Isosinensetin alleviates estrogen deficiency-induced osteoporosis via suppressing ROS-mediated NF-κB/MAPK signaling pathways

• Published in: Biomedicine & pharmacotherapy Vol. 160; p. 114347
• Main Authors: Qin, Yiwu, Song, Dezhi, Liao, Shijie, Chen, Junchun, Xu, Minglian, Su, Yuangang, Lian, Haoyu, Peng, Hui, Wei, Linhua, Chen, Kai, Xu, Jiake, Zhao, Jinmin, Liu, Qian
• Format: Journal Article
• Language: English
• Published: France Elsevier Masson SAS 01.04.2023; Elsevier
• Subjects: Animals; Antioxidants - metabolism; Antioxidants - pharmacology; Bone Resorption - metabolism; Cell Differentiation; Estrogens - pharmacology; Isosinensetin; MAP Kinase Signaling System; MAPK; Mice; NF-kappa B - metabolism; NF-κB; Osteoclasts; Osteogenesis; Osteoporosis; Osteoporosis - drug therapy; Osteoporosis - pathology; RANK Ligand - metabolism; Reactive Oxygen Species - pharmacology; ROS; X-Ray Microtomography; OBs; RANKL; M-CSF; ALP; Ctsk/CTSK; DMSO; JNK; PFA; RANK; TRAP; Homx-1/HO-1; AP-1; E2; TNF; BSA; NF-κB; Tb.Sp; Osteoporosis; FBS; Acp5; CCK-8; cDNA; qPCR; Cat/CAT; OCs; PBS; Nfatc1/NFATc1; DCF; H&E; Micro-CT; DAPI; MAPK; Mmp9; Nfe2l2/Nrf2; AR; ARE; MEM; PMSF; TRAF6; ROS; Tb.Th; GAPDH; ERK; Atp6v0d2/ATP6V0D2; NADPH; Gsr/GSR; Tb.N; H2DCFDA; IκB; OVX; BV/TV; OD; c-FOS/c-Fos; OP; BMM; Iss; TBST; NOX-1; EDTA; TRAFs; Keap1; Isosinensetin
• ISSN: 0753-3322; 1950-6007
• DOI: 10.1016/j.biopha.2023.114347

The formation of osteoclasts and their hyperactive bone resorption are related to the aggregation of intracellular reactive oxygen species (ROS). Flavonoids, derived from plant active ingredients, can alleviate the symptoms of osteoporosis (OP). Isosinensetin (Iss) is a flavonoid with antioxidant effects obtained mainly from citrus fruits, and its effect on osteoclastogenesis has not been reported. In this study, we investigated the antioxidant activity of Iss on osteoclast differentiation and function, as well as the therapeutic impact of Iss on OP. We found that Iss inhibited osteoclastogenesis and suppressed the bone resorption function of osteoclasts. Additionally, Iss reduced receptor activator of nuclear factor-κB ligand (RANKL)-induced intracellular ROS. Using quantitative real-time polymerase chain reaction and western blot, we further found that Iss inhibited osteoclast-specific genes and related proteins, while promoting the expression of antioxidant enzyme-related genes and proteins. Mechanistically, Iss reduces intracellular ROS by activating nuclear factor-erythroid 2-related factor 2 (Nrf2) and its related antioxidant enzymes and inhibits the downstream nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways of ROS, which in turn inhibits nuclear factor of activated T cells 1 (NFATc1), and ultimately inhibits osteoclastogenesis. In vivo, by micro-computed tomography (Micro-CT) assay and histological analyses, we found that Iss could reduce bone loss in ovariectomized (OVX) mice. Therefore, Iss has the potential as an OP preventative and therapeutic drug option. [Display omitted] •The formation of osteoblasts requires reactive oxygen species.•A flavonoid with antioxidant properties mainly found in citrus fruits.•Isosinensetin can inhibit osteoclasts by reducing reactive oxygen species.•Isosinensetin can attenuate estrogen deficiency-induced osteoporosis in mice.•Isosinensetin could be a potential drug against osteoporosis.