Effects of geraniin on osteoclastic bone resorption and matrix metalloproteinase-9 expression

Chronic Excess Iodine Intake Inhibits Bone Reconstruction Leading to Osteoporosis in Rats

BACKGROUND

Although iodine modulates bone metabolism in the treatment of thyroid disease, the effect of iodine intake on bone metabolism remains less known.

OBJECTIVE

This study evaluated the effect of excess iodine intake in rats on bone reconstruction in the 6th and 12th month of intervention.

METHOD

Rats were treated with different doses of iodinated water: the normal group (NI, 6.15 μg/d), 5-fold high iodine group (5HI, 30.75 μg/d), 10-fold high iodine group (10HI, 61.5 μg/d), 50-fold high iodine group (50HI, 307.5 μg/d), and 100-fold high iodine group (100HI, 615 μg/d). Thyroid hormone concentrations were determined by a chemiluminescent immunoassay. Morphometry and microstructure of bone trabecula were observed by hematoxylin and eosin staining and microcomputed tomography, respectively. Alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP) staining were performed to evaluate the activity of osteoblasts and osteoclasts, respectively.

RESULTS

The 24-h urine iodine concentration increased with iodine intake. The rats in the HI groups had higher serum thyroid-stimulating hormone and decreased serum free thyroxine concentrations in the 12th month than the NI group (all P < 0.05). The percentage of the trabecular bone area and osteoblast perimeter in the 100HI group were significantly lower than those in the NI group (P < 0.05). Increased structure model index was observed in the 50HI and 100HI groups compared with the NI group in the 6th month and increased trabecular separation in the 12th month (all P < 0.05). ALP and TRAP staining revealed osteoblastic bone formation was reduced, and the number of TRAP+ multinucleated cells decreased with increasing iodine intake.

CONCLUSIONS

Excess iodine intake may increase the risk of hypothyroidism in rats. Chronic excess iodine intake can lead to abnormal changes in skeletal structure, resulting in reduced activity of osteoblasts and osteoclasts, which inhibits the process of bone reconstruction and may lead to osteoporosis.

Computational Drug Discovery in Ankylosing Spondylitis-Induced Osteoporosis Based on Data Mining and Bioinformatics Analysis

BACKGROUND

Ankylosing spondylitis (AS) and osteoporosis (OP) are both prevalent illnesses in spine surgery, with OP being a possible consequence of AS. However, the mechanism of AS-induced OP (AS-OP) remains unknown, limiting etiologic research and therapy of the illness. To mine targetable medicine for the prevention and treatment of AS-OP, this study analyzes public data sets using bioinformatics to identify genes and biological pathways relevant to AS-OP.

METHODS

First, text mining was used to identify common genes associated with AS and OP, after which functional analysis was carried out. The STRING database and Cytoscape software were used to create protein-protein interaction networks. Hub genes and potential drugs were discovered using drug-gene interaction analysis and transcription factors-gene interaction analysis.

RESULTS

The results of text mining showed 241 genes common to AS and OP, from which 115 key symbols were sorted out by functional analysis. As options for treating AS-OP, protein-protein interaction analysis yielded 20 genes, which may be targeted by 13 medications.

CONCLUSIONS

Carlumab, bermekimab, rilonacept, rilotumumab, and ficlatuzumab were first identified as the potential drugs for the treatment of AS-OP, proving the value of text mining and pathway analysis in drug discovery.

3,4,5-Trihydroxybenzoic Acid Attenuates Ligature-Induced Periodontal Disease in Wistar Rats

BACKGROUND

3,4,5-Trihydroxybenzoic acid, which is also known as gallic acid, is an antiinflammatory agent that could provide beneficial effects in preventing periodontal inflammation. The present study aimed to evaluate the anti-inflammatory effects of gallic acid on experimental periodontitis in Wistar rats. Alveolar bone loss, osteoclastic activity, osteoblastic activity, and collagenase activity were also determined.

METHODS

Thirty-two Wistar rats were used in the present study. Study groups were created as following: Healthy control (C,n=8) group; periodontitis (P,n=8) group; periodontitis and 30 mg/kg gallic acid administered group (G30,n=8); periodontitis and 60 mg/kg gallic acid administered group (G60,n=8). Experimental periodontitis was created by placing 4-0 silk sutures around the mandibular right first molar tooth. Morphological changes in alveolar bone were determined by stereomicroscopic evaluation. Mandibles were undergone histological evaluation. Matrix metalloproteinase (MMP)-8, tissue inhibitor of MMPs (TIMP)-1, bone morphogenetic protein (BMP)-2 expressions, tartrateresistant acid phosphatase (TRAP) positive osteoclast cells, osteoblast, and inflammatory cell counts were determined.

RESULTS

The highest alveolar bone loss was observed in the periodontitis group. Both doses of gallic acid decreased alveolar bone loss as compared to the P group. TRAP-positive osteoclast cell counts were higher in the P group, and gallic acid successfully lowered these counts. Osteoblast cells also increased in gallic acid administered groups. Inflammation in the P group was also higher than those of C, G30, and G60 groups supporting the role of gallic acid in preventing inflammation. 30 and 60 mg/kg doses of gallic acid decreased MMP-8 levels and increased TIMP-1 levels. BMP levels increased in gallic acid administered groups, similar to several osteoblasts.

CONCLUSION

Present results revealed an anti-inflammatory effect of gallic acid, which was indicated by decreased alveolar bone loss and collagenase activity and increased osteoblastic activity.

Geraniin promotes osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) via activating β-catenin: a comparative study between BMSCs from normal and osteoporotic rats

Abnormal osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) has been correlated with the pathogenesis of osteoporosis. Geraniin, a polyphenolic compound isolated from Phyllanthus amarus, is effective in preventing osteoporosis, but the mechanisms of action of geraniin and the impact of osteoporotic condition on drug action are not known. In this study we compared the proliferation and osteoblastic differentiation potential of BMSCs from normal rats with that from osteoporotic rats, and examined the responses of both BMSCs to geraniin in parallel. BMSCs of rats subjected to ovariectomy or sham operation were isolated and treated with geraniin. Cell proliferation was measured by CCK-8 assay. Osteoblastic differentiation was quantified by Alizarin Red S staining and alkaline phosphatase assay. Nuclear translocation of β-catenin was monitored by immunofluorescent staining. Expression of β-catenin was determined by Western blot and quantitative real-time polymerase chain reaction. Results showed that the proliferation and osteoblast formation of osteoporotic BMSCs decreased in comparison to that of normal BMSCs. Geraniin enhanced proliferation and osteoblastic differentiation of both BMSCs, but the responses of osteoporotic BMSCs to geraniin were less than those of normal BMSCs. Expression and nuclear accumulation of β-catenin in osteoporotic BMSCs were found to be diminished. Geraniin increased nuclear translocation and expression of β-catenin in both BMSCs. This study associated the osteogenic effect of geraniin to activation of Wnt/β-catenin signaling, and provided rationale for pharmacological investigation of geraniin in osteoporosis prevention and treatment.

Molecular signaling mechanisms behind polyphenol-induced bone anabolism

For millennia, in the different cultures all over the world, plants have been extensively used as a source of therapeutic agents with wide-ranging medicinal applications, thus becoming part of a rational clinical and pharmacological investigation over the years. As bioactive molecules, plant-derived polyphenols have been demonstrated to exert many effects on human health by acting on different biological systems, thus their therapeutic potential would represent a novel approach on which natural product-based drug discovery and development could be based in the future. Many reports have provided evidence for the benefits derived from the dietary supplementation of polyphenols in the prevention and treatment of osteoporosis. Polyphenols are able to protect the bone, thanks to their antioxidant properties, as well as their anti-inflammatory actions by involving diverse signaling pathways, thus leading to bone anabolic effects and decreased bone resorption. This review is meant to summarize the research works performed so far, by elucidating the molecular mechanisms of action of polyphenols in a bone regeneration context, aiming at a better understanding of a possible application in the development of medical devices for bone tissue regeneration.

An UPLC Method for Determination of Geraniin in Rat Plasma and its Application to Pharmacokinetic Studies

Introduction:

Geraniin has many biological activities including anti-osteoporotic and anti-hyperglycemic efficacies.

Materials and Methods:

A rapid and simple method for the determination of geraniin in rat plasma using ultra performance liquid chromatography coupled to ultraviolet detector was developed. The plasma sample, spiked with epicatechin as an internal standard, was subjected to ethyl acetate extraction prior to analysis. Chromatographic separation was performed on the HSS T3 column and monitored at a wavelength of 280 nm. The limit of detection and lower limit of quantification was 0.07 μg/mL and 0.2 μg/mL in rat plasma, respectively.

Conclusion:

Good linearity was obtained in the range of 0.2 - 200 μg/mL, and the correlation coefficient was better than 0.997. The intra-day and inter-day precisions decreased 9.8%. The accuracy of QC samples ranged from 84.4% to 87.1%. The extraction recovery ranged from 88.4% to 90.3% and the matrix effect ranged from 84.4% to 87.2%. The analyte was stable in rat plasma when stored at room temperature for 12 hours, 4°C for 24 hours and -20°C for 15 days. t1/2 and t1/2 for i.v. was 0.21 ± 0.10 and 7.20 ± 2.20 h, respectively. Plasma clearance (CL) was 0.03 ± 0.02 L/h/kg and apparent volume of distribution (Vz) was 0.05 + 0.01 L/kg. The developed method was successfully applied to the pharmacokinetic study of geraniin in rats.

Geraniin inhibits TGF-β1-induced epithelial-mesenchymal transition and suppresses A549 lung cancer migration, invasion and anoikis resistance

The epithelial-mesenchymal transition (EMT) is an important cellular process during which epithelial polarized cells become motile mesenchymal-appeared cells, which, in turn, induces the metastatic of cancer. Geraniin is a polyphenolic component isolated from Phyllanthus amarus, which exhibits a wide range of pharmacological and physiological activities, such as antitumor, anti-hyperglycemic, anti-hypertensive, antimicrobial, and antiviral activities. However, the possible role of geraniin in the EMT is unclear. We investigated the effect of geraniin on the EMT. Transforming growth factor-beta 1 (TGF-β1) induces the EMT to promote lung adenocarcinoma migration, invasion, and anoikis resistance. To understand the suppressive role of geraniin in lung cancer migration, invasion, and anoikis resistance, we investigated the use of geraniin as inhibitors of TGF-β1-induced EMT in A549 lung cancer cells in vitro. Here, we show that geraniin remarkably increased expression of the epithelial marker E-cadherin and repressed Snail upregulation and expression of the mesenchymal marker N-cadherin and vimentin during the TGF-β1-induced EMT. Geraniin also inhibited the TGF-β1-induced increase in cell migration, invasion, and anoikis resistance of A549 lung cancer cells. Additionally, geraniin markedly inhibited TGF-β1-regulated activation of Smad2. Taken together, our findings provide new evidence that geraniin suppresses lung cancer migration, invasion, and anoikis resistance in vitro by inhibiting the TGF-β1-induced EMT.

Osteoprotective effect of geraniin against ovariectomy-induced bone loss in rats

In the present study, we investigated the antiosteoporotic effect of geraniin on osteoporosis induced by OVX in rats. The analysis of biochemical parameters showed that geraniin could significantly increase serum calcium, estradiol and calcitonin levels, and decrease serum ALP, tartrate-resistant acid phosphatase, serum crosslinked C-terminal telopeptide of type I collagen, and urinary deoxypyridinoline/creatinine ratio levels, respectively. Geraniin was also found to prevent OVX-induced bone loss in bone mineral density and bone mineral content, to elevate femur weight and bone calcium content, and to enhance the bone mechanical properties as compared with OVX group. In addition, geraniin was demonstrated to improve the histomorphological parameters of OVX-induced bone loss, including bone trabecular number, thickness, and separation. These results indicated that geraniin have a protective effect against OVX-induced rat osteoporosis.