Influence of traditional Turnera diffusa var. aphrodisiaca (Damiana) extract on
monoamine- and glutamate receptor-mediated neurotransmission
Felix Heiner1, Björn Feistel1, Kurt Appel2
1 Finzelberg GmbH & Co. KG, Koblenzer Strasse 48-56, 56626 Andernach, Germany 2 Vivacell Biotechnology GmbH, Ferdinand-Porsche Str. 5, 79211 Denzlingen, Germany
Bonn Polyphenols 2018: 12th World Congress On Polyphenols Applications September 25 - 28, 2018, Bonn
Damiana (Turnera diffusa var. aphrodisiaca, Passifloraceae) is an aromatic, up to 2 m high
shrub endemic to tropical regions of America: Caribbean, Mexico, South America. Its dried
leaves have been used as an aphrodisiac by indigenous peoples of Mesoamerica since pre-
Columbian times (both genders). Besides essential oil, terpenes, and phytosterols, the
plant contains polyphenolic compounds such as flavonoids and tannins. Commercial
products in form of tablets, containing a 90% ethanolic Damiana dry extract with a DER
native of 5–7:1, are marketed as aphrodisiacs (THMP).
Pharmacological evidence and plausibility are delivered by several studies. Hydro-
ethanolic Damiana extracts had shown to stimulate sexual behaviour in rats  and
demonstrated a time-dependent efficacy on mild erectile dysfunction in men . A variety
of mechanisms may contribute to the increase of sexual potency: 90% EtOH extract and
single polyphenols showed in vitro-inhibition of aromatase which might lead to higher
testosterone levels, having an impact on the libido of both genders [3,4]. Vasorelaxant
activity through NO-pathway and inhibition of PDE-V enhances blood flow in Corpus
cavernosum penis and clitoridis [4,5]. Also, central nervous actions, primarily attributed to
apigenin, may be part of the sexual stimulation .
Following this idea, the aim of our investigations was to analyze the traditional Damiana
leaf extract (EtOH 90% v/v; 50% native; manufactured by Finzelberg GmbH) concerning
effects on neurotransmitter receptors and uptake.
Monoamine neurotransmitter reuptake
The influence on dopamine, serotonin, and
noradrenaline uptake into rat synaptosomes by
the Damiana extract was measured.
The assays were initiated by addition of [³H]-
dopamine, [³H]-serotonin, or [³H]-norepine-
phrine to isolated rat synaptosomes and
graded concentrations of the extract in
incubation buffer. After incubation for 15 min
at 37 °C in the dark, samples were transferred
onto GF/C-filter plates and filter-bound
radioactivity was determined by a microplate
reader. The compounds GBR 12909 (DA),
imipramine (5HT), and protriptyline (NA)
served as reference inhibitors to approve the
suitability of the methods.
The calculated IC50-values revealed that the
Damiana extract is an outstanding inhibitor of
dopamine reuptake. Furthermore, noradrena-
line uptake was considerably inhibited and a
moderate inhibition of serotonin uptake could
[µg/mL] 2.7 ± 0.1
AMPA and NMDA receptor modulation
The ability of the Damiana
extract to interfere with
glutamate receptors, was
tested ex vivo with
hippocampus slice prepa-
Midsections of the hippo-
campi from 8 adult male
Sprague-Dawley rats that
received daily administration
of 60 mg/kg Damiana extract
or placebo for 7 days were
excised. Electrical stimulation
of Schaffer collaterals lead to
release of glutamate, result-
ing in excitation of the
postsynaptic pyramidal cells.
Compared to placebo-treated
rats, Damiana treatment
attenuated this response,
visible through significantly
lower amplitude of
population spikes (lower
excitability, Fig. 2).
We found important CNS effects of the traditional Damiana extract that is used in
commercial products. AMPA-antagonism has been linked to anxiolytic response  and
reuptake-inhibition of monoamine neurotransmitter, as well as NMDA modulation, are
associated with mood-enhancing / antidepressant properties . This might contribute to
the aphrodisiac activity of Damiana. Furthermore, it is known that sexual desire is not only
regulated by sex hormones; high levels of DA and NA also play their role. The mode of
action of flibanserin (for hypoactive sexual desire disorder) is based on this effect .
 Estrada-Reyes, R. et al.; Turnera diffusa Wild (Turneraceae) recovers sexual behavior in sexually exhausted males.
J Ethnopharm 123: 423-429, 2009
 Feistel, B., Walbroel, B.; Traditional aphrodisiaca Turnera diffusa WILLD. – new human aspects. Poster at 15th Internat.
Congress PHYTOPHARM, July 25-27 2011, Nuremberg, Germany, 2011
 Zhao, J. et al.; Anti-aromatase activity of the constituents of Damiana (Turnera diff.). J Ethnopharm 120: 387- 393, 2008
 Feistel, B., Appel, K., Pischel, I.; Traditional aphrodisiac Turnera diffusa WILLD. – new pharmacological aspects about
Damiana. PHYTO Therapie Austria 3-18: PA7, 2018
 Estrada-Reyes, R., Carro-Juárez, M., Martínez-Mota, L.; Pro-sexual effects of Turnera diffusa Wild (Turneraceae) in male
rats involves the nitric oxide pathway. J Ethnopharm 146: 164-172, 2013
 Kumar, S. et al.; Pharmacological evaluation of bioactive principle of Turnera aphrodisiaca. Indian J Pharm Sci 70: 740 -
 Andreasen, J.T. et al.; Differential role of AMPA receptors in mouse tests of antidepressive and anxiolytic action.
Brain Res 1601: 117-126, 2015
 Pochwat, B. et al.; NMDA antagonists under investigation for the treatment of major depressive disorder. Expert Opin
Investig Drugs 23: 1181-1192, 2014
 Stahl, S.M.; Mechanism of action of flibanserin, a multifunctional serotonin agonist and antagonist (MSAA), in
hypoactive sexual desire disorder. CNS spectrums 20: 1-6, 2015
Acknowledgement: We would like to thank Prof. Dr. Wilfried Dimpfel, NeuroCode AG, for his technical guidance.
In order to test the interference with specific glutamate receptors, glutamatergic
neurotransmission was tested in the presence of potent and selective agonists. There was
no difference between responses of Damiana-pretreatment only and Damiana + AMPAR
agonist (S)-(-)-5-Fluorowilardine (Fig. 3). The agonist was not able to exert its usual action
due to modulated AMPAR-mediated neurotransmission by the Damiana extract: direct
antagonism may be possible. Also, NMDAR-mediated transmission was slightly, but
significantly, influenced by the extract, implying a modulation of this particular glutamate
Fig. 1: Inhibition of neurotransmitter reuptake.
n=4; deviation expressed as SEM
Fig. 2: Damiana reduced glutamatergic neurotransmission provoked by
Fig. 3: Damiana antagonized actions of AMPAR agonist Fluorowilardine
Fig. 4: A multitude of mechanisms may contribute to sexual arousal and potency of both genders
Inhibition of PDE5
increased sexual desire