Effects of moringa isothiocyanate-rich seed extract on muscle atrophy in C2C12 cells

Moringa isothiocyanate-1 (MIC-1, also known as moringin) is an isothiocyanate that composes up to 40% of moringa seed extract (MSE). Previously it was shown that MIC-1 inhibited lipopolysaccharide-induced inflammation in skeletal muscle, however little it is known about the MSE and MIC-1’s effects on muscle atrophy-related pathways. To investigate the beneficial effects of MSE and MIC-1, muscle atrophy was induced by dexamethasone or lipopolysaccharide as models. MIC-1 (1 µM) and MSE (at equivalent dose of 1 µM MIC-1) did not reduce viability of muscle cells at different stages. Dexamethasone and lipopolysaccharide reduced myotubes size by upregulating the muscle atrophy-related molecular targets, the E3 ubiquitin ligases Trim63 (a.k.a. Murf1) and Fbxo32 (a.k.a. Atrogin1). However, MIC-1 and MSE partially prevented the muscle atrophy. The reduction of muscle atrophy markers by MSE and MIC-1 were strongly associated with the downregulation of Trim63, rather than Fbxo32. Furthermore, Trim63 was identified as a molecular target for MSE and MIC-1’s improvements on skeletal muscle health in C2C12 cells. These results suggest that Moringa oleifera extracts and their related isothiocyanates may improve skeletal muscle health at different conditions.