APHRODISIAC ACTIVITY OF SHILAJIT

By: INTERNATIONAL JOURNAL OF PHARMACEUTICAL RESEARCH A

Research Article CODEN: IJPRNK ISSN: 2277-8713
Gupta RB, IJPRBS, 2013; Volume 2(6): 42-56 IJPRBS
Available Online at www.ijprbs.com
42
EVALUATION OF APHRODISIAC ACTIVITY AND SPERMATOGENIC EFFECT OF
SHILAJIT
GUPTA RB1, AHUJA A,2 YADAV R,3 KABRA MP1
1. Kota College of Pharmacy, Kota (Raj.)
2. Sanjeevan College of Pharmacy, Dausa (Raj.)
3. Alwar College of Pharmacy, Alwar (Raj.)
Accepted Date: 20/10/2013; Published Date: 27/12/2013
Abstract: This study was designed to evaluate the aphrodisiac and spermatogenic potential of
the aqueous extract of Shilajit in rats. Male Wistar albino rats were divided into four groups.
Rats were orally treated with (1) Control group: distilled water (2) Viagra group: 4 mg/kg/day
sildenafil citrate (3) Shilajit 50 mg/kg/day and (4) Shilajit 100mg/kg/day and their sexual
behaviour was monitored 1h later using a receptive female. Their sexual behaviour was
evaluated on days 0, 7, 14, 21, 28, 35 and 42days of treatment by pairing with a oestrous phase
female rat. For sperm count the treatment was continued further in all groups except the
sildenafil citrate group for 42days. At 50 mg/kg, and 100mg/Kg/day dose of Shilajit had a
marked aphrodisiac action, Mount frequency (MF) Intromission frequency (IF) marked
increased, Similarly, Mount latency (ML): marked decrease. On day 43 day the sperm count
increased significantly in both the Shilajit groups, 50 mg/kg and 100g/kg, in a dose dependent
manner. Thus, Shilajit can be useful in the treatment of certain forms of sexual inadequacies,
such as premature ejaculation and oligospermia.
Keywords: Aphrodisiac, Spermatogenic, Premature ejaculation, Mount frequency, Shilajit
INTERNATIONAL JOURNAL OF
PHARMACEUTICAL RESEARCH AND BIO-SCIENCE
PAPER-QR CODE
Corresponding Author: MR. GUPTA RAMAN BIHARI
Access Online On:
www.ijprbs.com
How to Cite This Article:
Gupta RB, IJPRBS, 2013; Volume 2(6): 42-56
Research Article CODEN: IJPRNK ISSN: 2277-8713
Gupta RB, IJPRBS, 2013; Volume 2(6): 42-56 IJPRBS
Available Online at www.ijprbs.com
43
INTRODUCTION
Aphrodisiacs are the substances which are used to increase sexual activity and help in fertility.
Sexual feelings are an inevitable part of life. The basic and fundamental purpose of sex and
sexuality is the “continuation of progeny” and the survival of human race. [1] The sex is the
most intimate, indispensable and an integral part of every individual and can be a source of
pleasure and fulfillment. However, unfortunately, there has been a lot of ignorance, wrong
information, fear and negative attitude as for as sex is concerned. Myths and misconceptions
are rampant and are passed on from generation to generation. These sexual myths can result in
sexual dysfunctions, misery, silent suffering, disturbed interpersonal relationships and even
divorce. Sexual ignorance is a social disease and can only be resolved through comprehensive
sex education, which can increase awareness and improve the environment. [2] Infertility is
also a worldwide medical and social problem. It affects above 10-15% of married couples. WHO
estimates that there are 60-80 million infertile couples worldwide. Infertility in itself may not
threaten physical health but it can certainly have a serious impact on the mental and social
wellbeing of infertile couple. In many countries the stigma of infertility often leads to marital
disharmony, divorce or Ostracism. [3-4]
Research during the past two decades has an unfolded focus on impotence (erectile failure),
premature ejaculation and male infertility. There are a number of prescription drugs which may
act as sex stimulant and enhancing the sexual desire and activity in both men and women.
Although the use of allopathic medicines have shown significant improvement in treating sexual
disorders, but at the same time there are large number of side effects. These include
irregularities of the rhythm of the heart, suicidal tendencies, mental disorders and tremors. The
use of synthetic aphrodisiacs results in the dilation of blood vessels in other parts of the body
causing
headache and fainting. Other side effects include facial flushing, stomach upset, blurred vision
and sensitivity to light which usually occur at higher doses. [5]
Shilajit -is considered one of the wonder medicines of Ayurveda. Neither a plant nor animal
substance, it is a mineral pitch that oozes from the rocks of the Himalayas, as they become
warm in the summer months. There are four different varieties of shilajit which have been
described in charka Samhita, namely Savrana, Rajat, Tamra and Lauha shilajit. Savrana shilajit is
gold shilajit and is red in colour. Tamra is a copper shilajit and is blue in color. Rajat is a silver
shilajit and is white in color while the Lauha shilajit is an iron-containing shilajit and is brownishblack
in colour. Tamra and savrana shilajit are not found commonly but the last variety, i.e.
lauha shilajit is commonly found in Himalayan ranges and is supposed to be most effective
according to the therapeutic point of view. [6]
Research Article CODEN: IJPRNK ISSN: 2277-8713
Gupta RB, IJPRBS, 2013; Volume 2(6): 42-56 IJPRBS
Available Online at www.ijprbs.com
44
It is said to carry the healing power of these great mountains. Shilajit is an important drug of
the ancient Hindu materia medica and is to this day used extensively by the Hindu physicians
for a variety of diseases. Early ayurvedic writings from the Charaka Samhita and Susruta
Samhita describe shilajit as a cure for all disease as well as a rasayana (rejuvenative) able to
increasing longevity from 100 to 1000 years of age. It is composed of humus and organic plant
material that has been compressed by layers of rock mixed with microbial metabolites.
Traditional uses primarily focus on diabetes and diseases of the urinary tract, but also include
edema, tumors, wasting, epilepsy and even insanity. Modern indications extend to all system of
the human body with a significant number of additions in the reproductive and nervous system.
The Ayurvedic energenics vary depending on the base rock that the shilajit comes from but it is
generally thought to be tridoshic and only aggravating to Pitta (Fire) when used in excess.
Clinical research confirms many of the properties that shilajit is used for. However, further
investigations are required before many of shilajit’s actions can be affirmed. Shilajit is generally
considered safe in moderate doses and is readily available in the United States both as a standalone
product and in the traditional Ayurvedic formula Chandraprabha. It has also compounded
in many patent medicines from India. Shilajit is truly a remarkable substance with a long history
of human usage for healing and should be subjected to further investigations. [7][8]
Procurement of Shilajit
The Shilajit shuddh was purchased from Patanjali Arogya Kendra. Shilajit was dispersed in
purified water and used without any further purification. The final concentrations were
prepared 50mg/ml and 100mg/ml.
MATERIAL AND METHODS:
Animals
Healthy adult albino rats of wistar strain, weighing about 150-200 g were obtained from the
Arya College Animal house, Jaipur. The rats of either sex were isolated and housed in separate
cages during the course of experimental period and kept them at room temperature (24±2°C)
with a 12 h: 12 h light / dark cycle. The animals were fed with standard pellet diet and provided
water ad libitum. All the procedures in this study were performed in accordance with the NIH
guidelines for the care and use of laboratory animals, after getting the approval from the Arya
College Animal Ethics Committee. (Approval No.1013/PO/c/06/CPCSEA)
Preparation of male rats
The male rats were trained for sexual behavior, two times a day for a period of minimum of 10
days. The male rat which did not show any sexual interest during the test period was
Research Article CODEN: IJPRNK ISSN: 2277-8713
Gupta RB, IJPRBS, 2013; Volume 2(6): 42-56 IJPRBS
Available Online at www.ijprbs.com
45
considered as an inactive male. The sexually active male rats were selected for testing
aphrodisiac activity of the extracts.
Preparation of female rats
Female rats were housed in separate cages with food and water ad libitum. The female rats
were brought in oestrous phase by treating them with Estradiol valerate (10 microgram/kg S.C.
and Hydroxy progesterone 1.5mg/kg S.C., for 48 hours and 5 hours prior to experimentation,
respectively, to make them sexually acceptable and were selected for the study.[10]
Experimental details
The sexually active male rate separated and divided into 6 groups; each group consisting of 6
animals. The animals in the divided groups received the treatment orally. Different groups of
animals which received the Shilajit extract and the control are as follows (Table 1):
The sexual behavior of the experimental rats was observed weekly in a dim light at 10 a.m. in a
specially designed cage that has glasses and wood as shown in photograph. The male
experimental rat was first placed in the cage and then one female rat in estrous phase was
introduced. An initial period of 10 minutes was considered as acclimatization period. After 10
minutes activity of male rat in each group was recorded individually for 30 minutes.
To determine the aphrodisiac activity of the extracts, several parameters were observed. These
include measuring and observing the mount frequency, mount latency, intromission frequency:
(I) Mount latency (ML): Time taken for the first mount following the introduction of females.
(II) Mount frequency (MF): No. of mounts observed in 30 min;
(III) Intromission frequency (IF): No. of intromission observed in 30 min;
To determine the spermatogenic potential of the extracts, several parameters were observed.
(I) Weight of seminal vesicle.
(II) Weight of prostate gland.
(III) Weight of epididymis.
(VI) Effects on epididymis sperm count.
For evaluating the effect on sperm count the methods by Kempinas and Lamano-Carvalho
were followed with minor modifications. The drug treatment of the drug groups I, II and the
control group were continued up to 42 days. All the animals in the above three groups were
Research Article CODEN: IJPRNK ISSN: 2277-8713
Gupta RB, IJPRBS, 2013; Volume 2(6): 42-56 IJPRBS
Available Online at www.ijprbs.com
46
killed by decapitation on day 43. The left and right epididymis were from were isolated and
freed of adjoining fat. The cauda portion was cut off so as to separate it from the caput
epididymis portion and 5 ml of phosphate buffered saline (PBS) was aspirated into each cauda
epididymis and the aspirate from both the cauda was collected together to give sperm
suspension of 10 mL. This suspension was vortexed and diluted 10 times with PBS. This diluted
suspension was then used for the sperm count on a Neubauer haemocytometer. The
suspension was well mixed and charged into Neubauer’s counting chamber. The total sperm
count in four squares (except the centralerythrocyte area) of 1 mm2 each was determined and
multiplied by 1.25 × 105 to express the number of spermatozoa/cauda epididymis.[11],[12]
Calculation for sperm count.
Total no. of sperms in 4 squares (each of 0.1 mm3) =N.
Total no. of sperms in 4 squares (each of 0.1 mm3) =N.
N/0.4 mm3= no. of sperms/mm3 of diluted suspension
N*1000/0.4mm3 = no. of sperms/cc of diluted suspension
N *2500 = no. of sperms/cc of diluted suspension
N *2500 = dilution factor = no. of sperms/cc of undiluted suspension
Dilution factor= 10
N *2500*10 = no. of sperms/cc of undiluted suspension
N *25 000 = no. of sperms/cc of undiluted suspension
Total no. of sperms in undiluted 10 mL PBS suspension= N *25_000**10 = N *2.5 *105
Sperm count in 2 cauda epididymis= N *2.5 *105
Sperm count/cauda epididymis= N = 1.25 = 105
Statical Analysis: Data are expressed as Mean± SEM Statistical analysis was performed using
one-way ANOVA followed by Dunnett’s test. The p ≤ 0.05 were considered statistically
significant
Research Article CODEN: IJPRNK ISSN: 2277-8713
Gupta RB, IJPRBS, 2013; Volume 2(6): 42-56 IJPRBS
Available Online at www.ijprbs.com
47
RESULTS:
Aphrodisiac activity and Spermatogenic potential:
The aphrodisiac activity of aqueous extracts of Shilajit was studied on male Wistar albino rats at
two dosages. The parameters observed during the study were mount frequency, mount
latency, intromission frequency, weight of seminal vesicle, weight of testies, weight of prostate
gland, weight of epididymis and total sperm count.
Mount frequency:
Administration of Sildenafil citrate 4 mg/kg showed significant (pMount frequency on 7, 14 and 21, 28, 35, 42 day of observational period respectively as
compared with control. Administration of Shilajit (50 mg/kg) showed significant (ppcompared with control. Shilajit (100 mg/kg, p.o.) showed significant (pincrease in Mount frequency on 14, 21 and 28, 35, 42 day of observational period as compared
with control.
Mount latency :
Administration of (Sildenafil citrate 4 mg/kg p.o.) showed significant (pdecrease in Mount latency on 07, 14 and 21, 28, 35, 42 day of observational period respectively
as compared with control. Administration of Shilajit (50mg/kg) showed significant (pprespectively as compared with control. Shilajit (100 mg/kg, p.o.) showed significant (pPperiod respectively as compared with control.
Intromission frequency:
Administration of (Sildenafil citrate 4 mg/kg p.o.) showed significant (Pincrease intromission frequency on 7, 14 and 21, 28, 35, 42 day of observational period
respectively as compared with control. Administration of Shilajit (50mg/kg) showed significant
(pcompared with control. Shilajit (100 mg/kg, p.o.) showed significant (pincrease in Intromission frequency on 21, 28 and 35, 42 day of observational period respectively
as compared with control.
Research Article CODEN: IJPRNK ISSN: 2277-8713
Gupta RB, IJPRBS, 2013; Volume 2(6): 42-56 IJPRBS
Available Online at www.ijprbs.com
48
Sperm count: Administration of Shilajit (50mg/kg) showed significant (psperm count as compared with control. Shilajit (100 mg/kg, p.o.) showed significant (pincrease sperm count as compared with control.
Weight of organ: Administration of Shilajit (50mg/kg) and (100 mg/kg, p.o.) show increase in
weight of Testies, Seminal vesicle and prostate gland as compared with control but does not
show significant increase in weight.
DISCUSSION:
The data presented here provides evidence about the ability of extracts of Shilajit to enhance
male sexual behavior expression in sexually active rats. The data obtained reveal that an oral
administration of different doses of shilajit extracts effectively facilitate several aspects of
copulatory behavior. In the experimental analysis of male sexual activity, the concept of the
existence of two different physiological mechanisms responsible for sexual behavior expression
was introduced in the early 50s by Frank Beach. This notion holds that one of these
mechanisms is responsible for sexual arousal and the other for sexual performance. This
concept has been central for the neurobiology of sexual behavior. [13]
The Shilajit extracts were subjected for preliminary photochemical studies and aphrodisiac
activity. The reports of photochemical studies showed the presence of moisture, gums,
albuminoids, calcium, potassium, nitrogen, silica, resin, vegetable matter, magnesium, sulfur,
iron, chloride, phosphorous, iodine, glycosides, tannic acid, benzoic acid and a number of
vitamins and enzymes (US Patent No. 5,405,613). The Shilajit composition of biologically active
components disclosed in the US Patent (No. 6,440,436) contains 0.3% by weight of oxygenated
dibenzo-pyrone and 60% by weight of low molecular weight of fulvic acid. Amount these
compounds; some of the compounds definitely possess aphrodisiac activity. It was found that
an increased copulatory sexual behavior and mounting were observed.
Finally, based on this preliminary data, it can be concluded that the Shilajit is a safe drug
without any known adverse effects and can be very useful in enhancing the male sexual activity
and treating various sexual disorders like erectile failure, premature ejaculation, lack of sexual
desire and ejaculatory incompetence. However, further detailed studies are needed to confirm
the usefulness this extract in treating sexual disorders. This includes separation, purification,
and characterization of different chemical constituents of these extracts and testing the
aphrodisiac activity of purified compounds.
The results of the present study suggested that shilajit have a beneficial effect on male
reproductive functions in rats. These data are confirmed by our observation on the increased
sperm counts, motility. The increase in the absolute weight of the testis and epididymis could
Research Article CODEN: IJPRNK ISSN: 2277-8713
Gupta RB, IJPRBS, 2013; Volume 2(6): 42-56 IJPRBS
Available Online at www.ijprbs.com
49
therefore be due to increased androgen biosynthesis as evidenced by a significant increase in
serum testosterone levels in the experimental rats. Androgens have been shown to be
necessary for the development, growth and normal functioning of the testes and male
accessory reproductive glands and studies have shown that the level is positively correlated
with the weight of testis, epididymis, seminal vesicle and prostate glands. The increased sperm
count and motility thereby shows that treatment with shilajit improves and enhances the
fertilizing capacity of the Semen. These qualities were often used as a measure of sperm
production, testicular function and/ or male fertility.
CONCLUSION:
Hence, the results of present study revealed that, Shilajit extract improved sexual performance
as well as sperm count. The effectiveness of the shilajit in multiple preclinical models with
desire mechanism of action might be due to the presence of fulvic acid and minerals or both
synergistic actions of these constituents. However, the exact role of chemicals and their
mechanism of action need future investigation.
AKNOWLEDGEMENT:
We are very thankful to Dr. Anil Ahuja, Principal of Sanjeevan College of Pharmacy, Dausa,
(Raj.) & our friends for helping us in this experiment.
Table : 1 Dose distribution schedule in experimentation
Group
Drug Dose & Time
I Control (Normal saline) 2ml/kg per day at 9 a.m.
II Positive control
(Sildenafil citrate)
4mg/kg per day.[10]
III Aqueous extract of Shilajit 50 mg/kg per day at 9 a.m. [9]
IV Aques extract Shilajit 100mg/kg per day at 9 a.m.[9]
Research Article CODEN: IJPRNK ISSN: 2277-8713
Gupta RB, IJPRBS, 2013; Volume 2(6): 42-56 IJPRBS
Available Online at www.ijprbs.com
50
Table: 2 Mount Latency
Groups 0 day 7 day 14 day 21 day 28 day 35day 42 day
Control 244±
24.87
271.3±
55.89
240.5±
16.81
232±
18.09
253.5±
22.89
215.2±
10.83
221±
7.78
Shilajit 50
mg/kg
276.2±
18.86
240±
5.02
203.5±
11.52*
185.7±
10.25
155.2±
15.11*
146.5±
9.65*
120.3±
10.11**
Shilajit
100
mg/kg
219.5±
30.33
187.2±
17.93
191.7±
10.3
157±
14.03*
157.3±
14.96*
139.3±
16.39**
92±
9.352***
Sildenafil
citrate 4
mg/kg
227.7±
20.86
121.8±
10.14**
99.33±
6.596**
79.33±
11.3***
71.83±
6.61***
57.5±
3.334***
64.17±
10.02***
Table : 3 Mount Frequency
Groups 0 day 7 day 14 day 21 day 28 day 35day 42 day
Control 6.833±
0.4773

0.5164
6.667±
0.6667

1.033
6.833±
0.8724
7.667±
0.6146

0.5774
Shilajit
50
mg/kg
7.333±
0.4944
10.67±
0.4944
14.5±
1.839*
16.67±
1.563*
17±
1.653*
18.17±
1.537*
20.67±
1.726**
Shilajit
100
mg/kg
6.167±
0.4773
13.33±
0.8433
16.17±
0.8333*
16.83±
0.6009*
20.17±
1.537**
23.83±
1.249**
24±
1.033**
Sildenafil
citrate
4 mg/kg

0.5774
25.17±
1.579**
26.83±
1.515**
31.33±
1.874***
29.83±
2.167***
32.17±
2.725***
36.83±
1.99***
Research Article CODEN: IJPRNK ISSN: 2277-8713
Gupta RB, IJPRBS, 2013; Volume 2(6): 42-56 IJPRBS
Available Online at www.ijprbs.com
51
Table : 4 Inter Mission Frequency
Groups 0 day 7 day 14 day 21 day 28 day 35day 42 day
Control 0.6667±
0.2108
0.6667±
0.2108
0.6667±
0.2108
0.5±
0.2236
0.6667±
0.2108
0.6667±
0.2108
0.8333±
0.1667
Shilajit
50
mg/kg
0.6667±
0.2108
0.8333±
0.1667
1.5±
0.2236
1.833±
0.1667
2.5±
0.2236*
3.333±
0.2108*
3.833±
0.3073*
Shilajit
100
mg/kg
0.5±
0.2236

0
1.833±
0.3073

0.2582*

0.6831*
5.333±
0.5578**
7.5±
0.4282**
Sildenafil
citrate 4
mg/kg
0.8333±
0.1667
6.5±
1.118**
8.833±
1.078**
11±
0.5164***
12.67±
0.9189***
11.67±
0.3333***
14±
0.3651***
Table : 5 Epididymal sperm count
Sperm count Group Million/cauda Increase in sperm count
Compared with control (%)
Control 9.1 0
Shilajit 50 mg/kg 10.4* 14.2
Shilajit 100 mg/kg 10.8** 18.6
Table : 6 Weight of seminal vesicl e
Groups Wt. of seminal vesicle at 43days
Control 288± 3.992
Shilajit 50 mg/kg 308.8 ± 3.049
Shilajit 100mg/kg 315.7± 3.19
Research Article CODEN: IJPRNK ISSN: 2277-8713
Gupta RB, IJPRBS, 2013; Volume 2(6): 42-56 IJPRBS
Available Online at www.ijprbs.com
52
Table : 7 Weight of prostate gland
Groups Wt. of Prostate gland at 43 days
Control 228.7± 4.485
Shilajit 50 mg/kg 247± 3.406
Shilajit 100mg/kg 256.8± 3.156
Table : 8 Weight of epididymis
Groups Wt. of epididymis at 43 days
Control 547± 1.238
Shilajit 50 mg/kg 570.5±4.342
Shilajit 100mg/kg 595.2± 3.664
Fig.1 Photograph of Shilajit
Research Article CODEN: IJPRNK ISSN: 2277-8713
Gupta RB, IJPRBS, 2013; Volume 2(6): 42-56 IJPRBS
Available Online at www.ijprbs.com
53
Fig.2 Photograph of Shilajit
Fig. 3 Cage for aphrodisiac activity
Fig. 4 Rats during sexual act.
Research Article CODEN: IJPRNK ISSN: 2277-8713
Gupta RB, IJPRBS, 2013; Volume 2(6): 42-56 IJPRBS
Available Online at www.ijprbs.com
54
Fig. 5 Cauda part of Epididymis
Fig. 6 Sperm Counting
Fig. 7 Sperm Counting
Research Article CODEN: IJPRNK ISSN: 2277-8713
Gupta RB, IJPRBS, 2013; Volume 2(6): 42-56 IJPRBS
Available Online at www.ijprbs.com
55
Fig. 8 Sperm Counting
Fig. 9 Sperm Counting
REFERENCES:
1. Kothari P. Common sexual problems. UBS publishers, New Delhi, 2001;3: 1-6, 155, 203, 204,
221.
2. Kar N, Chandra G. Comprehensive Textbook of Sexual Medicine, Jaypee Brothers Medical
Publishers, New Delhi, 2005; 1:280-285, 309-313.
3. Badami S, Desai VB, Suresh B. Drugs play a major role in male infertility. Express Pharma
Pulse 2000; 2: 18.
Research Article CODEN: IJPRNK ISSN: 2277-8713
Gupta RB, IJPRBS, 2013; Volume 2(6): 42-56 IJPRBS
Available Online at www.ijprbs.com
56
4. World Health Organisation, Binnial Report, Prevention of infertility, edt. J.Khanna, Office of
Publication, W.H.O., Geneva, 1992-93; 32-33: 161-166.
5. Kulkarni SK, Reddy DS. Pharmacotherapy of Male Erectile Dysfunction with Sildenafil. Ind. J.
Pharmacol. 1998; 30: 367-378.
6. Agarwal SP, Khanna R, Karmarkar R, Khalid MD. Shilajit: A Review, phytotherapy research.
2007; 21: 401–405.
7. Acharya SB, Frotan MH, Goel RK, Tripathi SK, Das PK. Pharmacological actions of Shilajit.
Indian J Exp Biol. 1988 ; 26(10): 775-777.
8. Bhishagratna KK. Susruta Samhita Vol 2, Chapter XIII. Varanasi, India: Chowkhamba Sanskrit
Series Office, Varansi-1. 1998;2:198-201
9. Jeong-Sook P, Gee-Young K , Kun H . The spermatogenic and ovogenic effects of chronically
administered Shilajit to rats, Journal of Ethnopharmacology 2006; 107:349–353
10. Javeed AW, Rajeshwara N. Achur, Nema RK , Phytochemical Screening and Aphrodisiac
Property of Tinospora cordifolia, International Journal of Pharmaceutical and Clinical Research
2011; 3(2): 21-26
11. Kempinas WG, Lamano-Carvalho TL. A method for estimating the concentration of
spermatozoa in the rat cauda epididymidis. Lab Anim. 1988; 22: 154–156.
12. Narayana K, Prashanthi N, Nayanatara A et al. Effects of methyl parathion(o,odimethyl o-4-
nitrophenyl phosphorothioate) on rat sperm morphology and sperm count, but not fertility, are
associated with decreased ascorbic acid level in the testis. Mutat Res 2005; 588: 28-34.
13. Carro-Juarez M, Cervantes E, Cerevantes-Mendez M. Aphrodisiac properties of Montanoa
tomentosa aqueous crude extract in male rats. J. Pharmacol. Biochem and Behavior 2004; 78:
129-134.