Result of Protodioscin (Tribulus terrestris) treatment in males diagnosed with
infertility and impotence
K.M. Arsyad
Medical Biology Division of Andrology, University of Sriwijaya, Indonesia (1996)
SUMMARY
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.
INTRODUCTION
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 and non-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 SYSTEM
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.
extract.
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.
Gonadal steroid
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-alphahydroxyprogesterone. 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 1.
Figure 2. The biosynthetic steps of androgen production in the testes.
Testes
Secretion
Adrenal
Secretion
Peripheral
Conversion
Testosterone
95
<1
<5
Dihydrotestosterone
20
<1
80
Estradiol
20
<1
80
Estrone
2
<1
98
< 10
90
-
Androgen
DHEA-Sulphate
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 binding proteins.
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 target tissues.
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 DHTprotein 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 action.
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.
Parameter
Value
Volume
> 2.0 ml
pH
7.2 - 7.8
Sperm concentration
> 20 million sperms / ml
Sperm concentration /
ejaculate
> 40 million sperms / ejaculate
Motility
> 50% progressively motile category (a+b);
or
>25% rapid progressively motile (a)
within 60 minutes of ejaculation
Morphology
> 30% with normal morphology
Vitality
> 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:
alpha-glucosidase
zinc
citric acid
phosphatase
fructose
> 20 mU / ejaculate
< 2.4 µmol /ejaculate
>52 µmol / ejaculate
>200 U / ejaculate
>13 µmol / ejaculate
Table II. Parameter of semen analyses as determined by the World Health Organization (1992).
Nomenclature
Definition
Normozoospermia
Normal ejaculation based on concentration,
mobility and
morphology of sperms
Oligozoospermia
Concentration of sperm < 20 million / ml
Severe oligozoospermia
Concentration of sperm < 3 million / ml
Asthenozoospermia
Mobility < 50% (a+b) or grade a mobility <
30%
Teratozoospermia
Normal morphology < 30%
Oligoashtenoteratozoospermia Defects in concentration, mobility and
morphology of
sperms
Azoospermia
No sperm in ejaculate
Aspermia
No ejaculate
Hemospermia
Red blood cells in ejaculate
Pyospermia
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 glands, occurs.
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 excitement phases.
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
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
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.
DISCUSSION
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.
SUMMARY
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.
REFERENCES
Adimoelja A. Male infertility. Scientific IDI Meeting in Surabaya, Indonesia (1985).
Adimoelja A. Infertility therapy for men. National Congress of Indonesian Association of
Andrology Scientific Symposium VIII in Padang (1990).
Arsyad K.M. Steps to treat male infertility. Maj. Kedok. Indon. 44 (1): 19-24 (1994).
Arsyad K.M. Effect of Protodioscin on the quantity and quality of sperms from males with
moderate idiopathic oligozoospermia. Medika 22(8): 614-618 (1996).
Barry J.M., Hodges C.V. Impotence, a diagnostic approach. J. Urol. 119: 575-578 (1987).
Comhaire F.H. A logical approach to the management of male infertility. Clin. Adv. Androl. 1(3):
8-13 (1991).
Ellenberg M. Impotence in diabetes, the neurological factor. Ann. Int. Medicine 75: 213-219
(1971).
Greenspan F.S. Basic and clinical endocrinology, 3rd ed. pp. 407-442. Appleton & Lange, Nortwik
(1991).
Kolodny R.C., Masters W.H., and Johnson V.E. Textbook of sexual medicine. pp. 1-27. Little
Brown and Co. Boston (1979).
Lee H.Y. Evaluation and management of male infertility. Second Annual Conference of the Korean
Andrology Society (1983).
Moeloek N., Adimoelja A., Tanojo T., Pangkahila W. Trials on Tribulus terrestris on
oligozoospermia. National Congress of Indonesian Association of Andrology Scientific Meeting VI
in Manado, Indonesia.
Nasution A.W. Treatment of impotence with Libilov. National Congress of Indonesian Association
of Andrology Scientific Meeting X in Denpasar (1993).
Pangkahila J.A. Libilov™ increases men's sex drives. National Congress of Indonesian Association
of Andrology Scientific Meeting X in Denpasar (1993).
Rowe P.J., Comhaire F.H., Hargreave T.B., and Mellows H.J. World Health Organization manual
for the standardized investigation and diagnosis of the infertile couple. WHO, Cambridge
University Press, Cambridge (1993).
Susilo W. Impotence, causes and pharmacological solutions. Seminar in Solving Impotence in
Semarang, Indonesia (1994).
Viktorof I., Bozadjieva E., Protich M., et al. Pharmacological, pharmacokinetic, toxicological and
clinical studies on protodioscin. IIMS Therapeutic Focus Vol 2 (1994).
Watterauer U. Anatomy of the penis and physiology of erection. In Sexology. Eicher W., and
Kockott G. editors. Pp. 115-26. Springer-verlag Berlin, Heidelberg (1988).
World Health Organization manual for the examination of human semen and sperm-cervical mucus
inter- action, 3rd ed. WHO, Cambridge University Press, Cambridge (1992).