Water extract of tendril of Cucurbita Moschata Duch. suppresses RANKL-induced osteoclastogenesis by down-regulating p38 and ERK signaling

Abstract

Background: Pumpkin (Curcubita sp.) is a natural product that is commonly used in folk medicine. However, the inhibitory effect and molecular mechanisms of tendril of Cucurbita Moschata Duch. (TCMD) on osteoclast differentiation have yet to be clearly elucidated. Thus, the present study aimed to investigate the effect and underlying mechanism of water extract of TCMD on osteoclast differentiation. Methods: Bone marrow-derived macrophages (BMDMs), osteoclast precursors, were cultured with macrophage colony stimulating factor (M-CSF) 30 ng/ml and receptor activator of nuclear factor-kappa B ligand (RANKL) 100 ng/ml for four days. We investigated the effect of TCMD on RANKL-induced osteoclast differentiation, tartrate-resistant acid phosphatase (TRAP) staining, F-actin ring formation, and bone resorption assay. RANKL signaling pathways were determined through Western blotting, and osteoclast differentiation marker genes were confirmed by Real-time PCR. Results: TCMD inhibited the RANKL-induced osteoclast differentiation in a dose-dependent manner without cytotoxicity. Further, F-actin ring formation and bone resorption were reduced by TCMD in RANKL-treated BMDMs. In addition, TCMD decreased the phosphorylation of p38 and ERK as well as the expression of osteoclast-related genes in BMDMs treated with RANKL. Conclusion: These findings suggest that TCMD may have preventive and therapeutic effects for destructive bone diseases.

Pro-Osteogenic Properties of Violina pumpkin (Cucurbita moschata) Leaf Extracts: Data from In Vitro Human Primary Cell Cultures

“…A large body of evidence has been collected to show the potential of plant derivatives for the prevention and treatment of bone lesions [ 12 , 13 , 14 ]. Despite various discrepancies in the literature, there is agreement in attributing the positive effects of plant extracts, including those of the pumpkin tendrils, on the bone repair process, to antioxidant and anti-inflammatory action, and to the ability to increase angiogenesis and cell proliferation and differentiation [ 13 , 15 , 16 , 17 ]. Consistently with those observations, the few characteristics of pumpkin leaf extracts known prior to our study suggested that it would be reasonable to investigate their effects on bone cells.…”

New 8-C-p-Hydroxylbenzylflavonol Glycosides from Pumpkin (Cucurbita moschata Duch.) Tendril and Their Osteoclast Differentiation Inhibitory Activities

“…Recently, we reported that a water extract of pumpkin tendril suppresses RANKL-induced osteoclast differentiation and bone resorption by suppressing RANKL-mediated p38 and ERK phosphorylation [17]. In addition, water extract of pumpkin tendril treatment decreased the expression of osteoclast-related genes such as NFATc1, TRAP, Cathepsin K and TRAP [17]. In our study, new compounds isolated from a water extract of pumpkin tendril showed different levels of inhibitory effects at the same concentration.…”

“…Pumpkin tendril has also been found to inhibit inflammation, with rutin being identified as an anti-inflammatory compound in this material [16]. Recently, we reported that the water extract of pumpkin tendrils suppressed RANKL-induced osteoclast differentiation via downregulation of p38 and extracellular-signal-regulated kinase (ERK) [17]. Nevertheless, the results of our series of studies on pumpkin tendril suggested the presence of other unidentified bioactive compounds.…”

“…Furthermore, we confirmed that bone resorption was inhibited by isolated compounds. Recently, we reported that a water extract of pumpkin tendril suppresses RANKL-induced osteoclast differentiation and bone resorption by suppressing RANKL-mediated p38 and ERK phosphorylation [17]. In addition, water extract of pumpkin tendril treatment decreased the expression of osteoclast-related genes such as NFATc1, TRAP, Cathepsin K and TRAP [17].…”

Cilengitide inhibits osteoclast adhesion through blocking the αvβ3-mediated FAK/Src signaling pathway

“…The femur and tibia of C57BL/6 mice (age:7±1weeks, weight:22 ± 2 g, purchased from Kawensi, Changzhou, China) were utilized to harvest total bone marrow cells [ 22 ]. These cells were subsequently cultured in culture medium supplemented with 10% FBS, 1% penicillin and streptomycin, and 30 ng/ml M-CSF at 37 °C and 5% CO 2 [ 23 ]. Osteoclast induction was performed when cells reached 90%–100% confluence.…”