Psoralen and Bakuchiol Ameliorate M-CSF Plus RANKL-Induced Osteoclast Differentiation and Bone Resorption Via Inhibition of AKT and AP-1 Pathways in Vitro

Abstract

Background/Aims: Psoralen and bakuchiol are the main active compounds found in the traditional Chinese medicine Psoralea corylifolia L., and have been used to treat osteoporosis. This study aims to investigate the anti-osteoporosis effects of these two compounds using osteoclasts precursor differentiation and bone absorption assays in vitro. Methods: Primary mouse osteoclasts precursor cells were induced by M-CSF (macrophage colony stimulating factor) plus RANKL (receptor activator of nuclear factor kappa-B ligand) in vitro. TRACP (tartrate-resistant acid phosphatase) enzyme activity and toluidine blue staining were used to observe the effects of psoralen and bakuchiol on osteoclast differentiation and bone resorption, respectively. Gelatin zymography was used to assess MMP (matrix metalloproteinase) activity, and ELISA was performed to measure cathepsin K activity. Western blotting analysis for expression of phosphorylated AKT, ERK, NF-kB, and c-jun; and immunofluorescence analysis for c-jun and p65 nuclear translocation in induced osteoclasts were then used to determine the mechanism of anti-bone resorption of psoralen and bakuchiol. Results: Mature osteoclasts were induced by M-CSF plus RANKL from primary bone marrow macrophages in vitro. Both psoralen and bakuchiol significantly inhibited TRACP enzyme activity and slightly decreased the number of TRACP⁺ multinuclear osteoclasts induced by M-CSF plus RANKL. Bakuchiol significantly decreased bone lacunae area and attenuated MMP-2 activity induced by M-CSF plus RANKL in osteoclasts. Both psoralen and bakuchiol significantly decreased the expression and nuclear translocation of phosphorylated c-jun stimulated by M-CSF plus RANKL, but no significant effect on p65 translocation was observed in osteoclasts. Additionally, bakuchiol significantly attenuated the increased of M-CSF plus RANKL-induced phosphorylation of AKT in osteoclasts. Conclusions: Psoralen and bakuchiol ameliorated M-CSF plus RANKL-induced osteoclast differentiation and bone resorption via inhibition of AKT and AP-1 pathways activation in vitro.

The Coumarin Derivative 5′-Hydroxy Auraptene Suppresses Osteoclast Differentiation via Inhibiting MAPK and c-Fos/NFATc1 Pathways

“…Consistently, several naturally occurring coumarin compounds showed antiosteoclastic bone resorption effects in vitro and in vivo. ese include aesculin, psoralidin, daphnetin, bakuchiol, and esculetin [16,19,30,31]. us, coumarin derivatives can be used as promising natural pharmaceutical agents for the treatment of osteoporosis.…”

Therapeutic Anabolic and Anticatabolic Benefits of Natural Chinese Medicines for the Treatment of Osteoporosis

“…The osteogenic effects of BA and BK appear to be produced by up-regulation of the Wnt signalling pathway, and produce increased ALP levels, Ca serum concentration, and BMD (Lim et al, 2009; Weng et al, 2015). Further in vitro findings suggest that BK inhibits RANKL-induced osteoclast differentiation and bone resorption by disrupting the AKT and AP-1 signalling pathways (Chai et al, 2018).…”

“…Furthermore, the OVX -induced gene expression profile was reversed by PSO treatment, appearing to be mediated via the Notch signalling pathway, and resulted in regulation of the differentiation of bone mesenchymal stem cell, thus indicating the osteogenic potential of PSO for the treatment of postmenopausal osteoporosis (Yang et al, 2012). In vitro findings indicate that PSO may also attenuate osteoclast differentiation and bone resorption via inhibition of the AKT and AP-1 signalling pathways (Chai et al, 2018).…”

A Review of the Pharmacological Properties of Psoralen

“…However, the effect of psoralen on the phosphorylation of ASK1, JNK, and MAPK P38 in osteoblasts and osteoclasts remains controversial and requires further study (Li F. et al, 2017;Chen et al, 2017a;Chai et al, 2018;Zhang et al, 2019).…”

“…Chai et al reported that psoralen was able to significantly reduce the expression of phosphorylated JNK in osteoclasts. Finally, It has been suggested that psoralen ameliorates osteoclast differentiation and bone resorption through inhibition of AP-1 and AKT pathway activation in vitro (Chai et al, 2018).…”