Ligustilide inhibits tumour necrosis factor-alpha-induced autophagy during C2C12 cells differentiation

Ligustilide is widely thought to be the most potent bioactive constituent of Angelica sinensis. We have previously reported the role of ligustilide in preventing TNF-α-induced apoptosis and identified the presence of autophagosome clusters. Then, we hypothesised that autophagy may contribute to muscle loss and that ligustilide could protect cell fibres by regulating the autophagic process. The aim of this study was to identify the effects of ligustilide on autophagy regulation during cell differentiation in the presence of TNF-α. We then observed intracellular morphologic changes and autophagosome formation using transmission electron microscopy. LC3B expression was assessed by immunofluorescence and Atg-7, Atg-5, Atg-12 and LC3B expression levels were detected by western blot. The results revealed a reduction in the number of TNF-α-induced autophagosomes after ligustilide treatment accompanied by a decrease in Atg-7, Atg-5, Atg-12 and LC3B expression, as well as a reduction of the LC3BII/I ratio in a concentration-dependent manner. Our findings provide evidence supporting a protective effect of ligustilide against TNF-α-induced autophagy during myotubes formation.