Dendrobium officinale Orchid Extract Prevents Ovariectomy-Induced Osteoporosis in Vivo and Inhibits RANKL-Induced Osteoclast Differentiation in Vitro

Dendrobium offificinale polysaccharides prevents glucocorticoids-induced osteoporosis by destabilizing KEAP1-NRF2 interaction

Glucocorticoid-induced osteoporosis (GIOP) represents the foremost cause of secondary osteoporosis and fragility fractures. Novel therapeutic strategies for GIOP are needed, with improved safety profiles and reduced costs compared to current options. Dendrobium officinale (D. officinale) is a traditional Chinese medicine that has been reported to have beneficial effects on bone metabolism. Here, we sought to investigate the impacts of D. officinale polysaccharides (DOP), the main active constituents of D. officinale, on GIOP in vivo models and dexamethasone (DEX)-treated osteoblast lineage cells. We found that low concentrations of DOP are relatively safe in vitro and in vivo, respectively. Importantly, we found that DOP treatment significantly inhibited DEX-induced osteoporosis in two in vivo models, zebrafish and mice, while boosting osteogenic differentiation of hBMSCs exposed to DEX. Futhermore, our data reveal that DOP elevates nuclear Nrf2 levels under DEX treatment, by suppressing of Nrf2 ubiquitination. Leveraging Keap1b knockout zebrafish and RNAi approach, we demonstrated that DOP disrupts the association of Nrf2/Keap1, resulting in the inhibition of Nrf2 ubiquitination. Taken together, these results illuminate that DOP stimulates osteogenesis in the presence of DEX by destabilizing the Nrf2/Keap1 interaction. These findings suggest that DOP may serve as a novel drug against osteoporosis caused by glucocorticoids.

Chemical Constituents, Bioactivities, and Pharmacological Mechanisms of Dendrobium officinale: A Review of the Past Decade

Dendrobium officinale, a plant in the Orchidaceae family, has been used in traditional Chinese medicine for thousands of years. Sweet and slightly cold in nature, it can invigorate the stomach, promote fluid production, nourish Yin, and dissipate heat. Over the past decade, more than 60 compounds have been derived from D. officinale, including flavonoids, bibenzyl, and phenanthrene. Various studies have explored the underlying pharmacological mechanisms of these compounds, which have shown antitumor, hypoglycemic, hypertensive, gastrointestinal-regulatory, visceral organ protection, antiaging, and neurorestorative effects. This paper presents a systematic review of the structural classification, biological activity, and pharmacological mechanisms of different chemical components obtained from D. officinale over the past decade. This review aims to provide a reference for future study and establish a foundation for clinical applications. Furthermore, this review identifies potential shortcomings in current research as well as potential directions and methodologies in future plant research.

Traditional uses, chemical compositions and pharmacological activities of Dendrobium: A review

ETHNOPHARMACOLOGICAL RELEVANCE

Dendrobium is a kind of medicine food homology plant. Dendrobium has long been used to strengthen "Yin" and tonify five viscera.

AIM OF THIS REVIEW

This paper presents a systematic review of the folk usage, chemical composition and pharmacological activity of Dendrobium, aiming to provide a reference for subsequent in-depth understanding and better exploitation of health food, medicine, and natural products.

MATERIALS AND METHODS

Available information about the genus Dendrobium was collected via Web of Science, PubMed, Science Direct, Scopus, APA-Psy Articles, Google Scholar, Connected Papers, Springer Search, and KNCI. The keywords for this article are Dendrobium, traditional use, chemical diversity and pharmacological activity. Use the "Dictionary of Chinese Ethnic Medicine" to provide 23 kinds of Dendrobium with medicinal value, the Latin name of Dendrobium is verified by the Flora of China (www.iplant.cn), and its species distribution and related information are collected.

RESULTS

There are 78 species of Dendrobium in China, 14 of which are endemic to China. At present, 450 compounds including sesquiterpenoids, lignans compounds, phenolic compounds, phenanthrene compounds, bibenzyls, polysaccharides and flavonoids have been isolated and identified from at least 50 species of Dendrobium. Among them, bibenzyls and polysaccharides are the main active components, phenolics and lignans are widely distributed, sesquiterpenes are the most common chemical constituents in genus Dendrobium plants. The most popular research objects are Dendrobium officinale and Dendrobium huoshanense.

CONCLUSIONS

Based on traditional folk uses, chemical composition and pharmacological studies, Dendrobium is considered a promising medicinal and edible plant with multiple pharmacological activities. In addition, a large number of clinical applications and further studies on single chemical components based on the diversity of chemical structures should be conducted, which will lay the foundation for the scientific utilization of genus Dendrobium.

Metabolomics-Based Analysis of the Effects of Different Cultivation Strategies on Metabolites of Dendrobium officinale Kimura et Migo

Dendrobium officinale Kimura et Migo is a famous plant with a high medicinal value which has been recorded in the Chinese Pharmacopoeia (2020 Edition). The medicinal properties of D. officinale are based on its chemical composition. However, there are no reports on how different cultivation methods affect its chemical composition. In order to reveal this issue, samples of the D. officinale were collected in this study through tree epiphytic cultivation, stone epiphytic cultivation, and greenhouse cultivation. Polysaccharides were determined by phenol sulfuric acid method and secondary metabolites were detected by the UPLC-MS technique. In addition, with regards to metabolomics, we used multivariate analyses including principal component analysis (PCA) and orthogonal partial least squares analysis (OPLS-DA) to screen for differential metabolites which met the conditions of variable importance projection values >1, fold change >4, and p < 0.05. The differential metabolites were taken further for metabolic pathway enrichment analysis, which was based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, and validated by antioxidant activity. Comparing the three groups of samples according to the standards of the ChP (2020 edition), the results showed that the polysaccharide content of the samples from stony epiphytic cultivation and greenhouse cultivation was significantly higher than that of the samples from live tree epiphytic cultivation. Metabolomic analysis revealed that there were 185 differential metabolites among the 3 cultivation methods, with 99 of the differential metabolites being highest in the stone epiphytic cultivation. The results of the metabolic pathway enrichment analysis showed that the different cultivation strategies mainly effected four carbohydrate metabolic pathways, five secondary metabolite synthesis pathways, six amino acid metabolic pathways, one nucleotide metabolism pathway, three cofactor and vitamin metabolism pathways, and one translation pathway in genetic information processing. Furthermore, D. officinale from stone epiphytic cultivation which had the best antioxidant activity was implicated in differential metabolite production. This study revealed the effects of different cultivation methods on the chemical composition of D. officinale and also provided a reference for establishing the quality control standards to aid its development and utilization.

Modern interpretation of the traditional application of Shihu - A comprehensive review on phytochemistry and pharmacology progress of Dendrobium officinale

ETHNOPHARMACOLOGICAL RELEVANCE

The traditional Chinese medicine (TCM) "Shihu" has a long history of medicinal use in China from some species of Dendrobium. D. officinale is a major source of "Shihu" and is widely cultivated in south of China and listed separately as "Tiepi Shihu" by the Chinese Pharmacopoeia in now time. Traditionally, D. officinale has been widely used in daily health care and the treatment of diabetes and gastrointestinal diseases.

AIM OF THIS REVIEW

In order to better develop and utilize D. officinale, we conducted this systematic review of previous studies, showed clear structure of all isolates from D. officinale together with pharmacological progress, hoping to provide references for further research and utilization. In addition, specific display of the chemical components and the research progress of related activities can help to better understand the traditional records and modern pharmaceutical applications of the plant medicine.

MATERIALS AND METHODS

Information on phytochemistry and pharmacological studies of D. officinale was collected from various scientific databases including Web of Science, SciFinder, ACS, Springer, Scopus, PubMed, ScienceDirect, Google Scholar and CNKI.

RESULTS

More than 180 compounds isolated from D. officinale, including bibenzyls, phenols, phenylpropanoids, lignans, flavonoids and polysaccharides are listed in this review. Furthermore, modern pharmacological researches such as hypoglycemia, immune regulation, antioxidant, cardiovascular regulation and gastrointestinal protection are summarized.

CONCLUSION

Based on the summary of the research work of D. officinale, we systematically show the chemical composition of the plant, and concluded the relationship of those composition with plant habitat together with the relationship between the structure of chemical components and pharmacological activity. Moreover, we suggest that some of small molecule compounds could also be quality control of D. officinale besides polysaccharides.

Pomegranate juice fermented by tannin acyl hydrolase and Lactobacillus vespulae DCY75 enhance estrogen receptor expression and anti-inflammatory effect

Phenolics are phytochemicals in plants, fruits, and vegetables have potential health-promoting efficacies. However, mostly available as a complex form. So, to increase the contents and nutritional value of the phenolic compounds, fermentation is most readily used in the food industry. Especially, the hydrolyzable tannins present in the pomegranate that can be liberated into monomolecular substances, which enhances biological activity. Thus, this study aims to convert hydrolyzable tannins to ellagic acid by fermentation using Tannin acyl hydrolase (TAH) and a novel bacteria strain Lactobacillus vespulae DCY75, respectively to investigate its effect on Estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ) mRNA expression along with inflammation inhibition. As a result, the fermentation enhanced the ellagic acid content up to 70% by the synergetic effect of TAH and DCY75. Furthermore, fermented pomegranate (PG-F) increased cellular proliferation as well as upregulated the gene expression of estrogen regulators such as ERα, ERβ, and pS2 in breast cancer cell line (MCF-7), which commonly used to evaluate estrogenic activity. Moreover, to study the inflammation associated with low estrogen in menopause, we have analyzed the inhibition of nitric oxide (NO)/inducible nitric oxide synthase (iNOS) in RAW 264.7 cells. The PG-F juice did not exert any cytotoxicity in RAW 264.7 cells and inhibited NO production along with the downregulation of a major pro-inflammatory cytokine iNOS which indicates the anti-inflammatory potential of it. To sum it up, the fermented commercial pomegranate juice using a novel bacteria strain increased the amount of ellagic acid that the value added bioactive of pomegranate and it has significantly increased the estrogenic activity via upregulating estrogen related biomarkers expression and reduced the risk of related inflammation via NO/iNOS inhibition. This study could be a preliminary study to use fermented pomegranate as a potential health functional food after further evaluation.

Traditional Uses, Phytochemistry, Pharmacology, and Quality Control of Dendrobium officinale Kimura et. Migo

Dendrobium officinale, a well-known plant used as a medicinal and food homologous product, has been reported to contain various bioactive components, such as polysaccharides, bibenzyls, phenanthrenes, and flavonoids. It is also widely used as a traditional medicine to strengthen “Yin”, nourish heart, tonify five viscera, remove arthralgia, relieve fatigue, thicken stomach, lighten body, and prolong life span. These traditional applications are in consistent with modern pharmacological studies, which have demonstrated that D. officinale exhibits various biological functions, such as cardioprotective, anti-tumor, gastrointestinal protective, anti-diabetes, immunomodulatory, anti-aging, and anti-osteoporosis effects. In this review, we summarize the research progress of D. officinale from November 2016 to May 2021 and aim to better understand the botany, traditional use, phytochemistry, and pharmacology of D. officinale, as well as its quality control and safety. This work presents the development status of D. officinale, analyzes gaps in the current research on D. officinale, and raises the corresponding solutions to provide references and potential directions for further studies of D. officinale.

Acanthopanax senticosus aqueous extract ameliorates ovariectomy-induced bone loss in middle-aged mice by inhibiting the receptor activator of nuclear factor-κB ligand-induced osteoclastogenesis

Acanthopanax senticosus (Ciwujia) has broad-spectrum pharmacological activities, including osteoprotective effects. However, the mechanisms underlying these effects remain unclear. We investigated whether Acanthopanax senticosus aqueous extract (ASAE) ameliorates ovariectomy-induced bone loss in middle-aged mice through inhibition of osteoclastogenesis. In vitro, ASAE significantly suppressed the receptor activator of nuclear factor-κB ligand (RANKL)-stimulated osteoclast differentiation and formation of F-actin rings by downregulating the expression of the nuclear factor of activated T cells, cytoplasmic 1 (NFATc1), c-Fos, and osteoclastogenesis-related marker genes and proteins, including c-Src, tartrate-resistant acid phosphatase (TRAP), cathepsin K, β3-integrin, and matrix metallopeptidase-9 (MMP-9). This was achieved by inhibiting RANK signaling pathways, including p65, c-Jun N-terminal kinase, extracellular signal-regulated kinase, and p38 in osteoclast precursors. In vivo, ASAE markedly ameliorated bone loss in ovariectomized (OVX) middle-aged mice. ASAE significantly inhibited the serum levels of tartrate-resistant acid phosphatase 5b (TRACP-5b) and RANKL, whereas it increased those of osteocalcin, procollagen 1 N-terminal peptide (P1NP), and osteoprotegerin in OVX mice. ASAE significantly inhibited the OVX-induced expression of osteoclast-specific proteins and genes in the femur. In conclusion, ASAE prevents ovariectomy-induced bone loss in middle-aged mice by inhibiting RANKL-induced osteoclastogenesis through suppression of RANK signaling pathways and could be potentially used in mediated treatment of osteoclast-related diseases (e.g., osteoporosis).

Study on the morphological and metabolic changes of femur in laying hens with hypophosphatemia

Layer fatigue syndrome caused by the lack of calcium and phosphorus can cause fracture in laying hens. The effect of phosphorus deficiency on the femur of laying hens with layer fatigue syndrome has not been studied. In this study, sixty 22-week-old Roman white layers were randomly divided into control group (group C) and low phosphorus group (group P), 30 individuals in each group. The available phosphorus content of group P was 0.18%. At the age of 26, 30 and 34 weeks, the production performance, biomechanical index, protein expression, histopathological change of femur and serological index were detected. The results showed that the laying rate, egg quality and body weight of laying hens, bone density, cortical bone thickness, rigidity, flexural modulus, flexural rigidity, the maximum load of femur and expression of osteocalcin (OCN), receptor activator of nuclear factor kappa-Β (RANK) and receptor activator of nuclear factor kappa-Β ligand (RANKL) decreased of group P. The number of osteocytes was decreased, and the voids was increased. However, cell lacunae were not obvious. The levels of phosphorus, calcium and OCN were increased, and the content of estradiol (E₂), OPG and calcitonin (CT) were decreased in serum. In conclusion, the low phosphorus diet can induce layer fatigue syndrome and affect the content of OPG and E₂ in serum and the expression of OCN, OPG, RANK and RANKL in femur protein, which leads to the imbalance of bone homeostasis, the thinning of femur cortex bone and the decrease of bone density.

An update on the health benefits promoted by edible flowers and involved mechanisms

The aim of this review is to provide new findings on health effects of edible flowers since 2015. The antioxidant, anti-inflammatory, anti-cancer, hepatoprotective, neuroprotective, anti-diabetic, anti-osteoporosis, anti-obesity, and anti-hypertensive have been reviewed, and the effective concentrations of flower extracts have been summarized. Among all the health benefits mentioned, anti-osteoporosis, anti-obesity, and anti-hypertensive have rarely been mentioned before 2015. Some health benefits mechanisms of edible flowers were discussed frequently after 2015. Some newly found phytochemicals such as polysaccharides were shown to be beneficial to human health. Species of Rosa, Chrysanthemum, and Osmanthus have been reported to exert different health effects on human. For the toxicity studies, the safe level of flower extracts in cell and animal models were at hundreds of parts per million (ppm) level. In consideration of health promoting effects and toxicities of edible flowers, they could serve as potential natural health products for different health benefits.

Hydrogen gas protects against ovariectomy-induced osteoporosis by inhibiting NF-κB activation

OBJECTIVES

Osteoporosis is a prevalent condition among postmenopausal women, and lacks satisfactory therapeutic options. Hydrogen (H2) has been shown to be effective in alleviating many diseases. This study aimed to investigate the effects of H2 on inhibiting osteoclastogenesis and bone loss in ovariectomized mice.

METHODS

Osteoclast differentiation from Raw264.7 cells was induced with receptor activator NF-κB ligand (RANKL) with or without 60% H2. The number and resorption activity of osteocalsts were assessed by tartrate-resistant acid phosphatase staining and pit formation assay, respectively. The expression of osteoclast markers and NF-κB phosphorylation were detected by western blot. NF-κB nuclear translocation was assessed by immunofluorescence. NF-κB transcriptional activity was analyzed by luciferase assay. Bone loss in mice was induced by ovariectomy (OVX). OVX mice were given either regular air or 60% H2. Bone structure was analyzed by micro-computed tomography and hematoxylin and eosin staining. Cytokine levels were measured by enzyme-linked immunosorbent assay. The data were analyzed with one-way or two-way ANOVA followed by Bonferroni post hoc tests.

RESULTS

H2 did not have any measurable effect on the proliferation of Raw264.7 cells. The number of osteoclasts and size of resorption pits of RANKL+H2-treated cells were 3 to 4 times less than RANKL treated cells. The expression of osteoclast marker genes of RANKL+H2-treated cells was 30% to 60% lower than RANKL-treated cells (P < 0.05). H2 markedly inhibited RANKL-induced activation, nuclear translocation, and transcriptional activity of NF-κB (P < 0.05, RANKL+H2 vs RANKL). The amount and density of trabecular bone and bone mineral density of ovariectomized mice were significantly less than sham-operated mice (P < 0.05 OVX vs sham). The amount of trabecular bone and bone mineral density of OVX mice that inhaled H2 were more than 40% higher, whereas the levels of serum proinflammatory cytokine interleukin 1β, IL-6, and tumor necrosis factor-α were more than 50% lower than those of OVX mice (P < 0.05).

CONCLUSIONS

These results demonstrated that H2 could be an effective therapeutic agent of postmenopausal osteoporosis.

Corrigendum: Effect of Black Tea Extract and Thearubigins on Osteoporosis in Rats and Osteoclast Formation in vitro

[This corrects the article DOI: 10.3389/fphys.2018.01225.].

Anti-Menopausal Effects of Cornus officinalis and Ribes fasciculatum Extract In Vitro and In Vivo

Natural herbal medicines have been developed for the treatment and prevention of women’s menopausal symptoms. In this study, we investigated the anti-menopausal effects of Cornus officinalis (CO) and Ribes fasciculatum (RF) extracts in 3T3-L1 preadipocytes, MC3T3-E1 preosteoblasts, and COV434 granulosa cells in vitro and ovariectomized (OVX) ddY mice in vivo. Combination treatment of CO and RF extract at 7:3 ratio inhibited lipid accumulation via Plin1 and Adipoq downregulation in a cocktail of dexamethasone, 3-isobutyl-1-methylxanthine, and insulin (DMI)-induced differentiated 3T3-L1 cells. In addition, CO + RF treatment significantly enhanced osteoblastic differentiation, with mineralized nodule formation occurring through the upregulation of osteoblast-inducing markers in osteoblastic MC3T3-E1 cells. Increased production of estradiol and mRNA expression of ERα (ESR1) were observed in androstenedione-induced COV434 granulosa cells treated with the CO + RF extract. In CO + RF-treated mice, fatty hepatocyte deposition and abdominal visceral fat tissues reduced with OVX-induced uterine atrophy. Furthermore, bone mineral density and bone mineral content were significantly enhanced by CO + RF in mouse models of ovariectomy-induced femoral bone loss. Taken together, our findings suggested that CO + RF promoted estrogenic activity and had anti-obesity and anti-osteoporotic effects in vitro and in vivo. Thus, a combination of CO and RF extracts may be a good therapeutic strategy for managing women’s menopausal syndromes.

The anti-carcinogenesis properties of erianin in the modulation of oxidative stress-mediated apoptosis and immune response in liver cancer

In this study, erianin was found to reduce the viability of cancer cells, inhibit their proliferation and migration, induce G2/M phase arrest, enhance cancer cell apoptosis, promote an increase in levels of intracellular reactive oxygen species and a decrease in mitochondrial membrane potential, and regulate the expression levels of anti- and pro-apoptosis-related proteins in HepG2 and SMMC-7721 cells. Erianin inhibited tumor growth in HepG2- and SMMC-7721-xenograft tumor nude mouse models, reduced the expression levels of anti-apoptosis proteins and enhanced the expression levels of pro-apoptosis proteins in tumor tissues. Erianin inhibited tumor growth in immunosuppressed BALB/c mice bearing heterotopic tumors. Among 111 types of cytokines detected in proteome profiling of tumor tissues, erianin substantially influenced levels of 38 types of cytokines in HepG2-xenografted tumors and of 15 types of cytokines in SMMC-7721-xenografted tumors, most of which are related to immune functions. Erianin strongly affected the serum levels of cytokines, and regulated the activation of nuclear factor-kappa B (NF-κB), and the expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream proteins in spleen. The anti-liver cancer properties of erianin were found to be related mostly to its modulation of oxidative stress-mediated mitochondrial apoptosis and immune response.

Aqueous extract of Dendrobium officinale confers neuroprotection against hypoxic-ischemic brain damage in neonatal rats

Accumulating evidences have proved the protective role of traditional Chinese medicine in improving neurological damage induced by cerebral hypoxia-ischemia. Herein, we hypothesized that Dendrobium officinale aqueous extract exerted neuroprotection against brain damage. Initially, a model of hypoxic-ischemic brain damage (HIBD) was induced in neonatal rats, which were subsequently intragastrically administered with different doses of Dendrobium officinale aqueous extract. Next, the antioxidant capacity was examined by enzyme-linked immunosorbent assay. 2,3,5-Triphenyltetrazolium chloride and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling staining assays were adopted to determine neuronal apoptosis in brain tissues. Furthermore, neurotrophic factors and hypoxia-inducible factor-1α (HIF-1α) expression was identified by Western blot analysis. The neonatal rat models of HIBD presented impaired neurobehaviors and antioxidant capacity, increased neuronal apoptosis and expression of HIF-1α and histone deacetylase 1 (HDAC1), as well as diminished expression of neurotrophic factors and K⁺ -Cl^- -cotransporter 2 (KCC2). Notably, in response to different doses of Dendrobium officinale aqueous extract, the impairment on neurobehaviors and antioxidant capacity was alleviated, accompanied by reduced levels of nitric oxide synthase, nitric oxide, and malondialdehyde, and increased superoxide dismutase activity. Besides, the neuronal apoptosis was inhibited as reflected by down-regulated cleaved caspase-3 and Bax and up-regulated Bcl-2. Moreover, we also found accelerated expression of neurotrophic factors and KCC2 and diminished expression of HIF-1α and HDAC1. Altogether, this present study highlights that the aqueous extract of Dendrobium officinale can suppress the neuronal apoptosis and enhance the expression of neurotrophic factors to protect neonatal rats against HIBD.

Overview of Molecular Mechanisms Involved in Herbal Compounds for Inhibiting Osteoclastogenesis from Macrophage Linage RAW264.7

Differentiation from RAW264.7 cells to osteoclasts rely on many signaling pathways, such as NF-κB, MAPK, Akt and others. However, the specific underlying mechanisms are not clear. Recently, much works have focused on the inhibitory effects of plant derived compounds in the differentiation from RAW264.7 to osteoclasts. However, the specific mechanisms remain unclear. In this paper, we summarize a lot of plant derived compounds which exert blocking effect on the progression of differentiation via signaling pathways.

Protective effect of Glycyrrhiza glabra roots extract on bone mineral density of ovariectomized rats

Objective: The aim of this study was to evaluate the potential effect of the methanolic extract of plant Glycyrrhiza glabra roots on bone mineral density and femoral bone strength of ovariectomized rats.

Methods: Thirty 10-month-old Wistar rats were randomly separated into three groups of ten, Control, Ovariectomy and Ovariectomy-plus-Glycyrrhiza in their drinking water. Total and proximal tibial bone mineral density was measured in all groups before ovariectomy (baseline) and after 3 and 6 months post ovariectomy. Three-point-bending of the femurs and uterine weight and histology were examined at the end of the study.

Results: No significant difference was noted in bone density percentage change of total tibia from baseline to 3 months between Control and Ovariectomy-plus-Glycyrrhiza groups (+5.31% ± 4.75 and +3.30% ± 6.31 respectively, P = non significant), and of proximal tibia accordingly (+5.58% ± 6.92 and +2.61% ± 13.62, P = non significant) demonstrating a strong osteoprotective effect. There was notable difference in percentage change of total tibia from baseline to 6 months between groups Ovariectomy and Ovariectomy-plus-Glycyrrhiza (−13.03% ± 5.11 and −0.84% ± 7.63 respectively, P < 0.005), and of proximal tibia accordingly (−27.9% ± 3.69 and −0.81% ± 14.85 respectively, P < 0.001), confirming the protective effect of Glycyrrhiza glabra extract in preserving bone density of the Ovariectomy-plus-Glycyrrhiza group. Three-point-bending did not reveal any statistically significant difference between Ovariectomy and Ovariectomy-plus-Glycyrrhiza groups. Uterine weights of the Ovariectomy-plus-Glycyrrhiza group ranged between the other two groups with no statistically significant difference to each.

Conclusions: Glycyrrhiza glabra root extract notably protected tibial bone mineral density loss in Ovariectomy-plus-Glycyrrhiza rats in comparison with ovariectomized rats, but did not improve biomechanical strength.

Dendrobium officinale polysaccharides regulate age-related lineage commitment between osteogenic and adipogenic differentiation

Objectives

Excessive oxidative stress and diminished antioxidant defences could contribute to age‐related tissue damage and various diseases including age‐related osteoporosis. Dendrobium officinale polysaccharides (DOPs), a major ingredient from a traditional Chinese medicine, have a great potential of antioxidative activity. In this study, we explore the role of DOP in age‐related osteoporosis that remains elusive.

Materials and methods

Oxidative stimulation and DOP were used to treat bone marrow mesenchymal stem cells (BMSCs), whose lineage commitment was measured by adipogenic‐ and osteoblastic‐induced differentiation analysis. The oxidative stress and antioxidant capacity of BMSCs under the treatment of DOP were analysed by the level of MDA, SOD. Related mechanism studies were confirmed by qRT‐PCR, Western blotting and siRNA transfection. DOP was orally administrated in aged mice whose phenotype was confirmed by micro‐CT, immunofluorescence, immunochemistry and calcein double‐labelling analysis.

Results

Dendrobium officinale polysaccharide treatment markedly increased osteogenic differentiation of BMSCs, while inhibiting adipogenic differentiation. In vitro, DOP could rescue H2O2‐induced switch of BMSCs differentiation fate. However, this effect was abolished in BMSCs when interfered with Nrf2 siRNA. Furthermore, administration of DOP to aged mice significantly increased the bone mass and reduced the marrow adipose tissue (MAT) accompanied with decreased oxidative stress of BMSCs.

Conclusions

Our study reveals that DOP can attenuate bone loss and MAT accumulation through NRF2 antioxidant signalling, which may represent as potential therapeutic agent for age‐related osteoporosis.