Mechanisms underlying the antiapoptotic and anti-inflammatory effects of monotropein in hydrogen peroxide-treated osteoblasts

Abstract

Monotropein, the primary iridoid glycoside isolated from Morindacitrifolia, has been previously reported to possess potent antioxidant and antiosteoporotic properties. However, there is no direct evidence correlating the antiosteoporotic effect of monotropein with its observed antioxidant capacity, and the molecular mechanisms involved in mediating these processes remain unclear. Therefore, the aim of the present study was to investigate the protective effects of monotropein against oxidative stress in osteoblasts and the mechanisms involved in mediating this process. Osteoblast viability was evaluated using the MTT assay. The mitochondrial membrane potential and reactive oxygen species were detected by flow cytometry analyses. Western blotting and enzyme‑linked immunosorbent assays were performed to detect protein expression levels. A significant reduction in osteoblast viability was observed at 24 h following exposure to various concentrations (100‑1,000 µM) of H2O2 compared with untreated osteoblasts. The cytotoxic effect of H2O2 was notably reversed when osteoblasts were pretreated with 1‑10 µg/ml monotropein. Pretreatment with 1-10 µg/ml monotropein increased the mitochondrial membrane potential and reduced the generation of reactive oxygen species in osteoblasts following exposure to H2O2. In addition, the H2O2‑induced increase in apoptotic markers (caspase-3 and caspase-9) and H2O2-induced reduction in sirtuin 1 levels were significantly reversed following pretreatment of cells with monotropein. Furthermore, monotropein significantly reduced H2O2‑induced stimulation of NF‑κB expression, in addition to the expression of a number of proinflammatory mediators. These results indicate that monotropein suppresses apoptosis and the inflammatory response in H2O2‑induced osteoblasts through the activation of the mitochondrial apoptotic signaling pathway and inhibition of the NF‑κB signaling pathway.

Monotropein promotes angiogenesis and inhibits oxidative stress‐induced autophagy in endothelial progenitor cells to accelerate wound healing

“…Numerous studies have shown that multiple herbs and herbal extracts of traditional Chinese medicine (TCM) are effective in the treatment of vascular diseases, such as atherosclerosis . Monotropein (Mtp) is the primary iridoid glycoside extract from Morinda officinalis and has various bioactive effects, including stimulation of osteogenesis in an ovariectomized model , anti‐inflammatory activity in osteoarthritis and colitis and anti‐apoptotic and antioxidant effects in hydrogen peroxide‐treated osteoblasts . However, the regulation of cellular antioxidants by Mtp is poorly understood.…”

Monotropein alleviates H2O2‑induced inflammation, oxidative stress and apoptosis via NF‑κB/AP‑1 signaling

“…Mtp. it has previously been reported that Mtp is capable of inhibiting H 2 o 2 -induced roS generation in osteoblasts (21). in the present study, Mda content was estimated to evaluate membrane lipid peroxidation.…”

“…Previous studies have demonstrated that Mtp exerts antiapoptotic and anti-inflammatory effects in osteoarthritis chondrocytes (21,24,25). nevertheless, the potential functions of Mtp in the progression of cVd are not completely understood.…”

The PI3K/Akt and NF-κB signaling pathways are involved in the protective effects ofLithocarpus polystachyus(sweet tea) on APAP-induced oxidative stress injury in mice

“…10,11 It has the popular name "sweet tea" (ST) in folk medicine and serves as a traditional herbal medicine against various diseases. [12][13][14] The tender leaves of L. polystachyus have been used as a traditional Chinese herb and a sweet tonic drink for several hundreds of years in southern China. 15 In searching for the sweet components in the leaves, avonoid with a content up to 7% in the leaves 16,17 was determined as a sweet compound, among which trilobatin is also one of the main sweet sources.…”