Notopterol Inhibits TNF-α-Induced C2C12 Myoblast Apoptosis by Stimulating the PI3K/AKT Pathway

Abstract

Background: Qianghuo is the root and rhizome of the umbelliferae plant Notopterygium incisum Ting ex H.T. Chang (NI) or N. franchetii H. de Boiss. Notopterol (linear furocoumarin) is the most effective component of Notopterygium incisum. Notopterol exhibits antipyretic, analgesic, anti-inflammatory, anti-oxidation, and anti-apoptosis effects. However, the effects of notopterol on skeletal muscle cells are unclear. This study aims to evaluate the influence of notopterol on the activity of myoblast as well as its inhibiting effect on apoptosis induced by tumor necrosis factor-alpha (TNF-α). Method: We assessed the effect of notopterol on TNF-α-induced C2C12 apoptosis and its underlying mechanisms. Cell viability and apoptosis were evaluated using the CCK-8 and Annexin V-FITC/PI, respectively. The expressions of apoptosis-related proteins and pathways were assessed utilizing western blot (WB) analysis. Additionally, the role of notopterol in the phosphatidylinositol 3-kinases/AKT (PI3K/AKT) pathway was explored using specific inhibitors of PI3K. Results: We observed that notopterol increased the activity of TNF-α-treated myoblasts (p < 0.05). Furthermore, flow cytometry, Hoechst-33258 staining, and WB analysis revealed that notopterol reduced TNF-α-induced apoptosis of C2C12 myoblasts by increasing B Cell Lymphoma 2 (BCL-2) levels and decreasing BCL-2-associated X protein (BAX), caspase-3, and caspase-9 levels (p < 0.05). Additionally, notopterol can activate the PI3K/AKT pathway in the first place, then can increase AKT phosphorylation and BCL-2 expression and decrease BAX and caspase-3 expression sequentially. These effects were reversed with the introduction of LY294002, which is a specific inhibitor of PI3K (p < 0.05). Conclusions: Notopterol can affect C2C12 through PI3K/AKT, thus protecting against TNF-α-induced C2C12 myoblast apoptosis. Therefore, notopterol can be used to treat amyotrophy, providing insights into Sarcopenia prevention and treatment.