Nobiletin ameliorates hormone-induced osteoblast apoptosis by modulating JAK2/STAT3 signaling.

Our paper aimed to disclose the effects of nobiletin (NOB) on hormone-induced osteoblast apoptosis and potential action mechanism. MC3T3-E1 cells were randomly separated into normal group, glucocorticoid (GC) group, L-NOB group, M-NOB group, H-NOB group, and Colivelin group (Colivelin: JAK2/STAT3 activator). CCK-8 was applied to ascertain the activity of MC3T3-E1 cells. FITC-Annexin V/PI method was applied to measure cell apoptosis. Alkaline phosphatase (ALP) assay kit was applied to measure ALP activity. Enzyme linked immunosorbent assay (ELISA) was implemented to ascertain the levels of IL-6, IL-1β, TNF-α, and ROS. Western blotting was implemented to distinguish the expressions of JAK2/STAT3 pathway proteins. The viability of MC3T3-E1 cells, ALP activities, and bcl-2 protein level were considerably decreased, while the apoptotic rate, the levels of TNF-α, IL-1β, IL-6, ROS, and the expressions of pJAK2/JAK2, pSTAT3/STAT3, Caspase-3, and bax proteins were greatly increased in each group after GC treatment. In comparison with GC group, MC3T3-E1 cell viability, ALP activity, and bcl-2 protein level in the L-NOB group, M-NOB group, and H-NOB group were greatly increased. Conversely, the apoptotic rate, the levels of TNF-α, IL-1β, IL-6, ROS, and the expressions of pJAK2/JAK2, pSTAT3/STAT3, Caspase-3, and bax proteins were markedly reduced. In contrast to H-NOB group, the apoptotic rate, the levels of TNF-α, IL-1β, IL-6, ROS, and the expressions of pJAK2/JAK2, pSTAT3/STAT3, Caspase-3, and bax proteins in Colivelin group were considerably enhanced, while MC3T3-E1 cell viability, ALP activity, and bcl-2 protein level were greatly declined. NOB ameliorates hormone-induced osteoblast apoptosis by reducing JAK2/STAT3 signaling activity.