Ptychopetalum olacoides

Muira puama

Description

Muira puama has a long history in herbal medicine as an aphrodisiac, a nervine tonic, anti-rheumatic and digestive tonic. Muira puama, of the Olacaceae family, like all other medicinal plants, has many common names; potency wood, marapuama, marapama, muiratã, muiratam, pau-homen and potenzholz. The medicinal part is the bark and root. Not to be confused with Acnathea virilis or Liriosma ovata which are also known as muira puama.1

Muira puama is a bush or tree with small white flowers that have a pungent fragrance similar to jasmine. It can grow up to 15 m high and has a grey trunk, dark brown leaves and orange-yellow fruits. Muira puama is native to the Brazilian Amazon where it has been used as a tonic for neuromuscular problems, for massage and baths, and as a tea for the treatment of impotence, rheumatism, and gastrointestinal problems. Muira puama was an official component of the Brazilian Pharmacopeia of 1956 and is still listed in the British Herbal Pharmacopoeia. Its use in Europe can be traced back to the 1920s.1, 2

Constituents

Muira puama root bark contains a volatile oil containing alpha-pinene, alpha-humulene, beta-pinene, beta-caryophyllene, camphene, and camphor. Uncosanoic, tricosanoic, and pentacosanoic acids make up 20% of the constituents of muira puama. Other minor compounds include coumarin, fatty acid esters of sterols, free fatty acids, beta-sitosterol, lupeol and free sterols.(1, 2)

Pharmacological activities

Antioxidant and neuroprotective activity

Muira puama is used by Amazonian peoples to prepare traditional remedies for the treatment of various central nervous system conditions, in which free radicals are likely to be implicated. A recent study examined the in vivo antioxidant effect of muira puama extract. Ageing mice (14 months) were treated (i.p.) with saline, DMSO (20%) or muira puama extrct (100mg/kg body weight), and the hippocampus, cerebral cortex, striata, hypothalamus and cerebellum dissected out 60 minutes later to measure antioxidant enzyme activities, free-radical production and damage to macromolecules. Muira puama administration reduced free-radical production in the hypothalamus, lead to significant decrease in lipid peroxidation in the cerebral cortex, striatum and hypothalamus, as well as in the carbonyl content in cerebellum and striatum. In terms of antioxidant enzymes, catalase activity was increased in the cortex, striatum, cerebellum and hippocampus, while glutathione peroxidase activity was increased in the hippocampus. This study suggests that muira puama contains compounds able to improve the cellular antioxidant network efficacy in the brain, ultimately reducing the damage caused by oxidative stress.3

An earlier study examined the neuroprotective properties of an orally administrated ethanol extract of muira puama using hippocampal slices from Wistar rats exposed to oxygen and glucose deprivation followed by re-oxygenation. The ischemic condition significantly impaired cellular viability, and increased free radical generation. In normal tissue, incubation with the muira puama extract (0.6 microg/ml) increased mitochondrial activity by 40%, without affecting free radical levels. In damaged tissue, incubation during and after oxygen and glucose deprivation significantly increased cellular viability. Additionally, at the same concentration, muira puama extract prevented the increase of free radical content induced by oxygen and glucose deprivation. In view of the fact that respiratory chain inhibition and increased generation of free radicals are major consequences of the ischemic injury, this study suggests that muira puama contains useful antioxidant and neuroprotective compounds.4

Acetylcholinesterase (AChE) inhibition

Muira puama has been found to significantly inhibit acetylcholinesterase activity in areas of the brain related to memory function. The extract significantly inhibited acetylcholinesterase activity in vitro in a dose- and time-dependent manner in rat frontal cortex, hippocampus and striatum; a significant inhibition was also found in these same brain areas of aged (14 month old) mice after acute administration of muira puama extract (100 mg/kg ip). The researchers propose that such acetylcholinesterase inhibitory activity may explain a number of therapeutic properties traditionally claimed for muira puama, particularly those associated with cognition. As Alzheimer's disease is associated with cholinergic deficits, the acetylcholinesterase inhibiting activity of muira puama may help slow the memory decline in Alzheimer's disease.5

Memory enhancing activity

Amazonian peoples use muira puama root for the treatment of various age-related conditions. An experimental study found that a single intraperitoneal (i.p.) administration of a muira puama ethanol extract (50 and 100mg/kg) improved memory retrieval in step-down inhibitory avoidance test (p≤0.05 and p≤0.01, without interfering with acquisition or consolidation in adult mice. Comparable results were obtained with the oral administration of the same muira puama extract (800 and 1000mg/kg, (p≤ 0.05 and p≤0.01). Moreover, memory amelioration was also observed (p≤0.01) in ageing mice presenting memory deficit as compared to adult mice. The study found that ageing mice treated with with the muira puama extract (800 mg/kg, p.o.) performed as well as adult mice. Consistent with its traditional use, the data suggest that muira puama facilitates memory retrieval.(6) Adding to previous data, a recent study shows that a single i.p. administration of muira puama ethanol extract (50 and 100 mg/kg) improved step-down inhibitory avoidance short-term memory 3 hours after training in adult mice. Comparable results were obtained with the extract given orally at 800 mg/kg. Moreover, memory improvement was also observed in ageing mice presenting memory deficit as compared to adult mice. Furthermore, muira puama extract (100 mg/kg) improved non-aversive memory systems in adult mice in an object recognition paradigm. Consistent with its traditional use, this study builds upon previously reported data and reinforces that muira puama facilitates memory processes. The researchers suggest that the antioxidant and acetylcholinesterase inhibitory properties of the extract may not fully explain the molecular mechanism responsible for the improvement in memory retrieval.7

Anxiogenic activity

Alcohol extracts of the roots of muira puama, also known as marapuama, are used in the Brazilian Amazon as a 'nerve tonic'. Muira puama is regarded as a stimulant, claimed to enhance physical and mental performances. A study found that muira puama ethanol extract (30, 100 and 300 mg/kg) decreased the exploratory behaviour in the hole-board test, without interfering with locomotion or motor coordination (rota-rod test). The data was found to be comparable to that obtained with 40 mg/kg pentylenetetrazol (a GABA(A) receptor antagonist and prototypical anxiogenic drug, which is extensively utilised in animal models of anxiety), which makes the authors suggest that muira puama has an pro-anxiety (anxiogenic) effect.8 However, muira puama is considered a nervine tonic and used to treat neurathenia and depression but there is no suggestion that it causes anxiety. Similarily, yohimbe, probably the most effective herbal medicine for erectile dysfunction, which is also said to have anxiogenic activity, has actually been shown to be anxiolytic. In the latest in a series of studies of how mice acquire, express and extinguish conditioned fear, researchers have found that yohimbine assists mice to learn to overcome fear faster by enhancing the effects of the natural release of adrenaline. Adrenaline prompts physiological changes such as increased heart and metabolism rates in response to physical and mental stress. Mice treated with yohimbine overcame their fear four times as fast as those treated with a medication commonly used to treat symptoms of anxiety disorders by blunting the physiological effects of adrenaline.9 This would be similar to treating fear of heights by taking a patient straight to the top of a tall building in rapid succession, rather then taking them to increasingly higher floors over a lengthy period of time. Based on a single study, there is no cause to suggest that muira puama causes anxiety, however, it would be prudent nevertheless to exercise caution in anxious patients.

Effects on cavernosal tissue

A study in rabbits has found that the Brazilian herbal medicine Catuama and each of its plant constituents (Paullinia cupana, Trichilia catigua, Zingiber officinalis and Ptychopetalum olacoides (muira puama) have a relaxing effect on the corpus cavernosum. P. cupana was however the most effective when each plant extract was tested in isolation. Relaxation of the corpus cavernosum improves penile erection.10

Adaptogenic effects

A survey of Brazilian books on traditional herbal medicine identified seven herbs which, by the totality of their actions and indications, could be considered being classified as adaptogens. These incude muira puama together with Heteropteris aphrodisiaca (nó-de-cachorro), Paullinia cupana (guarana), Turnera diffusa (damiana), Trichilia catigua (catauba), Pfaffia glomerata (known as suma or fafia) and Pfaffia paniculata (suma, both Pfaffias are also called 'Brazilian ginseng').11

Actions

Nervine tonic, antioxidant, aphrodisiac, anti-actylcholinestrase, adaptogen.

Traditional usage

Historically, muira puama, has been taken orally to prevent sexual disorders, as an aphrodisiac, for dyspepsia, menstrual irregularities, paralysis, and rheumatism. Indigenous tribes in Brazil use the tea for treating neuromuscular problems, rheumatism, influenza, cardiac and gastrointestinal asthenia and to prevent baldness. In Europe, muira puama has a long history as a herbal medicine as an anti-rheumatic, aphrodisiac, nervine tonic, and for the treatment of gastrointestinal disorders.1;2

Muira puama is included in combination products as a remedy for sexual impotence. Recent studies show promising evidence that it may increase sexual vitality and treat erectile dysfunction in males.1

Muira puama was not approved by the now dismantled, Commission E of Germany, due to lack of scientific evidence for its traditional use. Muira puama is popular with bodybuilders as it is believed to improve stamina.

Clinical studies

Low libido in women

A product containing muira puama and ginkgo (Herbal vX) was assessed in 202 healthy women complaining of low sex drive. Various aspects of their sex life were rated before and after one month of treatment. Responses to self-assessment questionnaires showed significantly higher average total scores from baseline in 65% of the sample after taking the supplement. Statistically significant improvements occurred in frequency of sexual desires, sexual intercourse and sexual fantasies, as well as in satisfaction with sex life, intensity of sexual desires, excitement of fantasies, ability to reach orgasm, and intensity of orgasm. The compliance and tolerability were good. Although this study was based on self-assessment with all the potential biases of such a study design, the initial findings support the anecdotal evidence for the benefits of Herbal vX on the female sex drive.12

Erectile dysfunction

Muira puama has a long history in Brazil as a remedy for impotence. Relaxation of the corpus cavernosum improves erection and the in vitro study mentioned earlier has shown that muira puama extract has dose-dependent relaxation effects.10

A series of case studies by Waynberg et al suggest that muira puama may be beneficial. A muira puama extract (HV430, the extract also used in Herbal vY) was tested on 2000 otherwise healthy male adults presenting with sexual dysfunctions. The study excluded patients with organic disease, ejaculatory problems, marital difficulties, primary problems, severe psychiatric disease, drug addiction, or on medication which may interfere with normal sexual function. Subjects received six tablets containing 430 mg of the extract daily for 10 days. No other treatment or counseling was given until after the 30 day monitoring period was over. The study defined significant improvement as an increase of at least two ratings in the self-assessment questionnaire. Significant improvements were seen in 54% (41/175) of patients complaining of low libido, 72% (51/170) of patients who had a reduction in coital frequency, 55% (61/109) patients missing morning erections, 62% (173/278) of patients needing a greater latent time to achieve maximal erection, 52% (106/203) of patients with instability of erection during coitus, 40% (17/42) of patients with excessive feelings of post-coital fatigue, and 66% (807/1223) of patients with global inadequacy described as 'erectile dysfunction.' A total of 1,256 or 63% of all patients reported an overall improvement. No side effects were reported. This case series shows promising results that need to be interpreted with caution due to the lack of placebo controlled arm and introduction of possible bias of study personnel not being blinded to disease state.1

A case series of muira puama extract (Testor-plus®) on 100 otherwise healthy male patients with sexual asthenia presenting with impotence and/or loss of sexual desire has been published. Subjects received six oral doses of Testor-plus®, strength not provided by author, for a 10 day period. Outcome parameters included frequency of intercourse, changes in libido, and changes in morning erections. Results showed that Testor-plus® reestablished free circulation of sexual desire by lifting the inhibition of erection in common asthenia.1

The same author also published a case series of 262 patients who had complained to have lack of sexual desire and an inability to attain or maintain an erection. All patients received a daily dose of 1-1.5g of muira puama extract for two weeks. Primary outcome parameters were changes in libido and erectile dysfunction. Results revealed that 62% of patients with loss of libido experienced a 'dynamic' effect while 51% of patients with 'erection failures' experienced some benefit. Side effects were not reported. Although results appear promising, these findings need to be confirmed from randomised, controlled trials.1

Indications

  • Impotence, erectile dysfunction and low libido
  • Infertility
  • Nervous disorders including debility, anxiety and depression
  • Poor memory
  • Asthenia, low energy
  • Gastro-intestinal cramps and colic
  • Menstrual cramps and premenstrual syndrome
  • Rheumatic pains

Use in pregnancy

Not recommended in pregnancy. No information available.

Contraindications and cautions

Muira puama is generally considered by experts to be a safe herb, and no serious adverse effects have been reported in the available scientific literature. In Brazil, a herbal medicinal extract named Catuama containing a mixture of Paullinia cupana (guarana), Trichilia catigua (catuaba), Ptychopetalum olacoides (muirapuama) and Zingiber officinale (ginger) is used as a stimulant, energy tonic and aphrodisiac. The clinical study investigated the administration of 25 ml Catuama twice a day during 28 days for any toxic effect on healthy human volunteers of both sexes. No severe adverse reactions or haematological and biochemical changes were reported.13

Administration and dosage

Dried root

simmer 1 teaspoon of root and/or bark in one cup of water for 15 minutes and take 1/2 to 1 cup daily

Liquid extract

1:1 60% ethanol: 0.5 to 2.0 ml 3 times daily

Reference list

  1. Bevens A. Muira puama (Ptychopetalum olacoides). http://www.naturalstandard.com. 2007. Natural Standard Monograph. 10-1-2008. Ref Type: Electronic Citation
  2. Taylor L. Herbal Secrets of the Rain Forrest. Rocklin: Prima Health, 1998.
  3. Siqueira IR, Fochesatto C, Torres IL, da Silva AL, Nunes DS, Elisabetsky E et al. Antioxidant activities of Ptychopetalum olacoides ('muirapuama') in mice brain. Phytomedicine 2007; 14(11):763-769.
  4. Siqueira IR, Cimarosti H, Fochesatto C, Nunes DS, Salbego C, Elisabetsky E et al. Neuroprotective effects of Ptychopetalum olacoides Bentham (Olacaceae) on oxygen and glucose deprivation induced damage in rat hippocampal slices. Life Sci 2004; 75(15):1897-1906.
  5. Siqueira IR, Fochesatto C, da Silva AL, Nunes DS, Battastini AM, Netto CA et al. Ptychopetalum olacoides, a traditional Amazonian 'nerve tonic', possesses anticholinesterase activity. Pharmacol Biochem Behav 2003; 75(3):645-650.
  6. da Silva AL, Piato AL, Bardini S, Netto CA, Nunes DS, Elisabetsky E. Memory retrieval improvement by Ptychopetalum olacoides in young and aging mice. J Ethnopharmacol 2004; 95(2-3):199-203.
  7. da Silva AL, Piato AL, Ferreira JG, Martins BS, Nunes DS, Elisabetsky E. Promnesic effects of Ptychopetalum olacoides in aversive and non-aversive learning paradigms. J Ethnopharmacol 2007; 109(3):449-457.
  8. da Silva AL, Bardini S, Nunes DS, Elisabetsky E. Anxiogenic properties of Ptychopetalum olacoides Benth. (Marapuama). Phytother Res 2002; 16(3):223-226.
  9. Cain CK, Blouin AM, Barad M. Adrenergic transmission facilitates extinction of conditional fear in mice. Learning and Memory 2004;(11):179-187.
  10. Antunes E, Gordo WM, de Oliveira JF, Teixeira CE, Hyslop S, De Nucci G. The relaxation of isolated rabbit corpus cavernosum by the herbal medicine Catuama and its constituents. Phytother Res 2001; 15(5):416-421.
  11. Mendes FR, Carlini EA. Brazilian plants as possible adaptogens: an ethnopharmacological survey of books edited in Brazil. J Ethnopharmacol 2007; 109(3):493-500.
  12. Waynberg J, Brewer S. Effects of Herbal vX on libido and sexual activity in premenopausal and postmenopausal women. Adv Ther 2000; 17(5):255-262.
  13. Oliveira CH, Moraes ME, Moraes MO, Bezerra FA, Abib E, De Nucci G. Clinical toxicology study of an herbal medicinal extract of Paullinia cupana, Trichilia catigua, Ptychopetalum olacoides and Zingiber officinale (Catuama) in healthy volunteers. Phytother Res 2005; 19(1):54-57.