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An 8-O-4 '' norlignan exerts oestrogen-like actions in osteoblastic cells via rapid nongenomic ER signaling pathway

作者 Xiao, Hui-Hui; Gao, Quan-Gui; Ho, Ming-Xian; Zhang, Yan; Wong, Ka-Chun; Dai, Yi; Yao, Xin-Sheng; Wong, Man-Sau

期刊 JOURNAL OF ETHNOPHARMACOLOGY , JUL 21 2015,:170

DOI 10.1016/j.jep.2015.05.012 PubMed 25978953

摘要 Ethnopharmacological relevance: Sambucus williamsii Hance (SWH), which belongs to the Caprifoliaceae family distributed in various regions of China, Korea and Japan, has been used as a folk medicine for treatment of bone and joint diseases in China for thousands of years. In previous studies, SWH was shown to possess anti-osteoporosis, healing fracture, anti-inflammatory and analgesic activities. Our previous studies showed that SWH extract effectively suppressed ovariectomy-induced increase in bone turnover and improved bone mineral density and bone biomechanical strength in rats as well as in mice. An 8-O-4'' norlignan, (7R,8S)-1-(4-hydroxy-3-methoxyphenyl)-2-[4-(3-hydroxypropyl)-2-methoxyphenoxy]-1,3-propanediol (PPD) was previously isolated and identified as the bioactive ingredient in SWH. The present study aimed to characterize the bone protective effects as well as its mechanism of actions in osteoblasts.Materials and methods: Bone protective actions of PPD on different cells were determined by proliferation assay, alkaline phosphatase (ALP) activity assay, calcium deposition as well as real-time reverse transcriptase-polymerase chain reaction (RT-PCR). In addition, estrogen receptor (ER) antagonist ICI182,780 and mitogen-activated protein kinase kinase (MEK) inhibitor U0126 blocking assays, competitive ER radioligand binding assay, ERE-dependent luciferase reporter assay and immunoblotting were used to determine if PPD activated ER and if the effects of PPD on osteoblastic functions were ER dependent.Results: PPD exerted anabolic effects in osteoblasts and its effects were abolished by co-incubation with ICI182,780 or U0126. PPD induced mRNA expressions of Runx2, ALP, osteocalcin, and increased the ratio of osteoprotegerin/receptor activator of nuclear factor kappa B (OPG/RANKL). PPD failed to bind to either ER alpha or ER beta and did not activate ERE-luciferase activity via ER. PPD induced the phosphorylation of extracellular regulated kinases (ERK) and its effect was completely abolished by U0126. It also induced the phosphorylation of ER alpha at serine 118.Conclusion: These data show that PPD is a bioactive compound in SWH that exerts oestrogen-like actions in osteoblast-like cells via ligand-independent, estrogen response element (ERE)-independent and mitogen-activated protein (MAP) Kinase-mediated rapid nongenomic ER signaling pathway. (C) 2015 Elsevier Ireland Ltd. All rights reserved.

涉及物种 接骨木 Sambucus williamsii