Pharmacodynamic Material Basis and Potential Mechanism Study of Spatholobi Caulis in Reversing Osteoporosis

Investigating the protective effect of loganin in ovariectomy‑induced bone loss through network pharmacology and molecular docking

Loganin, a major iridoid glycoside derived from Cornus officinalis, exerts strong anti-inflammatory property. The present study aimed to investigate the underlying mechanism of loganin to reduce estrogen deficiency-induced bone loss through a combination of network pharmacology, molecular docking and in vivo validation. First, the drug targets and structural interactions of loganin with osteoclasts on postmenopausal osteoporosis (PMOP) were predicted through network pharmacology and molecular docking. An ovariectomized (OVX) mouse model was established to experimentally validate loganin's anti-PMOP efficacy, supported by its protective effect on bone destruction and excessive inflammatory cytokines. The top 10 core targets of loganin generated by a protein-protein interaction network were the following: GAPDH, VEGFA, EGFR, ESR1, HRAS, SRC, FGF2, HSP90AA1, PTGS2 and IL-2. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses indicated that loganin suppressed PMOP via mediating inflammation, bone formation, IL-17 signaling pathway and NF-κB signaling pathway. Molecular docking results indicated strong binding between loganin and core targets, in which the binding energy was approximately -5.2 and -7.4 kcal/mol. In vivo mouse model revealed that loganin inhibited the expression of pro-osteoclastic markers, such as tartrate-resistant acid phosphatase, C-terminal telopeptide, TNF-α and IL-6, enhanced the secretion of bone formation markers, such as procollagen type I intact n-terminal pro-peptide and IL-10, and improved bone micro-structure (bone volume/tissue volume and trabecular number), representative of the anti-resorptive effect mediated by loganin. In summary, the present study combined network pharmacology and molecular docking to predict the underlying mechanism of loganin against PMOP, validated by the in vivo mouse model showing that loganin attenuated OVX-induced bone loss by inhibiting inflammation.

Molecular identification and studies on genetic diversity and structure-related GC heterogeneity of Spatholobus Suberectus based on ITS2

To determine the role of internal transcribed spacer 2 (ITS2) in the identification of Spatholobus suberectus and explore the genetic diversity of S. suberectus. A total of 292 ITS2s from S. suberectus and 17 other plant species were analysed. S. suberectus was clustered separately in the phylogenetic tree. The genetic distance between species was greater than that within S. suberectus. Synonymous substitution rate (Ks) analysis revealed that ITS2 diverged the most recently within S. suberectus (Ks = 0.0022). These findings suggested that ITS2 is suitable for the identification of S. suberectus. The ITS2s were divided into 8 haplotypes and 4 evolutionary branches on the basis of secondary structure, indicating that there was variation within S. suberectus. Evolutionary analysis revealed that the GC content of paired regions (pGC) was greater than that of unpaired regions (upGC), and the pGC showed a decreasing trend, whereas the upGC remained unchanged. Single-base mutation was the main cause of base pair substitution. In both the initial state and the equilibrium state, the substitution rate of GC was higher than that of AU. The increase in the GC content was partly attributed to GC-biased gene conversion (gBGC). High GC content reflected the high recombination and mutation rates of ITS2, which is the basis for species identification and genetic diversity. We characterized the sequence and structural characteristics of S. suberectus ITS2 in detail, providing a reference and basis for the identification of S. suberectus and its products, as well as the protection and utilization of wild resources.

New-QiangGuYin-Containing Serum Inhibits Osteoclast-Derived Exosome Secretion and Down-Regulates Notum to Promote Osteoblast Differentiation

New-QiangGuYin (N-QGY), the addition of sea buckthorn on the basis of QGY formula, is herbal formula widely used clinically in China for the treatment of osteoporosis (OP), but its mechanism warrants further exploration. The mechanisms of QGY and N-QGY in the treatment of OP are probed from the perspective of osteoclast-osteoblast balance. Thirty Sprague-Dawley rats are randomly divided into N-QGY group, QGY group, and Control group. Beyond control rats that orally took normal saline, other rats are orally administered with isometric N-QGY or QGY twice every day for 3 days. The drug-containing serum and control serum are prepared and their effects on osteoclast-derived exosome secretion are determined by bicinchoninic acid assay (BCA), nanoparticle tracking analysis, and Western blot. GW4869 and Interleukin-1β (IL-1β) are adopted as the exosome inhibitor and inducer, respectively. Exosome uptake, cell counting kit-8, alkaline phosphatase (ALP) staining, alizarin red staining, enzyme-linked immunosorbent assay, quantitative real-time polymerase chain reaction, and Western blot are performed to examine the effects of altered osteoclast exosome content on osteogenic differentiation of mesenchymal stem cells (MSCs). N-QGY, QGY, and GW4869 inhibit osteoclast-derived exosome secretion and exosome uptake by MSCs, whereas IL-1β exerted the opposite effects (p < 0.05). Different from IL-1β, N-QGY, QGY, and GW4869 partially elevated MSC viability, osteocalcin secretion, ALP, RUNX Family Transcription Factor 2 (RUNX2) and Osteopontin (OPN) expressions, and calcium deposition in the osteoclast-MSCs coculture system (p < 0.05). Mechanically, osteoclasts increased Notum protein level but decreased β-catenin level, which is enhanced by IL-1β but is reversed by GW4869, QGY, and N-QGY (p < 0.05). And the effect of N-QGY is more conspicuous than that of QGY (P<0.05). N-QGY-containing serum inhibits exosome levels in osteoclasts, thereby enhancing osteogenic differentiation of MSCs via inhibition of Notum protein and promotion of β-catenin protein.

Oral Milk-Derived Extracellular Vesicles Inhibit Osteoclastogenesis and Ameliorate Bone Loss in Ovariectomized Mice by Improving Gut Microbiota

Milk-derived extracellular vesicles can improve intestinal health and have antiosteoporosis potential. In this paper, we explored the effects of bovine raw milk-derived extracellular vesicles (mEVs) on ovariectomized (OVX) osteoporotic mice from the perspective of the gut-bone axis. mEVs could inhibit osteoclast differentiation and improve microarchitecture. The level of osteoporotic biomarkers in OVX mice was restored after the mEVs intervened. Compared with OVX mice, mEVs could enhance intestinal permeability, reduce endotoxin levels, and improve the expression of TNF-α, IL-17, and IL-10. 16S rDNA sequencing indicated that mEVs altered the composition of gut microbiota, specifically for Bacteroides associated with short-chain fatty acids (SCFAs). In-depth analysis of SCFAs demonstrated that mEVs could restore acetic acid, propionic acid, valeric acid, and isovaleric acid levels in OVX mice. Correlation analysis revealed that changed gut microbiota and SCFAs were significantly associated with gut inflammation and osteoporotic biomarkers. This study demonstrated that mEVs could inhibit osteoclast differentiation and improve osteoporosis by reshaping the gut microbiota, increasing SCFAs, and decreasing the level of pro-inflammatory cytokines and osteoclast differentiation-related factors in OVX mice. These findings provide evidence for the use of mEVs as a food supplement for osteoporosis.

Exploring the boost of steaming with wine on Ligustri Lucidi Fructus in treating postmenopausal osteoporosis based on superior "multi-component structure" and iron/bone metabolism coregulation

BACKGROUND

Clinical studies indicated that postmenopausal osteoporosis (PMOP) often accompanied by iron overload risk factor, which exacerbated bone metabolism disorders and accelerated PMOP. Previous research found that multicomponent in Ligustri Lucidi Fructus (FLL) or wine-steamed FLL (WFLL) acted on the common targets of iron overload and PMOP simultaneously, which indicated that FLL and WFLL probably regulated iron/bone metabolism dually. Additionally, WFLL had more superior effect according to the theory of Chinese medicine for thousands of years.

PURPOSE

To reveal the "superior multi-component structure (SMCS)" and its molecular mechanisms in parallelly down-regulating iron overload and rescuing bone metabolism by WFLL.

DESIGNS AND METHODS

HPLC fingerprinting was established to compare the chemical profiles of FLL and WFLL; Then, the chemical compositions and quality markers of FLL and WFLL were analyzed by UPLC-Orbitrap-MS/MS coupled with OPLS-DA; the dynamic contents of quality markers and the multi-component structure at different wine steaming times (WST) were simultaneously determined by HPLC-DAD. Meanwhile, the dynamic efficacy of FLL at different WST were hunt by systematic zebrafish model. Subsequently, potential mechanism of WFLL in treating PMOP accompanied with iron overload was obtained from network pharmacology (NP) and molecular docking (MD). Finally, zebrafish and ovariectomy rat model were carried out to validate this potential mechanism.

RESULTS

HPLC fingerprints similarity of 15 batches in FLL and WFLL were among 0.9-1.0. 126 compositions were identified, including 58 iridoids, 25 terpenes, 30 phenylethanoids, 7 flavonoids and 6 others. 20 quality markers associated with WFLL was revealed, and the ratio of phenylethanols: Iridoids: Triterpenes (P/I/T) was converted from 1: 15: 4.5 to 1: 0.8: 0.9 during steaming (0 - 24 h) calculated by the quantification of 11 quality markers; the bone mineralization and motor performance of zebrafish larvae indicated that the optimum efficacy of WFLL at 12 h (p < 0.05) in which the SMCS of P/I/T was converted to 1: 4: 1.8. NP discovered that BMP-Smad pathway is one of the potential mechanisms of FLL in anti PMOP and then regulated bone formation and iron overload simultaneously. MD revealed that 17 active ingredients and 10 core targets genes could spontaneously bind with appropriate affinity. Rats model verified that FLL and WFLL significantly reversed PMOP, based on the improvement in bone formation indexes (ALP, OPG, OGN), iron metabolism indicators (hepcidin, ferritin), bone microstructure (BMD, BV/TV, Tb. Th, Tb. N); Moreover, WFLL significant enhanced reversal effect in anti-PMOP compared to FLL (p < 0.05). FLL and WFLL increased genes and proteins expression (Hep, BMP-6, p-Smad1/5, Smad4) related to BMP-Smad pathway compared with model group, and WFLL was more superior than FLL (p< 0.05).

CONCLUSION

The SMCS of FLL was optimized by wine-steam, WFLL represented a dual effect in downregulating iron overload and promoting bone formation, and the BMP-Smad pathway is one of the potential molecular mechanisms.