Nymphaea rubra ameliorates TNF-α-induced insulin resistance via suppression of c-Jun NH2-Terminal Kinase and Nuclear Factor-κB in the rat skeletal muscle cells

Abstract

In this work, we demonstrated insulin signaling and the anti-inflammatory effects by the chloroform fraction of ethanolic extract of Nymphaea rubra flowers in TNF-α induced insulin resistance in the rat skeletal muscle cell line (L6 myotubes) to dissect out its antihyperglycemic mechanism. Nymphaea rubra enhances the GLUT-4 mediated glucose transport in a dose dependent manner and also increases the tyrosine phosphorylation of both IR-β and IRS-1, and the IRS-1 associated PI-3 kinase activity in TNF-α treated L6 myotubes. Moreover, Nymphaea rubra decreases Ser307 phosphorylation of IRS-1 by the suppression of JNK and NF-κB activation. In conclusion, Nymphaea rubra reverses the insulin resistance by the inhibition of c-Jun NH2-Terminal Kinase and Nuclear-κB.