Eurycoma longifolia

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 10 m 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 10 m, often unbranched with reddish brown petioles. Leaves compound, even pinnate reaching 1 m meter in length. Each compound leaf consists of 30 to 40 leaflets, lanceolate to obovate-lanceolate. Each leaflet is about 15-20 cm long, 1.5-6 cm 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 does not support the use of Eurycoma longifolia as a supplement for any purpose.

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).

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.