Wenpei Bai

Effects of an isopropanolic-aqueous black cohosh extract on central body temperature of ovariectomized rats.

ETHNOPHARMACOLOGICAL RELEVANCE Black cohosh (Cimicifuga racemosa) is widely used in menopause symptoms strategy. AIM OF THE STUDY The aim of this study was to examine the effect of isopropanolic black cohosh extract (iCR) on the central body temperature (CBT) of ovariectomized rats (OVX) and elaborate its possible effects in alleviating menopause related hot flushes. MATERIALS AND METHODS 64 female Sprague-Dawley rats, weighing 230 ± 10g and aged 6-8 weeks, were divided into four groups: ovariectomy (OVX), sham, ovariectomy plus estradiol valerate (OVX+E), and ovariectomy plus iCR (OVX+ICR). The sham group underwent a sham surgery without ovariectomies, while the other three groups underwent bilateral ovariectomies under sterile conditions and a temperature implant was embedded in the abdominal cavity of all four groups. After 2-week recovery period, the temperature of all animals was monitored for 6 weeks. RESULTS CBT of four groups maintained a normal circadian rhythm, with a low day CBT and a high night CBT. CBTs of the sham group were lower than that of the other three groups. The day CBTs of the (OVX+E) group and (OVX+ICR) group were lower than that of the OVX group from day 2 and day 22 respectively. For the difference between day and night CBT, the sham group was smallest, while (OVX+E) and (OVX+ICR) groups were higher than that of OVX group. The amplitude of day and night CBT, CBT fluctuation frequency at 5 min intervals, were higher for the OVX group than the sham group; the amplitude of day and night CBT of (OVX+E) group and the amplitude of night CBT of (OVX+ICR) group were higher than those of OVX group; while the amplitude of day CBT of (OVX+ICR) group was lower than that of OVX group; CBT fluctuation frequency at 5 min intervals was higher for the (OVX+E) and (OVX+ICR) groups than the OVX group. CONCLUSIONS Ovariectomized rats had abnormal thermoregulation, demonstrating an increase in day and night CBT, greater difference between day and night CBT, higher amplitude of day and night CBT, and more CBT fluctuation frequency. For the herbal extract iCR, the onset of affecting abnormal thermoregulation took longer than that of estradiol valerate. ICR had a significant effect on day CBT but was only little effective on night CBT of ovariectomized rats.

Effects of Estradiol Valerate and Remifemin on Norepinephrine Signaling in the Brain of Ovariectomized Rats

Aims: We investigated the norepinephrine pathway changes from the locus coeruleus (LC) to the preoptic area of the hypothalamus (POAH) in the brain of ovariectomized rats under low estrogen levels and explored the therapeutic effects of estradiol valerate (E2) and Remifemin (ICR) on these changes. Methods: 40 female Sprague-Dawley rats were randomly divided into the following groups: surgery with vehicle (SHAM), ovariectomy surgery with vehicle (OVX), ovariectomy with E2 treatment (OVX + E2), and ovariectomy with Remifemin (OVX + ICR). After 4 weeks of treatment, we observed the changes by immunohistochemistry. Results: (1) The average optical density of DBH-ir fibers and the number of α1-adrenoreceptor- and estrogen receptor (ER)α-positive neurons in the main nuclei of POAH were all reduced in OVX rats compared with the SHAM group. The above changes were normalized in all nuclei of the POAH in the E2 group, while they were normalized in some nuclei in the ICR group. Coexpression of ERα and α1-adrenoreceptor was observed in the POAH. (2) The number of DBH- and ERα-positive neurons in the LC decreased in the OVX group compared with the SHAM group and increased after treatment with E2 and ICR. Coexpression of ERα and DBH was observed in the LC. Conclusion: Low estrogen (OVX) altered norepinephrine synthesis in the LC, the projection of norepinephrine fibers and α1-adrenoreceptor expression in the POAH. Both E2 and ICR normalized the norepinephrine pathway, but E2 achieved greater effects than ICR. ICR had different effects in different nuclei in the POAH and its therapeutic effect was better in the LC.

Effects of remifemin treatment on bone integrity and remodeling in rats with ovariectomy-induced osteoporosis.

This study aims to evaluate the effects of Remifemin (isopropanolic extract of Cimicifuga Racemosa) on postmenopausal osteoporosis. 120 female Sprague-Dawley rats were randomly assigned to four groups: sham surgery with vehicle, ovariectomy with vehicle, ovariectomy with estradiol valerate, or ovariectomy with Remifemin. Daily oral administrations of the vehicle, estradiol valerate, or Remifemin began 2 weeks after surgery and lasted to 4, 8, or 12 weeks. Ten rats in each group were sacrificed at each timestep with assessment of bone mineral density, trabecular bone structure, and biomechanical parameters of the femur and lumbar vertebra. Bone turnover markers were evaluated 12 weeks after surgery. Both drugs prevented bone density loss in the distal end of the femur and preserved the trabecular bone structure in both the lumbar vertebra and distal end of the femur following ovariectomy. Both drugs protected bone stiffness at the tested regions and reduced bone reabsorption in ovariectomized rats. The preventive effects of Remifemin against bone-loss can rival those of estradiol valerate if treatment duration is adequately extended. In conclusion, Remifemin may demonstrate equivalent effects to estradiol valerate in terms of preventing postmenopausal osteoporosis.

A Comparison of the Effects of Estrogen and Cimicifuga racemosa on the Lacrimal Gland and Submandibular Gland in Ovariectomized Rats

This study aims to observe the effects of estradiol and Cimicifuga racemosa on the lacrimal gland and submandibular gland of ovariectomized rats. We randomly divided 20 adult female SD rats into four groups—a sham-operated group (SHAM), ovariectomized (OVX) group, ovariectomized group treated with estradiol (OVX+ E), and ovariectomized group treated with the isopropanolic extract of Cimicifuga racemosa (OVX+ iCR). The SHAM group and OVX group used distilled water to instead the drugs. Two weeks after ovariectomy, the estradiol and iCR were administered for 4 weeks. Next, we used H&E staining and electron microscopy to observe any histological changes in the lacrimal and submandibular glands and immunohistochemical staining to observe the expressions of cleaved caspase-3 (Casp-3) and Cu-Zn SOD (superoxide dismutase). The H&E staining find that both drugs can prevent the cells of area from shrinkage in the two kinds of gland. But under the electron microscopy, estradiol and iCR have different efficacy. Estradiol is more effective at protecting mitochondria in lacrimal gland acinar cells than iCR, and iCR is more effective at suppressing endoplasmic reticulum expansion than estradiol. Both estradiol and iCR have a similar protective function on mitochondria in the submandibular gland. The protective function of the two glands may inhibit apoptosis by suppressing the expression of Casp-3. In addition, iCR increases the expression of Cu-Zn SOD in duct system of submandibular gland. The results suggest that both estradiol and iCR confer a protective effect on the lacrimal and submandibular glands of ovariectomized rats via different mechanisms.

Black Cohosh Ameliorates Metabolic Disorders in Female Ovariectomized Rats.

Estrogen deficiency is associated with metabolic derangements in menopausal women. Black cohosh has been widely used as an alternative therapy in the treatment of menopausal syndrome. However, its role in metabolism needs to be defined. The aim of the present study was to investigate the long-term effect of black cohosh on glucose and lipid metabolism in a rat model of post-menopause. Adult female Sprague-Dawley rats were sham operated (SHAM), ovariectomized (OVX), OVX with the treatment of estradiol valerate (OVX + E), or OVX with the treatment of isopropanolic black cohosh extract (OVX + iCR). Body weight, body composition, and blood glucose levels of the animals were monitored. The rats were then sacrificed after 3 months of the treatments. At the end of the experiment, OVX + iCR and OVX + E rats exhibited a significant decrease in body weight gain, body and abdominal fat mass, serum triglycerides levels, hepatic fat accumulation, and adipocyte hypertrophy compared with OVX rats. In addition, insulin resistance and glucose intolerance were improved in OVX + iCR but not in OVX + E rats. No hepatotoxicity was detected in OVX + iCR animals. Furthermore, western blot analysis suggested the increased lipolysis in adipose tissue of OVX + iCR and OVX + E rats. Data from in vitro experiments using cultured primary rat adipocytes also showed that black cohosh could affect lipolysis of adipocytes. In conclusion, the long-term treatment of black cohosh at a proper dosage ameliorated metabolic derangements in OVX rats. Thus, this drug is promising for the treatment of metabolic disorders in menopausal and post-menopausal women.

Estradiol Valerate and Remifemin ameliorate ovariectomy-induced decrease in a serotonin dorsal raphe–preoptic hypothalamus pathway in rats

Perimenopausal syndromes begin as ovarian function ceases and the most common symptoms are hot flushes. Data indicate that the projections of serotonin to hypothalamus may be involved in the mechanism of hot flushes. Therefore, the aim of this study is to investigate the potential role of the serotonin dorsal raphe-preoptic hypothalamus pathway for hot flushes in an animal model of menopause. We determined the changes in serotonin expression in the dorsal raphe (DR) and preoptic anterior hypothalamus (POAH) in ovariectomized rats. We also explored the therapeutical effects of estradiol valerate and Remifemin in this model. Eighty female Sprague-Dawley rats were randomly assigned to sham-operated (SHAM) group, ovariectomy (OVX) group with vehicle, ovariectomy with estradiol valerate treatment (OVX+E) group and ovariectomy with Remifemin (OVX+ICR) group. Serotonin expression was evaluated in the DR and POAH using immunofluorescence and quantified in the DR using an enzyme-linked immunosorbent assay (ELISA). Apoptosis was analyzed in the DR by TUNEL assay. The number of serotonin immunoreactive neurons and the level of serotonin expression in the DR decreased significantly following OVX compared to the SHAM group. No TUNEL-positive cells were detected in the DR in any group. In addition, following OVX, the number of serotonin-positive fibers decreased significantly in the ventromedial preoptic nucleus (VMPO), especially in the ventrolateral preoptic nucleus (VLPO). Treatment with either estradiol or Remifemin for 4 weeks countered the OVX-induced decreases in serotonin levels in both the DR and the hypothalamus, with levels in the treated rats similar to those in the SHAM group. A fluorescently labeled retrograde tracer was injected into the VLPO at the 4-week time point. A significantly lower percentage of serotonin with CTB double-labeled neurons in CTB-labeled neurons was demonstrated after ovariectomy, and both estradiol and Remifemin countered this OVX-induced decrease. We conclude that serotonin pathway is changed after ovariectomy, including the serotonin synthesis in DR and serotonin fibers in PO/AH, both E and Remifemin have an equivalent therapeutic effect on it.

Association between Menopausal Symptoms and Overactive Bladder: A Cross-Sectional Questionnaire Survey in China

Purpose The association between menopause and overactive bladder is controversial. The purpose of this study was to determine the association between menopausal symptoms and overactive bladder, and identify the risk factors for overactive bladder. Methods A cross-sectional study was performed. The study included 403 women aged 36–76 years who visited the menopause clinic at Peking University First Hospital between September 2012 and December 2013. The overactive bladder symptom score and modified Kupperman index questionnaires were used. Differences were assessed using descriptive statistics to determine any association between the overactive bladder symptom score and modified Kupperman index score, and to evaluate the risk factors for overactive bladder. Results A total of 304 women were finally enrolled. The prevalence of overactive bladder was 9.43%, and the modified Kupperman index score; number of sexual problems; and frequency of urinary tract infections, vertigo, melancholia, and mood swings were significantly higher in patients with overactive bladder than in the patients without overactive bladder (p < 0.05). Menopausal symptoms (modified Kupperman index score ≥ 15) (odds ratio: 1.049, 95% confidence interval: 1.006–1.095, p = 0.025) and a low frequency of sexual intercourse in the last 6 months (odds ratio: 2.580, 95% confidence interval: 1.228–5.422, p = 0.012) were identified as independent risk factors for overactive bladder. The frequency of sexual intercourse was found to decrease with an increase in the severity of overactive bladder (p = 0.004, linear-by-linear association = 0.001). Conclusion Menopausal symptoms may be closely associated with overactive bladder, and sexual activity may be associated with the severity of overactive bladder. Moreover, sexual problems, urinary tract infections, vertigo, melancholia, and mood swings may be associated with overactive bladder.

Effect of low estrogen on neurons in the preoptic area of hypothalamus of ovariectomized rats.

The purpose of this study was to investigate the difference in neuronal activity in the preoptic area of the hypothalamus (POAH) under low estrogen condition induced by ovariectomy. One hundred and twenty sham-operated (SHAM) and ovariectomized (OVX) rats were placed in different temperatures for 2h. Twelve rats from each group were stimulated by 4°C, 10°C, 25°C, 33°C and 38°C, respectively. c-Fos expression in the POAH was detected by immunohistochemistry. Following exposure to warm and cold stimuli, there were markedly lower c-Fos-positive cell densities in the OVX group compared with the SHAM group in the median preoptic nucleus (MnPO) at 4°C, 10°C, 33°C and 38°C, in the medial preoptic area (MPA) at 25°C and 38°C, in the ventromedial preoptic nucleus (VMPO) at 4°C, 10°C and 38°C and in the ventrolateral preoptic nucleus (VLPO) at 4°C and 38°C. Both temperature and surgery had an impact on c-Fos expression by two-way ANOVA method except in the lateral preoptic area (LPO). c-Fos expression differed within different nuclei of the two groups in the same and different temperature stimuli. This indicated that the temperature-sensitive nuclei in the POAH exhibited lower and different activities during temperature stimuli following ovariectomy, which possibly resulted in abnormal thermoregulation and menopausal symptoms.

Dehydroepiandrosterone-induced activation of mTORC1 and inhibition of autophagy contribute to skeletal muscle insulin resistance in a mouse model of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy in women of reproductive age and also an important metabolic disorder associated with insulin resistance (IR). Hyperandrogenism is a key feature of PCOS. However, whether hyperandrogenism can cause IR in PCOS remains largely unknown. The mammalian target of rapamycin complex 1 (mTORC1) and its regulated autophagy are closely associated with IR. In the present study, we investigated the role of mTORC1-autophagy pathway in skeletal muscle IR in a dehydroepiandrosterone (DHEA)-induced PCOS mouse model. DHEA-treated mice exhibited whole-body and skeletal muscle IR, along with the activated mTORC1, repressed autophagy, impaired mitochondria, and reduced plasma membrane glucose transporter 4 (GLUT4) expression in skeletal muscle of the mice. In cultured C2C12 myotubes, treatment with high dose testosterone activated mTORC1, reduced autophagy, impaired mitochondria, decreased insulin-stimulated glucose uptake, and induced IR. Inhibition of mTORC1 or induction of autophagy restored mitochondrial function, up-regulated insulin-stimulated glucose uptake, and increased insulin sensitivity. On the contrary, inhibition of autophagy exacerbated testosterone-induced impairment. Our findings suggest that the mTORC1-autophagy pathway might contribute to androgen excess-induced skeletal muscle IR in prepubertal female mice by impairing mitochondrial function and reducing insulin-stimulated glucose uptake. These data would help understanding the role of hyperandrogenism and the underlying mechanism in the pathogenesis of skeletal muscle IR in PCOS.