Total flavonoids from celery suppresses RANKL-induced osteoclast differentiation and bone resorption function via attenuating NF-κB and p38 pathways in RAW264.7 cells

In vitro and in vivo investigation of chrysin chelated copper complex as biocompatible materials for bone tissue engineering applications

Flavonoid metal complexes have interesting properties and are widely explored for bone regeneration owing to their potent biological activity. In the present study, we investigated the biocompatibility and osteogenic properties of the Copper(II)-chrysin complex (C/Cu). The biocompatibility of C/Cu was assessed in vitro with human osteoblastic cells and in vivo using chick embryo and zebrafish models. The C/Cu complex was found to be cytofriendly with good biocompatibility. The osteogenic property of C/Cu was studied at cellular and molecular levels. C/Cu promoted mineralization in osteoblastic cultures by increasing ALP activity. At the molecular level, C/Cu significantly promoted the mRNA levels of osteoblast differentiation marker genes such as runt-related transcription factor 2 (Runx2), Type 1 collagen and ALP. In addition to this, secretory proteins, osteonectin (ON) and osteocalcin (OC) levels were also stimulated. We have also identified that C/Cu exhibited enhanced osteogenic properties and antibacterial activity compared with Chrysin. Thus, C/Cu can be used as an osteogenic agent in bone tissue engineering.

Effects and Mechanisms of Rhus chinensis Mill. Fruits on Suppressing RANKL-Induced Osteoclastogenesis by Network Pharmacology and Validation in RAW264.7 Cells

Rhus chinensis Mill. fruits are a kind of widely distributed edible seasoning, which have been documented to possess a variety of biological activities. However, its inhibitory effect on osteoclast formation has not been determined. The objective of this study was to evaluate the effect of the fruits on osteoclast differentiation of RAW264.7 cells, induced by receptor activator of nuclear factor-κB ligand (RANKL) and to illuminate the potential mechanisms using network pharmacology and western blots. Results showed that the extract containing two organic acids and twelve phenolic substances could effectively inhibit osteoclast differentiation in RANKL-induced RAW264.7 cells. Network pharmacology examination and western blot investigation showed that the concentrate essentially decreased the expression levels of osteoclast-specific proteins, chiefly through nuclear factor kappa-B, protein kinase B, and mitogen-activated protein kinase signaling pathways, particularly protein kinase B α and mitogen-activated protein kinase 1 targets. Moreover, the extract likewise directly down regulated the expression of cellular oncogene Fos and nuclear factor of activated T-cells cytoplasmic 1 proteins. Citric acid, quercetin, myricetin-3-O-galactoside, and quercetin-3-O-rhamnoside were considered as the predominant bioactive ingredients. Results of this work may provide a scientific basis for the development and utilization of R. chinensis fruits as a natural edible material to prevent and/or alleviate osteoporosis-related diseases.

Anti-Osteoporosis Effect of Perilla frutescens Leaf Hexane Fraction through Regulating Osteoclast and Osteoblast Differentiation

Osteoporosis is the result of an imbalance in the bone-remodeling process via an increase in osteoclastic activity and a decrease in osteoblastic activity. Our previous studies have shown that Perilla frutescens seed meal has anti-osteoclastogenic activity. However, the role of perilla leaf hexane fraction (PLH) in osteoporosis has not yet been investigated and reported. In this study, we aimed to investigate the effects of PLH in osteoclast differentiation and osteogenic potential using cell-based experiments in vitro. From HPLC analysis, we found that PLH contained high luteolin and baicalein. PLH was shown to inhibit RANKL-induced ROS production and tartrate-resistant acid phosphatase (TRAP)-positive multi-nucleated osteoclasts. Moreover, PLH significantly downregulated the RANKL-induced MAPK and NF-κB signaling pathways, leading to the attenuation of NFATc1 and MMP-9 expression. In contrast, PLH enhanced osteoblast function by regulating alkaline phosphatase (ALP) and restoring TNF-α-suppressed osteoblast proliferation and osteogenic potential. Thus, luteolin and baicalein-rich PLH inhibits osteoclast differentiation but promotes the function of osteoblasts. Collectively, our data provide new evidence that suggests that PLH may be a valuable anti-osteoporosis agent.