Long-term effects of the rhapontic rhubarb extract ERr 731® on estrogen-regulated targets in the uterus and on the bone in ovariectomized rats

Phytotherapeutic approach for conquering menopausal syndrome and osteoporosis

Women face a significant change in their reproductive health as menopause sets in. It is marred with numerous physiological changes that negatively impact their quality of life. This universal, transition phase is associated with menopausal and postmenopausal syndrome, which may spread over 2-10 years. This creates a depletion of female hormones causing physical, mental, sexual and social problems and may, later on, manifest as postmenopausal osteoporosis leading to weak bones, causing fractures and ultimately morbidity and mortality. Menopausal hormone therapy generally encompasses the correction of hormone balance through various pharmacological agents, but the associated side effects often lead to cessation of therapy with poor clinical outcomes. However, it has been noticed that phytotherapeutics is trusted by women for the amelioration of symptoms related to menopause and for improving bone health. This could primarily be due to their reduced side effects and lesser costs. This review attempts to bring forth the suitability of phytotherapeutics/herbals for the management of menopausal, postmenopausal syndrome, and menopausal osteoporosis through several published research. It tries to enlist the available botanicals with their key constituents and mechanism of action for mitigating symptoms associated with menopause as well as osteoporosis. It also includes a list of a few herbal commercial products available for these complications. The article also intends to collate the findings of various clinical trials and patents available in this field and provide a window for newer research avenues in this highly important yet ignored health segment.

Efficacy evaluation of standardized Rheum rhaponticum root extract (ERr 731 ®) on symptoms of menopause: A systematic review and meta-analysis study

Menopause is characterized by various physical, mental and emotional symptoms. ERr 731 ® is a standardized extract from Rheum rhaponticum root and has been clinically studied for its role in reducing menopausal symptoms. The current systematic review and meta-analysis aimed to evaluate the efficacy of ERr 731 ® supplementation in alleviating the severity of menopausal symptoms. In this review, we searched across three online databases up to March 2023, evaluated the quality of the included studies by the Physiotherapy Evidence Database scale, and assessed the risk of bias by the Cochrane Risk of Bias tool. We then performed a meta-analysis using RevMan software to estimate the pooled mean difference (MD). The study protocol was registered in the Prospective Register of Systematic Reviews (CRD42023416808). After screening and evaluation, we included four high-quality studies (a total of 390 participants; the ERr 731 ® group: 193 participants; the control group: 197 participants) in the meta-analysis. The results showed that ERr 731 ® supplementation significantly reduced the Menopause Rating Scale score (MD: -15.12; P < 0.001), compared with control therapy. Sensitivity analysis revealed no effect of individual studies on the overall pooled estimate or overall observed heterogeneity. The current review provides evidence that ERr 731 ® supplementation is effective in reducing menopause symptoms. Potential bias and high heterogeneity in the results warrant further clinical studies.

Rheum rhaponticum and Rheum rhabarbarum Extracts as Modulators of Endothelial Cell Inflammatory Response

BACKGROUND

Inflammation, endothelial dysfunction, and alterations in blood physiology are key factors contributing to atherosclerosis and other cardiovascular disorders. Hence, modulation of endothelial function and reducing its pro-inflammatory and pro-thrombotic activity is considered one of the most important cardioprotective strategies. This study aimed to evaluate the anti-inflammatory potential of rhubarb extracts isolated from petioles and underground organs of Rheum rhabarbarum L. (garden rhubarb) and R. rhaponticum L. (rhapontic rhubarb) as well as two stilbenoids, typically found in these plants, i.e., rhapontigenin (RHPG) and its glycoside, rhaponticin (RHPT).

METHODS

Analysis of the anti-inflammatory effects of the indicated rhubarb-derived substances involved different aspects of the endothelial cells' (HUVECs) response: release of the inflammatory mediators; cyclooxygenase (COX-2) and 5-lipoxygenase (5-LOX) expression as well as the recruitment of leukocytes to the activated HUVECs. The ability of the rhubarb-derived extracts to inhibit COX-2 and 5-LOX activities was examined as well. The study was supplemented with the in silico analysis of major components of the analyzed extracts' interactions with COX-2 and 5-LOX.

RESULTS

The obtained results indicated that the examined plant extracts and stilbenes possess anti-inflammatory properties and influence the inflammatory response of endothelial cells. Biochemical and in silico tests revealed significant inhibition of COX-2, with special importance of rhaponticin, as a compound abundant in both plant species. In addition to the reduction in COX-2 gene expression and enzyme activity, a decrease in the cytokine level and leukocyte influx was observed. Biochemical tests and computational analyses indicate that some components of rhubarb extracts may act as COX-2 inhibitors, with marginal inhibitory effect on 5-LOX.

Rhaponticin contained Rheum officinale root extract improved Postmenopause symptom of Ovariectomized Rat

Postmenopausal women have decreased levels of the hormone estrogen. Reduced estrogen levels will often involve many symptoms that reduced quality of life. This research aims to analyze the effects of Rheum officinale root extract on postmenopausal model rats. To this end, thirty rats underwent ovariectomy (OVX) surgery and six rats were operated without having their ovaries removed. The OVX was confirmed by body weight–uterus weight ratio and a vaginal swab. Six groups of the rats were performed: SHAM group and negative control groups are given vehicle; the positive control was assigned tamoxifen; and the extract has been given three doses 7, 35, and 175 mg/200 g BW, respectively, for 30 days. The calcium content of bone ash was measured using atomic absorption spectrophotometer. Blood pressure was evaluated using CODA^®, and the metabolites in the blood were assessed using gas chromatography–mass spectrometry (MS) and high-performance liquid chromatography. As a result, using ultra-performance liquid chromatography (UPLC)-MS, we found that the extract's major component was rhaponticin and its metabolites. The bone calcium levels increased with increasing doses of the extract. In the OVX group, the bone calcium content was decreased significantly 51.56% ± 8.9% g compared with the SHAM group 62.97% ±5.6% g, and the administration of Rheum extract could restore the calcium content of the bone to become 69.27% ± 3.8% g. From the above data, we concluded that Rheum root extracts contain astrigin, rhaponticin, rhapontigenin, and desoxyrhaponticin. Rheum root extract could improve calcium content and lipid profiles of OVX rats by stimulation osteoblastogenesis. Rheum root extracts could control the blood pressure of OVX rats by reducing lipid profiles.

Ethnobotanical Uses, Phytochemistry and Pharmacology of Different Rheum Species (Polygonaceae): A Review

Today, there is an increased tendency to use herbal remedies. Rhubarb refers to several species of the genus Rheum L. in the Polygonaceae family. This species-rich genus is mainly distributed in Asian countries. Several medicinal effects have been attributed to the Rheum spp. in the traditional and modern medicine such as healing lungs, liver, kidney, womb and bladder diseases, cancer, diabetes, insect bites, relapsing fevers, diarrhea and constipation. Various in vitro, in vivo and clinical studies have investigated the therapeutic effect of extracts, fractions and pure compounds isolated from different species of this genus. Considering the positive findings, several pharmaceutical formulations containing rhubarb extract like capsules, drops, mouthwashes and different topical formulations are now present in the market. However, there are other traditional therapeutic effects of rhubarb that have not been studied yet and it is of great importance to perform confirmatory experiments or clinical investigations. The current review summarizes general information regarding botany, phytochemistry, ethnobotany and pharmacological aspects of Rheum spp. It is hoped that the present review could motivate subsequent research on the other medicinal properties of these plants that have been neglected until today.

Effects of 17β-HSD2 inhibition in bones on osteoporosis based on an animal rat model

Hormone replacement therapy is a viable option to protect bone from postmenopausal osteoporosis. Systemically elevated estrogen levels, however, are disadvantageous because of the risk of harmful side effects in other organs. The rationale of the study presented here is to target a key enzyme in estradiol (E2) and testosterone (T) metabolism to increase E2 levels in an organ-specific manner, thereby avoiding the disadvantages of systemically increased E2 levels. The 17ß-hydroxysteroid dehydrogenase (17β-HSD2), which is e.g. expressed in bone, catalyzes the oxidation of E2 and T into estrone (E1) and androstenedione. We postulate that inhibiting 17β-HSD2 should lead to elevated E2 and T levels in organs expressing the enzyme. Therefore, we can use the benefits of E2 directly, or those of T following aromatization into E2, in the bone without affecting systemic levels. We tested for the first time, the novel and potent 17β-HSD2 inhibitor, compound 24 (C24), to explore the therapeutic potential of a 17β-HSD2 inhibition in an ovariectomy (ovx)-induced rat model of bone loss. We tested the inhibitor alone and, together with low dose estrogen supplementation to model estrogen levels in the postmenopausal situation. Female mature Wistar-Hannover rats were treated for 8 weeks with doses of 2, 10, 50 mg C24 per kg body weight per day alone or in the presence of estradiol benzoate (E2B) supplementation to alleviate ovx-induced bone loss. Ovx placebo and sham operated animals served as negative and positive controls. The experiment was evaluated regarding aspects of efficacy and safety: Bone was analyzed to evaluate bone protective effects, and uterus for potential, unwanted E2-mediated side effects. We observed a good bioavailability of C24 as very high plasma concentrations were measured, up to a group mean of 15,412 nM for the ovx C24-high group. Histomorphometrical analyses and in vivo &ex vivo μCT revealed significant bone protective effects for the lowest inhibitor concentration used. Irrespective of the plasma concentration, no proliferative effects in the uterus could be observed. These results support our approach of intracellular targeting key enzymes of E2 and T metabolism to increase E2 and T levels in an organ specific manner.

Pregnancy and herbal medicines: An unnecessary risk for women's health-A narrative review

The indiscriminate use of herbal medicines to prevent or to heal diseases or even the use for questionable purposes such as weight loss has received both interest and scrutiny from the scientific community and general public alike. An increasing number of women put their own and the unborn child's health at risk due to a lack of knowledge about the phytochemical properties and adequate use of herbal medicine (phytomedicines or herbal supplements) and lack of communication with their healthcare provider. The purpose of this narrative review was to summarize the use of herbal medicines during pregnancy and their potential toxic effects to highlight the importance of caution when prescribing herbal medicines or supplements for women, because, in addition to suffering interactions and a great amount of information obtained in preclinical predictive studies, assessment of nephrotoxicity, neurotoxicity, hepatotoxicity, genotoxicity, and teratogenicity of traditional medicinal herbs still remains scarce in the clinical setting.

Comparison of estrogenic responses in bone and uterus depending on the parity status in Lewis rats

The reproductive transition of women through peri- to postmenopause is characterized by changes in steroid hormone levels due to the cessation of the ovarian function. Beside several complaints associated with these hormonal changes, the deterioration of the trabecular bone micro-architecture and the loss of skeletal mass can cause osteoporosis. At this life stage, women often have a reproductive history of one to several pregnancies. The ovariectomized skeletally mature rat (>10 months old) is one of the most commonly used animal models for postmenopausal osteoporosis research. Despite the fact that mammals can undergo up to several reproductive cycles (primi-/pluriparous), nulliparous animals are often used and the question whether changes in the hormonal milieu subsequently affect the skeleton and influence the outcome of intervention studies is often neglected in study designs. Therefore, the aim of the present study was to compare the estrogen responsiveness of nulliparous and pluriparous rats. For this purpose, one year old virgin or retired breeder Lewis rats were either sham operated or ovariectomized, whereas half of the ovariectomized animals received subcutaneous 17β-estradiol pellets eight weeks after surgery. After another four weeks, the effects on the uterus were determined by expression analysis of estrogen-dependently regulated steroid receptor genes and well-established marker genes. Moreover, trabecular bone parameters in the tibia were analyzed by micro-computed tomography (μCT). Parity-dependency in estrogen responsiveness was observed with respect to the achieved serum E2 levels in response to similar E2 treatment. This led to differences both on the uterus wet weight and on the expression level of uterine target genes. In addition, a reversal of the ovariectomy-induced changes of the bone architecture after 17β-estradiol substitution was only observed among the nulliparous. In conclusion, the observations of this study support parity-dependent differences in the responses to estrogenic compounds in the uterus and the bone of rats. These results indicate that the parity-status has an impact on the outcome of studies aiming at the investigation of estrogenic effects of compounds potentially used in hormone replacement and thus, this should be taken into consideration for further studies and particularly for the discussion of data obtained with the preclinical ovariectomized rat animal model.