HPLC determination of novel dithiolethione containing drugs and its application for in vivo studies in rats

The New Synthetic H2S-Releasing SDSS Protects MC3T3-E1 Osteoblasts against H2O2-Induced Apoptosis by Suppressing Oxidative Stress, Inhibiting MAPKs, and Activating the PI3K/Akt Pathway

Reactive oxygen species (ROS) are important in osteoporosis development. Oxidative stress induces apoptosis of osteoblasts and arrest of their differentiation. Both Danshensu (DSS) and hydrogen sulfide (H₂S) produce significant antioxidant effect in various systems. In this study, we synthesized SDSS, a novel H₂S-releasing compound derived from DSS, and studied its antioxidant effect in an H₂O₂-induced MC3T3-E1 osteoblastic cell injury model. We first characterized the H₂S releasing property of SDSS in both in vivo and in vitro models. HPLC chromatogram showed that intravenous injection of SDSS in adult rats released ADT-OH, a well proved H₂S sustained-release moiety, within several minutes in the rat plasma. Using an H₂S selective fluorescent probe, we further confirmed that SDSS released H₂S in MC3T3-E1 osteoblastic cells. Biological studies revealed that SDSS had no significant toxic effect but produced protective effects against H₂O₂-induced MC3T3-E1 cell apoptosis. SDSS also reversed the arrest of cell differentiation caused by H₂O₂ treatment. This was caused by the stimulatory effect of SDSS on bone sialoprotein, runt-related transcription factor 2, collagen expression, alkaline phosphatase activity, and bone nodule formation. Further studies revealed that SDSS reversed the reduced superoxide dismutase activity and glutathione content, and the increased ROS production in H₂O₂ treated cells. In addition, SDSS significantly attenuated H₂O₂-induced activation of p38-, ERK1/2-, and JNK-MAPKs. SDSS also stimulated phosphatidylinositol 3-kinase/Akt signaling pathway. Blockade of this pathway attenuated the cytoprotective effect of SDSS. In conclusion, SDSS protects MC3T3-E1 cells against H₂O₂-induced apoptosis by suppressing oxidative stress, inhibiting MAPKs, and activating the phosphatidylinositol 3-kinase/Akt pathway.