Even though there are many other legitimate medical areas of interest in Eurycoma longifolia (as evident from the quote included above), most Southeast Asians consume it for the plant's impact on sexual conduct. Already in 2001, Malaysian scientific researchers opened their peer-reviewed, Medline-archived report on Eurycoma longifolia's effect on lab rats with the statement "that Eurycoma longifolia Jack commonly known as Tongkat Ali has gained notoriety as a symbol of man's ego and strength by the Malaysian men because it increases male virility and sexual prowess during sexual activities."[6]
An article on the website of the scientific journal Nature referred to Eurycoma longifolia as Malaysia's home-grown Viagra and cited "increased sexual desire, enhanced performance and general well-being".[7] This journal article is also indexed on Medline, but without abstract.[7]
Some scientific studies found that it enhances sexual characteristics and performance in rodents.[8][9][10] Other laboratory animal tests have produced positive indications, with one extract having been observed to increase sexual activity in mature rats, including arousal, sniffing, and mounting behavior.
In an experiment conducted on male rats, it was found that eurycoma longifolia increases sperm count. The authors also reported that the plasma testosterone level of Eurycoma longifolia extract treated rats "was significantly increased when compared with that of the control and infertile animals."[11]
Another group of scientists confirmed that Eurycoma longifolia has the capacity to "reverse the inhibitory effects of estrogen on testosterone production and spermatogenesis."[12]
One Medline-indexed journal article cited as result that Eurycoma longifalia had an effect similar to testosterone replacement therapy in counteracting ostereoposis.[13]
An Italian study on Eurycoma longifolia noted improved sexual performance in lab animals and concluded that the "effect could be mainly ascribed to increased testosterone levels."[14]
After scientists investigating Eurycoma longifolia's effect on sexual parameters had established that sexualizing effects went hand-in-hand with increased testoterone tone, researchers in the field of sports medicine started to look into the anabolic potential of the plant.
In a placebo-controlled human study with healthy young men in a weight-training program, it was found that "the lean body mass of the treatment group showed a significant increment, from 52.26 (7.18) kg to 54.39 (7.43) kg (p = 0.012)." Furthermore, "the increase in strength in the treatment group was larger than in the placebo group (6.78% and 2.77% respectively)… The mean arm circumference of the treatment group increased significantly by 1.8 cm after the supplementation… but there was no significant increase in the placebo group." The results of the study were published in the peer-reviewed British Journal of Sports Medicine.[15]
The anabolic impact of Eurycoma longifolia has been confirmed in the animal model, when the size and weight of just one muscle was measured in treated and untreated rats of equal size. "Results showed that 800 mg/kg of butanol, methanol, water and chloroform fractions of E. longifolia Jack significantly increased (p<0.05) the leavator ani muscle…"[6]
Because of Eurycoma longifolia's testosterone-enhancing capacity, it has been included, at least by name, in numerous supplements, marketed primarily to bodybuilding men. One randomly selected Internet site selling bodybuilding supplements[16] listed 58 different products claiming to be Eurycoma longifolia or contain it as one of many ingredients. In gym circles, Eurycoma longifolia Jack is commonly referred to as Longjack.[17][18]
Most of the 58 Eurycoma longifolia supplements listed on the above-cited site exhibit all the elements of quackery, such as exaggerated claims and pseudo science,[19] outlandish -isms ("raise testosterone levels via Testobullism"[20]), "proprietary formulas",[21] often not stating how much of what was mixed together.
One such product lists Eurycoma longifolia as one of more than 30 unquantified ingredients.[22]
In such formulas, the minimal Eurycoma longifolia part isn't a therapeutic dose by any standard, as the quassinoids of Eurycoma longifolia are characterized by poor oral bioavailability.
A study into this aspect concluded: "The results indicate that eurycomanone is poorly bioavailable when given orally… the absolute bioavailability of the compound was low with 10.5%… its poor oral bioavailability may be due to poor membrane permeability in view of its low P value and/or high first-pass metabolism."[23]
In vivo studies with lab animals used root powder of 250, 500, or 1000 mg per kg of body weight,[14] or 200 to 800 mg/kg twice daily,[10][24] or 50, 100, and 200 mg of Eurycoma longifolia extract per kg of body weight.[11] At the higher dosages (800 mg of the water, chloroform, methanol, or butanol extracted fraction of Eurycoma longifolia per kg of body weight), the effects were more pronounced for both sexual motivation[25][26] and levator ani size increase.[6]
Apart from the testosterone-related effects, the antimalarial,[27] antibacterial,[28] antipyretic, antiulcer, antitumor,[29] and cytotoxic properties are well documented.
Taiwanese scientists isolated 65 biochemical compounds from the roots of Eurycoma longifolia, of which ten exhibited "strong cytotoxicity" towards human lung and breat cancer cell lines.[30]
Apart from the better-known quassinoids, the same group of scientist also isolated beta-carboline alkaloids, several of which were active against lung and breast cancer cell lines.[31]
Investigating the activity of 24 Eurycoma longifolia quassinoids against cancer cell lines, including lung cancer cells, medical researchers in Japan found that eurycomalactone was as effective against cancer cells as the established anti-cancer drug doxorubicin.[32]
The same group of researchers also discovered several new biochemical compounds in Eurycoma longifolia and screened them for cytotoxic properties. They concluded that different fractions were effective against different cancers.[33][34]
Another study confirmed that fractions of Eurycoma longifolia extract induced apoptosis in breast-cancer cells.[35]
One extract has since been co-patented by the government of Malaysia and the Massachusetts Institute of Technology.[36] However, the idea that products of nature on which there exists a large body of knowledge among indigenous peoples can be the subject of intellectual property rights, even of national governments, has long been challenged in peer-reviewed law journals.[37]
[edit] Products
Fake Eurycoma longifolia products have been pulled off the shelves in several countries but are still sold over the Internet, mostly shipped from the UK. In a medical journal article, published March 2010, it was noted that "estimates place the proportion of counterfeit medications sold over the Internet from 44% to 90%" with remedies for sexual dysfunction accounting for the greatest share.[38] It is therefore recommended that buyers of Eurycoma longifolia request from Internet vendors conclusive information, and proof, on the facilities where a product has been manufactured.In Malaysia, the common use of Eurycoma longifolia as a food and drink additive, coupled with a wide distribution of products using cheaper synthetic drugs in lieu of Eurycoma longifolia quassinoids, has led to the invention of an electronic tongue to determine the presence and concentration of genuine Eurycoma longifolia in products claiming to contain it.[39]
On the other hand, consumers who lack the sophisticated electronic tongue equipment invented in Malaysia for testing the presence of Eurycoma longifolia, but want more clarity on whether the product they obtained is indeed Eurycoma longifolia or a fake, can use their own tongue to taste the content of capsules for the bitterness of the material. Quassinoids, the biologically active components of Eurycoma longifolia root,[40][41][42] are extremly bitter. They are named after quassin, the long-isolated bitter principle of the quassia tree. Quassin is regarded the bitterest substance in nature, 50 times more bitter than quinine.[43] Anything that isn't bitter, and strongly so, cannot contain quassinoids from Eurycoma longifolia .
In the US, the FDA has banned numerous products such as Libidus,[44] claiming to use Eurycoma longifolia as principal ingredient, but which instead are concoctions designed around illegal prescription drugs, or even worse, analogues of prescription drugs that have not even been tested for safety in humans, such as acetildenafil.[45] In February 2009, the FDA warned against almost 30 illegal sexual enhancement supplements,[46] but the names of these products change quicker than the FDA can investigate them. Libidus, for example, is now sold as Maxidus, still claiming Eurycoma longifolia (tongkat ali) as principal ingredient.[47]
The government of Malaysia has banned numerous fake products which use drugs like sildenafil citrate instead of tongkat ali in their capsules. To avoid being hurt by bad publicity on one product name, those who sell fake tongkat ali from Malaysia have resorted to using many different names for their wares.[48]
The governments of Canada and Singapore have issued warnings against the product XP Tongkat Ali Supreme for containing the prescription drug tadalafil which can be life-threatening in some individuals.[49]
Products claiming various Eurycoma longifolia extract ratios of 1:20, 1:50, 1:100, and 1:200 are sold. Traditionally Eurycoma longifolia is extracted with water and not ethanol. However, the use of selling Eurycoma longifolia extract based on extraction ratio may be confusing and is not easily verifiable.
In expectation of a competitive edge, some manufacturers are claiming standardization of their extract based on specific ingredients. Alleged standards / markers are the glycosaponin content (35–45%) and eurycomanone (>2%). While eurycomanone is one of many quassinoids in Eurycoma longifolia, saponins, known in ethnobotany primarily as fish poison[50][51] played no role in the academic research on the plant.
A large number of Malaysian Eurycoma longifolia products (36 out of 100) have been shown to be contaminated with mercury beyond legally permitted limits.[52]
No comments:
Post a Comment