Activation of Insulin Signaling in Adipocytes and Myotubes by Sarcopoterium Spinosum Extract

Abstract

Sarcopoterium spinosum (S. spinosum) is a medicinal plant, traditionally used as an antidiabetic remedy. Previous studies demonstrated its beneficial properties in the treatment of insulin resistance. The aim of this study was to further clarify the effect of S. spinosum extract (SSE) on insulin signaling. Phosphoproteomic analysis, performed in 3T3-L1 adipocytes treated with SSE, revealed the activation of insulin receptor pathways. SSE increased Glut4-facilitated glucose uptake in adipocytes, with an additive effect between SSE and insulin. While the maximal effect of insulin on glucose uptake was found at days 15–16 of differentiation, SSE-induced glucose uptake was found at an earlier stage of differentiation. Inhibition of PI3K and Akt blocked SSE-dependent glucose uptake. Western blot analysis, performed on 3T3-L1 adipocytes and L6 myotubes, showed that in contrast to insulin action, Akt was only marginally phosphorylated by SSE. Furthermore, GSK3β and PRAS40 phosphorylation as well as glucose uptake were increased by the extract. SSE also induced the phosphorylation of ERK similar to insulin. In conclusion, SSE activates insulin signaling, although the upstream event mediating its effects should be further clarified. Identifying the active molecules in SSE may lead to the development of new agents for the treatment of insulin resistance.

Sarcopoterium spinosum Inhibited the Development of Non-Alcoholic Steatosis and Steatohepatitis in Mice

“…However, while in our previous studies SSE was given as a preventive protocol [16][17][18], in this study, we demonstrated a dose-dependent effect of SSE on glucose intolerance also when given after the development of the metabolic alteration. The mechanism mediating the effects of SSE on insulin sensitivity requires additional clarification, although we were able to show that in myotubes and adipocytes SSE activates both the metabolic and mitogenic arms of the insulin cascade [31]. These results suggest that the active compound/s act on an upstream component of the signal and has an insulin mimetic activity.…”

Xonotlite Nanowire-Containing Bioactive Scaffolds for the Therapy of Defective Adipose Tissue in Breast Cancer

“…Furthermore, the results verified that the CS nanowire extract could significantly promote the expression of adipogenesis-related genes, including PPARγ, adiponectin, FABP4, and leptin (Figure e–h). Bioactive Si ions may stimulate ADSCs to secrete insulin-like growth factor I (IGF1), which interacts with its receptor IGF1R and then influences the expression of downstream adipogenesis-related genes through the PI3K/AKT pathway, thus inducing the adipogenic differentiation of ADSCs. − …”