Effects of Aqueous Extracts of Cynanchum wilfordii in Rat Models for Postmenopausal Hot Flush

Compound of Cynanchum wilfordii and Humulus lupulus L. Ameliorates Menopausal Symptoms in Ovariectomized Mice

Cynanchum wilfordii and Humulus lupulus L. have been used for their various pharmacological properties in South Korea as a traditional medicine or health functional food, respectively, and their intake may relieve menopausal symptoms. The purpose of current study was to determine the effect of compound of Cynanchum wilfordii and Humulus lupulus L. (CWHL) in menopausal symptoms of ovariectomized (OVX) mice. OVX mice received CWHL or caudatin (an active ingredient of CWHL) once daily for 7 weeks. Values for hypothalamic serotonin (5-HT), dopamine, norepinephrine, estrogen receptor (ER)-β, 5-HT1A, and 5-HT2A were significantly enhanced, while value for hypothalamic monoamine oxidase A was reduced in CWHL and caudatin groups compared with the OVX group. CWHL and caudatin significantly reduced tail skin temperature and rectal temperature of OVX mice through partial recovering of the levels of serum estrogen, nitric oxide, follicle-stimulating hormone, luteinizing hormone, and receptor-activator of the NF-κB ligand (RANKL). Moreover, CWHL and caudatin improved bone mineral density via decreasing levels of serum RANKL, tartrate-resistant acid phosphatase, and collagen type 1 cross-linked N-telopeptide and improving levels of serum alkaline phosphatase, osteoprotegerin, and osteocalcin compared with the OVX group without adverse effects such as dyslipidemia. CWHL increased uterine ER-β levels but did not change uterus and vaginal weights. Taken together, the results indicate that CWHL may relieve menopausal symptoms by controlling depression-, hot flashes-, and osteoporosis-associated biomarkers. Therefore, we propose that CWHL might be a safe and potential candidate for management of menopause as a health functional food.

Comparative sub-chronic toxicity studies in rats of two indistinguishable herbal plants, Cynanchum wilfordii (Maxim.) Hemsley and Cynanchum auriculatum Royle ex Wight

Sub-chronic toxicity studies using rats have been conducted for Cynanchum wilfordii (Maxim.) Hemsley (CW) and Cynanchum auriculatum Royle ex Wight (CA). CW water extract didn’t show any adverse effects whereas administering CW powder decreased body weights in complication with decreased food consumptions. In the case of CA water extract, triglyceride and absolute/relative liver weights were elevated and vacuolation was observed in liver. Treated CA powder in male rats increased alanine aminotransferase and aspartate aminotransferase and induced single cell necrosis and multinucleated hepatocyte in liver. As for female rats, increased absolute/relative weights and hypertrophy/vacuolation in adrenal glands and vacuolation in ovaries were observed when administered CA powder. In conclusion, no observed adverse effect level (NOAEL) of CW water extract was over 5000 mg/kg/day, while NOAEL of CW powder was 700 mg/kg/day for female and 150 mg/kg/day for male. In case of CA, NOAEL of water extract was 1500 mg/kg/day for male and 2000 mg/kg/day for female, while NOAEL of powder was 150 mg/kg/day for both gender. To the best of our knowledge, this is the first sub-chronic toxicity study on the adverse effects, target organs and its dose levels of C. wilfordii (Maxim.) Hemsley and C. auriculatum Royle ex Wight following GLP protocols.

Cynanchum auriculatum Royle ex Wight., Cynanchum bungei Decne. and Cynanchum wilfordii (Maxim.) Hemsl.: Current Research and Prospects

Cynanchum auriculatum Royle ex Wight. (CA), Cynanchum bungei Decne. (CB) and Cynanchum wilfordii (Maxim.) Hemsl. (CW) are three close species belonging to the Asclepiadaceous family, and their dry roots as the bioactive part have been revealed to exhibit anti-tumor, neuroprotection, organ protection, reducing liver lipid and blood lipid, immunomodulatory, anti-inflammatory, and other activities. Until 2021, phytochemistry investigations have uncovered 232 compounds isolated from three species, which could be classified into C21-steroids, acetophenones, terpenoids, and alkaloids. In this review, the morphology characteristics, species identification, and the relationship of botany, extraction, and the separation of chemical constituents, along with the molecular mechanism and pharmacokinetics of bioactive constituents of three species, are summarized for the first time, and their phytochemistry, pharmacology, and clinical safety are also updated. Moreover, the direction and limitation of current research on three species is also discussed.

Selective activation of the estrogen receptor-β by the polysaccharide from Cynanchum wilfordii alleviates menopausal syndrome in ovariectomized mice

The menopausal syndrome caused by rapid changes in hormone levels greatly influences the quality of life of women. Though hormone replacement therapy (HRT) is widely used to treat the menopausal syndrome, it exhibits many side effects, including the risk of thrombosis, cardiovascular diseases, and increased incidence of breast cancer; thus, diversifying the interest for phytotherapy-based materials as alternatives to HRT. Here, we isolated a crude polysaccharide fraction (CWPF) from Cynanchum wilfordii root that alleviated the ovariectomy-induced uterine atrophy and bone loss without changes in plasma estradiol concentration in mice. Increased plasma levels of follicle-stimulating hormone (FSH), alkaline phosphatase (ALP), osteocalcin (OC) in ovariectomized mice were also reduced to normal levels by CWPF administration. We found that the inhibitory effects of CWPF on menopausal symptoms were mediated by the estrogen receptor β (ER-β) specific activation, not ER-α. Moreover, CWPF treatment suppressed the phosphorylation of Akt, suggesting that CWPF alleviates post-menopausal symptoms by regulating ER-β related Akt signaling pathway. These results demonstrate that the polysaccharides corresponding to CWPF among the water-soluble extracts of CW could be used as a beneficial herbal alternative for the development of therapeutic agents to prevent menopausal syndrome in women.

Changes in skin temperature of ovariectomized rats under different incubation temperatures

AIM

This study aimed to investigate changes in skin temperature in the main body regions of ovariectomized rats under different incubation temperatures to identify regions that are similar to hot flashes experienced by menopausal women.

METHODS

A total of 96 adult female Sprague-Dawley rats were randomly divided into sham, ovariectomized and ovariectomized with estrogen treatment groups, with treatment lasting for 4 weeks. After 3 weeks of treatment, each group was randomly divided into five subgroups and placed in separate incubators set at 4, 15, 25, and 37°C. Changes in the skin temperature in seven main regions (head, neck, chest, abdomen, back, tail, and paws) for four time intervals (0-3 min, 3-5 min, 5-10 min and 10-15 min) were monitored using infrared thermography.

RESULTS

All rats showed rapid changes in skin temperature followed by a gradual slowdown under different incubation temperatures. However, changes in ovariectomized rats were significantly different from that in normal rats, and changes on the back, tail and paws were more rapid and lasted longer. Estrogen treatment effectively controlled these abnormalities of ovariectomized rats.

CONCLUSIONS

Temperature responses in the back, tail and paws in ovariectomized rats might be similar to the face, neck and upper chest in menopausal women, where the symptoms of hot flashes are most obvious, which suggests that the back, tail and paws could be regarded as the focus of research on hot flashes, and offer theoretical foundations for mechanisms behind the occurrence of hot flashes in specific regions. Geriatr Gerontol Int 2020; ••: ••-••.

Cynanchum bungei Decne and its two related species for "Baishouwu": A review on traditional uses, phytochemistry, and pharmacological activities

ETHNOPHARMACOLOGICAL RELEVANCE

Cynanchum bungei Decne. (CB) (Asclepiadaceae) and its two related species Cynanchum auriculatum Royle ex Wight. (CA) and Cynanchum wilfordii (Maxim.) Hemsl. (CW) are well known Chinese herbal medicines known by the name Baishouwu. Among them, CB has long been used for nourishing the kidney and liver, strengthening the bones and muscles, and regulating stomachache. However, to date, no comprehensive review on Baishouwu has been published.

AIM OF THE REVIEW

This review aims to provide a comprehensive summary on traditional uses, phytochemistry, pharmacology, and toxicology of the three herbal components of Baishouwu with the ultimate objective of providing a guide for future scientific and therapeutic potential use of Baishouwu.

MATERIAL AND METHODS

A literature search was undertaken on CB, CA and CW by analyzing the information from scientific databases (SciFinder, Pubmed, Elsevier, Google Scholar, Web of Science, and Baidu Scholar). Information was also gathered from local classic herbal literatures and conference papers on ethnopharmacology and the information provided in this review has been obtained from peer-reviewed papers.

RESULTS

Comparative analysis of literature search indicate that ethnopharmacological use of CB was recorded in China, however, CA and CW have been used in China, Korea and Japan. To date, 151 chemical compounds have been isolated from these species, and the major chemical constituents have been revealed to be acetophenones, C₂₁-steroids, terpenoids, and alkaloids. These compounds and extracts have been proven to exhibit significant pharmacological activities, including anti-tumor, anti-inflammatory, immunomodulatory, hypolipidemic, anti-obesity, hepatoprotective, antifungal, antiviral, anti-depressant, vasodilating and estrogenic activities.

CONCLUSIONS

CB, CA and CW collectively known as Baishouwu are valuable medicinal herbs with multiple pharmacological activities. The traditional use for nourishing liver is closely associated with the hepatoprotective activity. The available literature performs that various of the activity of Baishouwu can be attributed to acetophenones and C₂₁-steroids. It is high time that more efforts should be focused on the underlying mechanisms of their beneficial bioactivities and the structure activity relationship of the constituents, as well as their potential synergistic and antagonistic effects. The proper toxicology evaluation is crucial to guarantee the safety, efficacy, and eligibility for medical use. Further research on the comprehensive evaluation of medicinal quality and the understanding of multi-target network pharmacology of Baishouwu is in great request.

Ethnobotany, Phytochemistry and Pharmacological Effects of Plants in Genus Cynanchum Linn. (Asclepiadaceae)

Genus Cynanchum L. belongs to the family Asclepiadaceae, which comprise more than 200 species distributed worldwide. In Chinese medical practice, numerous drugs (such as tablets and powders) containing different parts of plants of this genus are used to treat snake bites, bruises, osteoblasts, rheumatoid arthritis and tumors. A search for original articles published on the cynanchum genus was performed by using several resources, including Flora of China Official Website and various scientific databases, such as PubMed, SciFinder, the Web of Science, Science Direct, and China Knowledge Resource Integrated (CNKI). Advances in the botanical, ethnomedicinal, phytochemical, and pharmacological studies of this genus are reviewed in this paper. Results showed that more than 440 compounds, including C21 steroids, steroidal saponins, alkaloids, flavonoids and terpene, have been isolated and identified from Cynanchum plants up to now. In vivo and in vitro studies have shown that plants possess an array of biological activities, including anti-tumor, neuroprotective and anti-fungal effects. Popular traditional prescription of Cynanchum sp. was also summed up in this paper. However, many Cynanchum species have received little or no attention. Moreover, few reports on the clinical use and toxic effects of Cynanchum sp. are available. Further attention should be focused on the study of these species to gather information on their respective toxicology data and relevant quality-control measures and clinical value of the crude extracts, active compounds, and bioactive metabolites from this genus. Further research on Cynanchum sp. should be conducted, and bioactivity-guided isolation strategies should be emphasized. In addition, systematic studies of the chemical composition of plants should be enhanced.

Evaluation of estrogenic potential by herbal formula, HPC 03 for in vitro and in vivo

HPC 03 is herbal formula that consists of extracts from Angelica gigas, Cnidium officinale Makino and Cinnamomum cassia Presl. The present study evaluated the estrogenic potential of HPC 03 by using in vitro and in vivo models. The regulatory mechanisms of HPC 03 in estrogen-dependent MCF-7 cells were assessed. HPC 03 induced the proliferation of estrogen receptor-positive MCF-7 cells, and the proliferation was blocked by the addition of the estrogen antagonist tamoxifen. The estrogen receptor_α/β luciferase activities were significantly increased by HPC 03 treatment, which also increased the mRNA expression of the estrogen-responsive genes Psen2, Pgr and Ctsd Also, we evaluated the ameliorative effects of HPC 03 on menopausal symptoms in ovariectomized rats. HPC 03 treatment in OVX rats significantly affected the uterine weight, increased the expression of estrogen-responsive genes Pgr and Psen2 in uterus, increased bone mineral density loss in the femur and inhibited body weight increase. Serum E2, collagen type 1 and osteocalcin were significantly increased, while serum LH, FSH and ALP were decreased compared with OVX rats. HPC 03 may be a promising candidate for the treatment of menopause, but further research is necessary to determine whether the observed effects also occur in humans.