Ginkgo biloba extract enhances male copulatory behavior and reduces serum prolactin levels in rats

Ginkgo Biloba Extract Can Antagonize Subchronic Arsenite Exposure-Induced Hepatocyte Senescence by Inhibiting Oxidative Damage and Inflammation in Rats

A growing body of evidence suggests that long-term arsenic exposure can induce liver injury. Our previous studies have demonstrated that liver injury occurs in arsenic-poisoning patients and arsenic-exposed rats. However, therapeutic targets are still unclear, and there is a lack of effective drugs. This study aimed to investigate the effects of sodium arsenite (arsenite) exposure on hepatocyte senescence and the intervention effect of ginkgo biloba extract in rats. In this study, 24 male Sprague-Dawley rats (weighing 180-200 g) were randomized into three groups. The control group received a normal diet, and the arsenic-exposed group was given 10 mg/L arsenite for 3 months by free drinking along with a normal diet. The ginkgo biloba extract treatment group was consecutively administered EGb761 (10 mg/kg, by gavage) for 1 month following 2 months of arsenite exposure. Our results showed that exposure to 10 mg/L arsenite induced narrowing of the hepatic sinus space, enlargement of hepatocytes, and increased multinucleated hepatocytes and inflammatory cell infiltration in rat liver tissue compared with the normal control group. Moreover, 10 mg/L arsenite also caused abnormal expression of inflammation-related indices (IL1-β, IL-6, TNF-α), oxidative damage-related indices (SOD, MDA, GPx), and senescence-related proteins (p16, p-p53, E2F1). EGb761 could effectively reduce the pathological damage of liver tissue and antagonize the abnormal expression of liver tissue inflammation and oxidative damage-related indices as well as cellular senescence-related proteins caused by arsenite exposure. Notably, EGb761 reduced the accumulation of arsenic in rat liver tissues. These results suggested that EGb761 could effectively alleviate subchronic arsenic exposure-induced senescence of hepatocytes, which may be achieved partially through inhibiting inflammation and oxidative damage in rats. This study may provide a new therapeutic target for arsenic-induced liver injury.

Pregnenolone 16-Alpha Carbonitrile, an Agonist of Rodent Pregnane X Receptor, Regulates Testosterone Biosynthesis in Rodent Leydig Cells

Leydig cells (LCs) in the testes produce the male sex hormone testosterone (T). Several xenobiotics, including clinical drugs, supplements, and environmental chemicals, are known to disrupt T homeostasis. Notably, some of these xenobiotics are known to activate the pregnane X receptor (PXR), a ligand-dependent nuclear receptor. However, it is currently unknown whether PXR is expressed in LCs and whether PXR activation alters T synthesis in rodent LCs. Therefore, in this study, we sought to determine whether PXR is expressed in rodent LCs and whether pregnenolone 16-alpha carbonitrile (PCN), the prototype agonist of rodent PXR, regulates T biosynthesis in rodent LCs. Hormonal as well as protein and gene expression analyses were conducted in rat primary LCs and MA-10 mouse Leydig cells. Results showed that PXR was expressed at the mRNA and protein level in both rat primary LCs and MA-10 cells. Incubation of rat primary LCs with PCN resulted in a significant decrease in T secretion. This PCN-induced decrease in T secretion was associated with decreased protein expression of key steroidogenic enzymes such as 3β-HSD and CYP17A1. RNA-seq results from MA-10 cells showed that PCN down-regulated the transcripts of steroidogenic enzymes and proteins involved in the T synthesis pathway. Together, these results suggest that PCN, an agonist of rodent PXR, can regulate T biosynthesis in rodent LCs by down-regulating the expression of the steroidogenic enzymes involved in T biosynthesis. Our results are significant as they provide a potential novel mechanism for disruption of testosterone homeostasis by a variety of xenobiotics.

Effects of postnatal exposure to cadmium on male sexual incentive motivation and copulatory behavior: Estrogen and androgen receptors expression in adult brain rat

There are numerous evidence showing that cadmium (Cd) is an endocrine disruptor that exerts multiple toxic effects at different reproductive levels, including male sexual behavior (MSB). The effect of early exposure to Cd on sexual incentive motivation (SIM) and MSB in adult stage, and the immunoreactivity of receptors for hormones such as estrogens and androgens in brain regions that are relevant for the SIM and MSB display, have not been studied until now. The present study evaluated the effects of 0.5 and 1 mg/kg CdCl2 from day 1-56 of postnatal life on SIM and MSB in adults rats, as well as serum testosterone concentrations, Cd concentration in blood, testis, and brain areas, and the immunoreactivity in estrogen receptors (ER-α and -β), and androgen receptor (AR) in the olfactory bulbs (OB), medial preoptic area (mPOA), and medial amygdala (MeA). Our results showed that both doses of Cd decreased SIM and MSB, accompanied by low serum concentrations of testosterone. Also, there was a significant reduction in immunoreactivity of ER-α and AR in mPOA, and a significant reduction in AR in MeA on male rats treated with Cd 1 mg/kg. These results show that exposure to high doses of Cd in early postnatal life could alter the correct integration of hormonal signals in the brain areas that regulate and display SIM and MSB in adult male rats.

Diet, herbs and erectile function: A good friendship!

Plants and plant materials have been used for thousands of years to treat and control erectile dysfunction in men. This practice has spanned many cultures and traditions around the world, with the therapeutic effects of many plants attributed to their phytochemical constituents. This review explains how polyphenols (including phenolic acids, flavonoids, terpenoids, carotenoids, alkaloids and polyunsaturated fatty acids) in plants and plant food products interact with key enzymes (phosphodiesterase-5 [PDE-5], angiotensin-converting enzyme [ACE], acetylcholinesterase [AChE], adenosine deaminase [ADA] and arginase) associated with erectile dysfunction. By modulating or altering the activity of these physiologically important enzymes, various bioactive compounds from plants or plant products can synergistically or additively provide tremendous protection against male erectile problems.

Promising role of medicinal plants in the regulation and management of male erectile dysfunction

Male erectile dysfunction (ED) refers to incompetency to reaching and retaining adequate penile tumescence for sexual intercourse. Over 152 million men globally suffer from ED and by 2025, the number of affected individuals is anticipated to be around 322 million. Pharmacological and nonpharmacological therapies such as phosphodiesterase (PDE) inhibitors, alprostadil, penile prosthesis surgery, and hormonal replacement are available for management and recuperation of ED. Nevertheless, such therapies are reported to have adverse effects as well as life-threatening. Accordingly, diversity of medicinal plant species and bioactive active compounds are preferred as therapeutic options because they are natural, abundant, available, low-cost and cause fewer or no side effects. This current review will emphasise the aetiology, risk factors, mechanisms underlying the pathophysiology of ED, treatments of ED as well as their side effects. It also provides medicinal plants that are proven effective in vivo and in vitro for the mitigation and treatment of male ED. This knowledge could be used in the future in drug discovery for the development of more natural drugs with no side effects.

Ginkgo Biloba Extract in Ophthalmic and Systemic Disease, With a Focus on Normal-Tension Glaucoma

Glaucoma is a neurodegenerative eye disease that results in retinal ganglion cell loss and ultimately loss of vision. Elevated intraocular pressure (IOP) is the most common known risk factor for retinal ganglion cell damage and visual field loss, and the only modifiable risk factor proven to reduce the development and progression of glaucoma. This has greatly influenced our approach and assessment in terms of diagnosis and treatment. However, as many as ≥50% of patients with progressive vision loss from primary open angle glaucoma without IOP elevation (≤22 mm Hg) have been reported in the United States and Canada; 90% in Japan and 80% in Korea. Extensive research is currently underway to identify the etiology of risk factors for glaucoma other than or in addition to elevated IOP (so-called "normal-tension" glaucoma; NTG) and use this knowledge to expand available treatment options. Currently, Food and Drug Administration-approved medications for glaucoma exclusively target elevated IOP, suggesting the need for additional approaches to treatment options beyond the current scope as the definition of glaucoma changes to encompass cellular and molecular mechanisms. This review focuses on alternative medical approaches, specifically Ginkgo Biloba extract, as a potential treatment option for normal-tension glaucoma.

Opsin gene expression regulated by testosterone level in a sexually dimorphic lizard

Expression of nuptial color is usually energetically costly, and is therefore regarded as an 'honest signal' to reflect mate quality. In order to choose a mate with high quality, both sexes may benefit from the ability to precisely evaluate their mates through optimizing visual systems which is in turn partially regulated by opsin gene modification. However, how terrestrial vertebrates regulate their color vision sensitivity is poorly studied. The green-spotted grass lizard Takydromus viridipunctatus is a sexually dimorphic lizard in which males exhibit prominent green lateral colors in the breeding season. In order to clarify relationships among male coloration, female preference, and chromatic visual sensitivity, we conducted testosterone manipulation with mate choice experiments, and evaluated the change of opsin gene expression from different testosterone treatments and different seasons. The results indicated that males with testosterone supplementation showed a significant increase in nuptial color coverage, and were preferred by females in mate choice experiments. By using quantitative PCR (qPCR), we also found that higher levels of testosterone may lead to an increase in rhodopsin-like 2 (rh2) and a decrease in long-wavelength sensitive (lws) gene expression in males, a pattern which was also observed in wild males undergoing maturation as they approached the breeding season. In contrast, females showed the opposite pattern, with increased lws and decreased rh2 expression in the breeding season. We suggest this alteration may facilitate the ability of male lizards to more effectively evaluate color cues, and also may provide females with the ability to more effectively evaluate the brightness of potential mates. Our findings suggest that both sexes of this chromatically dimorphic lizard regulate their opsin expression seasonally, which might play an important role in the evolution of nuptial coloration.

Therapeutic effects of Schisandra chinensis on the hyperprolactinemia in rat

Prolactin (PRL) is secreted from the pituitary gland in response to eating, mating, and ovulation. Increased serum concentration of PRL during pregnancy contributes to enlargement of the mammary glands of the breasts and prepares for production of milk. However, high PRL levels derived from prolactinoma and hyperprolactinemia induce physiological disorders such as infertility and early menopause. Natural compounds isolated from S. chinensis have been known to possess anti-oxidative, anti-inflammatory and anti-diabetic effects. In the present study, we examined the therapeutic effect of S. chinensis and its single compounds on hyperprolactinemia in the pituitary gland. In rat pituitary cells, PRL expression levels were examined using real-time PCR and western blot assay. Crude S. chinensis extract and its single compound, gomisin N, reduced mRNA and protein levels of PRL in GH3 cells. In addition, cell proliferation and PRL target gene expression in cells were modulated by S. chinensis. Similar to the in vitro experiments, crude S. chinensis extract and gomisin N reduced PRL levels in the pituitary and serum of immature female rats. These results show that S. chinensis and its single compound, gomisin N, are regulators of PRL production and may be candidates for treatment of hyperprolactinemia and prolactinoma.

The drug treatment of delayed ejaculation

Delayed ejaculation (DE) is an uncommon and a challenging disorder to treat. It is often quite concerning to patients and it can affect psychosocial well-being. Here we reviewed how DE is treated pharmacologically .We also highlighted specific settings where drugs could be introduced to medical practice. Electronic databases were searched from 1966 to February 2016, including PubMed MEDLINE, EMBASE, EBCSO Academic Search Complete, Cochrane Systematic Reviews Database, and Google Scholar using key words; delayed ejaculation, retarded ejaculation, inhibited ejaculation, drugs, treatment, or pharmacology. To achieve the maximum sensitivity of the search strategy and to identify all studies, we combined “delayed ejaculation” as Medical Subject Headings (MeSH) terms or keywords with each of “testosterone” or “cabergoline” or “bupropion” or “amantadine” or “cyproheptadine” or “midodrine” or “imipramine” or “ephedrine” or “pseudoephedrine” or “yohimbine” or “buspirone” or “oxytocin” or “bethanechol” as MeSH terms or keywords. There are a number of drugs to treat patients with DE including: testosterone, cabergoline, bupropion, amantadine, cyproheptadine, midodrine, imipramine, ephedrine, pseudoephedrine, yohimbine, buspirone, oxytocin, and bethanechol. Although there are many pharmacological treatment options, the evidence is still limited to small trials, case series or case reports. Review of literature showed that evidence level 1 (Double blind randomized clinical trial) studies were performed with testosterone, oxytocin, buspirone or bethanechol treatment. It is concluded that successful drug treatment of DE is still in its infancy. The clinicians need to be aware of the pathogenesis of DE and the pharmacological basis underlying the use of different drugs to extend better care for these patients. Various drugs are available to address such problem, however their evidence of efficacy is still limited and their choice needs to be individualized to each specific case.

Aphrodisiac activity of polyherbal formulation in experimental models on male rats

Objective:

To investigate the aphrodisiac potential of polyherbal formulations prepared from different parts of Tribulus terrestris, Curculigo orchioides, Allium tuberosum, Cucurbita pepo, Elephant creeper, Mucuna pruriens, and Terminalia catappa in Albino rats in specified ratio as suspension.

Materials and Methods:

The different concentrations of prepared polyherbal formulations i.e. 150, 300, and 600 mg/kg and sildenafil citrate as standard (5 mg/kg) and vehicle (control) were administered orally to rats (n = 6 animals per group) for 3 weeks. Mating behavior parameters in male rats was monitored in first week and third week week of treatment pairing with receptive females. After termination of drug treatment, the mating performance, hormonal analysis, sperm count, and testes-body weight ratio were also evaluated.

Results:

The polyherbal formulation showed a significant increase in mating behavior as well as mating performance, serum hormonal levels, sperm count, and testes-body weight ratio with dose-dependent relationship as compared to vehicle control. But the dose of 600 mg/kg of polyherbal formulation assumes closer resemblance of above parameters with the standard used.

Conclusion:

The results of the study strongly suggest that the polyherbal formulations have a good aphrodisiac activity on rats in the above experimental models, which may be an alternative weapon for various sexual dysfunctions in future.

Noncontact erection is enhanced by Ginkgo biloba treatment in rats: role of neuronal NOS in the paraventricular nucleus and sacral spinal cord

RATIONALE

Nitric oxide (NO) is an important messenger mediating erection in the central nervous system (CNS). Paraventricular nucleus (PVN) neurons can be activated by NO and project the signals to the sacral spinal cord, which is involved in regulation of erection. Ginkgo biloba extract (EGb 761) facilitates noncontact erection (NCE) in rats; however, it is not clear whether EGb 761 increased NCE is associated with NO.

OBJECTIVE

The present study was designed to investigate the effects of neuronal nitric oxide synthase (nNOS) on NCE in rats following EGb 761 treatment.

METHODS

Adult Long-Evans male rats were treated with 50 mg/kg of EGb 761 or distilled water for 14 days. The NCE test was performed after 14 days of EGb 761 treatment and the NCE frequency was recorded. Approximately 14 h following the NCE behavioral tests, animals were sacrificed, and nNOS activity in the PVN and S6-L1 spinal cord was measured by immunohistochemistry and western blotting, respectively.

RESULTS

Treatment with 50 mg/kg of EGb 761 for 14 days increased the NCE numbers compared to either the controls treated with distilled water on the same day or the same group on day 0. Also, EGb 761 treatment enhanced nNOS-immunoreactive cell numbers in the PVN. Furthermore, western blot analysis showed that EGb 761-treated animals displayed higher levels of nNOS expression in the S1 spinal cord than controls.

CONCLUSION

Our results suggest that enhanced NCE in male rats administrated with EGb 761 may be related to the central nNOS activity in the PVN and the spinal cord.

Effect of aqueous extract of Arctium lappa L. (burdock) roots on the sexual behavior of male rats

BACKGROUND

Arctium lappa L. root has traditionally been recommended as an aphrodisiac agent. It is used to treat impotence and sterility in China, and Native Americans included the root in herbal preparations for women in labor. However, its use has not been scientifically validated. The present study therefore investigated the effects of aqueous extract of Arctium lappa L. roots on sexual behavior in normal male rats.

METHODS

Seventy-five albino male rats were randomly divided into five groups of 15 rats each. Rats in group 1 (control) were administered 10 mL/kg body weight distilled water (vehicle), group 2 received 60 mg/kg body weight sildenafil citrate (Viagra), while those in groups 3, 4, and 5 were given 300, 600, and 1,200 mg/kg body weight, respectively, of aqueous extract of Arctium lappa L. roots in the same volume. Female albino rats were made receptive by hormonal treatment. Sexual behavior parameters in male rats were monitored on days 3, 7 and 15 by pairing with receptive females (1:3). Male serum testosterone concentrations and potency were also determined.

RESULTS

Oral administration of Arctium lappa L. roots extract at 600 and 1,200 mg/kg body weight significantly increased the frequencies of mount, intromission, and ejaculation frequency (p < 0.05). The latencies of mount and intromission were significantly reduced and ejaculation latency was prolonged. Administration of the extract also reduced the post-ejaculatory interval. The standard drug (Viagra) was more effective than the extract. The extract significantly increased the frequencies of all components of penile reflexes as well as serum testosterone levels, compared with the distilled water controls.

CONCLUSIONS

The results of this study demonstrate that aqueous extract of Arctium lappa L. roots enhances sexual behavior in male rats. The aphrodisiac effects of the plant extract may be related to the presence of flavonoids, saponins, lignans and alkaloids, acting via a multitude of central and peripheral mechanisms. These results thus support the traditional use of Arctium lappa L. root extract for treating impotence and sterility.

Ginkgo biloba treatment increases copulation but not nNOS activity in the medial preoptic area in male rats

Nitric oxide (NO) is an important messenger in the central nervous system to mediate male copulatory behavior. EGb 761, a standardized extract of Gingko biloba, has been reported to facilitate male copulation in rats. The present study is to determine the effects of neuronal nitric oxide synthase (nNOS) in the medial preoptic area (MPOA) on copulation in male rats following EGb 761 treatment. Adult male rats were treated with 50mg/kg of EGb 761 or distilled water by oral gavage for 14 consecutive days. The animals were sacrificed approximately 14h after the last behavioral test and MPOA brain tissues were collected for nNOS immunohistochemistry. EGb 761 treatment for 14 days significantly increased the intromission frequency compared to the vehicle-treated controls on day 14. An increase in ejaculation frequency was also seen in the EGb 761-treated group compared to the vehicle-treated controls on day 14 and to the same group on day 0. However, EGb 761 treatment did not influence the number of nNOS-immunoreactive cells in the MPOA. These results suggest that enhanced male copulatory performance in sexually experienced rats administered EGb 761 may not be related to central nNOS activity in the MPOA.

Testicular histomorphometry and ultrastructure of rats treated with cadmium and Ginkgo biloba

The aim of this study is to investigate the association of a single low dose of Cd and daily doses of Ginkgo biloba extract (GbE) on the testis and accessory glands of rats. The animals were treated with a single dose of 3 µmol/kg body weight of cadmium chloride (CdCl₂) and/or 100 mg/kg body weight of GbE. The plasma testosterone levels; corporal, testicular, and accessory glands weight; gonadosomatic index, volumetric proportion; and absolute volume of testicular components did not change after the treatments. CdCl₂ caused significant reduction in Leydig cells volume and altered Leydig cell morphology, as well as vacuolated Sertoli cells cytoplasm, irregular chromatin condensation of late spermatids, and modified acrosome formation. However, animals that received GbE did not show these alterations. The reversal of Cd-induced alterations by the extract is a strong indication that G. biloba is helpful in diminishing the effect of Cd toxicity.

Ginkgo biloba extract enhances noncontact erection in rats: the role of dopamine in the paraventricular nucleus and the mesolimbic system

Penile erection is essential for successful copulation in males. Dopaminergic projections from the paraventricular nucleus (PVN) to the ventral tegmental area (VTA) and from the VTA to the nucleus accumbens (NAc) are thought to exert a facilitatory effect on penile erection. Our previous study showed that treatment with an extract of Ginkgo biloba leaves (EGb 761) enhances noncontact erection (NCE) in male rats. However, the relationship between NCE and dopaminergic activity in the PVN, VTA, and NAc remains unknown. The present study examined the relationship between NCE and central dopaminergic activity following EGb 761 treatment. We report here that, in comparison with the controls, there was a significant increase in the number of NCEs in rats after treatment with 50 mg/kg of EGb 761 for 14 days. EGb 761-treated rats also showed more NCEs than the same group before EGb 761 treatment. A significant increase in the expression of catecholaminergic neurons in the PVN and the VTA was seen by means of tyrosine hydroxylase immunohistochemistry, and tissue levels of dopamine and 3,4-dihydroxyphenylacetic acid in the NAc were also markedly increased in the EGb 761-treated animals. However, the norepinephrine tissue levels in the PVN and the NAc in the EGb 761-treated group were not significantly different from those in the controls. Together, these results suggest that administration of EGb 761 increases dopaminergic activity in the PVN and the mesolimbic system to facilitate NCE in male rats.

Fermented soymilk increases voluntary wheel running activity and sexual behavior in male rats

Wheel running by rodents is thought to reflect voluntary exercise in humans. The present study examined the effect of fermented soymilk (FSM) on voluntary wheel running in rats. FSM was prepared from soymilk (SM) using the bacteria Leuconostoc pseudomesenteroides . The rats were fed a normal diet for 3 weeks followed by a 3-week administration of diet containing FSM or SM (5% w/w), and then the diets were switched back to a normal diet for 3 weeks. The voluntary wheel running activity was increased by FSM administration, although no changes were observed by SM administration. This effect was observed 2 weeks after FSM administration and lasted 1 week after deprivation of FSM. Then we evaluated the effect of FSM on sexual behavior in male rats. FSM administration for 10 days significantly increased the number of mounts. The protein expression of tyrosine hydroxylase (TH) increased in the hippocampus by FSM administration and it is suggested that FSM may change norepinephrine or dopamine signaling in the brain. Our study provides the first evidence that FSM increases voluntary wheel running activity and sexual behavior and suggests that TH may be involved in these effects.

Effects of Ginkgo biloba extract on the embryo-fetal development in Wistar rats

BACKGROUND

Ginkgo biloba extract (GBE) is an herbal medicine used for treating neurodegenerative diseases, cerebrovascular insufficiency, peripheral arterial occlusive disease, and also vestibular disturbance. Some components of GBE have presented estrogenic effects and, in a previous study, high dosages of GBE caused intra-uterine growth retardation in fetuses of Wistar rats treated during the fetogenesis period.

METHODS

Pregnant Wistar rats were treated, through gavage, with different dosages of aqueous GBE (3.5, 7.0, and 14.0 mg/Kg/day), during the tubal transit and implantation period. Rats were killed on the 15th day of pregnancy and the following parameters were evaluated: clinical symptoms of maternal toxicity; maternal body weight; feed and water intake; maternal liver, kidney, and ovary weights; number of corpora lutea; implants per group ratio; pre- and post-implantation loss per group ratio; live fetuses mean; dead fetuses percentage; fetus and placenta weight per offspring ratio; and fetal external malformation.

RESULTS

No significant alteration was found for both the maternal and embryonic parameters evaluated.

CONCLUSIONS

The GBE treatment in pregnant Wistar rats, during the tubal transit and implantation period, caused no toxic effect on the maternal organism and did not induce embryonic death, growth retardation, and/or fetal malformations.

Ginkgo biloba extract treatment increases noncontact erections and central dopamine levels in rats: role of the bed nucleus of the stria terminalis and the medial preoptic area

RATIONALE

Penile erection is necessary for successful copulation in males. The extract of Ginkgo biloba leaves (EGb 761) significantly facilitates copulation in male rats, but the effect of EGb 761 on noncontact erection (NCE) remains unknown.

OBJECTIVE

The present study was conducted to evaluate the influence of EGb 761 on NCE in male rats.

MATERIALS AND METHODS

Adult Long-Evans male rats were treated with 50 mg/kg of EGb 761 (experimental group) or distilled water (control group) by gavage for 14 days. The NCE test was carried out after 14 days of EGb 761 treatment, and the latency and the numbers of NCE were recorded. Approximately 14 h following the NCE behavioral tests, animals were sacrificed by means of decapitation, and levels of dopamine in the bed nucleus of the stria terminalis (BNST) and medial preoptic area (MPOA) were measured by means of high-pressure liquid chromatography with electrochemical detection.

RESULTS

Chronic treatment with EGb 761 significantly decreased the NCE latency, but increased the number of NCEs and the dopamine levels in the BNST and MPOA in rats compared to the controls.

CONCLUSION

Treatment with EGb 761 increased both NCEs and the dopamine contents in the BNST and the MPOA. These results suggest that enhanced NCEs in the rats administered with EGb 761 may be related to dopaminergic activity in the BNST and MPOA.

Cynomorium songaricum induces spermatogenesis with glial cell-derived neurotrophic factor (GDNF) enhancement in rat testes

AIM OF THE STUDY

Cynomorium songaricum Ruprecht has been used in traditional Korean medicine to treat male infertility, including sexual dysfunction, by improving kidney function. Glial cell-derived neurotrophic factor (GDNF) produced by Sertoli cells induces the proliferation of undifferentiated spermatogonia. We investigated the effects of Cynomorium songaricum on sperm parameters and GDNF expression in rat testes.

MATERIALS AND METHODS

Sperm analysis, RT-PCR, and Western blotting assays were performed after administration of CS to 8-week-old male Wistar rats for 56 consecutive days (1.0g/kg/day, p.o.), the period of sperm formation in the rat.

RESULTS AND CONCLUSIONS

The CS-treated animals showed significant increases in epididymal sperm count and absolute testes weights compared to the control group. CS also increased the expression of GDNF at both the mRNA and protein levels. These results suggest that CS may improve male fertility by enhancing spermatogenesis and GDNF expression.

The Ginkgo biloba extract EGb 761(R) and its main constituent flavonoids and ginkgolides increase extracellular dopamine levels in the rat prefrontal cortex

BACKGROUND AND PURPOSE

Experimental and clinical data suggest that extracts of Ginkgo biloba improve cognitive function. However, the neurochemical correlates of these effects are not yet fully clarified. The purpose of this study was to examine the effects of acute and repeated oral administration of the standardized extract EGb 761((R)) on extracellular levels of dopamine, noradrenaline and serotonin (5-HT), and the dopamine metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in the prefrontal cortex (PFC) and striatum of conscious rats.

EXPERIMENTAL APPROACH

Monoamines and their metabolites were monitored by the use of microdialysis sampling and HPLC with electrochemical or fluorescence detection.

KEY RESULTS

A single oral dose of EGb 761 (100 mg.kg(-1)) had no effect on monoamine levels. However, following chronic (100 mg.kg(-1)/14 days/once daily) treatment, the same dose significantly increased extracellular dopamine and noradrenaline levels, while 5-HT levels were unaffected. Chronic treatment with EGb 761 showed dose-dependent increases in frontocortical dopamine levels and, to a lesser extent, in the striatum. The extracellular levels of HVA and DOPAC were not affected by either acute or repeated doses. Treatment with the main constituents of EGb 761 revealed that the increase in dopamine levels was mostly caused by the flavonol glycosides and ginkgolide fractions, whereas bilobalide treatment was without effect.

CONCLUSIONS AND IMPLICATIONS

The present results demonstrate that chronic but not acute treatment with EGb 761 increased dopaminergic transmission in the PFC. This finding may be one of the mechanisms underlying the reported effects of G. biloba in improving cognitive function.

Adverse endocrine and metabolic effects of psychotropic drugs: selective clinical review

The article critically reviews selected, clinically significant, adverse endocrine and metabolic effects associated with psychotropic drug treatments, including hyperprolactinaemia, hyponatraemia, diabetes insipidus, hypothyroidism, hyperparathyroidism, sexual dysfunction and virilization, weight loss, weight gain and metabolic syndrome (type 2 diabetes mellitus, dyslipidaemia and hypertension). Such effects are prevalent and complex, but can be managed clinically when recognized. They encourage continued critical assessment of benefits versus risks of psychotropic drugs and underscore the importance of close coordination of psychiatric and general medical care to improve long-term health of psychiatric patients. Options for management of hyperprolactinaemia include lowering doses, switching to agents such as aripiprazole, clozapine or quetiapine, managing associated osteoporosis, carefully considering the use of dopamine receptor agonists and ruling out stress, oral contraceptive use and hypothyroidism as contributing factors. Disorders of water homeostasis may include syndrome of inappropriate antidiuretic hormone (SIADH), managed by water restriction or slow replacement by hypertonic saline along with drug discontinuation. Safe management of diabetes insipidus, commonly associated with lithium, involves switching mood stabilizer and consideration of potassium-sparing diuretics. Clinical hypothyroidism may be a more useful marker than absolute cut-offs of hormone values, and may be associated with quetiapine, antidepressant and lithium use, and managed by thyroxine replacement. Hyper-parathyroidism requires comprehensive medical evaluation for occult tumours. Hypocalcaemia, along with multiple other psychiatric and medical causes, may result in decreased bone density and require evaluation and management. Strategies for reducing sexual dysfunction with psychotropics remain largely unsatisfactory. Finally, management strategies for obesity and metabolic syndrome are reviewed in light of the recent expert guidelines, including risk assessment and treatments, such as monoamine transport inhibitors, anticonvulsants and cannabinoid receptor antagonists, as well as lifestyle changes.

Influence of Eurycoma longifolia on the copulatory activity of sexually sluggish and impotent male rats

AIM OF THE STUDY

The root of Eurycoma longifolia Jack, native to South East Asia, has long been used as a male aphrodisiac remedy to treat sexual disorders. In the study we evaluated the influence of Eurycoma longifolia Jack on sexual behavior (including both motivation and copulatory performance) of sexually sluggish and impotent male rats.

MATERIALS AND METHODS

The root powder of the plant was orally administered to adult Sprague-Dawley male rats, classified as sexually sluggish or impotent taking in account their behavior in pre-experimental tests. Groups of 8 animals each were submitted to three different types of treatment: (1) acute at 3 dose levels (250, 500 and 1000 mg/kg); (2) subacute (daily for 6 days) at the dose of 500 mg/kg and (3) subchronic (daily for 12 days) at the same dose (500 mg/kg). Mount, intromission and ejaculation latencies and post-ejaculatory interval were recorded during the mating test in order to evaluate sexual performance. In addition the partner preference test was used to assess sexual motivation. Testosterone serum levels were measured in subacutely treated rats and compared with the values of controls receiving vehicle.

RESULTS

Concerning the copulatory activity of sexually sluggish rats, both acute (dosed at 500 and 1000 mg/kg) and subacute treatments with the root powder significantly reduced ejaculation latencies, increasing also the percentage of mounting and ejaculating animals; in addition the subacute administration reduced post-ejaculatory interval. In impotent rats both subacute and subchronic treatments increased the percentage of mounting and ejaculating rats. The motivational behavior of sluggish rats during the partner preference test was not affected by the treatments. Testosterone serum levels were increased in rats subacutely treated in comparison with controls.

CONCLUSION

Eurycoma longifolia root improved sexual performance but not motivation in sluggish rats after acute or subacute administration. The effect could be mainly ascribed to increased testosterone levels.

Medicinal plants as potential male anti-infertility agents: a review

For millions of couples, the inability to have a child is a personal tragedy and a large proportion of childless people are confronted with social stigmatization (blame) and personal frustration. Formerly assigned to women, infertility of a couple is nowadays equitably distributed between the two sexes. Among the methods used to treat male infertility problems, medicinal plants have been used empirically as extracts, decoctions, fractions or semi-purified compounds. These herbal products are used in the treatment of a dysfunctioning of the libido, sexual asthenia, erection, and sperm disorders. Pharmacological activities of many of these plants have been shown in vitro using cells, in vivo (on laboratory animals) and human studies. For instance, extracts of Panax ginseng, Panax quinquefolius and Lepidium meyenii have shown positive effects on sexual desire; while extracts of Astragalus membranaceus, Asparagus racemous, Withania somnifera, Andrographis paniculata and Acanthopanax senticosus improved sperm parameters. Plants provide a treatment option that is affordable and available for infertile couples, and phytotherapy is an essential form of treatment in our health system. However, herbal products are still anarchically used in many regions and countries, and a great proportion of medicinal plants used traditionally to solve male reproductive disorders have not yet been scientifically evaluated. Therefore in this review, we have summarized most of the data dealing with the effects of plant extracts on mammalian reproductive functions.

Different subregions of the medial preoptic area are separately involved in the regulation of copulation and sexual incentive motivation in male rats: a behavioral and morphological study

The purpose of this study was to investigate whether sexual incentive motivation and copulatory performance are regulated by different subregions of the medial preoptic area (MPOA). Sexual incentive motivation was measured by means of a partner preference test. Both copulatory behavior and sexual incentive motivation were tested in male rats treated with 50mg/kg of either EGb 761 or a vehicle (distilled water) by gavage for 14 days. Administration of EGb 761 increased the number of intromissions, but had no effect on the number of mounts, mount latency, intromission latency, ejaculation latency, or post-ejaculatory interval. In the partner preference test, the total duration of visits to estrous female rats in both of the groups was significantly different from the total duration of visits to sexually active males. EGb 761 treatment increased the number of ejaculations compared both to vehicle-treated controls on day 14 and the same group on day 0. In comparison with the controls, the EGb 761-treated group showed a significant increase in the number of tyrosine hydroxylase-expressing cells in the dorsal, but not the ventral, subregion of the MPOA, and significantly high dopamine levels in the MPOA. These results indicate that EGb 761 does not affect sexual incentive motivation, but facilitates copulatory performance in male rats, suggesting that the mechanisms responsible for sexual incentive motivation and copulatory performance may be associated with differential functions of MPOA subregions.

Aphrodisiac properties of Allium tuberosum seeds extract

AIM OF THE STUDY

In the present study, we examined the effect of Allium tuberosum seeds extract upon the expression of male rat sexual behavior, in order to know whether Allium tuberosum seeds extract possess aphrodisiac property.

MATERIALS AND METHODS

The aphrodisiac activity of Allium tuberosum seeds n-BuOH extract was investigated in male rats. The extract (500 mg/kg body weight/day) and L-dopa (100 mg/kg body weight/day) were administered orally by gavages for 40 days. Mount latency (ML), intromission latency (IL), ejaculation latency (EL),mounting frequency (MF), intromission frequency (IF), ejaculation frequency (EF) and post-ejaculatory interval (PEI) were the parameters observed before and during the sexual behavior study at day 0, 10, 20, 30 and 40.

RESULTS

The n-BuOH extract reduced significantly ML, IL, EL and PEI (p < 0.05). The extract also increased significantly MF, IF and EF (p < 0.05). These effects were observed in sexually active and inactive male rats.

CONCLUSIONS

Present findings provide experimental evidence that the n-BuOH extract preparation of Allium tuberosum seeds possesses aphrodisiac property.

Effects of Psoralea corylifolia on the cAMP-responsive element modulator (CREM) expression and spermatogenesis in rats

AIM OF THE STUDY

Psoralea corylifolia (PC) is a medicinal herb used to improve male reproductive function in Korean traditional medicine. It has been used for treatment of male infertility including sexual dysfunction by improving kidney function.

MATERIALS AND METHODS

To investigate the effect of PC on spermatogenesis, the cAMP-responsive element modulator (CREM) in rat testes was evaluated using sperm analysis, the reverse-transcription polymerase chain reaction, and Western blot analysis. PC was administered to 10-week-old male Wistar rats for 56 consecutive days, the sperm formation period of the rat.

RESULTS AND CONCLUSIONS

The PC-treated rats had increased sperm counts with enhanced levels of CREM messenger RNA and protein, suggesting that PC induces spermatogenesis via CREM activation in rat testes.