Protodioscin (Tribulus terrestris) treatment in males diagnosed
with infertility and impotence
Medical Biology Division of Andrology, University of Sriwijaya,
Libilov treatment consisting of oral administration of 3 x 1 to
3 x 2 tablets / day for 14 to 60 days was shown to be effective
in improving the concentration and quality of spermatozoa in patients
with oligozoospermia. Furthermore, the treated men also reported
improvement in sexual libido, erection, ejaculation and orgasm.
Libilov treatment also resulted in improved spermatogenesis in the
Sertoli and germinal cells, and increased the efficiency of testosterone
conversion to dihydrotestosterone (DHT). As DHT played an important
role in the improvement of red blood cell formation (erythropoiesis)
as well as muscle development, this contributed to the sense of
physical well-being and improved oxygen circulation in the body.
Indirectly, these effects also added to the improvement in sexual
functions, including libido, erection, and orgasm.
Protodioscin is the active ingredient found in the extract of the
plant Tribulus terrestris L., available under the tradename Libilov™.
This herbal plant has been traditionally used in Asian and European
countries to treat infertility and impotence (Viktorof et al. 1994).
Male fertility is defined as a man's ability to impregnate his spouse
or partner, leading to a successful birth within the first twelve
months of continuous effort to conceive. In contrast, the inability
of the male to achieve conception is defined as male infertility.
In primary male infertility, it is the woman's first time trying
to conceive. On the other hand, if a man has successfully impregnated
the woman in the past, leading to a normal pregnancy, or spontaneous
or intentional abortion, but is currently unable to impregnate his
wife successfully within one year of effort, then his infertility
is characterized as secondary infertility (Rowe et al. 1993).
Generally defined, impotence is a collection of sexual dysfunctions
that can be manifested as reduction in sexual drive, desire or libido,
penile erection, ejaculation or even the ability to achieve orgasm.
As impotence can occur in all sexual response phases, we can classify
impotence as follows (Susilo 1994, Adimoelja 1985, Barry and Hodges
1987, Ellenberg 1971):
1. Impotensia libidinis or impotensia concupiciency ( manifests
as lowered sexual drive)
2. Impotensia erectionis (the inability to achieve or maintain
penis erection for normal sexual intercourse)
3. Impotensia ejaculationis (involves ejaculation dysfunctions,
which includes premature, retarded, retrograde, incomplete ejaculations
4. Impotensia satisfactionis / emotionis (manifests as unsatisfactory
orgasm or inability to reach orgasm during sexual intercourse)
Here, we review the mechanism of how protodioscin treatment works,
as well as the result of Libilov clinical trials on male subjects
diagnosed with either impotence or infertility.
CLINICAL ACTION OF PROTODIOSCIN ON THE MALE REPRODUCTIVE
In comparison to currently available treatments for infertility
and impotence, protodioscin has been shown to be more efficient,
less costly, and more importantly, to carry significantly less risk
of unwanted side-effects. The rapid development of Libilov, a non-hormonal
and natural herbal preparation of Tribulus terrestris L., was accompanied
by intensive clinical and laboratory tests. Based on those tests,
we conclude that Libilov provides an effective viable alternative
in treating male impotence and infertility.
Chemical and Physical Characteristics of Protodioscin
Protodioscin is the active ingredient of the plant extract of Tribulus
terrestris L., and is produced by PT Teguhsindo Lestaritama, Indonesia.
Protodioscin is classified as a furostanol saponin, and is present
in the extract at no less than 45% of the total weight. The chemical
structure of this compound is shown below in Figure 1.
Figure 1. The chemical structure
of protodioscin, the active ingredient of Tribulus terrestris L.
Protodioscin is physically characterized as a bitter-tasting amorphous
powder, with a yellow-brown color. It is soluble in water, slightly
soluble in methanol, but not soluble in chloroform.
Three male sex steroids or androgens, namely testosterone, dihydrotestosterone
and estradiol, are important for the male reproductive system (Greenspan
1991). From a quantitative perspective, the most important androgen
is testosterone. More than 95% of this hormone is produced by Leydig
cells, with the rest produced by the adrenal glands. To supplement
testosterone, the testes also produces a small amount of potent
form of androgen called dihydrotestosterone (DHT), as well as weaker
forms such as dehydroepiandrosterone (DHEA) and androstenedione.
These cells also secrete a small quantity of estradiol (E), estrone,
pregnenolone, and progesterone, and 17-alpha-hydroxyprogesterone.
In addition to their production in testes, DHT and E are also produced
by the breakdown of androgens in the peripheral circulatory networks.
The biosynthetic steps of androgen in the testes is diagrammed in
Figure 2. The contribution of testes, adrenal and peripheral networks
on the serum level of the male sexual steroids is shown in Table
Figure 2. The biosynthetic steps
of androgen production in the testes.
|| Testes Secretion
|| Adrenal Secretion
|| Peripheral Conversion
|| < 1
|| < 5
|| < 1
|| < 1
|| < 1
|| < 10
Table I. The contribution of testes adrenal secretion
and peripheral network conversion on the total level of androgens
in the bloodstream. Values are in percent.
In the bloodstream, androgen and estrogen are either in free form,
or are in a form bound to serum proteins. Although approximately
38% of bound testosterone is bound to albumin, its major binding
partner is the Sex Hormone Binding Globulin (SHBG), which associates
with more than 60% of bound testosterone. SHBG is different from
the Androgen Binding Protein (ABP), which is synthesized by the
heart and the Sertoli cells, as SHBG level can be increased by treatment
with estrogen or thyroid hormones, or by medical conditions of hyperthyroidism
and hepatic cirrhosis. Conversely, treatment with growth hormone,
or condition of hypothyroidism, acromegaly or obesity can lower
the level of this protein. Approximately 20% of testosterone in
the bloodstream is in the unbound or free form. This form of testosterone
is free to enter and metabolically affect cells. In addition to
the level of the free form, the bioavailability of testosterone
is also influenced by the dissociation of testosterone from its
The majority of testosterone is converted in the heart into metabolites
such as androsterone and eticholanolone, which are secreted in the
urine after they react chemically with glucoronatic or sulfuric
acid into 17-keto-steroid. However, since this is not the major
source of 17-ketosteroid, simple measurement of this compound in
the urine does not provide an accurate picture of testes steroid
production. Moreover, this measurement would also not be able to
detect the small amount of testosterone that is converted into a
specific form of androgen called dihydrotestosterone (DHT) in specific
In the majority of target cells, some testosterone is enzymatically
converted into DHT by the microsomal enzyme 5-alpha-reductase. Similar
to testosterone, DHT is then bound by an intracytoplasmic receptor
protein specific for it (becoming DHT-Rc, Figure 3). After the DHT-protein
complex formation, the bound hormone is transported into the nucleus
(becoming DHT-Rn, Figure 3). There the protein complex undergoes
a conformational transformation, which is thought to involve chromatin
binding. This results in mRNA syntheses, and subsequently in syntheses
of cytoplasmic proteins, which lead to cell growth and other secondary
effects mediated by androgens (Figure 3).
Figure 3. The mechanism of the androgen's
action. Free testosterone is transported into the cell and some
is converted to dihydrotestosterone (DHT). Cytoplasmic receptors
(Rc) bind these molecules, which are subsequently transported into
the nucleus. These protein-hormone complexes (DHT-Rn, T-Rn) activate
transcriptions of androgen-sensitive genes, resulting in the production
of transcript mRNAs. These mRNAs are transported to the cytoplasm
and are translated into proteins responsible for the androgen's
The biological effects of androgens in males include the appropriate
fetal differentiation of the internal and external tissues which
comprise the male genitalia. During puberty, androgens act to stimulate
the development of the scrotum, epididymis, vas deferens, seminal
vesicles, prostate, and penis tissues development. The functional
integrity of these organs also depends on the androgen levels. Furthermore,
androgen also induced larynx and muscle developments, which lead
to the development of secondary sexual characteristics. The ambi-sexual
development of pubic and armpit hair, as well as the male-specific
development of facial, chest, abdomen, and back hairs are induced
by the stimulation of the sebaceous glands with androgen. Other
effects of androgens include stimulation of erythropoiesis, as well
as psychological and behavioral changes.
Mechanism of Protodioscin
Protodioscin acts by stimulating the enzyme 5-alpha-reductase,
which plays a role in the conversion of testosterone into dihydrotestosterone
(Viktorof et al. 1994). In addition, protodioscin also stimulates
the hypothalamus secretion of luteinizing hormone (LH), but not
of follicle stimulating hormone (FSH). Protodioscin is shown to
increase the density of the Leydig, but not that of the Sertoli
cells, and to improve the level of spermatogonia and to increase
the production of spermatocytes and spermatids without changing
the diameter of the seminiferous tubules. Physically, protodioscin
treatment results in increased male fertility and sexual functions.
In respect to improving fertility, protodioscin increases the level
of spermatogenesis by stimulating the Sertoli and germinal cells,
resulting in the increased production of sperms. In this process,
protodioscin improves the conversion of testosterone to DHT, which
in turn stimulates the production of Androgen Binding Protein (ABP)
in the Sertoli cells. Increased ABP production results in increased
formation of DHT-ABP complex, which stimulates spermatogenesis in
the germinal cells. Another fraction of the DHT-ABP complex is transported
to the epididymis, which increases the efficiency of the maturation
of spermatozoa into fertile sperms.
In respect to increasing sexual functions, protodioscin works by
increasing the conversion of testosterone into the potent DHT(Figure
4). In addition to the increase in sexual drive or libido, DHT also
stimulates erythropoiesis or production of red blood cells, and
muscle developments, thus contributing to the improvement of blood
circulation as well as the oxygen transport systems. Importantly,
regular use of protodioscin has also been shown to increase the
duration of penile erection and improve ejaculation in males.
Figure 4. The mechanism of protodioscin's
action. Protodioscin increases the production of serum testosterone
and the conversion of testosterone to dihydrotestosterone. Dihydrotestosterone,
in turn enhances erythropoiesis and muscle development. More erythropoiesis
or production of red blood cell increases the hemoglobin level,
which results in better oxygen transport throughout the body, resulting
in a more optimal health. Both increased production of testosterone
and better health contribute to the increase in sexual functions,
especially the increase in sex drive.
Fertility and the Male Sexual Potential
Male fertility is clinically quantified by laboratory analyses
of semen. The normal boundaries are determined by the World Health
Organization in 1992 as described in Table 2. Male sexual dysfunctions
are listed in Table 3.
|| > 2.0 ml
|| 7.2 - 7.8
| Sperm concentration
|| > 20 million sperms / ml
| Sperm concentration / ejaculate
|| > 40 million sperms / ejaculate
|| > 50% progressively motile category (a+b);
>25% rapid progressively motile (a)
within 60 minutes of ejaculation
|| > 30% with normal morphology
|| > 70% viability, i.e. without supravital color
| Leukocyte cells
|| < 1 million / ml
| Immune droplet test
|| Binding to less than 20% of sperms
| MAR test
|| Binding to less than 10% of sperms
| Other tests:
> 20 mU / ejaculate
< 2.4 µmol
>52 µmol / ejaculate
>200 U /
>13 µmol / ejaculate
Table II. Parameter of semen analyses as determined by the World
Health Organization (1992).
|| Normal ejaculation based on concentration, mobility
morphology of sperms
|| Concentration of sperm < 20 million / ml
| Severe oligozoospermia
|| Concentration of sperm < 3 million / ml
|| Mobility < 50% (a+b) or grade a mobility <
|| Normal morphology < 30%
|| Defects in concentration, mobility and morphology
|| No sperm in ejaculate
|| No ejaculate
|| Red blood cells in ejaculate
|| White blood cells in ejaculate at concentration
1 million / ml
Table III. Nomenclature of sexual dysfunctions
based on semen analyses.
Male infertility can be diagnosed by routine semen analyses or
by causative etiology (Comhaire 1991, Adimoelja 1990, Lee 1983,
Kolodny et al. 1979). In a routine semen analyses, abnormal semen
volume (hypo- or hyperspermia), abnormal sperm concentration such
as polyzoospermia (<25 million sperms / ml), oligozoospermia
(<20 million sperm / ml), and abnormal sperm quality, such as
asthenozoospermia or defect in motility, and teratozoospermia or
defect in morphology, can be detected. Some of these disorders,
such as oligozoospermia and abnormal sperm qualities, can be treated
either by medication or by artificial insemination. Causative etiology
allows doctors to distinguish infertility that are treatable, such
as that caused by varicocele, accessory glands infections, immunological
factors, psychological dysfunctions and endocrinopathy from those
that are currently not treatable such as Klinefelter's syndrome,
bilateral cryptorchidism, testes atrophy, Sertoli only syndrome
and vas deferens agenesis.
MALE SEXUAL FUNCTION
In order to understand the male sexual function, we need to understand
the male sexual response and mechanism of penile erection.
Sexual Response Phases
There are four sexual phases in both males and females (Kolodny
et al. 1979):
1. Excitement phase
This is the first sexual phase, reached after physical or psychological
sexual attraction or excitement. In males, this also takes the form
of penis erection.
2. Plateau phase
In this phase, sexual excitement reaches a high level. This level,
however, is below the level required for orgasm. In this phase,
the proximal penis glands increase in size and fluid that may contain
live spermatozoa is secreted from the bulbourethral (Cowper's) glands.
3. Orgasmic phase
Orgasm is the apex of sexual activity, and includes both physical
and psychological factors. This phase is triggered by a neural reflex
arc once the degree of excitement, or the discharge of semen due
to the cooperative contraction of the urethra, penis and the prostate
4. Resolution phase
After orgasm and ejaculation, males enter a resolution phase. In
this phase, ejaculation does not take place, although sometimes
erection can occur. Anatomic and physiological changes in the genitalia
organs take place to reset the reproductive systems to pre-sexual
Mechanism of Penile Erection
The physiology of penile erection mechanism, according to Watterauer
(1988), is divided into the following phases:
1. Sinusoid phase
In this phase, relaxation of the corpus cavernosum blood vessels
results in the elongation of the penis.
2. Arterial phase
Blood flows into penis arteries, resulting in increased volume
of the cavernosum until passive pressures stop the blood flow out
of the veins. This internal pressure in the cavernosum cavities
causes stiffening of the penis.
3. Vein phase
In this phase, erection is achieved due to increased blood flow
resistance in the capillaries of the penis.
4. Muscle phase
Increased bulbocavernosum and ischiocavernosum muscles activities
result in penile blood pressure much higher than that of the systolic
pressure. In this phase, penile erection reaches its maximum.
5. Resistance phase
In this phase there is increased sinusoidal muscle contraction
that causes blood to flow out of the penis. The penis begins to
lose stiffness and length.
Therapies for all classes of impotence include sexual counseling,
sex therapy, mechanical options, surgeries, and pharmacological
treatments (Susilo 1994).
RESULT AND DISCUSSION OF LIBILOV TREATMENT
Male infertility can manifest in many forms, including abnormalities
in sperm concentration and quality. The result of Libilov treatment
for infertility are discussed below.
1. Spermatozoa concentration
Viktorof et al. (1994) reported a significant increase in the spermatozoa
concentration. Oligoasthenozoospermic patients were given a dose
of 3 x 1 tablet / day for 60 days. Varicocelectomy patients were
given 3 x 1 to 3 x 2 tablets / day for 60 days.
Moeloek et al. (1994) reported an increase in the sperm concentration
in patients diagnosed with oligozoospermia. These patients were
given Libilov at a dose of 3 x 2 tablets / day for 9 weeks.
Arsyad (1996) reported that 3 x 2 tablets / day treatment of Libilov
for 60 days given to patients with idiopathic, moderate oligozoospermia
resulted in almost doubling of the spermatozoa concentration. This
increase in sperm concentration continued for 30 days post-administration
of the herbal preparation.
2. Spermatozoa quality
Moeloek et al. (1994) reported morphological, but not motility
improvement in patients diagnosed with oligozoospermia after treatment
with Libilov at 3 x 2 tablets / day for 9 weeks.
Viktorof et al. (1994) reported an increased spermatozoa motility.
In this study, oligoasthenozoospermic patients were given protodioscin
tablets at 3 x 1 tablet / day for 60 days. Patients diagnosed with
varicocele were given 3 x 1 to 3 x 2 tablets / day for 60 days.
Arsyad (1996) reported that 3 x 2 tablets / day for 60 days in
patients with moderate idiopathic oligozoospermia results in increased
motility and improved spermatozoa morphology in all patients. This
improvement continued for 30 days post-administration of the treatment.
Impotence can manifest itself in all phases of the sexual response.
Its most common forms are decreased sexual libido and erection,
and impairment in ejaculation and orgasm. According to Pangkahila
(1993), patients diagnosed with non-organic sexual dysfunctions
treated with Libilov 3 x 2 tablets / day for 90 days reported significant
increase in sex drive. Nasution (1993) reported that patients diagnosed
with libidinal and erectionic impotence treated with 3 x 1 tablets
/ day for 14 days showed significant improvement in libido and erection
without any side-effects. Finally, in Arsyad (1996), 33% of patients
with moderate idiopathic oligozoospermia treated with Libilov at
3 x 2 tablets / day dosage reported improvement in sex drives within
30 days. This number increased to 80% by day 60 of treatment. After
only 30 days of treatment, penis erection was improved in 53% of
the patients. Likewise, this increased to 87% of patients after
60 days of treatment. Better ejaculation was experienced by 47%
and 67% of patients after 30 and 60 days of treatment, respectively.
Importantly, orgasm was improved in 40% of males after 30 days of
treatment. This increased to 87% after 60 days.
The increase in the concentration, mobility and morphology of spermatozoa
after treatment with Libilov (protodioscin) can be expected from
what we know of its mechanism of action. Here, protodioscin treatment
results in improved spermatogenesis in the Sertoli and germinal
cells. Furthermore, protodioscin results in increased efficiency
of testosterone conversion to DHT. This results in the stimulation
of the Sertoli cells to produce Androgen Binding Protein, which
binds to DHT and improves the function of the epididymis tissues
in spermatozoa maturation. Protodioscin also increased the secretion
of luteinizing hormone that subsequently induced Leydig cells to
produce testosterone (Greenspan 1991).
The increase in the level of DHT, the most potent form of androgens,
is also an important mechanism of protodioscin treatment. DHT plays
an important role in the improvement of red blood cell formation
as well as muscle development. This contributes directly to the
sense of physical well-being and improves oxygen circulation in
the body (Greeenspan 1991). Indirectly, these effects also adds
to the improvement in sexual functions, including sexual libido,
erection, ejaculation and orgasm.
In this report we discussed male fertility and sexual functions,
as well as the mechanism of action of protodioscin or Libilov treatment.
We also briefly reviewed results of protodioscin treatment in males
diagnosed with infertility and impotence.
Generally, Libilov treatment consists of oral administration of
3 x 1 to 3 x 2 tablets / day for 14 to 60 days. This regiment has
been successfully shown to be effective in improving the concentration
and quality of spermatozoa in patients with oligozoospermia. Furthermore,
these men also report improvements in sexual libido, erection, ejaculation,
and orgasm after Libilov treatment.
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