Cytoprotective effect of Fufang Lurong Jiangu capsule against hydrogen peroxide-induced oxidative stress in bone marrow stromal cell-derived osteoblasts through the Nrf2/HO-1 signaling pathway.

Oxidative stress is increasingly recognized as a risk factor associated with the development and progression of osteoporosis. Fufang Lurong Jiangu Capsule (FLJC) has a known anti-osteoporotic effect, but its pharmacological effect on osteoblasts is not clearly understood. This study was designed to investigate FLJC effects/mechanisms on in vitro hydrogen peroxide (H2O2)-induced oxidative damage of osteoblasts and on in vivo lipopolysaccharide (LPS)-induced mice bone loss. FLJC alleviates osteoporosis via unknown pharmacological mechanisms. Chemical compositions of FLJC preparations were analyzed using high-performance liquid chromatographic fingerprinting. After rat bone marrow mesenchymal stem cell differentiation induction, resulting osteoblasts received various 48 h FLJC pretreatments before H2O2-based (200 μM) oxidative stress exposure. FLJC effects were measured on osteoblast cell viability, morphological changes, levels of intracellular reactive oxygen species (ROS), localization of mitochondria, activity of antioxidant enzymes, alkaline phosphatase (ALP) and mineralization, the secretion of Col I and expression of osteogenic markers. The percentages of apoptosis were determined by flow cytometric analysis; apoptosis-related protein levels, including nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and heme oxygenase-1 (HO-1) with or without Nrf2 inhibitor were analyzed via western blot. Hematoxylin and eosin (H&E) and ALP staining revealed in vivo FLJC effect on mice LPS-induced bone loss. Five chemical components in FLJC were identified, and fingerprint analysis showed good reproducibility. FLJC pretreatment significantly reduced H2O2-induced ROS levels in osteoblasts and increased antioxidant enzyme activities to reduce oxidative damage. With regard to osteoblast differentiation, FLJC pretreatment increased ALP expression, as well as levels of mineralization and osteoblast markers. Additionally, FLJC protected against H2O2-induced apoptosis by inhibiting changes in expression of major Bcl-2 family effector proteins of the mitochondrial apoptosis pathway. Furthermore, FLJC protected cells from H2O2-induced oxidative damage by up-regulating Nrf2 and HO-1 protein levels. Finally, we confirmed that FLJC administration could reverse the bone loss in LPS-induced mice. These results indicate that FLJC may significantly attenuate oxidative damage of osteoblasts induced by H2O2 via the Nrf2/HO-1 signaling pathway, providing new insights to guide development of treatments for osteoporosis induced by oxidative injury.

Jin W ，Zhu X ，Yao F ，Xu X ，Chen X ，Luo Z ，Zhao D ，Li X ，Leng X ，Sun L ... -  《-》

Cytoprotective effect of chlorogenic acid against hydrogen peroxide-induced oxidative stress in MC3T3-E1 cells through PI3K/Akt-mediated Nrf2/HO-1 signaling pathway.

Han D ，Chen W ，Gu X ，Shan R ，Zou J ，Liu G ，Shahid M ，Gao J ，Han B ... -  《Oncotarget》

Downregulation of Bach1 protects osteoblasts against hydrogen peroxide-induced oxidative damage in vitro by enhancing the activation of Nrf2/ARE signaling.

Oxidative-stress-induced osteoblast dysfunction plays an important role in the development and progression of osteoporosis. BTB and CNC homology 1 (Bach1) has been suggested as a critical regulator of oxidative stress; however, whether Bach1 plays a role in regulating oxidative-stress-induced osteoblast dysfunction remains unknown. Thus, we investigated the potential role and mechanism of Bach1 in regulating oxidative-stress-induced osteoblast dysfunction. Osteoblasts were treated with hydrogen peroxide (H2O2) to mimic a pathological environment for osteoporosis in vitro. H2O2 exposure induced Bach1 expression in osteoblasts. Functional experiments demonstrated that Bach1 silencing improved cell viability and reduced cell apoptosis and reactive oxygen species (ROS) production in H2O2-treated cells, while Bach1 overexpression produced the opposite effects. Notably, Bach1 inhibition upregulated alkaline phosphatase activity and osteoblast mineralization. Mechanism research revealed that Bach1 inhibition increased the activation of nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling and upregulated heme oxygenase 1 and NAD(P)H:quinone oxidoreductase 1 mRNA expression. The Bach1 inhibition-mediated protective effect was partially reversed by silencing Nrf2 in H2O2-exposed osteoblasts. Taken together, these results demonstrate that Bach1 inhibition alleviates oxidative-stress-induced osteoblast apoptosis and dysfunction by enhancing Nrf2/ARE signaling activation, findings that suggest a critical role for the Bach1/Nrf2/ARE regulation axis in osteoporosis progression. Our study suggests that Bach1 may serve as a potential therapeutic target for treating osteoporosis.

Tian X ，Cong F ，Guo H ，Fan J ，Chao G ，Song T ... -  《-》

Irradiation inhibits the maturation and mineralization of osteoblasts via the activation of Nrf2/HO-1 pathway.

Kook SH ，Kim KA ，Ji H ，Lee D ，Lee JC ... -  《-》

Astaxanthin protects ARPE-19 cells from oxidative stress via upregulation of Nrf2-regulated phase II enzymes through activation of PI3K/Akt.

Li Z ，Dong X ，Liu H ，Chen X ，Shi H ，Fan Y ，Hou D ，Zhang X ... -  《MOLECULAR VISION》