However, its mechanisms are not clearly understood

l and uterine tissues from avian and mammalian species. So, a reduction in TMOD3 and PTH1R gene expression after insemination to facilitate fertilization and zygote residence in the oviduct for some hours could be expected. Therefore, the data in the present study indicate a change in gene expression during male and female gametes encounter and interaction to form the zygote at the site of fertilization after a natural sperm selection within the female genital tract. These changes would indicate a modification of the environment preparing the oviduct for a successful fertilization and for an adequate zygote and embryo early stage milieu. New knowledge about the transcriptome modification around fertilization could be extended to the laboratory, adding new tools to increase IVF efficiency in mammals. Overall, a key question is whether there is any relationship PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19703425 between inappropriate expression or failure of expression of specific oviduct genes and subsequent fertilization or embryo migration. Exploitation of gene knock-out models could be a fruitful way forward in this context. ~~ Bone formation by osteoblasts and bone resorption by osteoclasts are balanced to maintain bone homeostasis. Enhanced bone resorption can lead to impaired bone structure and bone fracture in osteoporosis, rheumatoid arthritis, and bone metastatic disease. Osteoclasts differentiate from monocyte/macrophage lineage precursor cells; they are multinucleated giant cells with bone-resorbing activity. Receptor activator of nuclear factor-B ligand, proinflammatory cytokines, and lipopolysaccharide induce osteoclast differentiation and activation. RANKL, which is produced by osteoblasts and bone marrow stromal cells, binds to RANK on monocyte/macrophages followed by receptor oligomerization and recruitment of signaling adapter molecules such as TNF receptor-associated factor-B ligand 6. Subsequent TRAF6-TAK1 association activates the downstream signaling pathways NF-B and activator protein 1 and induces expression of NFATc1, which is the master osteoclast regulator. Interference with these signaling pathways may PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19702757 prevent excessive osteoclast formation and pathological bone loss. Herbal extracts are widely used as traditional medicines. Screening for phytochemicals with MEK 162 anti-osteoclastogenic activity may lead to the discovery and development of novel drugs to protect against or treat osteopenia and osteoporosis with minimal side effects. The shrub Rhinacanthus nasutus Kurz is distributed in Southeast Asia and is used in traditional medicines for the treatment of pneumonia, diabetes, hypertension, and skin diseases. The root and aerial portions of R. nasutus contain naphthoquinone esters, such as rhinacanthins C, D, N, and Q, which exhibit anti-inflammatory, anti-allergic, anti-tumor, and antiviral activities. Recently, we reported anti-osteoclastogenic activity in the ethyl acetatesoluble fraction of a methanol extract of the R. nasutus root. We isolated five components from the ethyl acetate-soluble fraction of this plant and found rhinacanthin C is a potent inhibitor of RANKL-stimulated osteoclastogenesis in mouse bone marrow macrophage cultures. In this study, we investigated the molecular mechanism by which rhinacanthin C suppresses RANKL-induced osteoclastogenesis of BMMs and validated its efficacy in vivo. Materials and Methods Materials Rhinacanthin C was isolated from the root of R. nasutus. The structure and purity of rhinacanthin C isolated from R. nasutus were co