Pterostilbene promotes the osteogenic differentiation of MC3T3-E1 cells inhibited by H2O2 by activating the AMPK signaling pathways

Abstract

Osteoporosis is one of the common degenerative skeletal diseases whose essential mechanism is the imbalance between bone resorption and formation. Currently, the close coordination of signaling pathways at genetic level during bone development is a hot topic of osteoporosis research. The present study is focused on whether pterostilbene protects against hydrogen peroxide (H2O2)-induced osteoblastic cell apoptosis, oxidative stress, and reveals the related underlying mechanisms. MC3T3-E1 osteoblastic cells were cultured and treated with different concentrations of H2O2 (0–1 mM) along with or without pterostilbene, and MTT assay or Annexin V-FITC/propidium iodide staining was applied for measuring cell viability and apoptosis. The in vitro cellular antioxidant analysis was performed using 2,7-dichlorodihydrofluorescein diacetate assay and enzyme-linked-immunosorbent serologic assay against glutathione peroxidase and malondialdehyde. In addition, cellular alkaline phosphatase activity was executed by Alizarin Red S staining. Western blot assay was conducted to determine the expression levels of osteogenic-related markers, including type I collagen, osteopontin, runt-related transcription factor 2, and the 5' adenosine monophosphate-activated protein kinase (AMPK) signaling pathways related proteins. The key finding was that pterostilbene could attenuate the H2O2-induced cellular apoptosis and oxidative stress. Pterostilbene also promoted osteogenic differentiation in H2O2-treated MC3T3-E1 cells through activation of the AMPK pathway. In conclusion, pterostilbene blocked the H2O2-induced MC3T3-E1 cells dysfunction, indicating its potential to be a promising medication for treating osteoporosis.