Yohimbine


Yohimbine
Yohimbine
Systematic (IUPAC) name
17α-hydroxy-yohimban-16α-
carboxylic acid methyl ester
Clinical data
Trade names Yocon
Pregnancy cat.  ?
Legal status OTC
Routes Oral
Identifiers
CAS number 146-48-5 YesY
ATC code G04BE04 QV03AB93
PubChem CID 8969
IUPHAR ligand 102
DrugBank DB01392
ChemSpider 8622 YesY
UNII 2Y49VWD90Q YesY
ChEBI CHEBI:10093 N
ChEMBL CHEMBL15245 YesY
Chemical data
Formula C21H26N2O3 
Mol. mass 354.44 g/mol (base)
390.90 g/mol (hydrochloride)
SMILES eMolecules & PubChem
 N(what is this?)  (verify)

Yohimbine is an alkaloid with stimulant and aphrodisiac effects found naturally in Pausinystalia yohimbe (Yohimbe). It is also found naturally in Rauwolfia serpentina (Indian Snakeroot), Alchornea floribunda (Niando), along with several other active alkaloids. Yohimbine has been used as both an over-the-counter dietary supplement in herbal extract form and prescription medicine in pure form for the treatment of sexual dysfunction. Yohimbine was explored as a remedy for type 2 diabetes in animal and human models carrying polymorphisms of the α2A-adrenergic receptor gene.[1]

Contents

Indications

Sexual

The NIH states that yohimbine hydrochloride is the standardized form of yohimbine that is available as a prescription medicine in the United States, and has been shown in human studies to be effective in the treatment of male impotence.[2]

Yohimbine Hydrochloride, USP—a standardized form of yohimbine—is a prescription medicine that has been used to treat erectile dysfunction.[3] Controlled studies suggest that it is not always an effective treatment for impotence, and evidence of increased sex drive (libido) is anecdotal only.[4]


It cannot be excluded that orally administered yohimbine can have a beneficial effect in some patients with ED. The conflicting results available may be attributed to differences in drug design, patient selection, and definitions of positive response. However, generally, available results of treatment are not impressive.[5]


Yohimbine blocks the pre- and post-synaptic alpha-2 adrenoceptors. Blockade of post-synaptic alpha-2 adrenoceptors leads to minor corpora cavernosa smooth muscle relaxation. In fact the majority of adrenoceptors in the corpora cavernosa are alpha-1. Blockade of pre-synaptic alpha-2 adrenoceptors leads to increased release of neurotransmitters in the Central Nervous System and in the corpora cavernosa penis such as nitric oxide, noradrenaline and dopamine. Whether Nitric Oxide released in the corpora cavernosa has a relaxing effect, noradrenaline has a much powerful constricting effect by stimulating the unblocked alpha-1 adrenoceptors. Concomitant use of an alpha-1 blocking agent will prevent constriction caused by the increased adrenergic stimulation.[6]

Pausinystalia Yohimbe (Yohimbe) doesn't contain just Yohimbine. It contains around 55 other alkaloids and Yohimbine accounts for 1% to 20% of total alkaloids. Among them Corynanthine is an alpha-1 adrenoceptor blocker. Hence the use of Yohimbe extract in sufficient dosages may provide concomitant alpha-1 and alpha-2 adrenoceptors blockade and thus may better enhance erections then Yohimbine alone.[7]


Yohimbine has been shown to be effective in the reversal of sexual satiety and exhaustion in male rats.[8] Yohimbine has also been shown to increase the volume of ejaculated semen in dogs, with the effect lasting at least five hours after administration.[9] Yohimbine has been shown to be effective in the treatment of orgasmic dysfunction in men.[10]

Fat loss

According to one study, oral yohimbine supplementation may actuate significant fat loss in athletes.[11] Numerous bodybuilding supplement companies sell formulations of yohimbine for transdermal delivery to effect a local reduction of adipose tissue, although the experimental evidence for its efficiency is limited.[12][13]

Other uses

Yohimbine has also been used for the treatment of sexual side effects caused by some antidepressants (SSRIs), female hyposexual disorder, as a blood pressure boosting agent in autonomic failure, xerostomia, and as a probe for noradrenergic activity.

The addition of yohimbine to fluoxetine or venlafaxine has also been found to potentiate the antidepressant action of both of these agents.[14]

Yohimbine has been used to facilitate recall of traumatic memories in the treatment of post traumatic stress disorder (PTSD).[15] Use of yohimbine outside therapeutic settings may not be appropriate for persons suffering from PTSD.[16] In pharmacology, yohimbine is used as a probe for α2-adrenoceptor. In veterinary medicine, yohimbine is used to reverse anesthesia from the drug xylazine in small and large animals.

Pharmacology

Yohimbine has high affinity for the α2-adrenergic receptor, moderate affinity for the α1-adrenergic, 5-HT1A, 5-HT1B, 5-HT1D, 5-HT1F, 5-HT2B, and D2 receptors, and weak affinity for the 5-HT1E, 5-HT2A, 5-HT5A, 5-HT7, and D3 receptors.[17][18] It behaves as an antagonist at α1-adrenergic, α2-adrenergic, 5-HT1B, 5-HT1D, 5-HT2A, 5-HT2B, and D2, and as a partial agonist at 5-HT1A.[17][19][20][21] Its intrinsic activities at the other sites listed are unclear/unknown, but it is probably mostly antagonistic at them.

Production

Yohimbine is the principal alkaloid of the bark of the West African evergreen Pausinystalia yohimbe (formerly Corynanthe yohimbe), family Rubiaceae (Madder family). There are 31 other yohimbane alkaloids found in Yohimbe. In Africa, yohimbe has traditionally been used as an aphrodisiac.[3] However, it is very important to note that while the terms yohimbine, yohimbine hydrochloride, and yohimbe bark extract are related, they are not interchangeable.[2]

The main active chemical present in yohimbe bark is yohimbine HCl (indole alkaloid), found in the bark of the Pausinystalia yohimbe tree.

However, the levels of yohimbine that are present in yohimbe bark extract are variable and often very low.[2] Therefore, although yohimbe bark has been used traditionally to reduce male erectile dysfunction, there is not enough scientific evidence to form a definitive conclusion in this area.

The tree is currently threatened with extinction in its native habitat due to international demand.[citation needed] Its conservation is difficult because the bioactivity of the tree has led many Western governments to declare it a proscribed species.

Adverse effects

Yohimbine has significant side effects, such as anxiety reactions. According to the Mayo Clinic, yohimbine can be dangerous if used in excessive amounts.[22]

Higher doses of oral yohimbine may create numerous side effects, such as rapid heart rate, high blood pressure, overstimulation, insomnia and/or sleeplessness. Some effects in rare cases were panic attacks, hallucinations, headaches, dizziness, and skin flushing.[23]

More serious adverse effects may include seizures and renal failure. Yohimbine should not be consumed by anyone with liver, kidney, heart disease, or a psychological disorder.[23]

The therapeutic index of yohimbine is quite low; the range between an effective dose and a dangerous dose is very narrow.[23] This may also lead to precipitation of panic disorder type reactions.

Yohimbine in combination with modafinil is frequently associated with nausea, dangerous acute rapid heart beat, and acute increased blood pressure. Yohimbine exhibits some degree of MAOI activity while modafinil has been shown to increase levels of various monamines, and therefore could result in severe risk of dangerous side effects.

See also

References

  1. ^ Rosengren, A. H.; Jokubka, R.; Tojjar, D.; Granhall, C.; Hansson, O.; Li, D.-Q.; Nagaraj, V.; Reinbothe, T. M. et al. (2009). "Overexpression of Alpha2A-Adrenergic Receptors Contributes to Type 2 Diabetes". Science 327 (5962): 217–20. doi:10.1126/science.1176827. PMID 19965390. 
  2. ^ a b c "Yohimbe: MedlinePlus Supplements". nlm.nih.gov. November 19, 2010. http://www.nlm.nih.gov/medlineplus/druginfo/natural/patient-yohimbe.html. Retrieved December 13, 2010. 
  3. ^ a b Yohimbe. National Center for Complementary and Alternative Medicine.
  4. ^ Andersson KE (September 2001). "Pharmacology of penile erection". Pharmacological Reviews 53 (3): 417–50. PMID 11546836. http://pharmrev.aspetjournals.org/cgi/pmidlookup?view=long&pmid=11546836. 
  5. ^ Andersson, Karl-Erik; Steers, William D. (1998). "The pharmacological basis of sexual therapeutics". In Morales, Alvaro. Erectile dysfunction: issues in current pharmacotherapy. London: Martin Dunitz. pp. 97–124 [114]. ISBN 978-1-85317-577-0. http://books.google.co.uk/books?id=VXPxffpHiXMC&pg=PA97. 
  6. ^ http://www.ncbi.nlm.nih.gov/pubmed/10845761
  7. ^ http://www.ncbi.nlm.nih.gov/pubmed/10845761
  8. ^ Fernández-Guasti A, Rodríguez-Manzo G (July 2003). "Pharmacological and physiological aspects of sexual exhaustion in male rats". Scandinavian Journal of Psychology 44 (3): 257–63. doi:10.1111/1467-9450.00343. PMID 12914589. 
  9. ^ Yonezawa A, Yoshizumii M, Ebiko M, Amano T, Kimura Y, Sakurada S (October 2005). "Long-lasting effects of yohimbine on the ejaculatory function in male dogs". Biomedical Research 26 (5): 201–6. doi:10.2220/biomedres.26.201. PMID 16295696. 
  10. ^ Adeniyi AA, Brindley GS, Pryor JP, Ralph DJ (May 2007). "Yohimbine in the treatment of orgasmic dysfunction". Asian Journal of Andrology 9 (3): 403–7. doi:10.1111/J.1745-7262.2007.00276.x. PMID 17486282. 
  11. ^ Ostojic SM (2006). "Yohimbine: the effects on body composition and exercise performance in soccer players". Research in Sports Medicine 14 (4): 289–99. doi:10.1080/15438620600987106. PMID 17214405. 
  12. ^ http://www.mesomorphosis.com/articles/volk/yohimbine-02.htm
  13. ^ Yohimbe Info and Products at Bodybuilding.com
  14. ^ Dhir, A; Kulkarni, SK (2007). "Effect of addition of yohimbine (alpha-2-receptor antagonist) to the antidepressant activity of fluoxetine or venlafaxine in the mouse forced swim test.". Pharmacology 80 (4): 239–43. doi:10.1159/000104877. PMID 17622775. 
  15. ^ van der Kolk, Bessel A. (1995). "The Treatment of Post Traumatic Stress Disorder". In Hobfoll, Stevan E.; De Vries, Marten W.. Extreme stress and communities: impact and intervention. Boston: Kluwer Academic Publishers. pp. 421–44. ISBN 978-0-7923-3468-2. http://books.google.com/books?id=sVuMSVEY83UC&pg=PA421. 
  16. ^ Morgan CA, Grillon C, Southwick SM, et al. (February 1995). "Yohimbine facilitated acoustic startle in combat veterans with post-traumatic stress disorder". Psychopharmacology 117 (4): 466–71. doi:10.1007/BF02246220. PMID 7604149. 
  17. ^ a b Millan MJ, Newman-Tancredi A, Audinot V, et al. (February 2000). "Agonist and antagonist actions of yohimbine as compared to fluparoxan at alpha(2)-adrenergic receptors (AR)s, serotonin (5-HT)(1A), 5-HT(1B), 5-HT(1D) and dopamine D(2) and D(3) receptors. Significance for the modulation of frontocortical monoaminergic transmission and depressive states". Synapse 35 (2): 79–95. doi:10.1002/(SICI)1098-2396(200002)35:2<79::AID-SYN1>3.0.CO;2-X. PMID 10611634. 
  18. ^ "PDSP Ki Database". http://pdsp.med.unc.edu/pdsp.php#search. 
  19. ^ Arthur JM, Casañas SJ, Raymond JR (June 1993). "Partial agonist properties of rauwolscine and yohimbine for the inhibition of adenylyl cyclase by recombinant human 5-HT1A receptors". Biochemical Pharmacology 45 (11): 2337–41. doi:10.1016/0006-2952(93)90208-E. PMID 8517875. 
  20. ^ Kaumann AJ (June 1983). "Yohimbine and rauwolscine inhibit 5-hydroxytryptamine-induced contraction of large coronary arteries of calf through blockade of 5 HT2 receptors". Naunyn-Schmiedeberg's Archives of Pharmacology 323 (2): 149–54. doi:10.1007/BF00634263. PMID 6136920. 
  21. ^ Baxter GS, Murphy OE, Blackburn TP (May 1994). "Further characterization of 5-hydroxytryptamine receptors (putative 5-HT2B) in rat stomach fundus longitudinal muscle". British Journal of Pharmacology 112 (1): 323–31. PMC 1910288. PMID 8032658. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1910288. 
  22. ^ Nippoldt, Todd B. Herbal viagra': Is it safe? Mayo Clinic
  23. ^ a b c Prescription for Nutritional Healing, fourth edition Phyllis A. Balch, CNC

External links


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Look at other dictionaries:

  • Yohimbine — Structure de la yohimbine Général Nom IUPAC 17α hydroxy yohimban 16α carboxylate de méthyle …   Wikipédia en Français

  • YOHIMBINE — Principal alcaloïde indolique extrait de l’écorce de Corynanthe yohimbe (rubiacée), encore connu sous les noms de corynine et d’aphrodine. Ce dernier vocable rappelle que la yohimbine aurait des propriétés aphrodisiaques, probablement en raison… …   Encyclopédie Universelle

  • yohimbine — [yō him′bēn] n. [< yohimbé, a tropical Afr tree (of Bantu orig.) + INE3] a poisonous alkaloid, C21H26N2O3, obtained from quebracho bark and the bark of a West African tree ( Corynanthe yohimbé) of the madder family: formerly used as an… …   English World dictionary

  • yohimbine — mˌbēn, bə̇n noun ( s) Etymology: International Scientific Vocabulary yohimbé+ ine 1. : a crystalline alkaloid C21H26N2O3 that is the principal alkaloid of yohimbé bark and that has sympathomimetic and hypotensive effects and has been used in the… …   Useful english dictionary

  • yohimbine — noun Etymology: International Scientific Vocabulary, from yohimbe Date: 1898 an alkaloid C21H26N2O3 obtained from the bark of the yohimbe that is a weak blocker of alpha adrenergic receptors and has been used as an aphrodisiac …   New Collegiate Dictionary

  • yohimbine — /yoh him been/, n. Pharm. an alkaloid, C21H26N2O3, extracted from the bark of Corynanthe johimbe or Rauwolfia serpentina, used as a selective alpha adrenergic receptor antagonist: purported to have aphrodisiac properties. [1895 1900; YOHIMB(E) +… …   Universalium

  • yohimbine — noun A tryptamine alkaloid, the active chemical constituent of the medicinal herb Pausinystalia yohimbe: a stimulant and supposed aphrodisiac. See Also: yohimbic acid …   Wiktionary

  • yohimbine — An alkaloid, the active principle of yohimbé, the bark of Corynanthe yohimbi (family Rubiaceae); it produces a competitive blockade, of limited duration, of adrenergic α receptors; has also been used for its alleged aphrodisiac properties. * * *… …   Medical dictionary

  • yohimbine — [jəʊ hɪmbi:n] noun Chemistry a toxic compound obtained from the yohimbe tree, used in the treatment of impotence …   English new terms dictionary

  • yohimbine — yo·him·bine …   English syllables