Psychoimmunological effects of dioscorea in ovariectomized rats: role of anxiety level

The effect of Dioscorea esculenta powder on prostaglandin E2 and cytochrome c oxidase subunit 2 levels, menstrual pain, and premenstrual syndrome in young women: A randomized double-blind controlled trial

Background Diosgenin, extracted from Dioscorea esculenta, has been reported to decrease prostaglandin E2 (PGE2) levels and any other inflammatory cytokine in rodents. However, it is still unclear whether D. esculenta intake suppressed PGE2 production and menstrual pain and premenstrual syndrome (PMS) in younger female. Aim This study aims to investigate the effect of D. esculenta intake on PGE2 and cytochrome c oxidase subunit 2 (COX-2) levels and on menstrual pain and PMS in young women. This is a randomized, double-blind, placebo-controlled, crossover study. Methods Ten healthy young females were administered either a placebo or D. esculenta (300 mg/day) for 4 weeks, followed by a 4-week washout period. Fasting blood sample was taken from the fingertips on the second day of menstrual cycle began and obtained 24h before the last D. esculenta to avoid acute effects. Participants then switched treatments for 4 weeks as a second trial. Plasma PGE2 and COX-2 levels were measured before and after each trial. The visual analogue scale (VAS), McGill pain questionnaire (MPQ), and Daily Record of Severity of Problems (DRSP) were also evaluated. The study was set and conducted from 2019 to 2020. Results PGE2 and COX-2 levels significantly decreased after D. esculenta intake compared to placebo (p = 0.038, p = 0.042 each). The VAS and DRSP scores were also significantly lower after D. esculenta intake (p = 0.046, p = 0.035 each). Conclusion Four-week D. esculenta intake suppressed PGE2 and COX-2 levels resulting in an improvement in PMS symptoms and menstrual pain in young women.

Possible involvement of l-arginine-nitric oxide pathway in the antidepressant activity of Auraptene in mice

Background

Depression is one of the most common mental illnesses worldwide. Nitric oxide (NO) is involved in the pathophysiology of depression. Auraptene (a coumarin derivative) has been shown to possess pharmacological effects on neurological diseases.

Purpose

The present study aimed to investigate the possible role of the NO pathway in Auraptene antidepressant effects in male mice.

Methods

Behavioral tests were used to assess depression-like behaviors. The mice received Auraptene at 10, 30, and 100 mg/kg, the combination of the sub-effective (ineffective) dose of Auraptene (10 mg/kg) and L-NAME, and the combination of the effective dose of Auraptene (30 mg/kg) and L-arginine. Finally, OFT, TST, FST, brain, serum MDA level, antioxidant capacity, hippocampus, and serum NO level were measured.

Results

The data analysis showed that Auraptene (30 mg/kg) improved depression-like behaviors. Auraptene (30 mg/kg) also significantly reduced serum NO levels (P < 0.05) and significantly increased serum MDA (10 mg/kg, P < 0.05). Auraptene at 30 mg/kg also increased serum antioxidant capacity (P < 0.01). Co-administration of L-NAME and the sub-effective dose of Auraptene enhanced the effects of Auraptene. However, co-administration of the effective dose of Auraptene and L-arginine reduced the impacts of Auraptene.

Conclusions

The results showed that Auraptene causes antidepressant effects in a dose-dependent manner and acts as a prooxidant at 100 mg/kg, and exacerbates oxidative stress. The antidepressant effects of this active molecule are exerted by reducing the NO level in the hippocampus and serum, increasing the antioxidant capacity, and reducing the MDA level in the serum.

Diosgenin via NMDA Receptor Exerted Anxiolytic-like Effect on Maternally Separated Mice

BACKGROUND AND AIM

Anxiety is one of the most common psychiatric disorders that lead to the disruption of daily life and also the quality of life. Routine medications have many side effects and cause physical dependence and psychosocial addiction. Diosgenin is a phytosteroid found in a number of herbs. The present study aimed to investigate the anxiolytic-like effect of diosgenin in the maternal separation model in male mice focusing on the role of NMDA receptors.

MATERIALS AND METHODS

Maternal separation (MS) paradigm was performed daily (3 h) from postnatal day (PND) 2-14. Male mice were treated with different doses of diosgenin to find effective and sub-effective doses. In the next step, mice were treated with an effective dose of diosgenin plus NMDA and or a sub-effective dose of diosgenin plus ketamine (NMDA antagonist). Valid behavioral tests for the evaluation of anxiety-like behavior were performed. Then, mice were euthanized, the hippocampus was dissected out and gene expression of NMDA receptors (NR2a and NR2b subunits) was assessed.

RESULTS

MS provokes anxiety-like behaviors in the open field test (OFT) and elevated plus maze (EPM) test. Diosgenin significantly mitigated the negative effects of MS. Co-administration of NMDA attenuated anxiolyticlike effect of the effective dose of diosgenin, while ketamine potentiated the anxiolytic effect of sub-effective dose of diosgenin. Furthermore, MS increased the expression of the NMDA receptor in the hippocampus which to some extent modulated with diosgenin.

CONCLUSION

Diosignin has an anxiolytic-like effect on MS mice which at least, in part, mediated through NMDA receptors.

Kami-shoyo-san ameliorates sociability deficits in ovariectomized mice, a putative female model of autism spectrum disorder, via facilitating dopamine D1 and GABAA receptor functions

ETHNOPHARMACOLOGICAL RELEVANCE

Kami-shoyo-san (KSS) is a Kampo formula used clinically for menopause-related symptoms in Japan. However, the effect of KSS on autism spectrum disorder (ASD), a developmental disorder with a higher prevalence in males than in females, has not been reported yet.

AIM OF THE STUDY

It is accepted generally that dysfunction in the GABAergic system is associated with pathogenesis of ASD. In our previous study, a decrease in brain allopregnanolone (ALLO), a positive allosteric GABA_A receptor modulator, induced ASD-like symptoms such as impaired sociability-related performance and increased repetitive self-grooming behavior in male mice, and that KSS ameliorated these behavioral abnormalities via GABA_A receptor- and dopamine D₁ receptor-mediated mechanisms. In this study, to better understand a gender difference in the prevalence of ASD, we examined whether dissection of ovary (OVX), a major organ secreting progesterone in females, causes ASD-like behaviors in a manner dependent on brain ALLO levels, and if so, how KSS affects the behaviors.

MATERIALS AND METHODS

Six-week-old ICR female mice received ovariectomy, and KSS (74 mg/kg and 222 mg/kg, p.o.) were treated before 1 h starting each behavioral test. The sociability, social anxiety-like behavior, and self-grooming behavior were analyzed by the resident-intruder test, mirror chamber test, and open field test, respectively. After finishing the behavioral experiment, the ALLO content in the brain was measured by ELISA. Furthermore, we examined the effects of OVX on the neuro-signaling pathways in the prefrontal cortex and striatum by Western blotting.

RESULTS

The results revealed that OVX induced sociability deficits and social anxiety-related behaviors, but not repetitive self-grooming behavior, and that these behavioral changes were accompanied not only by a decrease of brain ALLO levels, but also by impairment of CREB- and CaMKIIα-mediated neuro-signaling in the prefrontal cortex. Moreover, the administration of KSS had no effect on the brain ALLO level, but significantly ameliorated the OVX-induced behavioral and neurochemical changes via facilitation of GABA_A receptor and dopamine D₁ receptor-mediated neurotransmission.

CONCLUSIONS

These findings suggest that a decrease in gonadal hormone-derived ALLO plays a major role in ASD-like behaviors in female mice and that KSS is beneficial for the treatment of ASD in females.

Identification of Osteoporosis-Associated Protein Biomarkers from Ovariectomized Rat Urine

Objective:

Osteoporotic fracture is one of the most common health risks and aggravates the quality of life among postmenopausal women worldwide. In this study, osteoporosis-associated protein biomarkers were identified from urine of osteoporotic female Sprague-Dawley rats developed by ovariectomy.

Method:

Four months after the operation, the bone mineral density of the femur of ovariectomized rats was significantly lowered in comparison with that of the sham operated rats. The protein profiles of the urine samples collected from the sham, ovariectomized (OVX) and 2 month-old non-operated (Young) rats were compared by 2-D gel and MS spectrometry.

Results:

Proteins consistently expressed between Young and sham but differentially expressed in OVX rats were selected and identified. One down-regulated 21 kDa protein, superoxide dismutase (SOD), and 1 up-regulated 53-54 kDa protein, alph-1-antitrypsin (A1AT), were selected from urine of the ovariectomized rats by 2-D gel analysis. Further, a total of 30 with 19 up-regulated and 11-down-regulated proteins were selected by LC-MS analysis with more than 2-fold differences in spectral counts. The fact that SOD and A1AT are also listed in the 30 differential proteins suggests that our biomarker isolation procedure suitably represents osteoporosis-associated proteins in urine.

Conclusion:

Supporting the facts, the differential expressions of SOD and A1AT in urine could be validated by Western blotting. These urinary osteoporosis-associated proteins have high potentials to become candidates for non-invasive diagnosis of osteoporosis from urine.

Olive Leaf Extract Elevates Hepatic PPAR α mRNA Expression and Improves Serum Lipid Profiles in Ovariectomized Rats

We hypothesized that olive leaf extract might alleviate dyslipidemia resulting from estrogen deficiency. Serum lipid profile and mRNA expression of the related genes in the liver and adipose tissue were analyzed after providing olive leaf extract (200 or 400 mg/kg body weight; n=7 for each group) to ovariectomized rats for 10 weeks. After 10 weeks' administration, the rats in the olive leaf extract-administered groups showed significantly lower levels of serum triglyceride and very-low-density lipoprotein (VLDL)-cholesterol compared with the rats in the control group, whereas the administration of olive leaf extract did not significantly change the elevated low-density lipoprotein cholesterol levels. In addition, administration of high dose of olive leaf extract significantly decreased the liver triglyceride and increased serum estradiol levels. mRNA expressions of peroxisome proliferator-activated receptor alpha (PPAR α) and acyl-CoA oxidase (ACO) were not affected by ovariectomy, however, administration of olive leaf extract significantly increased both PPAR α and ACO mRNA expression. Expression of adiponectin mRNA in adipose tissue was significantly decreased in the ovariectomized control group. Rats administered low-dose olive leaf extract showed significantly elevated adiponectin mRNA expression compared with rats in the ovariectomized control group. Even though dose-dependent effects were not observed in most of the measurements, these results suggest that genes involved in lipid metabolism may be regulated by olive leaf extract administration in ovariectomized rats.

Protective Effects of Tualang Honey against Oxidative Stress and Anxiety-Like Behaviour in Stressed Ovariectomized Rats

The present study aims to evaluate the antioxidant and anxiolytic-like effect of Tualang honey in stressed ovariectomized (OVX) rats. The animals were divided into; (i) nonstressed sham-operated control rats, (ii) sham-operated control rats exposed to stress, (iii) nonstressed OVX rats, (iv) OVX rats exposed to stress, (v) OVX rats exposed to stress and treated with 17 β-oestradiol (E2) (20 μg daily, sc), and (vi) OVX rats exposed to stress and treated with Tualang honey (0.2 g/kg body weight, orally). The open field test was used to evaluate the anxiety-like behaviour and ELISA kits were used to measure oxidant/antioxidant status of the brain homogenates. The result showed that anxiety-like behavior was significantly increased in stressed OVX compared to other groups, and administering either E2 or Tualang honey significantly decreased anxiety-like behaviour in stressed OVX rats. The levels of malondialdehyde (MDA) and protein carbonyl (PCO) were significantly decreased while the levels/activities of superoxide dismutase (SOD), glutathione S-transferases (GST), glutathione peroxidase (GPx), and glutathione reductase (GR) were significantly increased in the brain homogenates of treated stressed OVX groups compared to untreated stressed OVX. In conclusion, Tualang honey has protective effects against brain oxidative stress and may be useful alternative anxiolytic agent especially for postmenopausal women.

Comparison of behavioral and biochemical deficits in rats with hereditary defined or D-galactose-induced accelerated senescence: evaluating the protective effects of diosgenin

One of the important factors in aging is oxidative stress and aging-related disturbances are believed be ameliorated by antioxidants. Diosgenin is a bio-active ingredient of dioscorea that is widely used in Chinese medicine, shows anti-oxidant activity and improves some aging-related deficits in senescent and menopausal animals. We compared alterations in behavior, biochemical parameters (plasma levels of the uric acid, creatinine, calcium, phosphate, total cholesterol, low-density lipoprotein cholesterol and triglycerides, and the plasma activity of aminotransferases AST and ALT), and sperm motility in two models of accelerated senescence (d-galactose-induced (150 mg/kg/day, i.p., 57 days) aging in Wistar rats vs. genetically defined in OXYS rats) and examined the protective effects of diosgenin (10 or 50mg/kg/day, p.o., 57 days). Both models had augmented levels of ALT activity indicating hepatopathology. Compared to d-galactose-treated animals, OXYS rats demonstrated profound biochemical alterations (hypocalcemia, hypophosphatemia, and hypocholesterolemia) and behavioral deficits (impaired object recognition, decreased sexual motivation and locomotor activity, retarded learning) that confirmed the difference in the mechanisms of accelerated senescence in these models. We first showed diminished sperm motility in males of both models of accelerated senescence studied. Chronic diosgenin treatment failed to improve biochemical and behavioral disturbances and had some undesirable side effects on body weight and working memory in OXYS rats. However, diosgenin restored moderately decreased sperm motility in d-galactose-treated Wistar males and might be recommended for treatment of mild age-related reproductive dysfunctions.

The Elevated Plus-Maze Test: Differential Psychopharmacology of Anxiety-Related Behavior

The role of individual factors in behavioral neuroscience is an important, but still neglected, area of research. For example, the Elevated Plus-Maze Test has been one of the most used paradigms to gauge unconditioned aversively motivated behavior in rodents. However, despite a great number of experiments with this test there have been only few efforts to assess systematic individual variations in the elevated plus-maze and related neurobiological functions. The present review aims to give, first, a general overview and introduction about the test, and second, an animal model of anxiety based on natural variance of plus-maze behavior within a given unselected population of rats. Finally, critical aspects of such approaches in animal research are discussed, and suggestions are given as to where to go from here.

Effects of diosgenin on myometrial matrix metalloproteinase-2 and -9 activity and expression in ovariectomized rats

Diosgenin, a traditional Yam extraction, has been used in hormone replacement for menopausal women. We aimed to investigate the influences of diosgenin administration upon the MMP-2 and -9 activity and expression and reproductive hormones of ovariectomized (OVX) rats, a model of menopausal status. Seven-week old female Wistar rats with bilateral OVX or sham operation (controls) were divided and administered different dosages of diosgenin (0, 10, 50, or 100 mg/kg/day) for 8 weeks. Serum was then sampled for progesterone (P4) and estradiol (E2) assay and uterine horns harvested. Myometrial MMP-2 and -9 activity and expression were surveyed and myometrial collagen expression was also assayed. The results show higher body weight in OVX rats across the 8 weeks post surgery and no significant differences were noted among OVX or Sham rats with diosgenin supplements. There were lower P4 and E2 concentrations in OVX rats compared to Sham rats, and higher P4 concentration of Sham rats post diosgenin supplement. MMP-2 and -9 mRNA expression and activity was lower in OVX rats, although higher MMP-2 and lower MMP-9 activity/mRNA expression was observed in OVX rats post diosgenin supplementation. Collagen mRNA expression was higher in OVX rats compared to Sham controls, and diosgenin administration decreased collagen mRNA expression in OVX rats. In conclusion, diosgenin is associated with gelatinase expression and collagen metabolism in OVX rats. Diosgenin administration can partially reverse the effects of OVX upon MMP functions and hormone status. Adequate diosgenin supplement might modulate myometrial gelatinase expression and collagen metabolism in menopausal subjects.

Anxiety-like behaviors and expression of SERT and TPH in the dorsal raphé of estrogen- and fluoxetine-treated ovariectomized rats

The anxiolytic effect of fluoxetine (Flx) was often ineffective in postmenopausal and estrogen-deficient patients, but such effect had not been experimentally demonstrated, particularly in the female rat model of estrogen deficiency. Here we determined the anxiety-like behaviors in ovariectomized (Ovx) rats treated for 4weeks with 10μg/kg 17β-estradiol s.c. (Ovx+E2), 10mg/kg Flx p.o. (Ovx+Flx) or a combination of both (Ovx+E2+Flx). Since Flx is known to induce anxiolysis in males, we first evaluated the Flx regimen in male rats. The results showed that anxiety-like behaviors were reduced in Flx-treated male rats. In contrast, Ovx+Flx rats still exhibited the same anxiety-like behaviors as in Ovx rats. Both Ovx+E2 and Ovx+E2+Flx rats, however, showed comparable reductions in anxiety-like behaviors, suggesting that Flx had no anxiolytic-like effect. Furthermore, E2 and E2+Flx similarly upregulated the mRNA expression of serotonin reuptake transporter (SERT) and tryptophan hydroxylase-2 in the dorsal raphé of Ovx rats, while having no effect on SERT expression in the frontal cortex, hippocampus, septum, amygdala and periaqueductal gray. In conclusion, Flx induced anxiolytic-like action in male rats. In Ovx rats, it was E2 and not Flx that exerted the anxiolytic-like action, which was mediated, in part, by altering serotonin metabolism in the dorsal raphé.

Anxiolytic-like effect of phytoestrogen genistein in rats with long-term absence of ovarian hormones in the black and white model

Postmenopause is mainly characterized by a reduction of ovarian hormones, which is accompanied by a major incidence of physical disorders and mood swings. Clinical and experimental evidence suggest that phytoestrogens could be used to ameliorate these alterations associated with menopause. However, the phytoestrogen effects on anxiety in rats with long-term absence of ovarian hormones, is unknown. Consequently, in the present study the authors compared the anxiolytic-like effect of phytoestrogen genistein (0.25, 0.5 y 1.0 mg/kg, i.p.) in Wistar rats with 12-weeks postovariectomy in the black and white model and in the open field test, and it was compared with diazepam (1.0 mg/kg, i.p.). In the black and white model, genistein (0.5 y 1.0 mg/kg) and diazepam reduced the latency to enter and increased the time spent into the white compartment; also, significantly increased frequency and time spent in exploration toward white compartment was seen, as compared with the control group (p<0.05). In the open field test, genistein and diazepam increased grooming and rearing, without significant changes in locomotor activity, as compared with the control group. In conclusion, phytoestrogen genistein produces an anxiolytic-like effect in Wistar rats with long-term absence of ovarian hormones in the black and white model, supporting the hypotheses that phytoestrogens could be used to ameliorate anxiety associated with menopause.

A postpartum model in rat: behavioral and gene expression changes induced by ovarian steroid deprivation

BACKGROUND

Postpartum depression (PPD) affects approximately 10% to 20% of women during the first 4 weeks of the postpartum period and is characterized by labile mood with prominent anxiety and irritability, insomnia, and depressive mood. During the postpartum period, elevated ovarian hormones abruptly decrease to the early follicular phase levels that are postulated to play a major role in triggering PPD. However, the underlying neurobiological mechanisms that contribute to PPD have not been determined.

METHODS

In the present study, we examined the effect of ovarian steroids, administered at levels that occur during human pregnancy followed by rapid withdrawal to simulate postpartum conditions, on behavior and gene expression in the rat.

RESULTS

The results of behavioral testing reveal that the hormone-simulated postpartum treatment results in the development of a phenotype relevant to PPD, including vulnerability for helplessness, increased anxiety, and aggression. Real-time quantitative polymerase chain reaction (PCR) demonstrated transient regulation of several genes, including Ca(2+)/calmodulin-dependent protein kinase II (CAMKII), serotonin transporter (SERT), myocyte enhancer factor 2A (MEF2A), brain-derived neurotrophic factor (BDNF), gamma-aminobutyric acid type A receptor alpha 4 (GABAARA4), mothers against decapentaplegic homolog 4 (SMAD4), and aquaporin 4 (AQP4) that could underlie these behavioral effects.

CONCLUSIONS

These studies provide an improved understanding of the effects of withdrawal from high doses of ovarian hormones on behavior and gene expression changes in the brain that could contribute to the pathophysiology of PPD.