View source for Siraitia grosvenorii

{{Taxobox
| color = lightgreen
| name = ''Siraitia grosvenorii''
| image = Fructus Momordicae.jpg
| image_width = 230px
| image_caption = ''Siraitia grosvenorii'' (''luohan guo'') fruits
| regnum = [[Plant]]ae
| divisio = [[Flowering plant|Magnoliophyta]]
| classis = [[Magnoliopsida]]
| ordo = [[Violales]]
| familia = [[Cucurbitaceae]]
| genus = '''''Siraitia'''''
| species = '''''S. grosvenorii'''''
| binomial = ''Siraitia grosvenorii''
| binomial_authority = ([[Walter Tennyson Swingle|Swingle]]) C.Jeffrey ex A.M.Lu & Zhi Y.Zhang
}}
'''''Siraitia grosvenorii''''' is an [[herbaceous]] [[perennial plant|perennial]] [[vine]] native to southern People's Republic of China and Northern Thailand and best known for its [[fruit]], the '''luo han guo''' (traditional Chinese: 羅漢果/simplified {{zh-cpl|c=[[wiktionary:罗|罗]][[wiktionary:汉|汉]][[wiktionary:果|果]]|p=luóhàn guǒ|l='''arhat fruit'''}} or monk's fruit).  It is one of four species in the genus '''''Siraitia'''''.  [[Botanical synonym]]s include ''Momordica grosvenorii'' and ''Thladiantha grosvenorii''.  The fruit is one of several that have been called [[longevity fruit]].<ref>Ling Yeouruenn, A New Compendium of Materia Medica, 1995 Science Press, Beijing.</ref>

The other species of the genus ''Siraitia'' are: ''S. siamensis'' from Thailand, ''S. sikkimensis'' and ''S. silomaradjae'' from India, and ''S. taiwaniana'' from the Republic of China (Taiwan).

The vine grows to 3 to 5 m long, climbing over other plants by means of [[tendril]]s which twine round anything they touch.  The narrow, heart-shaped [[leaf|leaves]] are 10&ndash;20 cm long. The [[fruit]] is globose, 5&ndash;7 cm in diameter, and contains a sweet, fleshy, edible pulp and numerous [[seed]]s.

The fruit extract is nearly 300 times [[sweetness|sweeter]] than sugar and has been used as a natural [[sweetener]] in China for nearly a millennium due to its flavor and lack of [[food energy]], only 2.3 [[calorie|kcal]]/g (9.6 [[joule|kJ]]/g). It has also been used in [[traditional Chinese medicine]].<ref>Ling Yeouruenn, A New Compendium of Materia Medica, 1995 Science Press, Beijing.</ref>

==Cultivation==
It is grown primarily in the [[Southwest China|southwestern Chinese]] province of [[Guangxi]] (mostly in the mountains of [[Guilin]]), as well as in [[Guangdong]], [[Guizhou]], [[Hunan]], and [[Jiangxi]].  These mountains lend the plants shadows and often are surrounded by mists; because of this the plants are protected from the worst of the sun. Nonetheless, the climate in this southern province is warm. The plant is rarely found in the wild and has hence been cultivated for hundreds of years.

Records as early as [[1813]] mention the cultivation of this plant in the Guangxi province.<ref>Dragon River Health Products, http://www.dragonriver.net/eng/home.html </ref> At present, the Guilin mountains harbor a plantation of 16 square kilometers with a yearly output of about 10,000 fruits. Most of the plantations are located in [[Yongfu County]] and [[Lingui County]], which in China are renowned for the extraordinary number of [[centenarian]]s. This is usually attributed to the consumption of this fruit and the unspoiled nature. The inhabitants themselves, however, are of the opinion that the reason lies in their calm lifestyle and simple nutrition.

[[Longjiang]] town ("Dragon River") in Yongfu County has acquired the name "home of the Chinese ''luohanguo'' fruit"; a number of companies specialised in making ''luohanguo'' extracts and finished products have been set up in the area. The Yongfu Pharmaceutical Factory is the oldest of these.

==Traditional uses==
The plant is most prized for its sweet fruits, which are used for medicinal purposes, and as a sweetener.<ref>Kinghorn AD and Soejarto DD, Discovery of terpenoid and phenolic sweeteners from plants, Pure Applied Chemistry 2002; 74(7): 1169-1179. </ref> The fruits are generally sold in dried form, and traditionally used in [[herbal tea]] or soup. They are used for respiratory ailments, sore throats and reputed to aid longevity.<ref>Dai Yinfang and Liu Chengjun, Fruit as Medicine, 1986 The Ram's Skull Press, Kuranda, Australia. </ref>

The best way to describe the medicinal use of luohan guo in southern China during the 20th century can be found in the book <ref>''Fruit as a medicine''</ref> written by Dai and Liu. It was written in Chinese in 1982 and translated into English in 1986. Here is their description:

:The dried fruit may be bought in a market. The surface of the fruit is round and smooth, it has a yellow-brownish or green-brownish colour, and is covered by fine hairs. The fruit has a hard but thin shell. Inside, one finds a partially dried, soft substance which contains the juice and a large quantity of seeds. All components are very sweet. Their nature is cool and not toxic. The fruit can act as a remedy for sun stroke, wet the lungs, remove [[phlegm]], stop cough and aid defecation.<ref>'''Fruits As Medicine: A Safe and Cheap Form of Traditional Chinese Food Therapy''' by Dai Yin-Fang, Liu Cheng-Jun, translated by Ron Edwards, and Gong Zhi-Mei  1986</ref>

<blockquote>
;Heat stroke and thirst: Take a fruit, break it open and pour hot water on it to make an infusion. Drink the infusion in place of tea.
;Acute or chronic infection of the larynx (aphonia): Take the halves of a fruit and 3 to 5 [[sterculia]] seeds, cover this with water and leave it to boil. Swallow very slowly. 
;Chronic cough: Take a piece of the fruit, cover it with water and leave it to boil. Drink the resulting liquid twice daily.
;Constipation due to old age: Take two fruits and, using only the soft parts and seeds, divide it into pieces. Cover these pieces with water, boil it, and drink the liquid before going to bed.
;Diabetes: Take an appropriate amount of fruit squash or boil it so as to get concentrated juice. Use this as a substitute for sugar in your nutrition..<ref>'''Fruits As Medicine: A Safe and Cheap Form of Traditional Chinese Food Therapy''' by Dai Yin-Fang, Liu Cheng-Jun, translated by Ron Edwards, and Gong Zhi-Mei  1986</ref>
</blockquote>

==Active agents==
The sweet taste of ''luohan guo'' comes mainly from the ''mogrosides'', a group of [[Triterpene]]-[[Glycosides]] that make up approximately 1% of the flesh of the fresh fruit. Through [[solvent extraction|extraction]], a powder containing 80% mogrosides can be obtained.<ref>http://www.itmonline.org/arts/luohanguo.htm Subhuti Dharmananda, Ph.D., Director, Institute for Traditional Medicine, Portland, Oregon ''Luo Han Guo -Sweet Fruit Used as Sugar Substitute and Medicinal Herb'' </ref>

Five different mogrosides are known and they are known by names with the numbers 1 to 5. The main mogroside in this plant is mogroside-5, that was previously known as ''esgoside''.<ref>http://www.itmonline.org/arts/luohanguo.htm Subhuti Dharmananda, Ph.D., Director, Institute for Traditional Medicine, Portland, Oregon </ref> 

[[image:LuHanGuo-Mogroside5.jpg|frame|Structural formula of mogroside 5|center]]

Other similar agents in ''luohan guo'' are Siamenoside and Neogroside.<ref>http://www.itmonline.org/arts/luohanguo.htm Subhuti Dharmananda, Ph.D., Director, Institute for Traditional Medicine, Portland, Oregon ''Luo Han Guo -Sweet Fruit Used as Sugar Substitute and Medicinal Herb'' </ref>

The pure mogroside mix present results in a sweetness that is 300 times [[sweet]]er than sugar. The 80% mix is approximately 250 times sweeter. Pure mogroside-5 and -5 can be up to 400 times as sweet.
 

===Toxicity===
There are no reported incidents of negative side effects of ''luohan guo'' that are known. It is classed by the American [[Food and Drug Administration]] as a GRAS ([[generally recognized as safe]]) product. There are no restrictions on consuming the fruit or its extracts.

===Current research===
Recent research on ''luohan guo'' suggests that the mogroside works as an [[antioxidant]]<ref>Shi H, et al., Antioxidant property of fructus momordicae extract, 1996 Biochemistry and Molecular Biology International 1996; 40 (6): 1111-1121. </ref> and that it helps to prevent [[cancer]].<ref>Konoshima T and Takasaki M, Cancer-chemopreventive effects of natural sweeteners and related compounds, Pure Applied Chemistry 2002; 74(7): 1309-1316. [http://www.iupac.org/publications/pac/2002/pdf/7407x1309.pdf] </ref><ref>Katiyar SK and Mukhtar H, Tea antioxidants in cancer chemoprevention, Journal of Cellular Biochemistry, Supplement 1997; 27: 59-67.</ref>

The use of ''luohan guo'' as a remedy for [[diabetes]] and overweight has been mentioned, as it can be used as a substitute for sugar.<ref>http://www.itmonline.org/arts/luohanguo.htm Subhuti Dharmananda, Ph.D., Director, Institute for Traditional Medicine, Portland, Oregon ''Luo Han Guo 
Sweet Fruit Used as Sugar Substitute and Medicinal Herb''</ref>

''Luohan guo'' has been shown to be useful against the [[Epstein-Barr]] virus. <ref>http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=ShowDetailView&TermToSearch=17477572 Akihisa T, Hayakawa Y, Tokuda H, Banno N, Shimizu N, Suzuki T, Kimura Y. ''Cucurbitane Glycosides from the Fruits of Siraitia grosvenorii and Their Inhibitory Effects on Epstein-Barr Virus Activation.'' J Nat Prod. 2007 May 25;70(5):783-788. Epub 2007</ref>

The plant also contains a glycoprotein called momorgrosvin, which has been shown to inhibit ribosomal protein synthesis<ref name="Tsang 2001">{{cite journal|author = Tsang, K.Y. and T.B. Ng | year = 2001 | title = Isolation and characterization of a new ribosome inactivating protein, momorgrosvin, from seeds of the monk's fruit Momordica grosvenorii | journal = Life Sciences | volume = 68 | pages = 773-784}} </ref>

==Cultivation and marketing==
=== Traditional processing ===
''Luohan guo'' is harvested in the form of a round green fruit, which becomes brown on drying. It is rarely used in its fresh form, as it is hard to store. Furthermore, it develops a rotten taste on fermentation, which adds to the unwanted flavours already present.

Thus the fruits are usually dried before further use and are sold in precisely this fashion in [[Chinese herbology|Chinese herbal]] shops. The fruits are slowly dried in ovens, which preserves it and removes most of the unwanted aromas. However, this technique also leads to the formation of several bitter and [[astringent]] aromas. This limits the use of the dried fruits and extracts to the preparation of diluted tea, soup, and as a sweetener for products that would usually have [[sugar]] or [[honey]] added to them.<ref>Hsu HY, et al., Oriental Materia Medica, 1986 Oriental Healing Arts Institute, Long Beach, California</ref>

===The Procter & Gamble process===
The process for the manufacture of a useful sweetener from ''luohan guo'' was [[patent]]ed in 1995 by [[Procter & Gamble]].  The patent states that, while ''luohan guo'' is very sweet, it has too many interfering aromas, which render it useless for general application. Thus the company developed a process for the removal of the interfering aromas.

In this process, the fresh fruit is harvested before it is fully mature, and is then matured in storage so that it may be processed precisely when it is mature. The shell and seeds are then removed, and the pulped fruit is made into a fruit concentrate or [[puree]]. This is then used in the further production of food. [[Solvent]]s are used, amongst other things, to remove the interfering aromas.

=== Products ===
There are a number of commercially prepared ''luohan guo'' products:

One of the most famous ones is powdered instant ''luohan guo'', which is also sold by the Yongfu company. It is sold in China, Hong Kong and in Chinese shops in the West.

In addition, there are a number of other  products which contain ''luohan guo'' either on its own or in a mix with other herbs. For example it is used with [[Ginkgo]] against cough, with [[chrysanthemum]] against [[heatstroke]] and [[headache]] or with [[asparagus]]<!--A. officinalis rare in China; other species meant?-->, ''[[Oldenlandia]]'', ''[[Scutellaria]]'', and [[pearl powder]] to [[detoxification|detoxify]].

==History==
During the [[Tang dynasty]], [[Guilin]] was one of the most important Buddhist retreats containing many temples. The fruit was named after the [[arhat]]s ({{zh-cp|c=[[wikt:罗汉|罗汉]]|p=luóhàn}}), a group of Buddhist monks who, due to their proper way of life and [[meditation]], achieved [[Enlightenment (concept) |enlightenment]] and were said to have been redeemed.  According to Chinese history, the fruit was first mentioned in the records of the [[13th century]] monks who used it.

However, plantation space was limited: it consisted mainly in the slopes of the [[Guangxi]] and [[Guangdong]] mountains, and to a lesser degree in [[Guizhou]], [[Hunan]], [[Jiangxi]], and [[Hainan]]. This and the difficulty of cultivation meant that the fruit did not become part of the Chinese herbal tradition, which depended on more readily available products. This is also the reason why one finds no mention of it in the traditional guides to herbs.

=== Rediscovery in the 20th century ===
The herb became better known in the 20th century. The first report on the herb in English was found in an unpublished manuscript written in 1938 by Professor G. W. Groff and Hoh Hin Cheung. The report stated that the fruits were often used as the main ingredients of "cooling drinks," that is, as remedies for hot weather, fever, or other dysfunctions traditionally associated with warmth or heat.

It was known that the juice of the fruits was very sweet.

Groff and Hoh realised that the fruit was an important Chinese domestic remedy for the treatment of cold and pneumonia when consumed with pork.

Interviews have confirmed that the fruit only recently gained importance in Chinese history. Nonetheless, it appears that a small group of people had mastered its cultivation a long time ago and had accumulated extensive knowledge on growth, pollination, and climatic requirements of the plant.

The fruit came to the United States in the early 20th century. Groff mentions that during a visit to the American ministry of agriculture in 1917, the botanic Frederick Coville showed him a ''luohanguo'' fruit bought in a Chinese shop in Washington. Seeds of the fruit which had been bought in Chinese shop in San Francisco were entered into the universal botanic description of the species in 1941.

The first research into the sweet component of ''luohanguo'' is attributed to C. H. Lee, who wrote an English report on it in 1975, and also to Tsunematsu Takemoto, who worked on it the early 1980s in Japan (later Takemoto decided to concentrate on the similar sweet plant, ''[[jiaogulan]]'').

The development of ''luohanguo'' products in China has continued ever since, focusing in particular on the development of concentrated extracts.

==References==
Much of the content of this article comes from [[:de:Luo Han Guo|the equivalent German-language Wikipedia article]] (retrieved [[February 16]], 2006).
 <references/>

==External links==
* [http://www.cucurbit.org/family/species/Siraitia/sirasp.html Cucurbit Network (enter 'Siraitia' in search box)]
* [http://www.itmonline.org/arts/luohanguo.htm]
* [http://www.dragonriver.net/eng/home.html Homepage of the Company ''Dragon River''] (404 2007-07-23)

[[Category:Cucurbitaceae]]
[[Category:Chinese cuisine]]
[[Category:Dietary supplements]]
[[Category:Fruit]]
[[Category:Herbs]]
[[Category:Medicinal plants]]
[[Category:Traditional Chinese medicine]]
[[Category:Sweeteners]]