Recent years have witnessed a dramatic rise in
the use of opioid drugs despite the documentation
of their numerous adverse effects in the literature.
One of these side effects is the negative impact on
sex hormone levels, libido, potency, and menorrhea
One of the most commonly used opioid drugs
is morphine. In a prospective, uncontrolled,
non-randomized study, a group of men with an
average pain duration of 11 years used intrathecal
morphine for 12 weeks. Most of the patients
reported poor libido and erectile difficulty toward
the end of the 12-week period; in addition,
testosterone and follicle-stimulating hormone
(FSH) levels significantly reduced. The intrathecal
opioid caused a reduction in hormone levels
Tribulus terrestris (TT), commonly known as
caltrop or devil’s eyelashes plays an important role
in traditional medicine. Most parts of this plant
are used in herbal medicine, for which TT can enhance
sex drive and treat urolithiasis, menorrhagia,
impotency, rheumatism pains, and premature
In studies conducted on animals, TT is thought
to have a luteinizing hormone (LH)-like activity,
which can induce corpus luteum formation in female
In light of the increasing fertility disorders in opioid users, the present study investigated the effect of TT on the sex hormones and gonadotropins of addicted male rats.
Adult male Wister rats that weighed 200 ± 25 g each (Razi Institute, Iran) were randomly divided into four groups, of 12 animals each: i. control, ii. TT-treated, iii. addicted and iv. TT-treated ad- Ghosian Moghaddam et al. dicted. The rats were housed in groups of three in cages at a temperature of 22-25˚C, on a 12 hour light/12 hour dark schedule and sufficient amounts of food and water.
After obtaining TT and verifying its suitability for our study via the Department of Botany at Shahid Beheshti University, we ground and combined the plant with pelleted food at a weight ratio of 6.25%.
Morphine addiction was induced according to
the method of Moini Zanjani et al. (
The water soluble morphine solution was given
in doses of 0.1, 0.2, and 0.3 mg/ml according to
the method of Swanston-Flatt et al. (
All techniques and methods were approved by the Ethics Committee of Shahed University of Medical Sciences. The laboratory animals were afforded due care in accordance with the regulations of the Committee for the Purpose of Control and Supervision on Experiments on Animals (CPCSEA).
After 21 days of treatment, at treatment termination, blood samples (3-5cc) were obtained from all the rats’ hearts to measure hormone levels. The sera were subsequently separated via centrifuge (Sigma 4-10, USA) at 2000 rpm for 10 minutes and stored at -70˚C in a freezer until hormone analysis.
The plasma concentrations of the sex hormones and gonadotropins were verified by the radioimmunoassay (RIA) method using kits manufactured by Monobind Inc. (USA), as well as ELISA kits (Labsystem, Finland).
Obtained data were expressed as mean ± SEM and statistically analyzed using the one-way analysis of variance (ANOVA), followed by the posthoc Tukey test. p<0.05 was considered statistically significant.
Our FSH analysis showed that the TT-treated control group had the least amount of FSH (0.271 ± 0.025 mIU/ml), while the morphine-addicted group had the highest FSH level (0.348 ± 0.022 mIU/ml). Morphine solely did not suppress FSH. The TT-treated addicted group had a higher FSH level (0.302 ± 0.01 mIU/ml) than did the TT-treated control group; there was, however, no significant change in any of the groups. Figure 1 illustrates these results.
The effect of Tribulus terrestris (TT) on FSH levels in control and addicted groups. Bars depict mean ± SEM of LH.
In LH analysis, the addicted group had decreased LH levels. The highest amount of LH belonged to the treated control group (0.207 ± 0.098 mIU/ml). Figure 2 shows a significantly lower LH level in the addicted group than the control group (0.0125 ± 0.017 mIU/ml), which was due to morphine suppression (p<0.027). The TT-treated addicted group had a significantly higher amount of LH (0.273 ± 0.066 mIU/ml) than did the control group p<0.031.
The effect of Tribulus terrestris (TT) on LH levels in control and addicted groups. Bars depict mean ± SEM of LH.* and $; P<0.05 compared between the control and treated control groups.
In this analysis, there was a reduction in the addicted group (0.122 ± 0.058 ng/ml). The highest amount of testosterone belonged to the control group (0.399 ± 0.04 ng/ml). Figure 3 shows that the addicted group had the least amount of testosterone, as a result of morphine suppression. The treated addicted group had a significantly lower hormone level (p<0.024) than did the treated control group (0.193 ± 0.057 ng/ml). The addicted group had a significantly lower testosterone level than did the control group (p<0.001).
The effect of Tribulus terrestris (TT) on testosterone levels in control and addicted groups.
Bars depict mean ± SEM of testosterone. *; P<0.05 compared between the control and treated control groups.
Our estrogen analysis revealed a decrease in the addicted group compared to the control group (22.70 ± 3.21 pg/ml). Figure 4 illustrates these results. Compared to the control group, estrogen decreased in the addicted group; there was a significant difference between these two groups (p<0.002). Figure 4 also shows a significant difference between the treated addicted group and the treated control group (p<0.048).
The effect of Tribulus terrestris (TT) on estrogen levels in control and addicted groups. Bars depict mean ± SEM of LH.
* and $; P<0.05 compared between the control and treated control groups.
There was an increase in the treated control group and a decrease in the addicted group according to progesterone analysis. Figure 5 shows that the treated control group had the highest hormone level (79.28 ± 5.2 pg/ml), which was due to TT. The addicted group had the least amount, which was due to the effects of morphine. The addicted group had a lower progesterone level than did the control group; the difference, however, was not significant. In comparison with the treated addicted group, the treated control group had a significant increase in hormone levels (p<0.002).
The effect of Tribulus terrestris (TT) on progesterone levels in the control and addicted groups. Bars depict mean ± SEM of progesterone.
*; P<0.05 compared between the control and treated control groups.
In this study, sex hormone and gonadotropin levels were evaluated based on the effect of TT on morphine-addicted rats. FSH, a stimulating hormone of the ovarian follicles, had a higher level in our morphine-addicted groups. In the treated morphine group, the FSH level had the most decrease, which demonstrated that TT suppressed FSH release in the addicted rats. A similar result was observed in the treated control group; however the difference was not significant.
Tabakova and his colleagues, in a comparison
of endocrinal functions before and after
TT therapy, reported that TT acted on the hypothalamus
and reduced FSH levels but did not
decrease ovarian hormones (estrogen and progesterone).
They concluded that TT could be
used to treat menopausal symptoms such as hot
flashes and increase sex drive. These researchers
speculated that the presence of saponin in
TT was responsible for FSH suppression and
the resultant alleviation of hot flashes, irritability,
and depression in menopausal women (
We observed a significant decrease in LH levels in the morphine-addicted group. The treated addicted group had a relatively higher LH than did the addicted group, which denoted that TT increased LH levels. Similarly, the treated control group had a significantly higher LH level than did the control group.
According to Neychev et al. (
Based on our study, estrogen decreased significantly in the addicted group but increased significantly in the treated addicted group. It can, therefore, be concluded that TT significantly increased the estrogen hormone level in male addicted rats. Of note, there was a dearth of specific studies on estrogen in the literature.
Progesterone decreased in our addicted group;
the amount, however, was insignificant. In contrast,
progesterone significantly increased in
the treated control group. We concluded that TT
increased progesterone in non-addicted cases;
however this increase was not significant in addicted
cases. Mazaro-Costa and colleagues have
reported that not only could TT treat sexual disorders
and dysfunction in menopausal women
but it could also enhance vasomotor actions.
There are, however, no reports on progesterone
The present study shows that addiction decreases sex hormones and gonadotropins. Treatment with TT can increase the hormone levels of testosterone, progesterone, estrogen, and LH. Nevertheless, TT did not increase the FSH levels in our male rats.