Genipin

Genipin ((+)-Genipin) is a natural crosslinking reagent derived from Gardenia jasminoides Ellis fruits. Genipin inhibits UCP2 (uncoupling protein 2) in cells. Genipin has a variety of bioactivities, including modulation on proteins, antitumor, anti-inflammation, immunosuppression, antithrombosis, and protection of hippocampal neurons. Genipin also can be used for type 2 diabetes research^[1][2]. In Vitro: Genipin increases mitochondrial membrane potential, increased ATP levels, closed KATP channels, and stimulated insulin secretion in pancreatic islet cells. Genipin causes suppression of insulin signal transduction through hyperactivation of c-Jun N-terminal kinase (JNK) and subsequent serine phosphorylation of insulin receptor substrate-1 (IRS-1), thus impairing insulin-stimulated glucose uptake in 3T3-L1 adipocytes^[1].
Genipin activates IRS-1, PI3-K, and downstream signaling pathway and increases concentrations of calcium, resulting in glucose transporter 4 (GLUT4) translocation and glucose uptake increase in C2C12 myotubes^[1].
Cytochrome c content increases significantly in the cytosol of Genipin-treated FaO cells. Activation of caspase-3 and caspase-7 is ultimately responsible for Genipin-induced apoptotic process in hepatoma cells. ROS level notably increases in Hep3B cells treated with 200 μM Genipin^[2].