Rhein-13C4

Rhein-13C4 is intended for use as an internal standard for the quantification of rhein by GC- or LC-MS. Rhein is an anti-inflammatory anthraquinone found in rhubarb and is the bioactive derivative of its prodrug diacerein . At 10 ?M, rhein inhibits IL-1? signaling, suppressing signaling through NF-?B, and reduces the expression of the matrix metalloproteases MMP-1 and MMP-13.1 It inhibits IKK? (IC50 = 11.8 ?M), decreasing iNOS and IL-6 expression in LPS-stimulated macrophages but paradoxically increasing TNF-?, IL-1?, and HMBG1 expression.2 Rhein shows efficacy against pancreatic fibrosis, chronic pancreatitis, and hyperglycemia-induced pancreatic ?-cell apoptosis.3,4 It also inhibits angiogenesis of breast cancer cells under normoxic and hypoxic conditions.5