Abstract
Insulin resistance is a characteristic finding in hyperglycaemia and type 2 diabetes. SIRT1 is a NAD+ dependent deacetylase that plays a central role in glucose homeostasis and energy metabolism. SIRT1 activators, including plant polyphenols such as resveratrol, improve insulin sensitivity in skeletal muscle tissue. We hypothesised that the novel plant-derived compounds, strigolactone and pinosylvin, beneficially enhance SIRT1 function, insulin signalling, glucose uptake, and mitochondrial biogenesis in skeletal muscle cells. Rat L6 skeletal muscle myotubes were treated with strigolactone analogue GR24 and pinosylvin. Resveratrol was included in experiments as a reference compound. We measured the effects of these compounds on SIRT1 function, insulin signalling, glucose uptake, mitochondrial biogenesis and gene expression profiles. Strigolactone GR24 upregulated and activated SIRT1 without activating AMPK, enhanced insulin signalling, glucose uptake, GLUT4 translocation and mitochondrial biogenesis. Pinosylvin activated SIRT1 in vitro and stimulated glucose uptake through the activation of AMPK. The regulation of SIRT1 by strigolactone GR24 and the activation of AMPK by pinosylvin may offer novel therapeutic approaches in the treatment of insulin resistance in skeletal muscle.