commonly known as vitamin C
Vitamin C
Vitamin C or L-ascorbic acid or L-ascorbate is an essential nutrient for humans and certain other animal species. In living organisms ascorbate acts as an antioxidant by protecting the body against oxidative stress...

), tocopherol
Tocopherol
Tocopherols are a class of chemical compounds of which many have vitamin E activity. It is a series of organic compounds consisting of various methylated phenols...

s, citric acid
Citric acid
Citric acid is a weak organic acid. It is a natural preservative/conservative and is also used to add an acidic, or sour, taste to foods and soft drinks...

, limonoid
Limonoid
Limonoids are phytochemicals, abundant in citrus fruit and other plants of the families Rutaceae and Meliaceae. Currently limonoids are under investigation for a wide variety of therapeutic effects such as antiviral or Viricide, antifungal, antibacterial, antineoplastic and antimalarial...

s, sterols, and minerals. A study suggests the consumption of the bioactive compounds found in grapefruit seed and pulp may help suppress the development of colon cancer. Another study showed the flavonoid
Flavonoid
Flavonoids , are a class of plant secondary metabolites....

 naringin is an excellent plasma lipid lowering and plasma antioxidant active elevating flavonone.

Preparations

Self-made pure GSE processed without solvents is prepared by grinding the grapefruit seed and juiceless pulp, then mixing with glycerin.

Commercially available GSE sold to consumers are made from the seed, pulp, glycerin, and synthetic preservatives all blended together.

Precautions

Grapefruit can have a number of interactions with certain drug
Drug
A drug, broadly speaking, is any substance that, when absorbed into the body of a living organism, alters normal bodily function. There is no single, precise definition, as there are different meanings in drug control law, government regulations, medicine, and colloquial usage.In pharmacology, a...

s, increasing the potency of many compounds, including warfarin
Warfarin
Warfarin is an anticoagulant. It is most likely to be the drug popularly referred to as a "blood thinner," yet this is a misnomer, since it does not affect the thickness or viscosity of blood...

 (coumadin). Grapefruit has components that inhibit the CYP3A4
CYP3A4
Cytochrome P450 3A4 , a member of the cytochrome P450 mixed-function oxidase system, is one of the most important enzymes involved in the metabolism of xenobiotics in the body. CYP3A4 is involved in the oxidation of the largest range of substrates of all the CYPs. As a result, CYP3A4 is present in...

 enzyme in the intestine. Thus, it is this effect that increases the rate of absorption of several drugs. There are concerns about the safety
Safety
Safety is the state of being "safe" , the condition of being protected against physical, social, spiritual, financial, political, emotional, occupational, psychological, educational or other types or consequences of failure, damage, error, accidents, harm or any other event which could be...

of ingesting synthetic preservatives found in grapefruit seed extract.

Controversy

GSE usage has been popularized by many companies within the scope of the health food industry. There are books exclusively dedicated to GSE. This extract is promoted by marketers on the internet and some health food stores recommend its use. Some consumers believe this extract is an effective natural preservative even though multiple scientific studies have concluded that the universal antimicrobial activity is merely from contamination with synthetic antimicrobials.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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