Tongkat Ali

''Eurycoma longifolia'' (commonly called ''tongkat ali'', ''pasak bumi'', or ''longjack'') is a flowering plant in the family Simaroubaceae. It is native to Indochina (Cambodia, Laos, Malaysia, Myanmar, Thailand and Vietnam) and Indonesia (the islands of Borneo and Sumatra), but has also been found in the Philippines. The plant is a medium-sized slender shrub that can reach in height, and is often unbranched. The root of the plant has been used in folk medicine of the South East Asian region, and in modern times has common use as supplements, as well as food and drink additives.

Names

''Eurycoma longifolia'' is also known by the common names , , , , , , , , , (all Malay-Indonesian); (Javanese); (Vietnamese); (Laotian); , , , , (all Thai); "long jack" (US); ''langir siam'' (Bahrain). Many of the common names refer to the plant's medicinal use and extreme bitterness. ''Penawar pahit'' translates simply as "bitter charm" or "bitter medicine". Older literature, such as a 1953 article in the ''Journal of Ecology'', may cite only ''penawar pahit'' as the plant's common Malay name.

As mentioned above, ''E.longifolia'' is known by common names "tongkat ali" and "pasak bumi" in the South East Asian region, but these names are also used for the physiologically similar species ''Polyalthia bullata''. The bark and root of ''E.longifolia'' is more white/yellow-ish compared to the darker-colored ''P. bullata'', which has led to the former being known as "tongkat ali/pasak bumi putih" or "tongkat ali/pasak bumi kuning", and the latter as "tongkat ali/pasak bumi hitam". ("Putih" means "white", "kuning" means "yellow", and "hitam" means "black" in Malay/Indonesian.) Indonesia also has a red-coloured variety known as "tongkat ali/pasak bumi merah" ("merah" meaning "red"), which is being studied by researchers and has not had its species classified.

''Eurycoma longifolia'' is also known by the species name ''Eurycoma longifolia Jack'', as this was the name used by botanist William Jack in his taxonomical description published in 1822.

Description

A medium size slender shrub reaching , often unbranched with reddish brown petioles. Leaves compound, even pinnate reaching meter in length. Each compound leaf consists of 30 to 40 leaflets, lanceolate to obovate-lanceolate. Each leaflet is about long, wide, and much paler on the ventral side.

Inflorecense axillary, in large brownish red panicle, very pubescent with very fine, soft, granular trichomes. Flowers are dioecious. Petals are small, very fine pubescent. Drupe hard, ovoid, yellowish brown when young and brownish red when ripe. The plant grows in the understorey of lowland forests, and survives on a variety of soils but prefers acidic, well-drained soil.

Uses

Many purported health benefits have been attributed to ''Eurycoma longifolia''. The plant is used in the traditional medicine of Indonesia, Malaysia and Vietnam. In Indonesia and Malaysia, the root of the plant is boiled in water, and the water is consumed as a health tonic for post-partum recovery, as an aphrodisiac, as well as the relief of fever, intestinal worms, dysentery, diarrhea, indigestion, and jaundice. In Vietnam, the flower and fruits are used to treat dysentery, and the root is used for malaria and fever. In Malaysia, a paste of the plant is applied topically to relieve headaches and stomach-aches. There is a traditional belief that ''E.longifolia'' is an aphrodisiac. Other health benefits attributed to this plant include antimalarial, antidiabetic, antimicrobial, antipyretic, anti-dengue and immunomodulation activities. In Indonesia and Malaysia, ''E.longifolia'' has been widely commercialized. Its root, which is highly bitter, has been used as the basis for supplements, as well as food and drink additives. In the US, the extract has self-affirmed generally recognized as safe (GRAS) status, as an ingredient. As a supplement, it has been marketed for the supposed benefits of sexual health improvement, as an energy and stamina booster, for improving blood circulation, to reduce stress, and fat reduction. In the drinks market, it is a common ingredient for coffee and beverages marketed as energy drinks.

Available clinical data supports the use of ''Eurycoma longifolia'' as a supplement. In 2012, a randomized, double-blind study of 109 male participants showed significant improvements in libido, sexual performance, satisfaction, physical performance, sperm volume and sperm motility after supplementation. In 2021, a University of Malaya study reported that E. longifolia led to increased testosterone in young men. A separate study published in the same year of 45 middle-aged male participants conducted by Santa Catarina State University in Brazil found that, over a 6 month period, ''E. longifolia'' caused increased muscle strength and testosterone levels.

Beyond increases in testosterone, Tongkat Ali has been shown to cause a reduction in cortisol.

Commercialization

Adulteration and contamination

There have been a number of cases of products falsely claiming to contain ''E.longifolia'' as an ingredient, as well as ''E.longifolia'' product contamination cases. In 2006 the U.S. Food and Drug Administration (FDA) banned seven dietary supplement products that claimed to include ''E.longifolia'' as a principal ingredient, but which additionally contained prescription drugs and even analogues of prescription drugs that have not yet been tested for safety in humans, such as acetildenafil.

In 2017, the FDA announced that two different brands of ''E.longifolia''-containing coffee were recalled after being found to be adulterated with active ingredients from erectile dysfunction drugs.

In Malaysia, there are over 200 registered ''E.longifolia'' products. However, a 2004 study determined, following quality testing, that 36% of these were contaminated with mercury beyond legally permitted limits.

Extracts

Products stating various ''E.longifolia'' extract ratios of ''1:50, 1:100, and 1:200'' are common on the market. However extracts based on this ratio system are often misleading and hard to verify. Scientific research done on herbal products in general indicates that in many cases the content of bioactive constituents varies between products. One perception is that a higher extraction ratio indicates a stronger product, but higher extract ratio just means that more of everything else that was part of the original material was removed, and is not a measure of how much actual ''E.longifolia'' mass is present.

Another option is for extraction techniques to utilize standardization methods to monitor the bioactive content and quality of the extract against standardization markers. Among standardization markers that have been used for ''E.longifolia'' are eurycomanone, total protein, total polysaccharide and glycosaponin, which have been recommended in a technical guideline developed by the Scientific and Industrial Research Institute of Malaysia (SIRIM).

Patents

An extract process and method of treatment for sexual dysfunction and male infertility was issued a U.S. patent in 2006, with subsequent international filings in the EU and Japan. Additional patent applications have been filed in the U.S. for various processes and indications, but as of August 2017 none have resulted in issued patents; the inclusion of three such patent applications follow this sentence. An attempt to patent ''E.longifolia'' led to protests due to its being a natural product with widely-known traditional uses, though the patent in question was allegedly meant only to cover a specific extraction process, rather than the plant itself. One of the patent licensees, Biotropics, clarified that the patent does not claim the plant itself nor "traditional knowledge" over the plant, but covers only "new scientific uses" relating to the plant.

Conservation and sustainability

''E.longifolia'' is mainly used for its roots, which necessitates uprooting the entire plant when it is harvested. This has led to concerns over the long-term sustainability of its use.

In Malaysia raw ''E.longifolia'' is banned from export, and the plant itself been listed as one of the priority medicinal species for conservation, and the harvesting of wild trees is restricted according to Act 686 on International Trade in Endangered Species. In 2016, Ahmad Shabery Cheek, the Malaysian Minister of Agriculture, said that the species may go extinct within twenty years if cultivation and replanting efforts are not made quickly. Despite this, the Malaysian government has encouraged the commercialization of high-value herbal products based on this plant, notably in its 2010 Economic Transformation Programme, where Tongkat Ali is listed among the top five herbs to be developed on a large scale until the year 2020. To support this commercialization, the Malaysian government made attempts to encourage the long-term commercial cultivation of the plant, through the provision of grants for farmers, enabling agronomy research by MARDI, and the formation of cluster farms under the East Coast Economic Region.

Chemical constituents

''Eurycoma longifolia'' has been reported to contain the glycoprotein compounds eurycomanol, eurycomanone, and eurycomalactone.

See also

* ''Labisia pumila''
* Quassinoid

References

{{Taxonbar, from=Q311710

Medicinal plants of Asia
Simaroubaceae
Flora of Indo-China
Flora of Borneo
Flora of Sumatra
Dioecious plants