Safranal inhibits estrogen-deficiency osteoporosis by targeting Sirt1 to interfere with NF-κB acetylation

Abstract

BackgroundOsteoporosis is a prevalent bone metabolic disease in menopause, and long-term medication is accompanied by serious side effects. Estrogen deficiency-mediated hyperactivated osteoclasts is the initiating factor for bone loss, which is regulated by nuclear factor-κB (NF-κB) signaling. Safranal (Saf) is a monoterpene aldehyde produced from Saffron (Crocus sativus L.) and possesses multiple biological properties, particularly the anti-inflammatory property. However, Saf's role in osteoporosis remains unknown. PurposeThis study aims to validate the role of Saf in osteoporosis and explore the potential mechanism. Study DesignThe RANKL-exposed mouse BMM (bone marrow monocytes) and the castration-mediated osteoporosis model were applied to explore the effect and mechanism of Saf in vitro and in vivo. MethodThe effect of Saf on osteoclast formation and function were assessed by TRAcP staining, bone-resorptive experiment, qPCR, immunoblotting and immunofluorescence, etc. Micro-CT, HE, TRAcP and immunohistochemical staining were performed to estimate the effects of Saf administration on OVX-mediated osteoporosis in mice at imaging and histological levels. ResultsSaf concentration-dependently inhibited RANKL-mediated osteoclast differentiation without affecting cellular viability. Meanwhile, Saf-mediated anti-osteolytic capacity and Sirt1 upregulation were also found in ovariectomized mice. Mechanistically, Saf interfered with NF-κB signaling by activating Sirt1 to increase p65 deacetylation and inactivating IKK to decrease IκBα degradation. ConclusionOur results support the potential application of Saf as a therapeutic agent for osteoporosis.