Nicotinamide is a form of vitamin B3 that plays essential roles in cell physiology through facilitating NAD+ redox homeostasis and providing NAD+ as a substrate to a class of enzymes that catalyze non-redox reactions. Nicotinamide is an inhibitor of SIRT1, it has insulinotropic action, it can induce differentiation and maturation of human fetal pancreatic islet cells. Nicotinamide may represent a safe treatment for Alzheimer's disease and other tauopathies, and that phosphorylation of tau at Thr231 may regulate tau stability.
Isobergapten is a plant growth regulating substance, it is the principal constituents responsible for the antimycobacterial activity of the roots of Heracleum maximum; it may form an important class of natural defensive agents against fungi.Isobergapten shows anti-proliferative activity and causes G2/M arrest at concentrations of 0.05-15.0 μM.
1. Gitogenin, tigogenin, and solasodine are novel selective inhibitors of UGT1A4, and do not inhibit the activities of major human CYP isoforms.
2. Gitogenin and (25S)-5α-furastan-3β,22,26-triol are the inhibitors of enzyme α-glucosidase with IC50 values of 37.2±0.18 and 33.5±0.22 uM, respectively.
3. Gitogenin shows moderate stimulation of release activity on growth hormone from rat pituitary cells.