of Terminalia catappa seeds on sexual behaviour and fertility of male
D. Ratnasooriya, M. G. Dharmasiri
of Zoology, University of Colombo, Colombo 3, Sri Lanka
Asian J Androl 2000 Sep; 2: 213-219
AbstractAim: To evaluate the aphrodisiac potential of Terminalia catappa Linn. seeds using a suspension of its kernel (SS) in 1% methyl cellulose in rats. Methods: Male rats were orally treated with 1500 mg/kg or 3000 mg/kg SS or vehicle, and their sexual behaviour was monitored 3 h later using a receptive female. Another group of rats was orally treated with either 3000 mg/kg SS or vehicle for 7 consecutive days. Their sexual behaviour and fertility were evaluated on days 1, 4 and 7 of treatment and day 7 post-treatment by pairing overnight with a pro-oestrous female. Results: The 1500 mg/kg dose, had a marked aphrodisiac action (prolongation of ejaculation latency) but no effect on libido (% mounting, % intromission and % ejaculation), sexual vigour (mounting-and-intromission frequency), or sexual performance (intercopulatory interval). In contrast, the higher dose (3000 mg/kg) reversibly inhibited all the parameters of sexual behaviour other than mounting-and-intromission frequency and copulatory efficiency. The effects of high dose SS were not due to general toxicity, liver toxicity, haemotoxicity, stress, muscle deficiency, muscle incoordination, analgesia, hypoglycaemia or reduction in blood testosterone level. They were due to marked sedation. Conclusion: The kernel of T. catappa seeds has aphrodisiac activity and may be useful in the treatment of certain forms of sexual inadequacies, such as premature ejaculation.
sexual inadequacy is a problem facing many men throughout the world.
Aphrodisiacs and drugs that inhibit premature ejaculation are useful
in certain forms of male sexual inadequacies.
In Sri Lanka, according to Ayurvedic system of medicine, several
plants are claimed to possess aphrodisiac potential[1, 2].
However, in most cases the validity of these claims has not been scientifically
tested. Kernels of
seeds of Terminalia catappa Linn. (Family: Combretaceae, Kottamba in Sinhala
and Amandi in Tamil) is one such plant.
2 Materials and methods
Animals, reagents and instruments
sexually experienced male (275-325 g) and female (180-200 g) crossbred
albino rats were kept in well ventilated animal house conditions (temperature: 28-31;
photoperiod: 12 h natural light and 12 h dark; humidity: 50-55%) with
free access to pelleted food (Vet House Ltd., Colombo, Sri Lanka) and
tap water. Methyl cellulose was purchased from Griffin and George Ltd
(London, UK), oestradiol benzoate, progesterone and ether from Fluka (Buchs,
Switzerland), and enzyme assay kits from Randox Laboratories Ltd. (Co.
Antrim, UK). The
purchased from Fison Scientific Equipments (Loughborough, UK), animal
balance (MP 6000) from Chyo Balance Corporation (Tokyo Japan), hot plate
(Model MK 350A) from Muromachi
kikai Co. Ltd. (Tokyo, Japan), Wifug Lab Centrifuge from Eltex
of Sweden Ltd. (Bradford, UK), spectrophotometer (Jasco V500) from Jasco
Corporation (Tokyo, Japan) and microscope from Olympus Optical Co. Ltd.
2.2 Collection of seeds, preparation of seed suspension (SS) and phytochemical analysis
and partially dried fruits (with gray coloured pericarp) of T. catappa were
collected from the campus of University of Colombo, Sri Lanka, during
March and April, 1999
and authenticated by Professor A. S. Seneviratne, Department of Botany,
University of Colombo. The seeds were decoated using a pen knife and the
white colored kernel was
exposed. The kernels
of the fruit were dried in an oven at 60 to a fixed weight (usually
within 4 days). These
were then macerated in
a porcelain mortar until a semisolid paste was obtained.
This material was stored at 4 until use.
The paste was suspended (SS) in 1% methyl cellulose (vehicle) 2-3
h prior to experimental use to obtain the desired concentrations (750,
1500, 3000 mg/kg ) in 1 mL.
semisolid paste was subjected to standard chemical tests as described
to determine the presence (qualitatively) or absence of alkaloids, flavonoids,
phenols, steroids and triterpenoids, oils, saponins, amino acids and peptides.
Effects on rat male sexual behaviour
total of 36 male rats were randomly divided into three groups (n=12
per group) and each group was orally treated either with 1 mL of 1500
mg/kg (SS) or 3000 mg/kg
SS or 1% methyl cellulose (vehicle).
These rats were individually placed in
cages 3 h following the administration and were given a 10 min adaptation
period. A female
that had been brought into oestrus (oestradiol benzoate 12 g in olive
oil injected subcutaneously 56 h prior to pairing plus progesterone 0.5
mg in olive oil injected subcutaneously 8 h prior to pairing) was placed
in the cage.
following parameters of sexual behaviour were monitored until ejaculation
or 15 min after pairing; mount frequency, intromission frequency, mount
latency (time from
the introduction of the receptive female to the first mount), intromission
latency (time from the introduction of the receptive female to the first
intromission), ejaculatory latency (time from the introduction of the
receptive female to ejaculation).
these measures the following parameters were computed: % mounted, % intromitted,
% ejaculated, copulatory efficiency (number of intromissions/number of
mounts) and intercopulatory interval (average time between intromissions).
the fertility study, male rats were randomly assigned to two groups.
One group (n=6)
was orally treated with 1 mL of 3000 mg/kg SS and the other group (n=6)
1 mL of vehicle (at 12:00) for 7 consecutive days.
Effects on male fertility
ejaculatory competence and fertility of these rats were assessed 7 days
prior to treatment, and on days 1, 4 and 7 during treatment, and day 7
male was paired overnight with a pro-oestrous female (at 16:30-17:00).
The pre-coital sexual behaviour (chasing, nosing, anogenital sniffing, genital
grooming and attempted clasping and mounts) of the paired rats was observed
1-2 h later. Successful
mating was confirmed by the presence of sperm in the vaginal smear the
following morning (08:00-08:30).
If spermatozoa were present, their numbers were estimated (in duplicate)
using an improved Neubauer haemocytometer and gross morphology were noted
by microscopic examination (400).
day 14 post-coitum the
mated females were subjected to laparotomy under ether
anaesthesia and the number of conceptus (both viable and dead) were counted. In
addition, the number and the gross morphology of the corpora lutea in
each ovary were recorded.
following reproductive parameters were then computed: index of libido=(number
mated/number paired)100%; quantal pregnancy = (number pregnant/number
mated)100%; fertility index=(number pregnant/number paired)100%; implantation
index=(total number of implantations/number mated)100%; pre-implantation
loss=(number of corpora lutea-number of implantations)/number of corpora
loss=(total number of implants-number of viable implants)/ total number
Effects on morphology and wet weights of accessory sexual organs
determine antiandrogenic effects of SS on wet weight of selected organs
of the male reproductive system
randomly selected male rats were orally treated with either 1 mL
of 3000 mg/kg of SS (n=6) or 1 mL vehicle daily for 7 consecutive
days (between 13:00-14:00).
On day 1 post-treatment, these rats were killed with an overdose
of ether and the animals were weighed.
The gross external morphology of the testes, excurrent ducts and
sexual accessory glands was noted.
Weights were recorded for the paired seminal vesicles with coagulation
glands (glandular sections were not removed), lateral prostates, testes,
epididymides or vasa deferentia and were expressed as a percentage of
body weight. The
rats were weighed before the commencement of treatment and on day 1 post-treatment.
Effects on haematology
day 1 post-treatment blood was collected from the tail of the rats (used
in 2.4) under aseptic
conditions and red blood cell (RBC) counts, white blood cell (WBC) counts,
packed cell volume (PCV), haemoglobin content and differential white cell
counts (DC) were estimated as described by Cheesbrough et al.
Evaluation of sedative potential
SS was evaluated using the rat hole-board technique.
Randomly selected male rats were treated orally either with 1 mL
750 (n=12), 1500 (n=12) or 3000
(n=12) mg/kg of SS or 1 mL of vehicle (n=12).
Three h later these rats were individually placed on the centre
of rat hole-board and given a 7.5 min trial period. The number of head
dips, rears, locomotory activity and the number of faecal boluses produced
were recorded. The
time per head dip was then calculated.
Evaluation of muscle strength and coordination
selected male rats were either orally treated with 1 mL of 3000 mg/kg SS
(n=9) or 1 mL of vehicle (n=9).
Three hours post-treatment each of these
rats was subjected to bar holding test (to evaluate muscle strength)
and the time taken (in sec) for the rat to fall from the bar was
following this test, these rats were subjected to Bridge test (to evaluate
and the latency to slide off (in sec) was recorded.
Evaluation of analgesic effect
activity of the SS was evaluated by means of
tail flick and
tests with a cut off time of 10 and 20 sec respectively, to prevent tissue
selected male rats were orally treated with either 1 mL of 3000 mg/kg
seed suspension (n=12) or 1 mL of vehicle (n=12).
Three-four hours before the treatment and 3 and 6 h post-treatment,
the time taken (in sec) to flick the tail (reaction time) when immersed
in a water bath (5-6 cm from the tip) at 55 and the time
taken (in sec) to lick either of the hind paws when placed on a hot plate
Evaluation of hypoglycaemic effect
male rats were deprived of food 14-16 h and randomly divided into two
groups. One group
was orally treated with 1 mL of 3000 mg/kg SS (n=6) and the other
with 1 mL of vehicle (n=6). Blood (3-5 drops) was collected from
the tail of these
rats using aseptic precautions under mild ether anaesthesia 20-30 min
before treatment and 3 h post-treatment.
Blood was allowed to clot at room temperature (28-30) and serum
was collected following centrifugation at 3200g for 5 min.
The serum was
stored at 4 until glucose levels were determined (within 12 h) using
Randox glucose oxidase-peroxidase kit and a spectrophotometer.
Effects on liver function
liver toxicity of the seed suspension was tested in randomly selected
male rats orally treated
with either 1 mL of 3000 or 1500 mg/kg of SS or vehicle (n=6 per
group) for 7 consecutive days (between 13:00-14:00).
On day 1, post-treatment 2 mL of blood was collected from the tail
using aseptic precautions under mild ether anaesthesia.
blood was allowed to clot (25-30 min) at room temperature (28-30) and
subjected to 15 min centrifugation using a Wifug Lab Centrifuge at 3200g.
Serum was collected
and activities of serum glutamic-oxaloacetic transaminase (EC 18.104.22.168,
SGOT) and glutamic-pyruvate transaminase (EC 22.214.171.124, SGPT) were determined
(within 1-2 h) using a Randox enzyme assay kit and a spectrophotometer.
All readings were taken within 10 min after incubation.
treated rats were observed at least once daily for any overt signs of
toxicity (salivation, rhinorrhoea, lachrymation, ptosis, squinted eyes,
writhing, convulsions, tremors, yellowing of fur, loss of hair) stress
(erection of fur, and exophthalmia) and changes in behaviour (such as
spontaneous movements in the cage, climbing, cleaning of face, nongenital
self grooming). In
addition, food and water intake were noted.
are represented as meanSEM.
Statistical analyses were made using Mann-Whitney U-test
and G-test(in the case of proportional data).
inferred when P<0.05.
chemical testing showed the presence of alkaloids, oils, amino acids and
peptides in the seed kernel. Detailed chemical isolation is ongoing.
1 summarises the data obtained with the sexual behaviour study. The only
significant effect observed with the lower dose of SS was the prolongation
of the time taken to mount, intromit or ejaculate.
In contrast, with the higher dose, all the behavioural parameters
monitored were significantly altered (Table 1) except the frequencies
of mounting and intromission, and copulatory efficiency.
1. Effects of oral administration of different doses of seed kernel suspension
(SS) of T. catappa on masculine sexual behaviour of rats (meanSEM, n=12,
ranges in parentheses).
cP<0.01, compared with controls
high dose of SS provoked a qualitative impairment of precoital sexual
behaviour on days 1, 3 and 7 of treatment.
However, pre-coital sexual behaviour of these rats was essentially
comparable to that of control rats on day 7 posttreatment.
contrast, none of the fertility parameters was significantly altered (Table
2) except for ejaculated sperm counts which were moderately but not significantly
increased (day 1 by 167%, day 4 by 7%, and day 7 by 60%).
2. Effect of 7-day oral administration 3000 mg/kg of seed kernel suspension
(SS) of T. catappa on some fertility parameters of male rats (meanSEM,
n=6, ranges in parentheses).
Morphology and wet weights of accessory organs
with high dose of SS, for 7 days, had no effect on the size and the appearance
of testes, excurrent ducts, or sexual accessory glands.
Further, their wet
weights were not altered (control vs treatment: testes, 936.718.9 vs
886.725.7; epididymis, 323.312.0 vs 340.05.8; vas deferens, 70.25.1
vs 74.02.3; seminal vesicle and coagulatory gland complex, 823.350.4
vs 836.739.2 and lateral prostate, 240.014.6 vs 253.319.4 mg/100
g body weight).
the nine blood parameters monitored in these rats, on day 1 post-treatment, none
was significantly altered by the high dose of SS (control vs treatment):
RBC count (5.970.15 vs 5.470.08106 cells/mm3),
WBC count (181261611 vs 216831270
cell/mm3); PCV (47.3%0.8% vs 47.0%0.6%); haemoglobin content
(16.20.4 vs 16.80.4 g/dL); and DC (neutrophils: 45.0%0.9% vs 21.5%2.5%,
lymphocytes: 52.4%0.7% vs 76.9%2.2%, eosinophils:
0.6%0.2% vs 0.0%0.0%, monocytes: 2.0%0.2% vs 1.3%0.2% and
basophils 0.0%0.0% vs 0.0%0.0%).
shown in Table 3, in the rat hole-board experiment, a 750 mg/kg dose of
SS did not alter any of the parameters monitored whilst a dose of 1500
mg/kg inhibited 3 parameters: number of rears (by 41%: P<0.05
), locomotor activity (by 45%: P<0.01) and number of head dips
(by 42%: P<0.05).
On the other hand, with the highest dose, only 2 parameters were
significantly inhibited: number of rears (by 62%; P<0.01) and
locomotor activity (by 69%; P<0.01).
EC50 values for the impairment of number of rears and locomotory
activity were 1313.5
and 1311.6 mg/kg, respectively.
Linear regression analysis was used to investigate the dose-response
relationships in the rat-hole board technique.
There was a highly significant relationship only between the doses
and locomotory activity (r2 = 0.96; P<0.01).
3. Effects of oral administration of different concentrations of seed
kernel suspension (SS) of T. catappa on the parameters of rat hole-board
n=12, ranges in parentheses).
compared with controls: bP<0.05, cP<0.01
Muscle relaxation and muscle coordination
3 h post-treatment, the high dose of the SS failed to alter the latency
to fall significantly in the bar holding test (control vs treatment: 51.442.98
vs 50.562.52 sec)
and the latency to slide off in the Bridge test (control vs treatment:
45.004.24 vs 46.004.08 sec).
high dose of SS failed to alter the reaction times significantly 3 and
6 h post-treatment
when evaluated both by the tail flick (control vs treatment at
3 h, 3.20.3 vs 3.40.5 sec and at 6 h, 2.70.2 vs 3.70.3 sec) and
hot plate (control vs treatment: at 3 h, 13.931.05 vs 16.581.72 sec
and at 6 h, 11.480.57
vs 15.652.80 sec) techniques.
high dose of SS had no effect on the fasting blood glucose level 3 h post
treatment (data not shown). The high dose of SS also had no effect on
the fasting blood glucose level 3 h post treatment (control vs treatment:
75.53.2 vs 83.46.9
day treatment of high dose of SS caused significant elevations in both
SGOT (by 34%) (control vs treatment: 57.56.6 vs 77.35.6 U/L; P<0.05)
and SGPT (by 73% ) (control vs treatment: 17.51.4 vs 30.3 vs 5.1 U/L;
P<0.01). In contrast,
with the lower dose there was no significant change in either of these
enzyme activities SGOT (control vs treatment: 57.56.6 vs 43.310.3
U/L) or SGPT (control vs treatment: 17.51.4 vs 20.23.5 U/L) level.
Other adverse effects
were neither treatment-related defects nor overt clinical signs of toxicity,
stress or changes in behaviour and appearance evident.
the doses tested, SS of T. catappa had no effect on orgasm or immediate fertility
but caused marked changes in the male sexual behaviour.
The nature and severity of these demasculinisation effects, however,
differed according to the dose used;
the lower dose impaired sexual arousability whilst the higher dose
in addition, decreased sexual performance, sexual interest and libido.
the dose these inhibitory effects on sexual behaviour had a rapid onset
these data suggest a receptor-mediated action in the brain.
Alkaloids and aminoacids
are present in the SS of T. catappa and these can inhibit male sexual
behaviour of rats[10,11] in a similar fashion, as was evident
in this study, through
cholinergic and serotonergic receptors.
Subchronic treatment of high dose of SS caused moderate elevations
in SGOT and SGPT activity indicating liver toxicity. This is a matter
for concern. However, liver toxicity was not elicited with the lower dose.
other than this effect on the liver, there were no overt signs of general
toxicity, haemotoxicity, motor deficiencies, motor incoordination, general
lethargy, behavioural abnormalities, stress or a lowering of body weight
and suppression of food intake.
the antimasculine effects of SS can not be a consequence of generalised
toxic effects but is due to a selective action.
With the lower dose only the time required for treated rats to
mount, intromit or ejaculate was greatly prolonged whilst the other sexual
parameters remained unchanged.
Taken together, the prolongation of these three latencies suggest
a reduction in sexual arousability/motivation: as an inverse relationship
exists between these three parameters of male sexual behaviour and sexual
the other hand, the prolongation of the ejaculatory latency by itself
suggests an aphrodisiac action.
All the treated rats mounted and intromitted without any
inhibition of mount-and-intromission frequencies or copulatory efficiency or
This suggests that libido, sexual vigour and sexual performance
were unimpaired during the aphrodisiac action.
similar effect on copulatory behaviour of rats is reported with a water
extract of Piper betel leaves.
Further, the nonimpairment in the number of rats attempting intromission
and in the number of intromissions made strongly suggests that the lower
dose does not disrupt penile erectile function: in the rat, anteroflexions
or flips are essential for penile insertion during copulation.
The inability of the SS to prolong the reaction times in the tail
flick and hot plate techniques suggest that the aphrodisiac action is
not mediated via an impairment of penile sensitivity resulting from analgesia.
Nevertheless, SS induced elevation in threshold of cutaneous penile
receptors cannot be ruled out.
higher dose of SS, on the other hand, impaired all the parameters of sexual
behaviour other than mounting-and-intromission frequency and copulatory
efficiency indicating that sexual vigour remained uninhibited.
However, the anti-libido effect, at this dose, would reduce the
aphrodisiac value of T. catappa seeds.
The rapid onset and reversibility of the sexual behavioural changes
as well as the lack
of a significant change in either the absolute or relative weights of
sexual accessory organs and unimpaired index of libido strongly suggest
that the anti-libido effect is not mediated through a change in the blood
in males causes deterioration of their sexual behaviour and libido.
However, this mechanism seems unlikely to be operative in this
study because it is generally accepted that only long-term hyperprolactenaemia
can induce deficient sexual behaviour.
Here, sexual behaviour was inhibited as early as 3 h of treatment.
Sedatives inhibit libido and sexual performance. The SS showed a sedative activity in a dose related manner as judged by the inhibition of three of the four parameters in the rat hole-board technique. Thus sedative activity of the SS can account for the observed impairments of sexual behaviour and libido. The failure of the SS to alter latencies of bar holding and Bridge tests provides further support to this notion: as false positive results are evident in rat hole-board technique by muscle deficiencies and their incoordinations. The SS had no hypoglycaemic activity, thus, the sedation is unlikely to be mediated through a reduction in blood glucose level.
In conclusion, the present findings show that seeds of T. catappa possess potent aphrodisiac activity and provides scientific evidence in favour of the claims made in Ayurvedic medicine in Sri Lanka regarding this action. The results also suggest that moderate consumption of kernel of seed of T. catappa could be useful in the treatment of men with sexual dysfunctions resulting primarily from premature ejaculation.
Jayasinghe DM. Ayurveda
Pharmacopoeia Colombo. Sri Lanka: Department of
Ayurveda; 1997. p 67-8.
W. D. Ratnasooriya, Department of Zoology,
University of Colombo, Colombo 03, Sri Lanka.